feat: add support for new arrow types and enhance use case diagram features

on-behalf-of: @Mermaid-Chart <hello@mermaidchart.com>

.build/antlr-cli.ts

@@ -0,0 +1,92 @@
+/* eslint-disable no-console */
+
+import { exec } from 'node:child_process';
+import { promisify } from 'node:util';
+import { resolve, dirname } from 'node:path';
+import { readFile, mkdir, access } from 'node:fs/promises';
+import { existsSync } from 'node:fs';
+
+const execAsync = promisify(exec);
+
+interface AntlrGrammarConfig {
+  id: string;
+  grammar: string;
+  outputDir: string;
+  language: string;
+  generateVisitor?: boolean;
+  generateListener?: boolean;
+}
+
+interface AntlrConfig {
+  projectName: string;
+  grammars: AntlrGrammarConfig[];
+  mode: string;
+}
+
+export async function generateFromConfig(configFile: string): Promise<void> {
+  const configPath = resolve(configFile);
+
+  if (!existsSync(configPath)) {
+    throw new Error(`ANTLR config file not found: ${configPath}`);
+  }
+
+  const configContent = await readFile(configPath, 'utf-8');
+  const config: AntlrConfig = JSON.parse(configContent);
+
+  const configDir = dirname(configPath);
+
+  for (const grammarConfig of config.grammars) {
+    await generateGrammar(grammarConfig, configDir);
+  }
+}
+
+async function generateGrammar(grammarConfig: AntlrGrammarConfig, baseDir: string): Promise<void> {
+  const grammarFile = resolve(baseDir, grammarConfig.grammar);
+  const outputDir = resolve(baseDir, grammarConfig.outputDir);
+
+  // Check if grammar file exists
+  try {
+    await access(grammarFile);
+  } catch {
+    throw new Error(`Grammar file not found: ${grammarFile}`);
+  }
+
+  // Ensure output directory exists
+  await mkdir(outputDir, { recursive: true });
+
+  // Build ANTLR command arguments
+
+  // eslint-disable-next-line @cspell/spellchecker
+  const args = ['antlr-ng', `-Dlanguage=${grammarConfig.language}`];
+
+  if (grammarConfig.generateVisitor) {
+    args.push('--generate-visitor');
+  }
+
+  if (grammarConfig.generateListener) {
+    args.push('--generate-listener');
+  }
+
+  args.push('-o', `"${outputDir}"`, `"${grammarFile}"`);
+
+  const command = `npx ${args.join(' ')}`;
+
+  try {
+    await execAsync(command);
+    console.log(`Generated ANTLR files for ${grammarConfig.id}`);
+  } catch (error) {
+    console.error(`Failed to generate ANTLR files for ${grammarConfig.id}:`);
+    throw error;
+  }
+}
+
+// CLI interface
+if (import.meta.url === `file://${process.argv[1]}`) {
+  const configFile = process.argv[2] || './packages/parser/antlr-config.json';
+  try {
+    await generateFromConfig(configFile);
+    console.log('ANTLR generation completed successfully!');
+  } catch (error) {
+    console.error('ANTLR generation failed:', error.message);
+  }
+}

.build/generateAntlr.ts

@@ -0,0 +1,5 @@
+import { generateFromConfig } from './antlr-cli.js';
+
+export async function generateAntlr() {
+  await generateFromConfig('./packages/parser/antlr-config.json');
+}

.build/jsonSchema.ts

@@ -28,6 +28,7 @@ const MERMAID_CONFIG_DIAGRAM_KEYS = [
   'packet',
   'architecture',
   'radar',
+  'usecase',
 ] as const;
 
 /**

.changeset/deep-pumas-run.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+chore: Fix mindmap rendering in docs and apply tidytree layout

.changeset/four-eyes-wish.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Ensure edge label color is applied when using classDef with edge IDs

.changeset/loud-results-melt.md

@@ -0,0 +1,5 @@
+---
+'mermaid': minor
+---
+
+feat: Add half-arrowheads (solid & stick) and central connection support

.changeset/moody-fans-try.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Resolve gantt chart crash due to invalid array length

.changeset/proud-colts-smell.md

@@ -0,0 +1,5 @@
+---
+'mermaid': minor
+---
+
+feat: Add IDs in architecture diagrams

.changeset/revert-marked-dependency.md

@@ -0,0 +1,9 @@
+---
+'mermaid': patch
+---
+
+chore: revert marked dependency from ^15.0.7 to ^16.0.0
+
+- Reverted marked package version to ^16.0.0 for better compatibility
+- This is a dependency update that maintains API compatibility
+- All tests pass with the updated version

.changeset/slow-lemons-know.md

@@ -0,0 +1,5 @@
+---
+'@mermaid': patch
+---
+
+fix: Mindmap breaking in ELK layout

.changeset/sweet-games-build.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix(er-diagram): prevent syntax error when using 'u', numbers, and decimals in node names

.cspell/code-terms.txt

@@ -143,6 +143,9 @@ typeof
 typestr
 unshift
 urlsafe
+usecase
+Usecase
+USECASE
 verifymethod
 VERIFYMTHD
 WARN_DOCSDIR_DOESNT_MATCH

.cspell/mermaid-terms.txt

@@ -8,6 +8,7 @@ compositTitleSize
 cose
 curv
 doublecircle
+elem
 elems
 gantt
 gitgraph

.esbuild/build.ts

@@ -4,6 +4,7 @@ import { packageOptions } from '../.build/common.js';
 import { generateLangium } from '../.build/generateLangium.js';
 import type { MermaidBuildOptions } from './util.js';
 import { defaultOptions, getBuildConfig } from './util.js';
+import { generateAntlr } from '../.build/generateAntlr.js';
 
 const shouldVisualize = process.argv.includes('--visualize');
 
@@ -95,6 +96,7 @@ const buildTinyMermaid = async () => {
 
 const main = async () => {
   await generateLangium();
+  await generateAntlr();
   await mkdir('stats', { recursive: true });
   const packageNames = Object.keys(packageOptions) as (keyof typeof packageOptions)[];
   // it should build `parser` before `mermaid` because it's a dependency

.github/workflows/codeql.yml

@@ -26,8 +26,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        language: ['javascript']
-        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
+        language: ['javascript', 'actions']
+        # CodeQL supports [ 'actions', 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
         # Learn more about CodeQL language support at https://aka.ms/codeql-docs/language-support
 
     steps:
@@ -36,7 +36,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@b56ba49b26e50535fa1e7f7db0f4f7b4bf65d80d # v3.28.10
+        uses: github/codeql-action/init@5378192d256ef1302a6980fffe5ca04426d43091 # v3.28.21
         with:
           config-file: ./.github/codeql/codeql-config.yml
           languages: ${{ matrix.language }}
@@ -48,7 +48,7 @@ jobs:
       # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
       # If this step fails, then you should remove it and run the build manually (see below)
       - name: Autobuild
-        uses: github/codeql-action/autobuild@b56ba49b26e50535fa1e7f7db0f4f7b4bf65d80d # v3.28.10
+        uses: github/codeql-action/autobuild@5378192d256ef1302a6980fffe5ca04426d43091 # v3.28.21
 
       # ℹ️ Command-line programs to run using the OS shell.
       # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
@@ -62,4 +62,4 @@ jobs:
       #   make release
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@b56ba49b26e50535fa1e7f7db0f4f7b4bf65d80d # v3.28.10
+        uses: github/codeql-action/analyze@5378192d256ef1302a6980fffe5ca04426d43091 # v3.28.21

.github/workflows/e2e-applitools.yml

@@ -53,7 +53,7 @@ jobs:
           args: -X POST "$APPLITOOLS_SERVER_URL/api/externals/github/push?apiKey=$APPLITOOLS_API_KEY&CommitSha=$GITHUB_SHA&BranchName=${APPLITOOLS_BRANCH}$&ParentBranchName=$APPLITOOLS_PARENT_BRANCH"
 
       - name: Cypress run
-        uses: cypress-io/github-action@18a6541367f4580a515371905f499a27a44e8dbe # v6.7.12
+        uses: cypress-io/github-action@108b8684ae52e735ff7891524cbffbcd4be5b19f # v6.7.16
         id: cypress
         with:
           start: pnpm run dev

.github/workflows/e2e-timings.yml

@@ -27,12 +27,12 @@ jobs:
         with:
           node-version-file: '.node-version'
       - name: Install dependencies
-        uses: cypress-io/github-action@18a6541367f4580a515371905f499a27a44e8dbe # v6.7.12
+        uses: cypress-io/github-action@108b8684ae52e735ff7891524cbffbcd4be5b19f # v6.7.16
         with:
           runTests: false
 
       - name: Cypress run
-        uses: cypress-io/github-action@18a6541367f4580a515371905f499a27a44e8dbe # v6.7.12
+        uses: cypress-io/github-action@108b8684ae52e735ff7891524cbffbcd4be5b19f # v6.7.16
         id: cypress
         with:
           install: false
@@ -58,7 +58,7 @@ jobs:
           echo "EOF" >> $GITHUB_OUTPUT
 
       - name: Commit and create pull request
-        uses: peter-evans/create-pull-request@18e469570b1cf0dfc11d60ec121099f8ff3e617a
+        uses: peter-evans/create-pull-request@915d841dae6a4f191bb78faf61a257411d7be4d2
         with:
           add-paths: |
             cypress/timings.json

.github/workflows/e2e.yml

@@ -45,7 +45,7 @@ jobs:
           node-version-file: '.node-version'
       - name: Cache snapshots
         id: cache-snapshot
-        uses: actions/cache@0c907a75c2c80ebcb7f088228285e798b750cf8f # v4.2.1
+        uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
         with:
           path: ./cypress/snapshots
           key: ${{ runner.os }}-snapshots-${{ env.targetHash }}
@@ -59,7 +59,7 @@ jobs:
 
       - name: Install dependencies
         if: ${{ steps.cache-snapshot.outputs.cache-hit != 'true' }}
-        uses: cypress-io/github-action@18a6541367f4580a515371905f499a27a44e8dbe # v6.7.12
+        uses: cypress-io/github-action@108b8684ae52e735ff7891524cbffbcd4be5b19f # v6.7.16
         with:
           # just perform install
           runTests: false
@@ -95,13 +95,13 @@ jobs:
       # These cached snapshots are downloaded, providing the reference snapshots.
       - name: Cache snapshots
         id: cache-snapshot
-        uses: actions/cache/restore@0c907a75c2c80ebcb7f088228285e798b750cf8f # v4.2.1
+        uses: actions/cache/restore@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
         with:
           path: ./cypress/snapshots
           key: ${{ runner.os }}-snapshots-${{ env.targetHash }}
 
       - name: Install dependencies
-        uses: cypress-io/github-action@18a6541367f4580a515371905f499a27a44e8dbe # v6.7.12
+        uses: cypress-io/github-action@108b8684ae52e735ff7891524cbffbcd4be5b19f # v6.7.16
         with:
           runTests: false
 
@@ -117,7 +117,7 @@ jobs:
       # Install NPM dependencies, cache them correctly
       # and run all Cypress tests
       - name: Cypress run
-        uses: cypress-io/github-action@18a6541367f4580a515371905f499a27a44e8dbe # v6.7.12
+        uses: cypress-io/github-action@108b8684ae52e735ff7891524cbffbcd4be5b19f # v6.7.16
         id: cypress
         with:
           install: false

.github/workflows/link-checker.yml

@@ -32,7 +32,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Restore lychee cache
-        uses: actions/cache@0c907a75c2c80ebcb7f088228285e798b750cf8f # v4.2.1
+        uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
         with:
           path: .lycheecache
           key: cache-lychee-${{ github.sha }}

.github/workflows/release.yml

@@ -36,7 +36,7 @@ jobs:
 
       - name: Create Release Pull Request or Publish to npm
         id: changesets
-        uses: changesets/action@c8bada60c408975afd1a20b3db81d6eee6789308 # v1.4.9
+        uses: changesets/action@06245a4e0a36c064a573d4150030f5ec548e4fcc # v1.4.10
         with:
           version: pnpm changeset:version
           publish: pnpm changeset:publish

.github/workflows/scorecard.yml

@@ -20,18 +20,18 @@ jobs:
         with:
           persist-credentials: false
       - name: Run analysis
-        uses: ossf/scorecard-action@f49aabe0b5af0936a0987cfb85d86b75731b0186 # v2.4.1
+        uses: ossf/scorecard-action@05b42c624433fc40578a4040d5cf5e36ddca8cde # v2.4.2
         with:
           results_file: results.sarif
           results_format: sarif
           publish_results: true
       - name: Upload artifact
-        uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
           name: SARIF file
           path: results.sarif
           retention-days: 5
       - name: Upload to code-scanning
-        uses: github/codeql-action/upload-sarif@b56ba49b26e50535fa1e7f7db0f4f7b4bf65d80d # v3.28.10
+        uses: github/codeql-action/upload-sarif@5378192d256ef1302a6980fffe5ca04426d43091 # v3.28.21
         with:
           sarif_file: results.sarif

.github/workflows/update-browserlist.yml

@@ -19,7 +19,7 @@ jobs:
           message: 'chore: update browsers list'
           push: false
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@67ccf781d68cd99b580ae25a5c18a1cc84ffff1f # v7.0.6
+        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e # v7.0.8
         with:
           branch: update-browserslist
           title: Update Browserslist

.gitignore

@@ -51,5 +51,8 @@ demos/dev/**
 tsx-0/**
 vite.config.ts.timestamp-*
 
-# autogenereated by langium-cli
+# autogenereated by langium-cli and antlr-cli
 generated/
+
+# autogenereated by antlr-cli
+.antlr/

.vite/build.ts

@@ -10,6 +10,7 @@ import type { TemplateType } from 'rollup-plugin-visualizer/dist/plugin/template
 import istanbul from 'vite-plugin-istanbul';
 import { packageOptions } from '../.build/common.js';
 import { generateLangium } from '../.build/generateLangium.js';
+import { generateAntlr } from '../.build/generateAntlr.js';
 
 const visualize = process.argv.includes('--visualize');
 const watch = process.argv.includes('--watch');
@@ -123,6 +124,7 @@ const main = async () => {
 };
 
 await generateLangium();
+await generateAntlr();
 
 if (watch) {
   await build(getBuildConfig({ minify: false, watch, core: false, entryName: 'parser' }));

cypress/integration/other/configuration.spec.js

@@ -98,12 +98,12 @@ describe('Configuration', () => {
     it('should handle arrowMarkerAbsolute set to true', () => {
       renderGraph(
         `flowchart TD
-        A[Christmas] -->|Get money| B(Go shopping)
-        B --> C{Let me think}
-        C -->|One| D[Laptop]
-        C -->|Two| E[iPhone]
-        C -->|Three| F[fa:fa-car Car]
-        `,
+    A[Christmas] -->|Get money| B(Go shopping)
+    B --> C{Let me think}
+    C -->|One| D[Laptop]
+    C -->|Two| E[iPhone]
+    C -->|Three| F[fa:fa-car Car]
+    `,
         {
           arrowMarkerAbsolute: true,
         }
@@ -113,8 +113,7 @@ describe('Configuration', () => {
         cy.get('path')
           .first()
           .should('have.attr', 'marker-end')
-          .should('exist')
-          .and('include', 'url(http\\:\\/\\/localhost');
+          .and('include', 'url(http://localhost');
       });
     });
     it('should not taint the initial configuration when using multiple directives', () => {

cypress/integration/rendering/erDiagram.spec.js

@@ -369,4 +369,92 @@ ORDER ||--|{ LINE-ITEM : contains
       );
     });
   });
+
+  describe('Special characters and numbers syntax', () => {
+    it('should render ER diagram with numeric entity names', () => {
+      imgSnapshotTest(
+        `
+        erDiagram
+          1 ||--|| ORDER : places
+          ORDER ||--|{ 2 : contains
+          2 ||--o{ 3.5 : references
+        `,
+        { logLevel: 1 }
+      );
+    });
+
+    it('should render ER diagram with "u" character in entity names and cardinality', () => {
+      imgSnapshotTest(
+        `
+        erDiagram
+          CUSTOMER ||--|| u : has
+          u ||--|| ORDER : places
+          PROJECT u--o{ TEAM_MEMBER : "parent"
+        `,
+        { logLevel: 1 }
+      );
+    });
+
+    it('should render ER diagram with decimal numbers in relationships', () => {
+      imgSnapshotTest(
+        `
+        erDiagram
+          2.5 ||--|| 1.5 : has
+          CUSTOMER ||--o{ 3.14 : references
+          1.0 ||--|{ ORDER : contains
+        `,
+        { logLevel: 1 }
+      );
+    });
+
+    it('should render ER diagram with numeric entity names and attributes', () => {
+      imgSnapshotTest(
+        `
+        erDiagram
+          1 {
+            string name
+            int value
+          }
+          1 ||--|| ORDER : places
+          ORDER {
+            float price
+            string description
+          }
+        `,
+        { logLevel: 1 }
+      );
+    });
+
+    it('should render complex ER diagram with mixed special entity names', () => {
+      imgSnapshotTest(
+        `
+        erDiagram
+          CUSTOMER ||--o{ 1 : places
+          1 ||--|{ u : contains
+          1.5
+          u ||--|| 2.5 : processes
+          2.5 {
+            string id
+            float value
+          }
+          u {
+            varchar(50) name
+            int count
+          }
+        `,
+        { logLevel: 1 }
+      );
+    });
+    it('should render ER diagram with numeric entity names and attributes', () => {
+      imgSnapshotTest(
+        `erDiagram
+         PRODUCT ||--o{ ORDER-ITEM : has
+         1.5
+         u
+         1
+        `,
+        { logLevel: 1 }
+      );
+    });
+  });
 });

cypress/integration/rendering/flowchart-elk.spec.js

@@ -109,7 +109,7 @@ describe('Flowchart ELK', () => {
       const style = svg.attr('style');
       expect(style).to.match(/^max-width: [\d.]+px;$/);
       const maxWidthValue = parseFloat(style.match(/[\d.]+/g).join(''));
-      verifyNumber(maxWidthValue, 380);
+      verifyNumber(maxWidthValue, 380, 15);
     });
   });
   it('8-elk: should render a flowchart when useMaxWidth is false', () => {
@@ -128,7 +128,7 @@ describe('Flowchart ELK', () => {
       const width = parseFloat(svg.attr('width'));
       // use within because the absolute value can be slightly different depending on the environment ±5%
       // expect(height).to.be.within(446 * 0.95, 446 * 1.05);
-      verifyNumber(width, 380);
+      verifyNumber(width, 380, 15);
       expect(svg).to.not.have.attr('style');
     });
   });

cypress/integration/rendering/flowchart-v2.spec.js

@@ -1186,4 +1186,17 @@ end
       imgSnapshotTest(graph, { htmlLabels: false });
     });
   });
+
+  it('V2 - 17: should apply class def colour to edge label', () => {
+    imgSnapshotTest(
+      ` graph LR
+    id1(Start) link@-- "Label" -->id2(Stop)
+    style id1 fill:#f9f,stroke:#333,stroke-width:4px
+
+class id2 myClass
+classDef myClass fill:#bbf,stroke:#f66,stroke-width:2px,color:white,stroke-dasharray: 5 5
+class link myClass
+`
+    );
+  });
 });

cypress/integration/rendering/gantt.spec.js

@@ -803,4 +803,34 @@ describe('Gantt diagram', () => {
       {}
     );
   });
+  it('should handle numeric timestamps with dateFormat x', () => {
+    imgSnapshotTest(
+      `
+     gantt
+     title Process time profile (ms)
+     dateFormat x
+     axisFormat %L
+     tickInterval 250millisecond
+
+     section Pipeline
+     Parse JSON p1: 000, 120
+    `,
+      {}
+    );
+  });
+  it('should handle numeric timestamps with dateFormat X', () => {
+    imgSnapshotTest(
+      `
+     gantt
+     title Process time profile (ms)
+     dateFormat X
+     axisFormat %L
+     tickInterval 250millisecond
+
+     section Pipeline
+     Parse JSON p1: 000, 120
+    `,
+      {}
+    );
+  });
 });

cypress/integration/rendering/sequencediagram-v2.spec.js

@@ -655,5 +655,126 @@ describe('Sequence Diagram Special Cases', () => {
         expect(svg).to.not.have.attr('style');
       });
     });
+
+    describe('Central Connection Rendering Tests', () => {
+      it('should render central connection circles on actor vertical lines', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        participant Charlie
+        Alice ()->>() Bob: Central connection
+        Bob ()-->> Charlie: Reverse central connection
+        Charlie ()<<-->>() Alice: Dual central connection`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections with different arrow types', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()->>() Bob: Solid open arrow
+        Alice ()-->>() Bob: Dotted open arrow
+        Alice ()-x() Bob: Solid cross
+        Alice ()--x() Bob: Dotted cross
+        Alice ()->() Bob: Solid arrow`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections with bidirectional arrows', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()<<->>() Bob: Bidirectional solid
+        Alice ()<<-->>() Bob: Bidirectional dotted`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections with activations', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        participant Charlie
+        Alice ()->>() Bob: Activate Bob
+        activate Bob
+        Bob ()-->> Charlie: Message to Charlie
+        Bob ()->>() Alice: Response to Alice
+        deactivate Bob`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections mixed with normal messages', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        participant Charlie
+        Alice ->> Bob: Normal message
+        Bob ()->>() Charlie: Central connection
+        Charlie -->> Alice: Normal dotted message
+        Alice ()<<-->>() Bob: Dual central connection
+        Bob -x Charlie: Normal cross message`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections with notes', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        participant Charlie
+        Alice ()->>() Bob: Central connection
+        Note over Alice,Bob: Central connection note
+        Bob ()-->> Charlie: Reverse central connection
+        Note right of Charlie: Response note
+        Charlie ()<<-->>() Alice: Dual central connection`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections with loops and alternatives', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+        participant Alice
+        participant Bob
+        participant Charlie
+        loop Every minute
+            Alice ()->>() Bob: Central heartbeat
+            Bob ()-->> Charlie: Forward heartbeat
+        end
+        alt Success
+            Charlie ()<<-->>() Alice: Success response
+        else Failure
+            Charlie ()-x() Alice: Failure response
+        end`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+
+      it('should render central connections with different participant types', () => {
+        imgSnapshotTest(
+          `sequenceDiagram
+          participant Alice
+          actor Bob
+          participant Charlie@{"type":"boundary"}
+          participant David@{"type":"control"}
+          participant Eve@{"type":"entity"}
+          Alice ()->>() Bob: To actor
+          Bob ()-->> Charlie: To boundary
+          Charlie ()->>() David: To control
+          David ()<<-->>() Eve: To entity
+          Eve ()-x() Alice: Back to participant`,
+          { look: 'classic', sequence: { diagramMarginX: 50, diagramMarginY: 10 } }
+        );
+      });
+    });
   });
 });

cypress/integration/rendering/sequencediagram.spec.js

@@ -1053,4 +1053,167 @@ describe('Sequence diagram', () => {
       ]);
     });
   });
+  describe('render new arrow type', () => {
+    it('should render Solid half arrow top', () => {
+      imgSnapshotTest(
+        `
+    sequenceDiagram
+      Alice -|\\  John: Hello John, how are you? 
+      Alice-|\\  John: Hi Alice, I can hear you!
+      Alice -|\\  John: Test
+      `
+      );
+    });
+    it('should render Solid half arrow bottom', () => {
+      imgSnapshotTest(
+        `
+    sequenceDiagram
+      Alice-|/John: Hello John, how are you?
+      Alice-|/John: Hi Alice, I can hear you!
+      Alice-|/John: Test
+      `
+      );
+    });
+
+    it('should render Stick half arrow top ', () => {
+      imgSnapshotTest(
+        `
+     sequenceDiagram
+      Alice-\\\\John: Hello John, how are you?
+      Alice-\\\\John: Hi Alice, I can hear you!
+      Alice-\\\\John: Test
+      `
+      );
+    });
+    it('should render Stick half arrow bottom ', () => {
+      imgSnapshotTest(
+        `
+       sequenceDiagram
+      Alice-//John: Hello John, how are you?
+      Alice-//John: Hi Alice, I can hear you!
+      Alice-//John: Test
+      `
+      );
+    });
+    it('should render Solid half arrow top reverse ', () => {
+      imgSnapshotTest(
+        `
+       sequenceDiagram
+      Alice/|-John: Hello Alice, how are you?
+      Alice/|-John: Hi Alice, I can hear you!
+      Alice/|-John: Test
+
+      `
+      );
+    });
+
+    it('should render Solid half arrow bottom reverse ', () => {
+      imgSnapshotTest(
+        `sequenceDiagram
+        Alice \\|- John: Hello Alice, how are you?
+        Alice \\|- John: Hi Alice, I can hear you!
+        Alice \\|- John: Test`
+      );
+    });
+
+    it('should render Stick half arrow top reverse ', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      Alice //-John: Hello Alice, how are you?
+      Alice //-John: Hi Alice, I can hear you!
+      Alice //-John: Test`
+      );
+    });
+
+    it('should render Stick half arrow bottom reverse ', () => {
+      imgSnapshotTest(
+        `
+       sequenceDiagram
+      Alice \\\\-John: Hello Alice, how are you?
+      Alice \\\\-John: Hi Alice, I can hear you!
+      Alice \\\\-John: Test`
+      );
+    });
+
+    it('should render Solid half arrow top dotted', () => {
+      imgSnapshotTest(
+        `
+     sequenceDiagram
+      Alice --|\\John: Hello John, how are you?
+      Alice --|\\John: Hi Alice, I can hear you!
+      Alice --|\\John: Test`
+      );
+    });
+
+    it('should render Solid half arrow bottom dotted', () => {
+      imgSnapshotTest(
+        `
+     sequenceDiagram
+      Alice --|/John: Hello John, how are you?
+      Alice --|/John: Hi Alice, I can hear you!
+      Alice --|/John: Test`
+      );
+    });
+
+    it('should render Stick half arrow top dotted', () => {
+      imgSnapshotTest(
+        `
+     sequenceDiagram
+      Alice--\\\\John: Hello John, how are you?
+      Alice--\\\\John: Hi Alice, I can hear you!
+      Alice--\\\\John: Test`
+      );
+    });
+
+    it('should render Stick half arrow bottom dotted', () => {
+      imgSnapshotTest(
+        `
+     sequenceDiagram
+      Alice--//John: Hello John, how are you?
+      Alice--//John: Hi Alice, I can hear you!
+      Alice--//John: Test`
+      );
+    });
+
+    it('should render Solid half arrow top reverse dotted', () => {
+      imgSnapshotTest(
+        `
+  sequenceDiagram
+      Alice/|--John: Hello Alice, how are you?
+      Alice/|--John: Hi Alice, I can hear you!
+      Alice/|--John: Test`
+      );
+    });
+
+    it('should render Solid half arrow bottom reverse dotted', () => {
+      imgSnapshotTest(
+        `
+  sequenceDiagram
+      Alice\\|--John: Hello Alice, how are you?
+      Alice\\|--John: Hi Alice, I can hear you!
+      Alice\\|--John: Test`
+      );
+    });
+
+    it('should render Stick half arrow top reverse dotted ', () => {
+      imgSnapshotTest(
+        `
+  sequenceDiagram
+      Alice//--John: Hello Alice, how are you?
+      Alice//--John: Hi Alice, I can hear you!
+      Alice//--John: Test`
+      );
+    });
+
+    it('should render Stick half arrow bottom reverse dotted ', () => {
+      imgSnapshotTest(
+        `
+  sequenceDiagram
+      Alice\\\\--John: Hello Alice, how are you?
+      Alice\\\\--John: Hi Alice, I can hear you!
+      Alice\\\\--John: Test`
+      );
+    });
+  });
 });

cypress/integration/rendering/usecase.spec.ts

@@ -0,0 +1,425 @@
+import { imgSnapshotTest, renderGraph } from '../../helpers/util.ts';
+
+describe('Usecase diagram', () => {
+  it('should render a simple usecase diagram with actors and use cases', () => {
+    imgSnapshotTest(
+      `
+      usecase
+        actor User
+        actor Admin
+        User --> Login
+        Admin --> "Manage Users"
+        User --> "View Profile"
+      `
+    );
+  });
+
+  it('should render usecase diagram with quoted actor names', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "Customer Service"
+        actor "System Administrator"
+        "Customer Service" --> "Handle Tickets"
+        "System Administrator" --> "Manage System"
+      `
+    );
+  });
+
+  it('should render usecase diagram with different arrow types', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        actor Admin
+        User --> Login
+        Admin <-- Logout
+        User -- "View Data"
+      `
+    );
+  });
+
+  it('should render usecase diagram with edge labels', () => {
+    imgSnapshotTest(
+      `usecase
+        actor Developer
+        actor Manager
+        Developer --important--> "Write Code"
+        Manager --review--> "Code Review"
+        Developer --urgent--> Manager
+      `
+    );
+  });
+
+  it('should render usecase diagram with node ID syntax', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        User --> a(Login)
+        User --> b("View Profile")
+        User --> c("Update Settings")
+      `
+    );
+  });
+
+  it('should render usecase diagram with comma-separated actors', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "Customer Service", "Technical Support", "Sales Team"
+        actor SystemAdmin
+        "Customer Service" --> "Handle Tickets"
+        "Technical Support" --> "Resolve Issues"
+        "Sales Team" --> "Process Orders"
+        SystemAdmin --> "Manage System"
+      `
+    );
+  });
+
+  it('should render usecase diagram with actor metadata', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User@{ "type" : "primary", "icon" : "user" }
+        actor Admin@{ "type" : "secondary", "icon" : "admin" }
+        actor System@{ "type" : "hollow", "icon" : "system" }
+        User --> Login
+        Admin --> "Manage Users"
+        System --> "Process Data"
+      `
+    );
+  });
+
+  it('should render usecase diagram with system boundaries (rect type)', () => {
+    imgSnapshotTest(
+      `usecase
+        actor Admin, User
+        systemBoundary "Authentication"
+          Login
+          Logout
+          "Reset Password"
+        end
+        "Authentication"@{ type: rect }
+        Admin --> Login
+        User --> Login
+        User --> "Reset Password"
+      `
+    );
+  });
+
+  it('should render usecase diagram with system boundaries (package type)', () => {
+    imgSnapshotTest(
+      `usecase
+        actor Admin, User
+        systemBoundary "Authentication"
+          Login
+          Logout
+          "Reset Password"
+        end
+        "Authentication"@{ type: package }
+        Admin --> Login
+        User --> Login
+        User --> "Reset Password"
+      `
+    );
+  });
+
+  it('should render complex usecase diagram with all features', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "Customer Service"@{ "type" : "primary", "icon" : "user" }
+        actor "System Admin"@{ "type" : "secondary", "icon" : "admin" }
+        actor "Database"@{ "type" : "hollow", "icon" : "database" }
+
+        systemBoundary "Customer Support System"
+          "Handle Tickets"
+          "View Customer Info"
+        end
+        "Customer Support System"@{ type: package }
+
+        systemBoundary "Administration"
+          "User Management"
+          "System Config"
+        end
+
+        "Customer Service" --priority--> "Handle Tickets"
+        "Customer Service" --> "View Customer Info"
+        "System Admin" --manage--> "User Management"
+        "System Admin" --> "System Config"
+        "Database" <-- "Handle Tickets"
+        "Database" <-- "View Customer Info"
+        "Database" <-- "User Management"
+      `
+    );
+  });
+
+  it('should render usecase diagram with actor-to-actor relationships', () => {
+    imgSnapshotTest(
+      `usecase
+        actor Manager
+        actor Developer
+        actor Tester
+        
+        Manager --supervises--> Developer
+        Manager --coordinates--> Tester
+        Developer --collaborates--> Tester
+        
+        Developer --> "Write Code"
+        Tester --> "Test Code"
+        Manager --> "Review Progress"
+      `
+    );
+  });
+
+  it('should render usecase diagram with mixed relationship types', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        actor Admin
+        
+        User --> "Basic Login"
+        Admin --> "Advanced Login"
+        User --includes--> "View Profile"
+        Admin --extends--> "Manage Profiles"
+        
+        "Basic Login" <-- "Advanced Login"
+      `
+    );
+  });
+
+  it('should render usecase diagram with long labels and text wrapping', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "Customer Service Representative"
+        actor "System Administrator with Extended Privileges"
+        
+        "Customer Service Representative" --Process--> "Handle Complex Customer Support Tickets"
+        "System Administrator with Extended Privileges" --> "Manage System Configuration and User Permissions"
+      `
+    );
+  });
+
+  it('should render usecase diagram with special characters in names', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "User@Company.com"
+        actor "Admin (Level-1)"        
+        "User@Company.com" --> a("Login & Authenticate")
+        "Admin (Level-1)" --> b("Manage Users & Permissions")
+      `
+    );
+  });
+
+  it('should render usecase diagram when useMaxWidth is true (default)', () => {
+    renderGraph(
+      `usecase
+        actor User
+        actor Admin
+        User --> Login
+        Admin --> "Manage System"
+        User --> "View Profile"
+      `,
+      { usecase: { useMaxWidth: true } }
+    );
+    cy.get('svg').should((svg) => {
+      expect(svg).to.have.attr('width', '100%');
+      const style = svg.attr('style');
+      expect(style).to.match(/^max-width: [\d.]+px;$/);
+    });
+  });
+
+  it('should render usecase diagram when useMaxWidth is false', () => {
+    renderGraph(
+      `usecase
+        actor User
+        actor Admin
+        User --> Login
+        Admin --> "Manage System"
+      `,
+      { usecase: { useMaxWidth: false } }
+    );
+    cy.get('svg').should((svg) => {
+      const width = parseFloat(svg.attr('width'));
+      expect(width).to.be.greaterThan(200);
+      expect(svg).to.not.have.attr('style');
+    });
+  });
+
+  it('should render empty usecase diagram', () => {
+    imgSnapshotTest(`usecase`);
+  });
+
+  it('should render usecase diagram with only actors', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        actor Admin
+        actor Guest
+      `
+    );
+  });
+
+  it('should render usecase diagram with implicit use case creation', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        User --> Login
+        User --> Register
+        User --> "Forgot Password"
+      `
+    );
+  });
+
+  it('should render usecase diagram with nested system boundaries', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        actor Admin
+
+        systemBoundary "Main System"
+          Login
+          Logout
+          "Create User"
+          "Delete User"
+        end
+
+        User --> Login
+        User --> Logout
+        Admin --> "Create User"
+        Admin --> "Delete User"
+      `
+    );
+  });
+
+  it('should render usecase diagram with multiple edge labels on same relationship', () => {
+    imgSnapshotTest(
+      `usecase
+        actor Developer
+        actor Manager
+
+        Developer --"code review"--> Manager
+        Developer --"status update"--> Manager
+        Manager --"feedback"--> Developer
+        Manager --"approval"--> Developer
+      `
+    );
+  });
+
+  it('should render usecase diagram with various actor icon types', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User@{ "icon": "user" }
+        actor Admin@{ "icon": "admin" }
+        actor Database@{ "icon": "database" }
+        actor API@{ "icon": "api" }
+        actor Mobile@{ "icon": "mobile" }
+        actor Web@{ "icon": "web" }
+
+        User --> "Access System"
+        Admin --> "Manage System"
+        Database --> "Store Data"
+        API --> "Provide Services"
+        Mobile --> "Mobile Access"
+        Web --> "Web Access"
+      `
+    );
+  });
+
+  it('should render usecase diagram with mixed arrow directions and labels', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        actor System
+        actor Admin
+
+        User --request--> System
+        System --response--> User
+        System <--monitor-- Admin
+        Admin --configure--> System
+        User -- "direct access" -- Admin
+      `
+    );
+  });
+
+  it('should render usecase diagram with boundary-less use cases', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User
+        actor Admin
+
+        systemBoundary "Secure Area"
+          "Admin Panel"
+          "User Management"
+        end
+
+        User --> "Public Login"
+        User --> "Guest Access"
+        Admin --> "Public Login"
+        Admin --> "Admin Panel"
+        Admin --> "User Management"
+      `
+    );
+  });
+
+  it('should render usecase diagram with complex metadata combinations', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "Primary User"@{ "type": "primary", "icon": "user", "fillColor": "lightblue" }
+        actor "Secondary User"@{ "type": "secondary", "icon": "client", "strokeColor": "red" }
+        actor "System Service"@{ "type": "hollow", "icon": "service", "strokeWidth": "3" }
+
+        "Primary User" --"high priority"--> a("Critical Process")
+        "Secondary User" --"low priority"--> b("Background Task")
+        "System Service" --"automated"--> c("System Maintenance")
+      `
+    );
+  });
+
+  it('should render usecase diagram with Unicode characters', () => {
+    imgSnapshotTest(
+      `usecase
+        actor "用户"@{ "icon": "user" }
+        actor "管理员"@{ "icon": "admin" }
+
+        "用户" --"登录"--> "系统访问"
+        "管理员" --"管理"--> "用户管理"
+        "用户" --> "数据查看"
+      `
+    );
+  });
+
+  it('should render large usecase diagram with many elements', () => {
+    imgSnapshotTest(
+      `usecase
+        actor User1, User2, User3, User4
+        actor Admin1, Admin2
+        actor System1@{ "icon": "system" }
+        actor System2@{ "icon": "database" }
+
+        systemBoundary "Module A"
+          "Feature A1"
+          "Feature A2"
+          "Admin A1"
+        end
+        "Module A"@{ type: package }
+
+        systemBoundary "Module B"
+          "Feature B1"
+          "Feature B2"
+          "Admin B1"
+        end
+
+        User1 --> "Feature A1"
+        User2 --> "Feature A2"
+        Admin1 --> "Admin A1"
+        User3 --> "Feature B1"
+        User4 --> "Feature B2"
+        Admin2 --> "Admin B1"
+
+        System1 <-- "Feature A1"
+        System1 <-- "Feature B1"
+        System2 <-- "Admin A1"
+        System2 <-- "Admin B1"
+
+        User1 --"collaborates"--> User2
+        Admin1 --"supervises"--> Admin2
+      `
+    );
+  });
+});

cypress/platform/knsv2.html

@@ -32,26 +32,8 @@
       href="https://fonts.googleapis.com/css2?family=Kalam:wght@300;400;700&family=Rubik+Mono+One&display=swap"
       rel="stylesheet"
     />
-    <link rel="preconnect" href="https://fonts.googleapis.com" />
-    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
-    <link
-      href="https://fonts.googleapis.com/css2?family=Recursive:wght@300..1000&display=swap"
-      rel="stylesheet"
-    />
 
     <style>
-      .recursive-mermaid {
-        font-family: 'Recursive', sans-serif;
-        font-optical-sizing: auto;
-        font-weight: 500;
-        font-style: normal;
-        font-variation-settings:
-          'slnt' 0,
-          'CASL' 0,
-          'CRSV' 0.5,
-          'MONO' 0;
-      }
-
       body {
         /* background: rgb(221, 208, 208); */
         /* background: #333; */
@@ -63,9 +45,7 @@
       h1 {
         color: grey;
       }
-      .mermaid {
-        border: 1px solid red;
-      }
+
       .mermaid2 {
         display: none;
       }
@@ -103,11 +83,6 @@
         width: 100%;
       }
 
-      .class2 {
-        fill: red;
-        fill-opacity: 1;
-      }
-
       /* tspan {
               font-size: 6px !important;
             } */
@@ -130,10 +105,10 @@
   </head>
 
   <body>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
       ---
       config:
-        layout: tidy-tree
+        layout: elk
       ---
       mindmap
       root((mindmap))
@@ -143,63 +118,223 @@
           Popularisation
             British popular psychology author Tony Buzan
         Research
-          On effectiveness<br/>and features
+          On effectiveness&lt;br/>and features
           On Automatic creation
             Uses
                 Creative techniques
                 Strategic planning
                 Argument mapping
         Tools
-          Pen and paper
-          Mermaid
+              id)I am a cloud(
+                  id))I am a bang((
+                    Tools
+    </pre>
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      flowchart
+       aid0
+  </pre
+    >
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      mindmap
+      aid0
 
     </pre>
     <pre id="diagram4" class="mermaid">
       ---
       config:
-        layout: tidy-tree
+        layout: ogdc
       ---
-      mindmap
-      root((mindmap is a long thing))
-        A
-        B
-        C
-        D
-      </pre
+      flowchart-elk TB
+      c1-->a2
+      subgraph one
+      a1-->a2
+      end
+      subgraph two
+      b1-->b2
+      end
+      subgraph three
+      c1-->c2
+      end
+      one --> two
+      three --> two
+      two --> c2
+
+</pre
     >
     <pre id="diagram4" class="mermaid">
       ---
       config:
-        layout: tidy-tree
+        layout: elk
       ---
-      mindmap
-      root((mindmap))
-        A
-        B
-      </pre
+      flowchart TB
+
+        process_C
+      subgraph container_Alpha
+        subgraph process_B
+          pppB
+        end
+        subgraph process_A
+          pppA
+        end
+        process_B-->|via_AWSBatch|container_Beta
+        process_A-->|messages|container_Beta
+      end
+
+</pre
     >
     <pre id="diagram4" class="mermaid">
       ---
       config:
-        layout: tidy-tree
+        layout: elk
       ---
-      mindmap
-      root((mindmap))
-        A
-          a
-            apa[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-            apa2[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-          b
-          c
-          d
-        B
-            apa3[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-        D
-          apa5[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-          apa4[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
+      flowchart TB
+      subgraph container_Beta
+        process_C
+      end
+      subgraph container_Alpha
+        subgraph process_B
+          pppB
+        end
+        subgraph process_A
+          pppA
+        end
+        process_B-->|via_AWSBatch|container_Beta
+        process_A-->|messages|container_Beta
+      end
 
-    </pre>
+</pre
+    >
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      flowchart TB
+      subgraph container_Beta
+        process_C
+      end
 
+        process_B-->|via_AWSBatch|container_Beta
+
+
+</pre
+    >
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      classDiagram
+      note "I love this diagram!\nDo you love it?"
+      Class01 <|-- AveryLongClass : Cool
+      &lt;&lt;interface&gt;&gt; Class01
+      Class03 "1" *-- "*" Class04
+      Class05 "1" o-- "many" Class06
+      Class07 "1" .. "*" Class08
+      Class09 "1" --> "*" C2 : Where am i?
+      Class09 "*" --* "*" C3
+      Class09 "1" --|> "1" Class07
+      Class12 <|.. Class08
+      Class11 ..>Class12
+      Class07 : equals()
+      Class07 : Object[] elementData
+      Class01 : size()
+      Class01 : int chimp
+      Class01 : int gorilla
+      Class01 : -int privateChimp
+      Class01 : +int publicGorilla
+      Class01 : #int protectedMarmoset
+      Class08 <--> C2: Cool label
+      class Class10 {
+        &lt;&lt;service&gt;&gt;
+        int id
+        test()
+      }
+      note for Class10 "Cool class\nI said it's very cool class!"
+</pre
+    >
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      requirementDiagram
+        requirement test_req {
+        id: 1
+        text: the test text.
+        risk: high
+        verifymethod: test
+        }
+
+        element test_entity {
+        type: simulation
+        }
+
+        test_entity - satisfies -> test_req
+</pre
+    >
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      flowchart-elk TB
+      internet
+      nat
+      router
+      compute1
+
+      subgraph project
+      router
+      nat
+        subgraph subnet1
+          compute1
+        end
+      end
+
+      %% router --> subnet1
+      subnet1  --> nat
+      %% nat --> internet
+</pre
+    >
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+      ---
+      flowchart-elk TB
+      internet
+      nat
+      router
+      lb1
+      lb2
+      compute1
+      compute2
+      subgraph project
+      router
+      nat
+        subgraph subnet1
+          compute1
+          lb1
+        end
+        subgraph subnet2
+          compute2
+          lb2
+        end
+      end
+      internet --> router
+      router --> subnet1 & subnet2
+      subnet1 & subnet2 --> nat --> internet
+</pre
+    >
     <pre id="diagram4" class="mermaid">
 ---
 config:
@@ -227,91 +362,35 @@ treemap
     "Leaf 2.2": 25
     "Leaf 2.3": 12
 
-classDef class1   fill:red,color:blue,stroke:#FFD600;
+    </pre>
+    <pre id="diagram5" class="mermaid">
+      ---
+      config:
+        layout: elk
+        flowchart:
+          curve: rounded
+      ---
+      flowchart LR
+          I["fa:fa-code Text"] -- Mermaid js --> D["Use<br/>the<br/>editor!"]
+          I --> D & D
+          D@{ shape: question}
+          I@{ shape: question}
 
-
-</pre
-    >
-    <pre id="diagram4" class="mermaid2">
----
-config:
-  treemap:
-    valueFormat: '$0,0'
----
-treemap
-"Budget"
-    "Operations"
-        "Salaries": 7000
-        "Equipment": 2000
-        "Supplies": 1000
-    "Marketing"
-        "Advertising": 4000
-        "Events": 1000
-
-</pre
-    >
+    </pre>
     <pre id="diagram4" class="mermaid">
-    treemap
-      title Accessible Treemap Title
-      "Category A"
-          "Item A1": 10
-          "Item A2": 20
-      "Category B"
-          "Item B1": 15
-          "Item B2": 25
-    </pre>
-    <pre id="diagram4" class="mermaid2">
       ---
       config:
         layout: tidy-tree
       ---
       mindmap
       root((mindmap))
-        a
-          apa[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-          apa2[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-        b
-          apa3[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-          apa4[I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on. I am a long long multline string passing several levels of text. Lorum ipsum and so on]
-
-
-    </pre>
-    <pre id="diagram4" class="mermaid2">
-      ---
-      config:
-        layout: tidy-tree
-      ---
-      flowchart TB
-          A --> n0["1"]
-          A --> n1["2"]
-          A --> n2["3"]
-          A --> n3["4"] --> Q & R & S & T
-    </pre>
-    <pre id="diagram4" class="mermaid2">
-      ---
-      config:
-        layout: elk
-      ---
-      flowchart TB
-          A --> n0["1"]
-          A --> n1["2"]
-          A --> n2["3"]
-          A --> n3["4"] --> Q & R & S & T
-    </pre>
-    <pre id="diagram4" class="mermaid2">
-      ---
-      config:
-        layout: dagre
-      ---
-      mindmap
-      root((mindmap is a long thing))
         Origins
           Long history
           ::icon(fa fa-book)
           Popularisation
             British popular psychology author Tony Buzan
         Research
-          On effectiveness&lt;br/>and features
+          On effectiveness<br/>and features
           On Automatic creation
             Uses
                 Creative techniques
@@ -320,128 +399,112 @@ treemap
         Tools
           Pen and paper
           Mermaid
+
     </pre>
-    <pre id="diagram4" class="mermaid2">
-      ---
-      config:
-        layout: cose-bilkent
-      ---
-      mindmap
-      root((mindmap))
-        Origins
-          Long history
-          ::icon(fa fa-book)
-          Popularisation
-            British popular psychology author Tony Buzan
-        Research
-          On effectiveness&lt;br/>and features
-          On Automatic creation
-            Uses
-                Creative techniques
-                Strategic planning
-                Argument mapping
-        Tools
-          Pen and paper
-          Mermaid
-    </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
       ---
       config:
         layout: elk
-      ---
-      mindmap
-      root((mindmap))
-        Origins
-          Long history
-          ::icon(fa fa-book)
-          Popularisation
-            British popular psychology author Tony Buzan
-        Research
-          On effectiveness&lt;br/>and features
-          On Automatic creation
-            Uses
-                Creative techniques
-                Strategic planning
-                Argument mapping
-        Tools
-          Pen and paper
-          Mermaid
-    </pre>
-    <pre id="diagram4" class="mermaid2">
-      ---
-      config:
-        layout: cose-bilkent
+        flowchart:
+          curve: linear
       ---
       flowchart LR
-      root{mindmap} --- Origins --- Europe
-      Origins --> Asia
-      root --- Background --- Rich
-      Background --- Poor
-      subgraph apa
-        Background
-        Poor
-      end
-
-
-
+          A[A] --> B[B]
+          A[A] --- B([C])
+          A@{ shape: diamond}
+          %%B@{ shape: diamond}
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
       ---
       config:
         layout: elk
+        flowchart:
+          curve: linear
       ---
       flowchart LR
-      root{mindmap} --- Origins --- Europe
-      Origins --> Asia
-      root --- Background --- Rich
-      Background --- Poor
-
-
-
+          A[A] -- Mermaid js --> B[B]
+          A[A] -- Mermaid js --- B[B]
+          A@{ shape: diamond}
+          B@{ shape: diamond}
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
-      flowchart
-        D(("for D"))
-    </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+        flowchart:
+          curve: rounded
+      ---
       flowchart LR
-        A e1@==> B
-        e1@{ animate: true}
+          D["Use the editor"] -- Mermaid js --> I["fa:fa-code Text"]
+          I --> D & D
+          D@{ shape: question}
+          I@{ shape: question}
     </pre>
-    <pre id="diagram4" class="mermaid2">
-flowchart LR
-  A e1@--> B
-  classDef animate stroke-width:2,stroke-dasharray:10\,8,stroke-dashoffset:-180,animation: edge-animation-frame 6s linear infinite, stroke-linecap: round
-  class e1 animate
-    </pre>
-    <h2>infinite</h2>
-    <pre id="diagram4" class="mermaid2">
-flowchart LR
-  A e1@--> B
-  classDef animate stroke-dasharray: 9\,5,stroke-dashoffset: 900,animation: dash 25s linear infinite;
-  class e1 animate
-    </pre>
-    <h2>Mermaid - edge-animation-slow</h2>
-    <pre id="diagram4" class="mermaid2">
-flowchart LR
-  A e1@--> B
-e1@{ animation: fast}
-    </pre>
-    <h2>Mermaid - edge-animation-fast</h2>
-    <pre id="diagram4" class="mermaid2">
-flowchart LR
-  A e1@--> B
-  classDef animate stroke-dasharray: 1000,stroke-dashoffset: 1000,animation: dash 10s linear;
-  class e1 edge-animation-fast
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+        flowchart:
+          curve: rounded
+        elk:
+          nodePlacementStrategy: NETWORK_SIMPLEX
+      ---
+      flowchart LR
+          D["Use the editor"] -- Mermaid js --> I["fa:fa-code Text"]
+          D --> I & I
+          a["a"]
+          D@{ shape: trap-b}
+          I@{ shape: lean-l}
     </pre>
+    <pre id="diagram4" class="mermaid">
+---
+config:
+  layout: elk
 
-    <pre id="diagram4" class="mermaid2">
+---
+flowchart LR
+ %% subgraph s1["Untitled subgraph"]
+        C["Evaluate"]
+ %% end
 
-info    </pre
-    >
-    <pre id="diagram4" class="mermaid2">
+    B --> C
+    </pre>
+    <pre id="diagram4" class="mermaid">
+---
+config:
+  layout: elk
+  flowchart:
+    //curve: linear
+---
+flowchart LR
+%% A ==> B
+%% A2 --> B2
+A{A} --> B((Bo boo)) & B & B & B
+
+    </pre>
+    <pre id="diagram4" class="mermaid">
+      ---
+      config:
+        layout: elk
+        theme: default
+        look: classic
+      ---
+      flowchart LR
+       subgraph s1["APA"]
+              D{"Use the editor"}
+        end
+       subgraph S2["S2"]
+              s1
+              I>"fa:fa-code Text"]
+              E["E"]
+        end
+          D -- Mermaid js --> I
+          D --> I & E
+          E --> I
+    </pre>
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -466,7 +529,7 @@ config:
       end
       end
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -479,45 +542,7 @@ config:
       D-->I
       D-->I
     </pre>
-    <pre id="diagram4" class="mermaid2">
----
-config:
-  layout: elk
----
-      flowchart LR
-      a
-      subgraph s0["APA"]
-      subgraph s8["APA"]
-      subgraph s1["APA"]
-        D{"X"}
-        E[Q]
-      end
-      subgraph s3["BAPA"]
-        F[Q]
-        I
-      end
-            D --> I
-            D --> I
-            D --> I
-
-      I{"X"}
-      end
-      end
-    </pre>
-    <pre id="diagram4" class="mermaid2">
----
-config:
-  layout: elk
----
-      flowchart LR
-      a
-        D{"Use the editor"}
-
-      D -- Mermaid js --> I{"fa:fa-code Text"}
-      D-->I
-      D-->I
-    </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -556,7 +581,7 @@ flowchart LR
     n8@{ shape: rect}
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -572,7 +597,7 @@ flowchart LR
 
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -581,7 +606,7 @@ flowchart LR
     A{A} --> B & C
 </pre
     >
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -593,7 +618,7 @@ flowchart LR
     end
 </pre
     >
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   layout: elk
@@ -611,7 +636,7 @@ flowchart LR
 
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   kanban:
@@ -630,81 +655,81 @@ kanban
     task3[💻 Develop login feature]@{ ticket: 103 }
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Default] --> A@{ icon: 'fa:bell', form: 'rounded' }
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Style] --> A@{ icon: 'fa:bell', form: 'rounded' }
 style A fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Class] --> A@{ icon: 'fa:bell', form: 'rounded' }
 A:::AClass
 classDef AClass fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
   nA[Class] --> A@{ icon: 'logos:aws', form: 'rounded' }
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Default] --> A@{ icon: 'fa:bell', form: 'square' }
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Style] --> A@{ icon: 'fa:bell', form: 'square' }
 style A fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Class] --> A@{ icon: 'fa:bell', form: 'square' }
 A:::AClass
 classDef AClass fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
   nA[Class] --> A@{ icon: 'logos:aws', form: 'square' }
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Default] --> A@{ icon: 'fa:bell', form: 'circle' }
 
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Style] --> A@{ icon: 'fa:bell', form: 'circle' }
 style A fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
 nA[Class] --> A@{ icon: 'fa:bell', form: 'circle' }
 A:::AClass
 classDef AClass fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
   nA[Class] --> A@{ icon: 'logos:aws', form: 'circle' }
   A:::AClass
   classDef AClass fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 flowchart LR
   nA[Style] --> A@{ icon: 'logos:aws', form: 'circle' }
   style A fill:#f9f,stroke:#333,stroke-width:4px
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 kanban
   id2[In progress]
     docs[Create Blog about the new diagram]@{ priority: 'Very Low', ticket: MC-2037, assigned: 'knsv' }
     </pre>
-    <pre id="diagram4" class="mermaid2">
+    <pre id="diagram4" class="mermaid">
 ---
 config:
   kanban:
@@ -768,18 +793,22 @@ kanban
         alert('It worked');
       }
       await mermaid.initialize({
-        // theme: 'forest',
+        // theme: 'base',
         // theme: 'default',
         // theme: 'forest',
         // handDrawnSeed: 12,
         // look: 'handDrawn',
         // 'elk.nodePlacement.strategy': 'NETWORK_SIMPLEX',
         // layout: 'dagre',
-        // layout: 'elk',
+        layout: 'elk',
         // layout: 'fixed',
         // htmlLabels: false,
         flowchart: { titleTopMargin: 10 },
-        fontFamily: "'Recursive', sans-serif",
+
+        // fontFamily: 'Caveat',
+        // fontFamily: 'Kalam',
+        // fontFamily: 'courier',
+        fontFamily: 'arial',
         sequence: {
           actorFontFamily: 'courier',
           noteFontFamily: 'courier',

cypress/tsconfig.json

@@ -2,7 +2,7 @@
   "compilerOptions": {
     "target": "es2020",
     "lib": ["es2020", "dom"],
-    "types": ["cypress", "node", "@argos-ci/cypress/dist/support.d.ts"],
+    "types": ["cypress", "node", "@argos-ci/cypress/support"],
     "allowImportingTsExtensions": true,
     "noEmit": true
   },

demos/er-multiline.html

@@ -11,7 +11,7 @@
       rel="stylesheet"
     />
     <link
-      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css"
+      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.2/css/all.min.css"
       rel="stylesheet"
     />
     <link

demos/usecase.html

@@ -0,0 +1,234 @@
+<html>
+  <head>
+    <link href="https://fonts.googleapis.com/css?family=Montserrat&display=swap" rel="stylesheet" />
+    <link href="https://unpkg.com/tailwindcss@^1.0/dist/tailwind.min.css" rel="stylesheet" />
+    <link
+      rel="stylesheet"
+      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css"
+    />
+    <link
+      href="https://cdn.jsdelivr.net/npm/@mdi/font@6.9.96/css/materialdesignicons.min.css"
+      rel="stylesheet"
+    />
+    <link
+      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css"
+      rel="stylesheet"
+    />
+    <link
+      href="https://fonts.googleapis.com/css?family=Noto+Sans+SC&display=swap"
+      rel="stylesheet"
+    />
+    <link rel="preconnect" href="https://fonts.googleapis.com" />
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+    <link
+      href="https://fonts.googleapis.com/css2?family=Kalam:wght@300;400;700&display=swap"
+      rel="stylesheet"
+    />
+    <link
+      href="https://fonts.googleapis.com/css2?family=Caveat:wght@400..700&family=Kalam:wght@300;400;700&family=Rubik+Mono+One&display=swap"
+      rel="stylesheet"
+    />
+    <link
+      href="https://fonts.googleapis.com/css2?family=Kalam:wght@300;400;700&family=Rubik+Mono+One&display=swap"
+      rel="stylesheet"
+    />
+    <link
+      href="https://fonts.googleapis.com/css2?family=Recursive:wght@300..1000&display=swap"
+      rel="stylesheet"
+    />
+
+    <style>
+      .recursive-500 {
+        font-family: 'Recursive', serif;
+        font-optical-sizing: auto;
+        font-weight: 500;
+        font-style: normal;
+        font-variation-settings:
+          'slnt' 0,
+          'CASL' 0,
+          'CRSV' 0.5,
+          'MONO' 0;
+      }
+      body {
+        /* background: rgb(221, 208, 208); */
+        /* background: #333; */
+        /* font-family: 'Arial'; */
+        font-family: 'Recursive', serif;
+        font-optical-sizing: auto;
+        font-weight: 500;
+        font-style: normal;
+        font-variation-settings:
+          'slnt' 0,
+          'CASL' 0,
+          'CRSV' 0.5,
+          'MONO' 0;
+        /* color: white; */
+        /* font-size: 18px !important; */
+      }
+      .gridify.tiny {
+        background-image:
+          linear-gradient(transparent 11px, rgba(220, 220, 200, 0.8) 12px, transparent 12px),
+          linear-gradient(90deg, transparent 11px, rgba(220, 220, 200, 0.8) 12px, transparent 12px);
+        background-size:
+          100% 12px,
+          12px 100%;
+      }
+
+      .gridify.dots {
+        background-image: radial-gradient(
+          circle at center,
+          rgba(220, 220, 200, 0.8) 1px,
+          transparent 1px
+        );
+        background-size: 24px 24px;
+      }
+
+      h1 {
+        color: grey;
+      }
+
+      .mermaid2 {
+        display: none;
+      }
+
+      .mermaid svg {
+        font-size: 16px !important;
+        font-family: 'Recursive', serif;
+        font-optical-sizing: auto;
+        font-weight: 500;
+        font-style: normal;
+        font-variation-settings:
+          'slnt' 0,
+          'CASL' 0,
+          'CRSV' 0.5,
+          'MONO' 0;
+      }
+
+      pre {
+        width: 100%;
+        /*box-shadow: 4px 4px 0px 0px #0000000F;*/
+      }
+    </style>
+  </head>
+
+  <body class="gridify dots">
+    <p class="mb-20">Test Diagram</p>
+    <div class="w-full h-64">
+      <pre id="diagram4" class="mermaid">
+usecase
+direction LR
+        actor User1, User2, User3, User4
+        actor Admin1, Admin2
+        actor System1@{ "icon": "bell" }
+        actor System2@{ "icon": "database" }
+
+        systemBoundary "Module A"
+          "Feature A1"
+          "Feature A2"
+          "Admin A1"
+
+        end
+        "Module A"@{ type: package }
+
+        systemBoundary "Module B"
+          "Feature B1"
+          "Feature B2"
+          "Admin B1"
+        end
+
+        User1 --important--> "Feature A1"
+        User2 --> "Feature A2"
+        Admin1 --> "Admin A1"
+        User3 --> "Feature B1"
+        User4 --> "Feature B2"
+        Admin2 --> "Admin B1"
+
+        System1 <-- "Feature A1"
+        System1 <-- "Feature B1"
+        System2 <-- "Admin A1"
+        System2 <-- "Admin B1"
+
+        User1 --"collaborates"--> User2
+        Admin1 --"supervises"--> Admin2
+
+    </pre
+      >
+    </div>
+
+    <script type="module">
+      import mermaid from './mermaid.esm.mjs';
+      import layouts from './mermaid-layout-elk.esm.mjs';
+
+      const staticBellIconPack = {
+        prefix: 'fa6-regular',
+        icons: {
+          bell: {
+            body: '<path fill="currentColor" d="M224 0c-17.7 0-32 14.3-32 32v19.2C119 66 64 130.6 64 208v25.4c0 45.4-15.5 89.5-43.8 124.9L5.3 377c-5.8 7.2-6.9 17.1-2.9 25.4S14.8 416 24 416h400c9.2 0 17.6-5.3 21.6-13.6s2.9-18.2-2.9-25.4l-14.9-18.6c-28.3-35.5-43.8-79.6-43.8-125V208c0-77.4-55-142-128-156.8V32c0-17.7-14.3-32-32-32m0 96c61.9 0 112 50.1 112 112v25.4c0 47.9 13.9 94.6 39.7 134.6H72.3c25.8-40 39.7-86.7 39.7-134.6V208c0-61.9 50.1-112 112-112m64 352H160c0 17 6.7 33.3 18.7 45.3S207 512 224 512s33.3-6.7 45.3-18.7S288 465 288 448"/>',
+            width: 448,
+          },
+        },
+        width: 512,
+        height: 512,
+      };
+
+      mermaid.registerIconPacks([
+        {
+          name: 'logos',
+          loader: () =>
+            fetch('https://unpkg.com/@iconify-json/logos@1/icons.json').then((res) => res.json()),
+        },
+        {
+          name: 'fa',
+          loader: () =>
+            fetch('https://unpkg.com/@iconify-json/fa6-solid/icons.json').then((res) => res.json()),
+        },
+      ]);
+      mermaid.registerLayoutLoaders(layouts);
+      mermaid.parseError = function (err, hash) {
+        console.error('Mermaid error: ', err);
+      };
+      window.callback = function () {
+        alert('A callback was triggered');
+      };
+      function callback() {
+        alert('It worked');
+      }
+      await mermaid.initialize({
+        startOnLoad: false,
+        theme: 'default',
+        // theme: 'forest',
+        // handDrawnSeed: 12,
+        // 'elk.nodePlacement.strategy': 'NETWORK_SIMPLEX',
+        layout: 'dagre',
+        // layout: 'elk',
+        // layout: 'fixed',
+        // htmlLabels: false,
+        flowchart: { titleTopMargin: 10 },
+
+        // fontFamily: 'Caveat',
+        // fontFamily: 'Kalam',
+        // fontFamily: 'courier',
+        fontFamily: 'Recursive',
+        sequence: {
+          actorFontFamily: 'courier',
+          noteFontFamily: 'courier',
+          messageFontFamily: 'courier',
+        },
+        kanban: {
+          htmlLabels: false,
+        },
+        fontSize: 16,
+        logLevel: 0,
+        securityLevel: 'loose',
+        callback,
+      });
+      // setTimeout(() => {
+      mermaid.init(undefined, document.querySelectorAll('.mermaid'));
+      // }, 1000);
+      mermaid.parseError = function (err, hash) {
+        console.error('In parse error:');
+        console.error(err);
+      };
+    </script>
+  </body>
+</html>

docs/community/contributing.md

@@ -29,7 +29,8 @@ In GitHub, you first [**fork a mermaid repository**](https://github.com/mermaid-
 
 Then you **clone** a copy to your local development machine (e.g. where you code) to make a copy with all the files to work with.
 
-> **💡 Tip** > [Here is a GitHub document that gives an overview of the process](https://docs.github.com/en/get-started/quickstart/fork-a-repo).
+> **💡 Tip**
+> [Here is a GitHub document that gives an overview of the process](https://docs.github.com/en/get-started/quickstart/fork-a-repo).
 
 ```bash
 git clone git@github.com/your-fork/mermaid

docs/community/intro.md

@@ -33,7 +33,8 @@ mindmap
 
 ## Join the Development
 
-> **💡 Tip** > **Check out our** [**detailed contribution guide**](./contributing.md).
+> **💡 Tip**
+> **Check out our** [**detailed contribution guide**](./contributing.md).
 
 Where to start:
 
@@ -47,7 +48,8 @@ Where to start:
 
 ## A Question Or a Suggestion?
 
-> **💡 Tip** > **Have a look at** [**how to open an issue**](./questions-and-suggestions.md).
+> **💡 Tip**
+> **Have a look at** [**how to open an issue**](./questions-and-suggestions.md).
 
 If you have faced a vulnerability [report it to us](./security.md).
 

docs/config/directives.md

@@ -22,7 +22,6 @@ While directives allow you to change most of the default configuration settings,
 Mermaid basically supports two types of configuration options to be overridden by directives.
 
 1. _General/Top Level configurations_ : These are the configurations that are available and applied to all the diagram. **Some of the most important top-level** configurations are:
-
    - theme
    - fontFamily
    - logLevel

docs/config/setup/defaultConfig/variables/configKeys.md

@@ -12,4 +12,4 @@
 
 > `const` **configKeys**: `Set`<`string`>
 
-Defined in: [packages/mermaid/src/defaultConfig.ts:292](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/defaultConfig.ts#L292)
+Defined in: [packages/mermaid/src/defaultConfig.ts:295](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/defaultConfig.ts#L295)

docs/config/setup/mermaid/interfaces/ExternalDiagramDefinition.md

@@ -10,7 +10,7 @@
 
 # Interface: ExternalDiagramDefinition
 
-Defined in: [packages/mermaid/src/diagram-api/types.ts:94](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L94)
+Defined in: [packages/mermaid/src/diagram-api/types.ts:96](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L96)
 
 ## Properties
 
@@ -18,7 +18,7 @@ Defined in: [packages/mermaid/src/diagram-api/types.ts:94](https://github.com/me
 
 > **detector**: `DiagramDetector`
 
-Defined in: [packages/mermaid/src/diagram-api/types.ts:96](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L96)
+Defined in: [packages/mermaid/src/diagram-api/types.ts:98](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L98)
 
 ---
 
@@ -26,7 +26,7 @@ Defined in: [packages/mermaid/src/diagram-api/types.ts:96](https://github.com/me
 
 > **id**: `string`
 
-Defined in: [packages/mermaid/src/diagram-api/types.ts:95](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L95)
+Defined in: [packages/mermaid/src/diagram-api/types.ts:97](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L97)
 
 ---
 
@@ -34,4 +34,4 @@ Defined in: [packages/mermaid/src/diagram-api/types.ts:95](https://github.com/me
 
 > **loader**: `DiagramLoader`
 
-Defined in: [packages/mermaid/src/diagram-api/types.ts:97](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L97)
+Defined in: [packages/mermaid/src/diagram-api/types.ts:99](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L99)

docs/config/setup/mermaid/interfaces/LayoutLoaderDefinition.md

@@ -10,7 +10,7 @@
 
 # Interface: LayoutLoaderDefinition
 
-Defined in: [packages/mermaid/src/rendering-util/render.ts:21](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L21)
+Defined in: [packages/mermaid/src/rendering-util/render.ts:24](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L24)
 
 ## Properties
 
@@ -18,7 +18,7 @@ Defined in: [packages/mermaid/src/rendering-util/render.ts:21](https://github.co
 
 > `optional` **algorithm**: `string`
 
-Defined in: [packages/mermaid/src/rendering-util/render.ts:24](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L24)
+Defined in: [packages/mermaid/src/rendering-util/render.ts:27](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L27)
 
 ---
 
@@ -26,7 +26,7 @@ Defined in: [packages/mermaid/src/rendering-util/render.ts:24](https://github.co
 
 > **loader**: `LayoutLoader`
 
-Defined in: [packages/mermaid/src/rendering-util/render.ts:23](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L23)
+Defined in: [packages/mermaid/src/rendering-util/render.ts:26](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L26)
 
 ---
 
@@ -34,4 +34,4 @@ Defined in: [packages/mermaid/src/rendering-util/render.ts:23](https://github.co
 
 > **name**: `string`
 
-Defined in: [packages/mermaid/src/rendering-util/render.ts:22](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L22)
+Defined in: [packages/mermaid/src/rendering-util/render.ts:25](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L25)

docs/config/setup/mermaid/interfaces/MermaidConfig.md

@@ -105,7 +105,7 @@ You can set this attribute to base the seed on a static string.
 
 > `optional` **dompurifyConfig**: `Config`
 
-Defined in: [packages/mermaid/src/config.type.ts:213](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L213)
+Defined in: [packages/mermaid/src/config.type.ts:214](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L214)
 
 ---
 
@@ -179,7 +179,7 @@ See <https://developer.mozilla.org/en-US/docs/Web/CSS/font-family>
 
 > `optional` **fontSize**: `number`
 
-Defined in: [packages/mermaid/src/config.type.ts:215](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L215)
+Defined in: [packages/mermaid/src/config.type.ts:216](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L216)
 
 ---
 
@@ -292,7 +292,7 @@ Defines which main look to use for the diagram.
 
 > `optional` **markdownAutoWrap**: `boolean`
 
-Defined in: [packages/mermaid/src/config.type.ts:216](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L216)
+Defined in: [packages/mermaid/src/config.type.ts:217](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L217)
 
 ---
 
@@ -424,7 +424,7 @@ Defined in: [packages/mermaid/src/config.type.ts:198](https://github.com/mermaid
 
 > `optional` **suppressErrorRendering**: `boolean`
 
-Defined in: [packages/mermaid/src/config.type.ts:222](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L222)
+Defined in: [packages/mermaid/src/config.type.ts:223](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L223)
 
 Suppresses inserting 'Syntax error' diagram in the DOM.
 This is useful when you want to control how to handle syntax errors in your application.
@@ -466,11 +466,19 @@ Defined in: [packages/mermaid/src/config.type.ts:196](https://github.com/mermaid
 
 ---
 
+### usecase?
+
+> `optional` **usecase**: `UsecaseDiagramConfig`
+
+Defined in: [packages/mermaid/src/config.type.ts:213](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L213)
+
+---
+
 ### wrap?
 
 > `optional` **wrap**: `boolean`
 
-Defined in: [packages/mermaid/src/config.type.ts:214](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L214)
+Defined in: [packages/mermaid/src/config.type.ts:215](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts#L215)
 
 ---
 

docs/config/setup/mermaid/interfaces/RenderOptions.md

@@ -10,7 +10,7 @@
 
 # Interface: RenderOptions
 
-Defined in: [packages/mermaid/src/rendering-util/render.ts:7](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L7)
+Defined in: [packages/mermaid/src/rendering-util/render.ts:10](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L10)
 
 ## Properties
 
@@ -18,4 +18,4 @@ Defined in: [packages/mermaid/src/rendering-util/render.ts:7](https://github.com
 
 > `optional` **algorithm**: `string`
 
-Defined in: [packages/mermaid/src/rendering-util/render.ts:8](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L8)
+Defined in: [packages/mermaid/src/rendering-util/render.ts:11](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/rendering-util/render.ts#L11)

docs/config/setup/mermaid/type-aliases/SVG.md

@@ -12,4 +12,4 @@
 
 > **SVG** = `d3.Selection`<`SVGSVGElement`, `unknown`, `Element` | `null`, `unknown`>
 
-Defined in: [packages/mermaid/src/diagram-api/types.ts:126](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L126)
+Defined in: [packages/mermaid/src/diagram-api/types.ts:128](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L128)

docs/config/setup/mermaid/type-aliases/SVGGroup.md

@@ -12,4 +12,4 @@
 
 > **SVGGroup** = `d3.Selection`<`SVGGElement`, `unknown`, `Element` | `null`, `unknown`>
 
-Defined in: [packages/mermaid/src/diagram-api/types.ts:128](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L128)
+Defined in: [packages/mermaid/src/diagram-api/types.ts:130](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/diagram-api/types.ts#L130)

docs/ecosystem/mermaid-chart.md

@@ -29,7 +29,6 @@ Try the Ultimate AI, Mermaid, and Visual Diagramming Suite by creating an accoun
 - **Plugins** - A plugin system for extending the functionality of Mermaid.
 
   Official Mermaid Chart plugins:
-
   - [Mermaid Chart GPT](https://chatgpt.com/g/g-684cc36f30208191b21383b88650a45d-mermaid-chart-diagrams-and-charts)
   - [Confluence](https://marketplace.atlassian.com/apps/1234056/mermaid-chart-for-confluence?hosting=cloud&tab=overview)
   - [Jira](https://marketplace.atlassian.com/apps/1234810/mermaid-chart-for-jira?tab=overview&hosting=cloud)

docs/news/announcements.md

@@ -35,13 +35,11 @@ The Mermaid Chart team is excited to introduce a new Visual Editor for Flowchart
 Learn more:
 
 - Visual Editor For Flowcharts
-
   - [Blog post](https://www.mermaidchart.com/blog/posts/mermaid-chart-releases-new-visual-editor-for-flowcharts)
 
   - [Demo video](https://www.youtube.com/watch?v=5aja0gijoO0)
 
 - Visual Editor For Sequence diagrams
-
   - [Blog post](https://www.mermaidchart.com/blog/posts/mermaid-chart-unveils-visual-editor-for-sequence-diagrams)
 
   - [Demo video](https://youtu.be/imc2u5_N6Dc)

docs/news/blog.md

@@ -6,6 +6,18 @@
 
 # Blog
 
+## [The Essential Guide to Mermaid Chart Plugin for VS Code \[08/2025\]](https://docs.mermaidchart.com/blog/posts/the-essential-guide-to-mermaid-chart-plugin-for-vs-code-08-2025)
+
+9/9/2025 • 5 mins
+
+Creating diagrams in VS Code has never been easier—the Mermaid VS Code plugin transforms text-based syntax into clear, professional visuals right inside your editor. With live previews, smart editing, and AI-powered diagram generation, it removes the friction from visualization so you can focus on coding.
+
+## [How to Create Perfect Flowcharts Using AI in 2025 Step-by-Step Guide](https://docs.mermaidchart.com/blog/posts/how-to-create-perfect-flowcharts-using-ai-in-2025-step-by-step-guide)
+
+7/22/2025 • 8 mins
+
+In 2025, AI tools make creating flowcharts faster and easier than ever. With Mermaid’s AI flowchart generator, you can turn plain text into clear, accurate diagrams in seconds. This guide walks through how it works and how to get the most out of it for technical and business workflows alike.
+
 ## [Mermaid introduces the Visual Editor for Entity Relationship diagrams](https://docs.mermaidchart.com/blog/posts/mermaid-introduces-the-visual-editor-for-entity-relationship-diagrams)
 
 7/15/2025 • 7 mins

docs/syntax/architecture.md

@@ -194,7 +194,7 @@ architecture-beta
 ## Icons
 
 By default, architecture diagram supports the following icons: `cloud`, `database`, `disk`, `internet`, `server`.
-Users can use any of the 200,000+ icons available in iconify.design, or [add custom icons](../config/icons.md).
+Users can use any of the 200,000+ icons available in iconify.design, or add other custom icons, by [registering an icon pack](../config/icons.md).
 
 After the icons are installed, they can be used in the architecture diagram by using the format "name:icon-name", where name is the value used when registering the icon pack.
 

docs/syntax/c4.md

@@ -139,7 +139,6 @@ The following unfinished features are not supported in the short term.
 - [ ] Legend
 
 - [x] System Context
-
   - [x] Person(alias, label, ?descr, ?sprite, ?tags, $link)
   - [x] Person_Ext
   - [x] System(alias, label, ?descr, ?sprite, ?tags, $link)
@@ -153,7 +152,6 @@ The following unfinished features are not supported in the short term.
   - [x] System_Boundary
 
 - [x] Container diagram
-
   - [x] Container(alias, label, ?techn, ?descr, ?sprite, ?tags, $link)
   - [x] ContainerDb
   - [x] ContainerQueue
@@ -163,7 +161,6 @@ The following unfinished features are not supported in the short term.
   - [x] Container_Boundary(alias, label, ?tags, $link)
 
 - [x] Component diagram
-
   - [x] Component(alias, label, ?techn, ?descr, ?sprite, ?tags, $link)
   - [x] ComponentDb
   - [x] ComponentQueue
@@ -172,18 +169,15 @@ The following unfinished features are not supported in the short term.
   - [x] ComponentQueue_Ext
 
 - [x] Dynamic diagram
-
   - [x] RelIndex(index, from, to, label, ?tags, $link)
 
 - [x] Deployment diagram
-
   - [x] Deployment_Node(alias, label, ?type, ?descr, ?sprite, ?tags, $link)
   - [x] Node(alias, label, ?type, ?descr, ?sprite, ?tags, $link): short name of Deployment_Node()
   - [x] Node_L(alias, label, ?type, ?descr, ?sprite, ?tags, $link): left aligned Node()
   - [x] Node_R(alias, label, ?type, ?descr, ?sprite, ?tags, $link): right aligned Node()
 
 - [x] Relationship Types
-
   - [x] Rel(from, to, label, ?techn, ?descr, ?sprite, ?tags, $link)
   - [x] BiRel (bidirectional relationship)
   - [x] Rel_U, Rel_Up

docs/syntax/flowchart.md

@@ -344,6 +344,7 @@ Below is a comprehensive list of the newly introduced shapes and their correspon
 | Display                           | Curved Trapezoid       | `curv-trap`    | Represents a display           | `curved-trapezoid`, `display`                                    |
 | Divided Process                   | Divided Rectangle      | `div-rect`     | Divided process shape          | `div-proc`, `divided-process`, `divided-rectangle`               |
 | Document                          | Document               | `doc`          | Represents a document          | `doc`, `document`                                                |
+| Ellipse                           | Ellipse                | `ellipse`      | Ellipse shape                  | `oval`                                                           |
 | Event                             | Rounded Rectangle      | `rounded`      | Represents an event            | `event`                                                          |
 | Extract                           | Triangle               | `tri`          | Extraction process             | `extract`, `triangle`                                            |
 | Fork/Join                         | Filled Rectangle       | `fork`         | Fork or join in process flow   | `join`                                                           |

docs/syntax/gantt.md

@@ -360,7 +360,8 @@ gantt
   weekday monday
 ```
 
-> **Warning** > `millisecond` and `second` support was added in v10.3.0
+> **Warning**
+> `millisecond` and `second` support was added in v10.3.0
 
 ## Output in compact mode
 

docs/syntax/sequenceDiagram.md

@@ -329,7 +329,11 @@ Messages can be of two displayed either solid or with a dotted line.
 [Actor][Arrow][Actor]:Message text
 ```
 
-There are ten types of arrows currently supported:
+Lines can be solid or dotted, and can end with various types of arrowheads, crosses, or open arrows.
+
+#### Supported Arrow Types
+
+**Standard Arrow Types**
 
 | Type     | Description                                          |
 | -------- | ---------------------------------------------------- |
@@ -344,6 +348,58 @@ There are ten types of arrows currently supported:
 | `-)`     | Solid line with an open arrow at the end (async)     |
 | `--)`    | Dotted line with a open arrow at the end (async)     |
 
+**Half-Arrows (v\<MERMAID_RELEASE_VERSION>+)**
+
+The following half-arrow types are supported for more expressive sequence diagrams. Both solid and dotted variants are available by increasing the number of dashes (`-` → `--`).
+
+---
+
+| Type    | Description                                          |
+| ------- | ---------------------------------------------------- |
+| `-\|\`  | Solid line with top half arrowhead                   |
+| `--\|\` | Dotted line with top half arrowhead                  |
+| `-\|/`  | Solid line with bottom half arrowhead                |
+| `--\|/` | Dotted line with bottom half arrowhead               |
+| `/\|-`  | Solid line with reverse top half arrowhead           |
+| `/\|--` | Dotted line with reverse top half arrowhead          |
+| `\\-`   | Solid line with reverse bottom half arrowhead        |
+| `\\--`  | Dotted line with reverse bottom half arrowhead       |
+| `-\\`   | Solid line with top stick half arrowhead             |
+| `--\\`  | Dotted line with top stick half arrowhead            |
+| `-//`   | Solid line with bottom stick half arrowhead          |
+| `--//`  | Dotted line with bottom stick half arrowhead         |
+| `//-`   | Solid line with reverse top stick half arrowhead     |
+| `//--`  | Dotted line with reverse top stick half arrowhead    |
+| `\\-`   | Solid line with reverse bottom stick half arrowhead  |
+| `\\--`  | Dotted line with reverse bottom stick half arrowhead |
+
+## Central Connections (v\<MERMAID_RELEASE_VERSION>+)
+
+Mermaid sequence diagrams support **central lifeline connections** using a `()`.
+This is useful to represent messages or signals that connect to a central point, rather than from one actor directly to another.
+
+To indicate a central connection, append `()` to the arrow syntax.
+
+#### Basic Syntax
+
+```mermaid-example
+sequenceDiagram
+    participant Alice
+    participant John
+    Alice->>()John: Hello John
+    Alice()->>John: How are you?
+    John()->>()Alice: Great!
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice
+    participant John
+    Alice->>()John: Hello John
+    Alice()->>John: How are you?
+    John()->>()Alice: Great!
+```
+
 ## Activations
 
 It is possible to activate and deactivate an actor. (de)activation can be dedicated declarations:

docs/syntax/userJourney.md

@@ -38,3 +38,5 @@ Each user journey is split into sections, these describe the part of the task
 the user is trying to complete.
 
 Tasks syntax is `Task name: <score>: <comma separated list of actors>`
+
+Score is a number between 1 and 5, inclusive.

package.json

@@ -63,36 +63,36 @@
     ]
   },
   "devDependencies": {
-    "@applitools/eyes-cypress": "^3.44.9",
-    "@argos-ci/cypress": "^5.0.2",
+    "@applitools/eyes-cypress": "^3.55.2",
+    "@argos-ci/cypress": "^6.1.3",
     "@changesets/changelog-github": "^0.5.1",
-    "@changesets/cli": "^2.27.12",
+    "@changesets/cli": "^2.29.7",
     "@cspell/eslint-plugin": "^8.19.4",
-    "@cypress/code-coverage": "^3.12.49",
+    "@cypress/code-coverage": "^3.14.6",
     "@eslint/js": "^9.26.0",
-    "@rollup/plugin-typescript": "^12.1.2",
-    "@types/cors": "^2.8.17",
-    "@types/express": "^5.0.0",
+    "@rollup/plugin-typescript": "^12.1.4",
+    "@types/cors": "^2.8.19",
+    "@types/express": "^5.0.3",
     "@types/js-yaml": "^4.0.9",
     "@types/jsdom": "^21.1.7",
-    "@types/lodash": "^4.17.15",
+    "@types/lodash": "^4.17.20",
     "@types/mdast": "^4.0.4",
-    "@types/node": "^22.13.5",
+    "@types/node": "^22.18.6",
     "@types/rollup-plugin-visualizer": "^5.0.3",
-    "@vitest/coverage-v8": "^3.0.6",
-    "@vitest/spy": "^3.0.6",
-    "@vitest/ui": "^3.0.6",
+    "@vitest/coverage-v8": "^3.2.4",
+    "@vitest/spy": "^3.2.4",
+    "@vitest/ui": "^3.2.4",
     "ajv": "^8.17.1",
     "chokidar": "3.6.0",
-    "concurrently": "^9.1.2",
+    "concurrently": "^9.2.1",
     "cors": "^2.8.5",
     "cpy-cli": "^5.0.0",
     "cross-env": "^7.0.3",
-    "cspell": "^9.1.3",
-    "cypress": "^14.5.1",
+    "cspell": "^9.2.1",
+    "cypress": "^14.5.4",
     "cypress-image-snapshot": "^4.0.1",
-    "cypress-split": "^1.24.14",
-    "esbuild": "^0.25.0",
+    "cypress-split": "^1.24.23",
+    "esbuild": "^0.25.10",
     "eslint": "^9.26.0",
     "eslint-config-prettier": "^10.1.8",
     "eslint-plugin-cypress": "^4.3.0",
@@ -106,30 +106,30 @@
     "eslint-plugin-tsdoc": "^0.4.0",
     "eslint-plugin-unicorn": "^59.0.1",
     "express": "^5.1.0",
-    "globals": "^16.0.0",
-    "globby": "^14.0.2",
+    "globals": "^16.4.0",
+    "globby": "^14.1.0",
     "husky": "^9.1.7",
-    "jest": "^30.0.4",
+    "jest": "^30.1.3",
     "jison": "^0.4.18",
     "js-yaml": "^4.1.0",
     "jsdom": "^26.1.0",
     "langium-cli": "3.3.0",
-    "lint-staged": "^16.1.2",
+    "lint-staged": "^16.1.6",
     "markdown-table": "^3.0.4",
     "nyc": "^17.1.0",
     "path-browserify": "^1.0.1",
-    "prettier": "^3.5.2",
-    "prettier-plugin-jsdoc": "^1.3.2",
+    "prettier": "^3.6.2",
+    "prettier-plugin-jsdoc": "^1.3.3",
     "rimraf": "^6.0.1",
     "rollup-plugin-visualizer": "^6.0.3",
-    "start-server-and-test": "^2.0.10",
+    "start-server-and-test": "^2.1.2",
     "tslib": "^2.8.1",
-    "tsx": "^4.7.3",
+    "tsx": "^4.20.5",
     "typescript": "~5.7.3",
     "typescript-eslint": "^8.38.0",
-    "vite": "^7.0.3",
+    "vite": "^7.0.7",
     "vite-plugin-istanbul": "^7.0.0",
-    "vitest": "^3.0.6"
+    "vitest": "^3.2.4"
   },
   "nyc": {
     "report-dir": "coverage/cypress"

packages/examples/package.json

@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "description": "Mermaid examples package",
   "author": "Sidharth Vinod",
+  "license": "MIT",
   "type": "module",
   "module": "./dist/mermaid-examples.core.mjs",
   "types": "./dist/mermaid.d.ts",

packages/examples/src/examples/usecase.ts

@@ -0,0 +1,51 @@
+import type { DiagramMetadata } from '../types.js';
+
+export default {
+  id: 'usecase',
+  name: 'Use Case Diagram',
+  description: 'Visualize system functionality and user interactions',
+  examples: [
+    {
+      title: 'Basic Use Case',
+      isDefault: true,
+      code: `usecase
+actor User
+actor Admin
+User --> (Login)
+User --> (View Profile)
+Admin --> (Manage Users)
+Admin --> (View Reports)`,
+    },
+    {
+      title: 'System Boundary',
+      code: `usecase
+actor Customer
+actor Support
+
+SystemBoundary@{ type: rect } "E-commerce System" {
+  Customer --> (Browse Products)
+  Customer --> (Place Order)
+  Customer --> (Track Order)
+}
+
+SystemBoundary@{ type: package } "Admin Panel" {
+  Support --> (Process Orders)
+  Support --> (Handle Returns)
+}`,
+    },
+    {
+      title: 'Actor Relationships',
+      code: `usecase
+actor Developer1
+actor Developer2
+actor Manager
+
+Developer1 --> (Write Code)
+Developer2 --> (Review Code)
+Manager --> (Approve Release)
+
+Developer1 --> Developer2
+Manager --> Developer1`,
+    },
+  ],
+} satisfies DiagramMetadata;

packages/examples/src/index.ts

@@ -21,6 +21,7 @@ import quadrantChart from './examples/quadrant-chart.js';
 import packetDiagram from './examples/packet.js';
 import blockDiagram from './examples/block.js';
 import treemapDiagram from './examples/treemap.js';
+import usecaseDiagram from './examples/usecase.js';
 
 export const diagramData: DiagramMetadata[] = [
   flowChart,
@@ -45,4 +46,5 @@ export const diagramData: DiagramMetadata[] = [
   packetDiagram,
   blockDiagram,
   treemapDiagram,
+  usecaseDiagram,
 ];

packages/mermaid-example-diagram/package.json

@@ -37,12 +37,12 @@
     ]
   },
   "dependencies": {
-    "@braintree/sanitize-url": "^7.0.4",
+    "@braintree/sanitize-url": "^7.1.1",
     "d3": "^7.9.0",
     "khroma": "^2.1.0"
   },
   "devDependencies": {
-    "concurrently": "^9.1.2",
+    "concurrently": "^9.2.1",
     "mermaid": "workspace:*",
     "rimraf": "^6.0.1"
   },

packages/mermaid-layout-elk/src/__tests__/geometry.spec.ts

@@ -0,0 +1,67 @@
+import { describe, it, expect } from 'vitest';
+import {
+  intersection,
+  ensureTrulyOutside,
+  makeInsidePoint,
+  tryNodeIntersect,
+  replaceEndpoint,
+  type RectLike,
+  type P,
+} from '../geometry.js';
+
+const approx = (a: number, b: number, eps = 1e-6) => Math.abs(a - b) < eps;
+
+describe('geometry helpers', () => {
+  it('intersection: vertical approach hits bottom border', () => {
+    const rect: RectLike = { x: 0, y: 0, width: 100, height: 50 };
+    const h = rect.height / 2; // 25
+    const outside: P = { x: 0, y: 100 };
+    const inside: P = { x: 0, y: 0 };
+    const res = intersection(rect, outside, inside);
+    expect(approx(res.x, 0)).toBe(true);
+    expect(approx(res.y, h)).toBe(true);
+  });
+
+  it('ensureTrulyOutside nudges near-boundary point outward', () => {
+    const rect: RectLike = { x: 0, y: 0, width: 100, height: 50 };
+    // near bottom boundary (y ~ h)
+    const near: P = { x: 0, y: rect.height / 2 - 0.2 };
+    const out = ensureTrulyOutside(rect, near, 10);
+    expect(out.y).toBeGreaterThan(rect.height / 2);
+  });
+
+  it('makeInsidePoint keeps x for vertical and y from center', () => {
+    const rect: RectLike = { x: 10, y: 5, width: 100, height: 50 };
+    const outside: P = { x: 10, y: 40 };
+    const center: P = { x: 99, y: -123 }; // center y should be used
+    const inside = makeInsidePoint(rect, outside, center);
+    expect(inside.x).toBe(outside.x);
+    expect(inside.y).toBe(center.y);
+  });
+
+  it('tryNodeIntersect returns null for wrong-side intersections', () => {
+    const rect: RectLike = { x: 0, y: 0, width: 100, height: 50 };
+    const outside: P = { x: -50, y: 0 };
+    const node = { intersect: () => ({ x: 10, y: 0 }) } as any; // right side of center
+    const res = tryNodeIntersect(node, rect, outside);
+    expect(res).toBeNull();
+  });
+
+  it('replaceEndpoint dedup removes end/start appropriately', () => {
+    const pts: P[] = [
+      { x: 0, y: 0 },
+      { x: 1, y: 1 },
+    ];
+    // remove duplicate end
+    replaceEndpoint(pts, 'end', { x: 1, y: 1 });
+    expect(pts.length).toBe(1);
+
+    const pts2: P[] = [
+      { x: 0, y: 0 },
+      { x: 1, y: 1 },
+    ];
+    // remove duplicate start
+    replaceEndpoint(pts2, 'start', { x: 0, y: 0 });
+    expect(pts2.length).toBe(1);
+  });
+});

packages/mermaid-layout-elk/src/geometry.ts

@@ -0,0 +1,209 @@
+/* Geometry utilities extracted from render.ts for reuse and testing */
+
+export interface P {
+  x: number;
+  y: number;
+}
+
+export interface RectLike {
+  x: number; // center x
+  y: number; // center y
+  width: number;
+  height: number;
+  padding?: number;
+}
+
+export interface NodeLike {
+  intersect?: (p: P) => P | null;
+}
+
+export const EPS = 1;
+export const PUSH_OUT = 10;
+
+export const onBorder = (bounds: RectLike, p: P, tol = 0.5): boolean => {
+  const halfW = bounds.width / 2;
+  const halfH = bounds.height / 2;
+  const left = bounds.x - halfW;
+  const right = bounds.x + halfW;
+  const top = bounds.y - halfH;
+  const bottom = bounds.y + halfH;
+
+  const onLeft = Math.abs(p.x - left) <= tol && p.y >= top - tol && p.y <= bottom + tol;
+  const onRight = Math.abs(p.x - right) <= tol && p.y >= top - tol && p.y <= bottom + tol;
+  const onTop = Math.abs(p.y - top) <= tol && p.x >= left - tol && p.x <= right + tol;
+  const onBottom = Math.abs(p.y - bottom) <= tol && p.x >= left - tol && p.x <= right + tol;
+  return onLeft || onRight || onTop || onBottom;
+};
+
+/**
+ * Compute intersection between a rectangle (center x/y, width/height) and the line
+ * segment from insidePoint -\> outsidePoint. Returns the point on the rectangle border.
+ *
+ * This version avoids snapping to outsidePoint when certain variables evaluate to 0
+ * (previously caused vertical top/bottom cases to miss the border). It only enforces
+ * axis-constant behavior for purely vertical/horizontal approaches.
+ */
+export const intersection = (node: RectLike, outsidePoint: P, insidePoint: P): P => {
+  const x = node.x;
+  const y = node.y;
+
+  const dx = Math.abs(x - insidePoint.x);
+  const w = node.width / 2;
+  let r = insidePoint.x < outsidePoint.x ? w - dx : w + dx;
+  const h = node.height / 2;
+
+  const Q = Math.abs(outsidePoint.y - insidePoint.y);
+  const R = Math.abs(outsidePoint.x - insidePoint.x);
+
+  if (Math.abs(y - outsidePoint.y) * w > Math.abs(x - outsidePoint.x) * h) {
+    // Intersection is top or bottom of rect.
+    const q = insidePoint.y < outsidePoint.y ? outsidePoint.y - h - y : y - h - outsidePoint.y;
+    r = (R * q) / Q;
+    const res = {
+      x: insidePoint.x < outsidePoint.x ? insidePoint.x + r : insidePoint.x - R + r,
+      y: insidePoint.y < outsidePoint.y ? insidePoint.y + Q - q : insidePoint.y - Q + q,
+    };
+
+    // Keep axis-constant special-cases only
+    if (R === 0) {
+      res.x = outsidePoint.x;
+    }
+    if (Q === 0) {
+      res.y = outsidePoint.y;
+    }
+    return res;
+  } else {
+    // Intersection on sides of rect
+    if (insidePoint.x < outsidePoint.x) {
+      r = outsidePoint.x - w - x;
+    } else {
+      r = x - w - outsidePoint.x;
+    }
+    const q = (Q * r) / R;
+    let _x = insidePoint.x < outsidePoint.x ? insidePoint.x + R - r : insidePoint.x - R + r;
+    let _y = insidePoint.y < outsidePoint.y ? insidePoint.y + q : insidePoint.y - q;
+
+    // Only handle axis-constant cases
+    if (R === 0) {
+      _x = outsidePoint.x;
+    }
+    if (Q === 0) {
+      _y = outsidePoint.y;
+    }
+
+    return { x: _x, y: _y };
+  }
+};
+
+export const outsideNode = (node: RectLike, point: P): boolean => {
+  const x = node.x;
+  const y = node.y;
+  const dx = Math.abs(point.x - x);
+  const dy = Math.abs(point.y - y);
+  const w = node.width / 2;
+  const h = node.height / 2;
+  return dx >= w || dy >= h;
+};
+
+export const ensureTrulyOutside = (bounds: RectLike, p: P, push = PUSH_OUT): P => {
+  const dx = Math.abs(p.x - bounds.x);
+  const dy = Math.abs(p.y - bounds.y);
+  const w = bounds.width / 2;
+  const h = bounds.height / 2;
+  if (Math.abs(dx - w) < EPS || Math.abs(dy - h) < EPS) {
+    const dirX = p.x - bounds.x;
+    const dirY = p.y - bounds.y;
+    const len = Math.sqrt(dirX * dirX + dirY * dirY);
+    if (len > 0) {
+      return {
+        x: bounds.x + (dirX / len) * (len + push),
+        y: bounds.y + (dirY / len) * (len + push),
+      };
+    }
+  }
+  return p;
+};
+
+export const makeInsidePoint = (bounds: RectLike, outside: P, center: P): P => {
+  const isVertical = Math.abs(outside.x - bounds.x) < EPS;
+  const isHorizontal = Math.abs(outside.y - bounds.y) < EPS;
+  return {
+    x: isVertical
+      ? outside.x
+      : outside.x < bounds.x
+        ? bounds.x - bounds.width / 4
+        : bounds.x + bounds.width / 4,
+    y: isHorizontal ? outside.y : center.y,
+  };
+};
+
+export const tryNodeIntersect = (node: NodeLike, bounds: RectLike, outside: P): P | null => {
+  if (!node?.intersect) {
+    return null;
+  }
+  const res = node.intersect(outside);
+  if (!res) {
+    return null;
+  }
+  const wrongSide =
+    (outside.x < bounds.x && res.x > bounds.x) || (outside.x > bounds.x && res.x < bounds.x);
+  if (wrongSide) {
+    return null;
+  }
+  const dist = Math.hypot(outside.x - res.x, outside.y - res.y);
+  if (dist <= EPS) {
+    return null;
+  }
+  return res;
+};
+
+export const fallbackIntersection = (bounds: RectLike, outside: P, center: P): P => {
+  const inside = makeInsidePoint(bounds, outside, center);
+  return intersection(bounds, outside, inside);
+};
+
+export const computeNodeIntersection = (
+  node: NodeLike,
+  bounds: RectLike,
+  outside: P,
+  center: P
+): P => {
+  const outside2 = ensureTrulyOutside(bounds, outside);
+  return tryNodeIntersect(node, bounds, outside2) ?? fallbackIntersection(bounds, outside2, center);
+};
+
+export const replaceEndpoint = (
+  points: P[],
+  which: 'start' | 'end',
+  value: P | null | undefined,
+  tol = 0.1
+) => {
+  if (!value || points.length === 0) {
+    return;
+  }
+
+  if (which === 'start') {
+    if (
+      points.length > 0 &&
+      Math.abs(points[0].x - value.x) < tol &&
+      Math.abs(points[0].y - value.y) < tol
+    ) {
+      // duplicate start remove it
+      points.shift();
+    } else {
+      points[0] = value;
+    }
+  } else {
+    const last = points.length - 1;
+    if (
+      points.length > 0 &&
+      Math.abs(points[last].x - value.x) < tol &&
+      Math.abs(points[last].y - value.y) < tol
+    ) {
+      // duplicate end remove it
+      points.pop();
+    } else {
+      points[last] = value;
+    }
+  }
+};

packages/mermaid-layout-elk/src/render.ts

@@ -1,11 +1,26 @@
+import type { InternalHelpers, LayoutData, RenderOptions, SVG, SVGGroup } from 'mermaid';
+// @ts-ignore TODO: Investigate D3 issue
 import { curveLinear } from 'd3';
 import ELK from 'elkjs/lib/elk.bundled.js';
-import type { InternalHelpers, LayoutData, RenderOptions, SVG, SVGGroup } from 'mermaid';
 import { type TreeData, findCommonAncestor } from './find-common-ancestor.js';
 
+import {
+  type P,
+  type RectLike,
+  outsideNode,
+  computeNodeIntersection,
+  replaceEndpoint,
+  onBorder,
+} from './geometry.js';
+
 type Node = LayoutData['nodes'][number];
-// Used to calculate distances in order to avoid floating number rounding issues when comparing floating numbers
-const epsilon = 0.0001;
+
+// Minimal structural type to avoid depending on d3 Selection typings
+interface D3Selection<T extends Element> {
+  node(): T | null;
+  attr(name: string, value: string): D3Selection<T>;
+}
+
 interface LabelData {
   width: number;
   height: number;
@@ -16,18 +31,9 @@ interface LabelData {
 interface NodeWithVertex extends Omit<Node, 'domId'> {
   children?: LayoutData['nodes'];
   labelData?: LabelData;
-  domId?: Node['domId'] | SVGGroup | d3.Selection<SVGAElement, unknown, Element | null, unknown>;
-}
-interface Point {
-  x: number;
-  y: number;
-}
-function distance(p1?: Point, p2?: Point): number {
-  if (!p1 || !p2) {
-    return 0;
-  }
-  return Math.sqrt(Math.pow(p2.x - p1.x, 2) + Math.pow(p2.y - p1.y, 2));
+  domId?: D3Selection<SVGAElement | SVGGElement>;
 }
+
 export const render = async (
   data4Layout: LayoutData,
   svg: SVG,
@@ -61,7 +67,7 @@ export const render = async (
 
     // Add the element to the DOM
     if (!node.isGroup) {
-      // Create a clean node object for ELK with only the properties it expects
+      // const child = node as NodeWithVertex;
       const child: NodeWithVertex = {
         id: node.id,
         width: node.width,
@@ -78,22 +84,24 @@ export const render = async (
         parentId: node.parentId,
       };
       graph.children.push(child);
-      nodeDb[node.id] = child;
+      nodeDb[node.id] = node;
 
       const childNodeEl = await insertNode(nodeEl, node, { config, dir: node.dir });
       const boundingBox = childNodeEl.node()!.getBBox();
       // Store the domId separately for rendering, not in the ELK graph
       child.domId = childNodeEl;
-      child.calcIntersect = node.calcIntersect;
       child.width = boundingBox.width;
       child.height = boundingBox.height;
     } else {
       // A subgraph
       const child: NodeWithVertex & { children: NodeWithVertex[] } = {
         ...node,
+        domId: undefined,
         children: [],
       };
+      // Let elk render with the copy
       graph.children.push(child);
+      // Save the original containing the intersection function
       nodeDb[node.id] = child;
       await addVertices(nodeEl, nodeArr, child, node.id);
 
@@ -157,7 +165,7 @@ export const render = async (
         domId: { node: () => any; attr: (arg0: string, arg1: string) => void };
       }) {
         if (node) {
-          nodeDb[node.id] = node;
+          nodeDb[node.id] ??= {};
           nodeDb[node.id].offset = {
             posX: node.x + relX,
             posY: node.y + relY,
@@ -168,7 +176,7 @@ export const render = async (
             height: node.height,
           };
           if (node.isGroup) {
-            log.debug('id abc88 subgraph = ', node.id, node.x, node.y, node.labelData);
+            log.debug('Id abc88 subgraph = ', node.id, node.x, node.y, node.labelData);
             const subgraphEl = subgraphsEl.insert('g').attr('class', 'subgraph');
             // TODO use faster way of cloning
             const clusterNode = JSON.parse(JSON.stringify(node));
@@ -177,10 +185,10 @@ export const render = async (
             clusterNode.width = Math.max(clusterNode.width, node.labelData.width);
             await insertCluster(subgraphEl, clusterNode);
 
-            log.debug('id (UIO)= ', node.id, node.width, node.shape, node.labels);
+            log.debug('Id (UIO)= ', node.id, node.width, node.shape, node.labels);
           } else {
             log.info(
-              'id NODE = ',
+              'Id NODE = ',
               node.id,
               node.x,
               node.y,
@@ -222,25 +230,19 @@ export const render = async (
       });
     });
 
-    subgraphs.forEach(function (subgraph: { id: string | number }) {
-      const data: any = { id: subgraph.id };
-      if (parentLookupDb.parentById[subgraph.id] !== undefined) {
-        data.parent = parentLookupDb.parentById[subgraph.id];
-      }
-    });
     return parentLookupDb;
   };
 
   const getEdgeStartEndPoint = (edge: any) => {
-    const source: any = edge.start;
-    const target: any = edge.end;
+    // edge.start and edge.end are IDs (string/number) in our layout data
+    const sourceId: string | number = edge.start;
+    const targetId: string | number = edge.end;
 
-    // Save the original source and target
-    const sourceId = source;
-    const targetId = target;
+    const source = sourceId;
+    const target = targetId;
 
-    const startNode = nodeDb[edge.start.id];
-    const endNode = nodeDb[edge.end.id];
+    const startNode = nodeDb[sourceId];
+    const endNode = nodeDb[targetId];
 
     if (!startNode || !endNode) {
       return { source, target };
@@ -263,6 +265,112 @@ export const render = async (
   /**
    * Add edges to graph based on parsed graph definition
    */
+  // Edge helper maps and utilities (de-duplicated)
+  const ARROW_MAP: Record<string, [string, string]> = {
+    arrow_open: ['arrow_open', 'arrow_open'],
+    arrow_cross: ['arrow_open', 'arrow_cross'],
+    double_arrow_cross: ['arrow_cross', 'arrow_cross'],
+    arrow_point: ['arrow_open', 'arrow_point'],
+    double_arrow_point: ['arrow_point', 'arrow_point'],
+    arrow_circle: ['arrow_open', 'arrow_circle'],
+    double_arrow_circle: ['arrow_circle', 'arrow_circle'],
+  };
+
+  const computeStroke = (
+    stroke: string | undefined,
+    defaultStyle?: string,
+    defaultLabelStyle?: string
+  ) => {
+    // Defaults correspond to 'normal'
+    let thickness = 'normal';
+    let pattern = 'solid';
+    let style = '';
+    let labelStyle = '';
+
+    if (stroke === 'dotted') {
+      pattern = 'dotted';
+      style = 'fill:none;stroke-width:2px;stroke-dasharray:3;';
+    } else if (stroke === 'thick') {
+      thickness = 'thick';
+      style = 'stroke-width: 3.5px;fill:none;';
+    } else {
+      // normal
+      style = defaultStyle ?? 'fill:none;';
+      if (defaultLabelStyle !== undefined) {
+        labelStyle = defaultLabelStyle;
+      }
+    }
+    return { thickness, pattern, style, labelStyle };
+  };
+
+  const getCurve = (edgeInterpolate: any, edgesDefaultInterpolate: any, confCurve: any) => {
+    if (edgeInterpolate !== undefined) {
+      return interpolateToCurve(edgeInterpolate, curveLinear);
+    }
+    if (edgesDefaultInterpolate !== undefined) {
+      return interpolateToCurve(edgesDefaultInterpolate, curveLinear);
+    }
+    // @ts-ignore TODO: fix this
+    return interpolateToCurve(confCurve, curveLinear);
+  };
+  const buildEdgeData = (
+    edge: any,
+    defaults: {
+      defaultStyle?: string;
+      defaultLabelStyle?: string;
+      defaultInterpolate?: any;
+      confCurve: any;
+    },
+    common: any
+  ) => {
+    const edgeData: any = { style: '', labelStyle: '' };
+    edgeData.minlen = edge.length || 1;
+    // maintain legacy behavior
+    edge.text = edge.label;
+
+    // Arrowhead fill vs none
+    edgeData.arrowhead = edge.type === 'arrow_open' ? 'none' : 'normal';
+
+    // Arrow types
+    const arrowMap = ARROW_MAP[edge.type] ?? ARROW_MAP.arrow_open;
+    edgeData.arrowTypeStart = arrowMap[0];
+    edgeData.arrowTypeEnd = arrowMap[1];
+
+    // Optional edge label positioning flags
+    edgeData.startLabelRight = edge.startLabelRight;
+    edgeData.endLabelLeft = edge.endLabelLeft;
+
+    // Stroke
+    const strokeRes = computeStroke(edge.stroke, defaults.defaultStyle, defaults.defaultLabelStyle);
+    edgeData.thickness = strokeRes.thickness;
+    edgeData.pattern = strokeRes.pattern;
+    edgeData.style = (edgeData.style || '') + (strokeRes.style || '');
+    edgeData.labelStyle = (edgeData.labelStyle || '') + (strokeRes.labelStyle || '');
+
+    // Curve
+    // @ts-ignore - defaults.confCurve is present at runtime but missing in type
+    edgeData.curve = getCurve(edge.interpolate, defaults.defaultInterpolate, defaults.confCurve);
+
+    // Arrowhead style + labelpos when we have label text
+    const hasText = (edge?.text ?? '') !== '';
+    if (hasText) {
+      edgeData.arrowheadStyle = 'fill: #333';
+      edgeData.labelpos = 'c';
+    } else if (edge.style !== undefined) {
+      edgeData.arrowheadStyle = 'fill: #333';
+    }
+
+    edgeData.labelType = edge.labelType;
+    edgeData.label = (edge?.text ?? '').replace(common.lineBreakRegex, '\n');
+
+    if (edge.style === undefined) {
+      edgeData.style = edgeData.style ?? 'stroke: #333; stroke-width: 1.5px;fill:none;';
+    }
+
+    edgeData.labelStyle = edgeData.labelStyle.replace('color:', 'fill:');
+    return edgeData;
+  };
+
   const addEdges = async function (
     dataForLayout: { edges: any; direction?: string },
     graph: {
@@ -284,7 +392,6 @@ export const render = async (
     const edges = dataForLayout.edges;
     const labelsEl = svg.insert('g').attr('class', 'edgeLabels');
     const linkIdCnt: any = {};
-    const dir = dataForLayout.direction || 'DOWN';
     let defaultStyle: string | undefined;
     let defaultLabelStyle: string | undefined;
 
@@ -314,105 +421,24 @@ export const render = async (
           linkIdCnt[linkIdBase]++;
           log.info('abc78 new entry', linkIdBase, linkIdCnt[linkIdBase]);
         }
-        const linkId = linkIdBase + '_' + linkIdCnt[linkIdBase];
+        const linkId = linkIdBase; // + '_' + linkIdCnt[linkIdBase];
         edge.id = linkId;
         log.info('abc78 new link id to be used is', linkIdBase, linkId, linkIdCnt[linkIdBase]);
         const linkNameStart = 'LS_' + edge.start;
         const linkNameEnd = 'LE_' + edge.end;
 
-        const edgeData: any = { style: '', labelStyle: '' };
-        edgeData.minlen = edge.length || 1;
-        edge.text = edge.label;
-        // Set link type for rendering
-        if (edge.type === 'arrow_open') {
-          edgeData.arrowhead = 'none';
-        } else {
-          edgeData.arrowhead = 'normal';
-        }
-
-        // Check of arrow types, placed here in order not to break old rendering
-        edgeData.arrowTypeStart = 'arrow_open';
-        edgeData.arrowTypeEnd = 'arrow_open';
-
-        /* eslint-disable no-fallthrough */
-        switch (edge.type) {
-          case 'double_arrow_cross':
-            edgeData.arrowTypeStart = 'arrow_cross';
-          case 'arrow_cross':
-            edgeData.arrowTypeEnd = 'arrow_cross';
-            break;
-          case 'double_arrow_point':
-            edgeData.arrowTypeStart = 'arrow_point';
-          case 'arrow_point':
-            edgeData.arrowTypeEnd = 'arrow_point';
-            break;
-          case 'double_arrow_circle':
-            edgeData.arrowTypeStart = 'arrow_circle';
-          case 'arrow_circle':
-            edgeData.arrowTypeEnd = 'arrow_circle';
-            break;
-        }
-
-        let style = '';
-        let labelStyle = '';
-
-        edgeData.startLabelRight = edge.startLabelRight;
-        edgeData.endLabelLeft = edge.endLabelLeft;
-
-        switch (edge.stroke) {
-          case 'normal':
-            style = 'fill:none;';
-            if (defaultStyle !== undefined) {
-              style = defaultStyle;
-            }
-            if (defaultLabelStyle !== undefined) {
-              labelStyle = defaultLabelStyle;
-            }
-            edgeData.thickness = 'normal';
-            edgeData.pattern = 'solid';
-            break;
-          case 'dotted':
-            edgeData.thickness = 'normal';
-            edgeData.pattern = 'dotted';
-            edgeData.style = 'fill:none;stroke-width:2px;stroke-dasharray:3;';
-            break;
-          case 'thick':
-            edgeData.thickness = 'thick';
-            edgeData.pattern = 'solid';
-            edgeData.style = 'stroke-width: 3.5px;fill:none;';
-            break;
-        }
-
-        edgeData.style = edgeData.style += style;
-        edgeData.labelStyle = edgeData.labelStyle += labelStyle;
-
         const conf = getConfig();
-        if (edge.interpolate !== undefined) {
-          edgeData.curve = interpolateToCurve(edge.interpolate, curveLinear);
-        } else if (edges.defaultInterpolate !== undefined) {
-          edgeData.curve = interpolateToCurve(edges.defaultInterpolate, curveLinear);
-        } else {
-          // @ts-ignore TODO: fix this
-          edgeData.curve = interpolateToCurve(conf.curve, curveLinear);
-        }
-
-        if (edge.text === undefined) {
-          if (edge.style !== undefined) {
-            edgeData.arrowheadStyle = 'fill: #333';
-          }
-        } else {
-          edgeData.arrowheadStyle = 'fill: #333';
-          edgeData.labelpos = 'c';
-        }
-
-        edgeData.labelType = edge.labelType;
-        edgeData.label = (edge?.text || '').replace(common.lineBreakRegex, '\n');
-
-        if (edge.style === undefined) {
-          edgeData.style = edgeData.style || 'stroke: #333; stroke-width: 1.5px;fill:none;';
-        }
-
-        edgeData.labelStyle = edgeData.labelStyle.replace('color:', 'fill:');
+        const edgeData = buildEdgeData(
+          edge,
+          {
+            defaultStyle,
+            defaultLabelStyle,
+            defaultInterpolate: edges.defaultInterpolate,
+            // @ts-ignore - conf.curve exists at runtime but is missing from typing
+            confCurve: conf.curve,
+          },
+          common
+        );
 
         edgeData.id = linkId;
         edgeData.classes = 'flowchart-link ' + linkNameStart + ' ' + linkNameEnd;
@@ -421,13 +447,11 @@ export const render = async (
 
         // calculate start and end points of the edge, note that the source and target
         // can be modified for shapes that have ports
-        // @ts-ignore TODO: fix this
-        const { source, target, sourceId, targetId } = getEdgeStartEndPoint(edge, dir);
+
+        const { source, target, sourceId, targetId } = getEdgeStartEndPoint(edge);
         log.debug('abc78 source and target', source, target);
         // Add the edge to the graph
         graph.edges.push({
-          // @ts-ignore TODO: fix this
-          id: 'e' + edge.start + edge.end,
           ...edge,
           sources: [source],
           targets: [target],
@@ -461,6 +485,7 @@ export const render = async (
       case 'RL':
         return 'LEFT';
       case 'TB':
+      case 'TD': // TD is an alias for TB in Mermaid
         return 'DOWN';
       case 'BT':
         return 'UP';
@@ -484,6 +509,203 @@ export const render = async (
     }
   }
 
+  // Node bounds helpers (global)
+  const getEffectiveGroupWidth = (node: any): number => {
+    const labelW = node?.labels?.[0]?.width ?? 0;
+    const padding = node?.padding ?? 0;
+    return Math.max(node.width ?? 0, labelW + padding);
+  };
+
+  const boundsFor = (node: any): RectLike => {
+    const width = node?.isGroup ? getEffectiveGroupWidth(node) : node.width;
+    return {
+      x: node.offset.posX + node.width / 2,
+      y: node.offset.posY + node.height / 2,
+      width,
+      height: node.height,
+      padding: node.padding,
+    };
+  };
+  // Helper utilities for endpoint handling around cutter2
+  type Side = 'start' | 'end';
+  const approxEq = (a: number, b: number, eps = 1e-6) => Math.abs(a - b) < eps;
+  const isCenterApprox = (pt: P, node: { x: number; y: number }) =>
+    approxEq(pt.x, node.x) && approxEq(pt.y, node.y);
+
+  const getCandidateBorderPoint = (
+    points: P[],
+    node: any,
+    side: Side
+  ): { candidate: P; centerApprox: boolean } => {
+    if (!points?.length) {
+      return { candidate: { x: node.x, y: node.y } as P, centerApprox: true };
+    }
+    if (side === 'start') {
+      const first = points[0];
+      const centerApprox = isCenterApprox(first, node);
+      const candidate = centerApprox && points.length > 1 ? points[1] : first;
+      return { candidate, centerApprox };
+    } else {
+      const last = points[points.length - 1];
+      const centerApprox = isCenterApprox(last, node);
+      const candidate = centerApprox && points.length > 1 ? points[points.length - 2] : last;
+      return { candidate, centerApprox };
+    }
+  };
+
+  const dropAutoCenterPoint = (points: P[], side: Side, doDrop: boolean) => {
+    if (!doDrop) {
+      return;
+    }
+    if (side === 'start') {
+      if (points.length > 0) {
+        points.shift();
+      }
+    } else {
+      if (points.length > 0) {
+        points.pop();
+      }
+    }
+  };
+
+  const applyStartIntersectionIfNeeded = (points: P[], startNode: any, startBounds: RectLike) => {
+    let firstOutsideStartIndex = -1;
+    for (const [i, p] of points.entries()) {
+      if (outsideNode(startBounds, p)) {
+        firstOutsideStartIndex = i;
+        break;
+      }
+    }
+    if (firstOutsideStartIndex !== -1) {
+      const outsidePointForStart = points[firstOutsideStartIndex];
+      const startCenter = points[0];
+      const startIntersection = computeNodeIntersection(
+        startNode,
+        startBounds,
+        outsidePointForStart,
+        startCenter
+      );
+      replaceEndpoint(points, 'start', startIntersection);
+      log.debug('UIO cutter2: start-only intersection applied', { startIntersection });
+    }
+  };
+
+  const applyEndIntersectionIfNeeded = (points: P[], endNode: any, endBounds: RectLike) => {
+    let outsideIndexForEnd = -1;
+    for (let i = points.length - 1; i >= 0; i--) {
+      if (outsideNode(endBounds, points[i])) {
+        outsideIndexForEnd = i;
+        break;
+      }
+    }
+    if (outsideIndexForEnd !== -1) {
+      const outsidePointForEnd = points[outsideIndexForEnd];
+      const endCenter = points[points.length - 1];
+      const endIntersection = computeNodeIntersection(
+        endNode,
+        endBounds,
+        outsidePointForEnd,
+        endCenter
+      );
+      replaceEndpoint(points, 'end', endIntersection);
+      log.debug('UIO cutter2: end-only intersection applied', { endIntersection });
+    }
+  };
+
+  const cutter2 = (startNode: any, endNode: any, _points: any[]) => {
+    const startBounds = boundsFor(startNode);
+    const endBounds = boundsFor(endNode);
+
+    if (_points.length === 0) {
+      return [];
+    }
+
+    // Copy the original points array
+    const points: P[] = [..._points] as P[];
+
+    // The first point is the center of sNode, the last point is the center of eNode
+    const startCenter = points[0];
+    const endCenter = points[points.length - 1];
+
+    // Minimal, structured logging for diagnostics
+    log.debug('PPP cutter2: bounds', { startBounds, endBounds });
+    log.debug('PPP cutter2: original points', _points);
+
+    let firstOutsideStartIndex = -1;
+
+    // Single iteration through the array
+    for (const [i, point] of points.entries()) {
+      if (firstOutsideStartIndex === -1 && outsideNode(startBounds, point)) {
+        firstOutsideStartIndex = i;
+      }
+      if (outsideNode(endBounds, point)) {
+        // keep scanning; we'll also scan from the end for the last outside point
+      }
+    }
+
+    // Calculate intersection with start node if we found a point outside it
+    if (firstOutsideStartIndex !== -1) {
+      const outsidePointForStart = points[firstOutsideStartIndex];
+      const startIntersection = computeNodeIntersection(
+        startNode,
+        startBounds,
+        outsidePointForStart,
+        startCenter
+      );
+      log.debug('UIO cutter2: start intersection', startIntersection);
+      replaceEndpoint(points, 'start', startIntersection);
+    }
+
+    // Calculate intersection with end node
+    let outsidePointForEnd = null;
+    let outsideIndexForEnd = -1;
+
+    for (let i = points.length - 1; i >= 0; i--) {
+      if (outsideNode(endBounds, points[i])) {
+        outsidePointForEnd = points[i];
+        outsideIndexForEnd = i;
+        break;
+      }
+    }
+
+    if (!outsidePointForEnd && points.length > 1) {
+      outsidePointForEnd = points[points.length - 2];
+      outsideIndexForEnd = points.length - 2;
+    }
+
+    if (outsidePointForEnd) {
+      const endIntersection = computeNodeIntersection(
+        endNode,
+        endBounds,
+        outsidePointForEnd,
+        endCenter
+      );
+      log.debug('UIO cutter2: end intersection', { endIntersection, outsideIndexForEnd });
+      replaceEndpoint(points, 'end', endIntersection);
+    }
+
+    // Final cleanup: Check if the last point is too close to the previous point
+    if (points.length > 1) {
+      const lastPoint = points[points.length - 1];
+      const secondLastPoint = points[points.length - 2];
+      const distance = Math.sqrt(
+        (lastPoint.x - secondLastPoint.x) ** 2 + (lastPoint.y - secondLastPoint.y) ** 2
+      );
+      if (distance < 2) {
+        log.debug('UIO cutter2: trimming tail point (too close)', {
+          distance,
+          lastPoint,
+          secondLastPoint,
+        });
+        points.pop();
+      }
+    }
+
+    log.debug('UIO cutter2: final points', points);
+
+    return points;
+  };
+
   // @ts-ignore - ELK is not typed
   const elk = new ELK();
   const element = svg.select('g');
@@ -495,17 +717,19 @@ export const render = async (
     id: 'root',
     layoutOptions: {
       'elk.hierarchyHandling': 'INCLUDE_CHILDREN',
-      'elk.layered.crossingMinimization.forceNodeModelOrder':
-        data4Layout.config.elk?.forceNodeModelOrder,
-      'elk.layered.considerModelOrder.strategy': data4Layout.config.elk?.considerModelOrder,
-
       'elk.algorithm': algorithm,
       'nodePlacement.strategy': data4Layout.config.elk?.nodePlacementStrategy,
       'elk.layered.mergeEdges': data4Layout.config.elk?.mergeEdges,
       'elk.direction': 'DOWN',
-      'spacing.baseValue': 35,
+      'spacing.baseValue': 40,
+      'elk.layered.crossingMinimization.forceNodeModelOrder':
+        data4Layout.config.elk?.forceNodeModelOrder,
+      'elk.layered.considerModelOrder.strategy': data4Layout.config.elk?.considerModelOrder,
       'elk.layered.unnecessaryBendpoints': true,
       'elk.layered.cycleBreaking.strategy': data4Layout.config.elk?.cycleBreakingStrategy,
+
+      // 'elk.layered.cycleBreaking.strategy': 'GREEDY_MODEL_ORDER',
+      // 'elk.layered.cycleBreaking.strategy': 'MODEL_ORDER',
       // 'spacing.nodeNode': 20,
       // 'spacing.nodeNodeBetweenLayers': 25,
       // 'spacing.edgeNode': 20,
@@ -513,22 +737,28 @@ export const render = async (
       // 'spacing.edgeEdge': 10,
       // 'spacing.edgeEdgeBetweenLayers': 20,
       // 'spacing.nodeSelfLoop': 20,
+
       // Tweaking options
+      // 'nodePlacement.favorStraightEdges': true,
       // 'elk.layered.nodePlacement.favorStraightEdges': true,
       // 'nodePlacement.feedbackEdges': true,
-      // 'elk.layered.wrapping.multiEdge.improveCuts': true,
-      // 'elk.layered.wrapping.multiEdge.improveWrappedEdges': true,
+      'elk.layered.wrapping.multiEdge.improveCuts': true,
+      'elk.layered.wrapping.multiEdge.improveWrappedEdges': true,
       // 'elk.layered.wrapping.strategy': 'MULTI_EDGE',
-      // 'elk.layered.edgeRouting.selfLoopDistribution': 'EQUALLY',
-      // 'elk.layered.mergeHierarchyEdges': true,
+      // 'elk.layered.wrapping.strategy': 'SINGLE_EDGE',
+      'elk.layered.edgeRouting.selfLoopDistribution': 'EQUALLY',
+      'elk.layered.mergeHierarchyEdges': true,
+
       // 'elk.layered.feedbackEdges': true,
       // 'elk.layered.crossingMinimization.semiInteractive': true,
       // 'elk.layered.edgeRouting.splines.sloppy.layerSpacingFactor': 1,
       // 'elk.layered.edgeRouting.polyline.slopedEdgeZoneWidth': 4.0,
       // 'elk.layered.wrapping.validify.strategy': 'LOOK_BACK',
       // 'elk.insideSelfLoops.activate': true,
+      // 'elk.separateConnectedComponents': true,
       // 'elk.alg.layered.options.EdgeStraighteningStrategy': 'NONE',
       // 'elk.layered.considerModelOrder.strategy': 'NODES_AND_EDGES', // NODES_AND_EDGES
+      // 'elk.layered.considerModelOrder.strategy': 'EDGES', // NODES_AND_EDGES
       // 'elk.layered.wrapping.cutting.strategy': 'ARD', // NODES_AND_EDGES
     },
     children: [],
@@ -538,7 +768,7 @@ export const render = async (
   log.info('Drawing flowchart using v4 renderer', elk);
 
   // Set the direction of the graph based on the parsed information
-  const dir = data4Layout.direction || 'DOWN';
+  const dir = data4Layout.direction ?? 'DOWN';
   elkGraph.layoutOptions['elk.direction'] = dir2ElkDirection(dir);
 
   // Create the lookup db for the subgraphs and their children to used when creating
@@ -569,15 +799,16 @@ export const render = async (
 
     // Subgraph
     if (parentLookupDb.childrenById[node.id] !== undefined) {
+      // Set label and adjust node width separately (avoid side effects in labels array)
       node.labels = [
         {
           text: node.label,
-          width: node?.labelData?.width || 50,
-          height: node?.labelData?.height || 50,
+          width: node?.labelData?.width ?? 50,
+          height: node?.labelData?.height ?? 50,
         },
-        (node.width = node.width + 2 * node.padding),
-        log.debug('UIO node label', node?.labelData?.width, node.padding),
       ];
+      node.width = node.width + 2 * node.padding;
+      log.debug('UIO node label', node?.labelData?.width, node.padding);
       node.layoutOptions = {
         'spacing.baseValue': 30,
         'nodeLabels.placement': '[H_CENTER V_TOP, INSIDE]',
@@ -641,14 +872,16 @@ export const render = async (
   try {
     g = await elk.layout(elkGraph);
     log.debug('APA01 after - success');
-    log.debug('APA01 layout result:', JSON.stringify(g, null, 2));
+    log.info('APA01 layout result:', JSON.stringify(g, null, 2));
   } catch (error) {
     log.error('APA01 ELK layout error:', error);
+    log.error('APA01 elkGraph that caused error:', JSON.stringify(elkGraph, null, 2));
     throw error;
   }
 
   // debugger;
   await drawNodes(0, 0, g.children, svg, subGraphsEl, 0);
+
   g.edges?.map(
     (edge: {
       sources: (string | number)[];
@@ -702,10 +935,10 @@ export const render = async (
           // sw = Math.max(bbox.width, startNode.width, startNode.labels[0].width);
           sw = Math.max(startNode.width, startNode.labels[0].width + startNode.padding);
           // sw = startNode.width;
-          log.debug(
+          log.info(
             'UIO width',
             startNode.id,
-            startNode.with,
+            startNode.width,
             'bbox.width=',
             bbox.width,
             'lw=',
@@ -725,7 +958,7 @@ export const render = async (
           log.debug(
             'UIO width',
             startNode.id,
-            startNode.with,
+            startNode.width,
             bbox.width,
             'EW = ',
             ew,
@@ -733,38 +966,109 @@ export const render = async (
             startNode.innerHTML
           );
         }
+        startNode.x = startNode.offset.posX + startNode.width / 2;
+        startNode.y = startNode.offset.posY + startNode.height / 2;
+        endNode.x = endNode.offset.posX + endNode.width / 2;
+        endNode.y = endNode.offset.posY + endNode.height / 2;
 
-        if (startNode.calcIntersect) {
-          const intersection = startNode.calcIntersect(
-            {
-              x: startNode.offset.posX + startNode.width / 2,
-              y: startNode.offset.posY + startNode.height / 2,
-              width: startNode.width,
-              height: startNode.height,
-            },
-            edge.points[0]
-          );
+        // Only add center points for non-subgraph nodes or when the edge path doesn't already end near the target
+        const shouldAddStartCenter = startNode.shape !== 'rect33';
+        const shouldAddEndCenter = endNode.shape !== 'rect33';
 
-          if (distance(intersection, edge.points[0]) > epsilon) {
-            edge.points.unshift(intersection);
-          }
-        }
-        if (endNode.calcIntersect) {
-          const intersection = endNode.calcIntersect(
-            {
-              x: endNode.offset.posX + endNode.width / 2,
-              y: endNode.offset.posY + endNode.height / 2,
-              width: endNode.width,
-              height: endNode.height,
-            },
-            edge.points[edge.points.length - 1]
-          );
-
-          if (distance(intersection, edge.points[edge.points.length - 1]) > epsilon) {
-            edge.points.push(intersection);
-          }
+        if (shouldAddStartCenter) {
+          edge.points.unshift({
+            x: startNode.x,
+            y: startNode.y,
+          });
         }
 
+        if (shouldAddEndCenter) {
+          edge.points.push({
+            x: endNode.x,
+            y: endNode.y,
+          });
+        }
+
+        // Debug and sanitize points around cutter2
+        const prevPoints = Array.isArray(edge.points) ? [...edge.points] : [];
+        const endBounds = boundsFor(endNode);
+        log.debug(
+          'PPP cutter2: Points before cutter2:',
+          JSON.stringify(edge.points),
+          'endBounds:',
+          endBounds,
+          onBorder(endBounds, edge.points[edge.points.length - 1])
+        );
+        // Block for reducing variable scope and guardrails for the cutter function
+        {
+          const startBounds = boundsFor(startNode);
+          const endBounds = boundsFor(endNode);
+
+          const startIsGroup = !!startNode?.isGroup;
+          const endIsGroup = !!endNode?.isGroup;
+
+          const { candidate: startCandidate, centerApprox: startCenterApprox } =
+            getCandidateBorderPoint(prevPoints as P[], startNode, 'start');
+          const { candidate: endCandidate, centerApprox: endCenterApprox } =
+            getCandidateBorderPoint(prevPoints as P[], endNode, 'end');
+
+          const skipStart = startIsGroup && onBorder(startBounds, startCandidate);
+          const skipEnd = endIsGroup && onBorder(endBounds, endCandidate);
+
+          dropAutoCenterPoint(prevPoints as P[], 'start', skipStart && startCenterApprox);
+          dropAutoCenterPoint(prevPoints as P[], 'end', skipEnd && endCenterApprox);
+
+          if (skipStart || skipEnd) {
+            if (!skipStart) {
+              applyStartIntersectionIfNeeded(prevPoints as P[], startNode, startBounds);
+            }
+            if (!skipEnd) {
+              applyEndIntersectionIfNeeded(prevPoints as P[], endNode, endBounds);
+            }
+
+            log.debug('PPP cutter2: skipping cutter2 due to on-border group endpoint(s)', {
+              skipStart,
+              skipEnd,
+              startCenterApprox,
+              endCenterApprox,
+              startCandidate,
+              endCandidate,
+            });
+            edge.points = prevPoints;
+          } else {
+            edge.points = cutter2(startNode, endNode, prevPoints);
+          }
+        }
+        log.debug('PPP cutter2: Points after cutter2:', JSON.stringify(edge.points));
+        const hasNaN = (pts: { x: number; y: number }[]) =>
+          pts?.some((p) => !Number.isFinite(p?.x) || !Number.isFinite(p?.y));
+        if (!Array.isArray(edge.points) || edge.points.length < 2 || hasNaN(edge.points)) {
+          log.warn(
+            'POI cutter2: Invalid points from cutter2, falling back to prevPoints',
+            edge.points
+          );
+          // Fallback to previous points and strip any invalid ones just in case
+          const cleaned = prevPoints.filter((p) => Number.isFinite(p?.x) && Number.isFinite(p?.y));
+          edge.points = cleaned.length >= 2 ? cleaned : prevPoints;
+        }
+        log.debug('UIO cutter2: Points after cutter2 (sanitized):', edge.points);
+        // Remove consecutive duplicate points to avoid zero-length segments in path builders
+        const deduped = edge.points.filter(
+          (p: { x: number; y: number }, i: number, arr: { x: number; y: number }[]) => {
+            if (i === 0) {
+              return true;
+            }
+            const prev = arr[i - 1];
+            return Math.abs(p.x - prev.x) > 1e-6 || Math.abs(p.y - prev.y) > 1e-6;
+          }
+        );
+        if (deduped.length !== edge.points.length) {
+          log.debug('UIO cutter2: removed consecutive duplicate points', {
+            before: edge.points,
+            after: deduped,
+          });
+        }
+        edge.points = deduped;
         const paths = insertEdge(
           edgesEl,
           edge,
@@ -772,8 +1076,10 @@ export const render = async (
           data4Layout.type,
           startNode,
           endNode,
-          data4Layout.diagramId
+          data4Layout.diagramId,
+          true
         );
+        log.info('APA12 edge points after insert', JSON.stringify(edge.points));
 
         edge.x = edge.labels[0].x + offset.x + edge.labels[0].width / 2;
         edge.y = edge.labels[0].y + offset.y + edge.labels[0].height / 2;

packages/mermaid-zenuml/package.json

@@ -33,7 +33,7 @@
   ],
   "license": "MIT",
   "dependencies": {
-    "@zenuml/core": "^3.35.2"
+    "@zenuml/core": "^3.41.4"
   },
   "devDependencies": {
     "mermaid": "workspace:^"

packages/mermaid/CHANGELOG.md

@@ -168,7 +168,6 @@
 ### Minor Changes
 
 - [#6408](https://github.com/mermaid-js/mermaid/pull/6408) [`ad65313`](https://github.com/mermaid-js/mermaid/commit/ad653138e16765d095613a6e5de86dc5e52ac8f0) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - fix: restore curve type configuration functionality for flowcharts. This fixes the issue where curve type settings were not being applied when configured through any of the following methods:
-
   - Config
   - Init directive (%%{ init: { 'flowchart': { 'curve': '...' } } }%%)
   - LinkStyle command (linkStyle default interpolate ...)
@@ -187,14 +186,12 @@
 ### Minor Changes
 
 - [#6187](https://github.com/mermaid-js/mermaid/pull/6187) [`7809b5a`](https://github.com/mermaid-js/mermaid/commit/7809b5a93fae127f45727071f5ff14325222c518) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - Flowchart new syntax for node metadata bugs
-
   - Incorrect label mapping for nodes when using `&`
   - Syntax error when `}` with trailing spaces before new line
 
 - [#6136](https://github.com/mermaid-js/mermaid/pull/6136) [`ec0d9c3`](https://github.com/mermaid-js/mermaid/commit/ec0d9c389aa6018043187654044c1e0b5aa4f600) Thanks [@knsv](https://github.com/knsv)! - Adding support for animation of flowchart edges
 
 - [#6373](https://github.com/mermaid-js/mermaid/pull/6373) [`05bdf0e`](https://github.com/mermaid-js/mermaid/commit/05bdf0e20e2629fe77513218fbd4e28e65f75882) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - Upgrade Requirement and ER diagram to use the common renderer flow
-
   - Added support for directions
   - Added support for hand drawn look
 

packages/mermaid/package.json

@@ -47,7 +47,7 @@
     "docs:verify-version": "tsx scripts/update-release-version.mts --verify",
     "types:build-config": "tsx scripts/create-types-from-json-schema.mts",
     "types:verify-config": "tsx scripts/create-types-from-json-schema.mts --verify",
-    "checkCircle": "npx madge --circular ./src",
+    "checkCircle": "npx madge --circular ./src --exclude '.*generated.*'",
     "prepublishOnly": "pnpm docs:verify-version"
   },
   "repository": {
@@ -67,29 +67,29 @@
     ]
   },
   "dependencies": {
-    "@braintree/sanitize-url": "^7.0.4",
-    "@iconify/utils": "^3.0.1",
+    "@braintree/sanitize-url": "^7.1.1",
+    "@iconify/utils": "^3.0.2",
     "@mermaid-js/parser": "workspace:^",
     "@types/d3": "^7.4.3",
-    "cytoscape": "^3.29.3",
+    "cytoscape": "^3.33.1",
     "cytoscape-cose-bilkent": "^4.1.0",
     "cytoscape-fcose": "^2.2.0",
     "d3": "^7.9.0",
     "d3-sankey": "^0.12.3",
     "dagre-d3-es": "7.0.11",
-    "dayjs": "^1.11.13",
+    "dayjs": "^1.11.18",
     "dompurify": "^3.2.5",
     "katex": "^0.16.22",
     "khroma": "^2.1.0",
     "lodash-es": "^4.17.21",
-    "marked": "^15.0.7",
+    "marked": "^16.3.0",
     "roughjs": "^4.6.6",
     "stylis": "^4.3.6",
     "ts-dedent": "^2.2.0",
     "uuid": "^11.1.0"
   },
   "devDependencies": {
-    "@adobe/jsonschema2md": "^8.0.2",
+    "@adobe/jsonschema2md": "^8.0.5",
     "@iconify/types": "^2.0.0",
     "@types/cytoscape": "^3.21.9",
     "@types/cytoscape-fcose": "^2.2.4",
@@ -105,30 +105,30 @@
     "@types/stylis": "^4.2.7",
     "@types/uuid": "^10.0.0",
     "ajv": "^8.17.1",
-    "canvas": "^3.1.0",
+    "canvas": "^3.2.0",
     "chokidar": "3.6.0",
-    "concurrently": "^9.1.2",
+    "concurrently": "^9.2.1",
     "csstree-validator": "^4.0.1",
-    "globby": "^14.0.2",
+    "globby": "^14.1.0",
     "jison": "^0.4.18",
-    "js-base64": "^3.7.7",
+    "js-base64": "^3.7.8",
     "jsdom": "^26.1.0",
     "json-schema-to-typescript": "^15.0.4",
     "micromatch": "^4.0.8",
     "path-browserify": "^1.0.1",
-    "prettier": "^3.5.2",
+    "prettier": "^3.6.2",
     "remark": "^15.0.1",
     "remark-frontmatter": "^5.0.0",
     "remark-gfm": "^4.0.1",
     "rimraf": "^6.0.1",
-    "start-server-and-test": "^2.0.10",
-    "type-fest": "^4.35.0",
-    "typedoc": "^0.28.9",
-    "typedoc-plugin-markdown": "^4.8.0",
+    "start-server-and-test": "^2.1.2",
+    "type-fest": "^4.41.0",
+    "typedoc": "^0.28.13",
+    "typedoc-plugin-markdown": "^4.8.1",
     "typescript": "~5.7.3",
     "unist-util-flatmap": "^1.0.0",
     "unist-util-visit": "^5.0.0",
-    "vitepress": "^1.0.2",
+    "vitepress": "^1.6.4",
     "vitepress-plugin-search": "1.0.4-alpha.22"
   },
   "files": [

packages/mermaid/scripts/docs.spec.ts

@@ -189,6 +189,7 @@ This Markdown should be kept.
         | Display                           | Curved Trapezoid       | \`curv-trap\`    | Represents a display           | \`curved-trapezoid\`, \`display\`                                    |
         | Divided Process                   | Divided Rectangle      | \`div-rect\`     | Divided process shape          | \`div-proc\`, \`divided-process\`, \`divided-rectangle\`               |
         | Document                          | Document               | \`doc\`          | Represents a document          | \`doc\`, \`document\`                                                |
+        | Ellipse                           | Ellipse                | \`ellipse\`      | Ellipse shape                  | \`oval\`                                                           |
         | Event                             | Rounded Rectangle      | \`rounded\`      | Represents an event            | \`event\`                                                          |
         | Extract                           | Triangle               | \`tri\`          | Extraction process             | \`extract\`, \`triangle\`                                            |
         | Fork/Join                         | Filled Rectangle       | \`fork\`         | Fork or join in process flow   | \`join\`                                                           |

packages/mermaid/src/config.type.ts

@@ -210,6 +210,7 @@ export interface MermaidConfig {
   packet?: PacketDiagramConfig;
   block?: BlockDiagramConfig;
   radar?: RadarDiagramConfig;
+  usecase?: UsecaseDiagramConfig;
   dompurifyConfig?: DOMPurifyConfiguration;
   wrap?: boolean;
   fontSize?: number;
@@ -1623,6 +1624,50 @@ export interface RadarDiagramConfig extends BaseDiagramConfig {
    */
   curveTension?: number;
 }
+/**
+ * The object containing configurations specific for usecase diagrams.
+ *
+ * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * via the `definition` "UsecaseDiagramConfig".
+ */
+export interface UsecaseDiagramConfig extends BaseDiagramConfig {
+  /**
+   * Font size for actor labels
+   */
+  actorFontSize?: number;
+  /**
+   * Font family for actor labels
+   */
+  actorFontFamily?: string;
+  /**
+   * Font weight for actor labels
+   */
+  actorFontWeight?: string;
+  /**
+   * Font size for usecase labels
+   */
+  usecaseFontSize?: number;
+  /**
+   * Font family for usecase labels
+   */
+  usecaseFontFamily?: string;
+  /**
+   * Font weight for usecase labels
+   */
+  usecaseFontWeight?: string;
+  /**
+   * Margin around actors
+   */
+  actorMargin?: number;
+  /**
+   * Margin around use cases
+   */
+  usecaseMargin?: number;
+  /**
+   * Padding around the entire diagram
+   */
+  diagramPadding?: number;
+}
 /**
  * This interface was referenced by `MermaidConfig`'s JSON-Schema
  * via the `definition` "FontConfig".

packages/mermaid/src/defaultConfig.ts

@@ -264,6 +264,9 @@ const config: RequiredDeep<MermaidConfig> = {
   radar: {
     ...defaultConfigJson.radar,
   },
+  usecase: {
+    ...defaultConfigJson.usecase,
+  },
   treemap: {
     useMaxWidth: true,
     padding: 10,

packages/mermaid/src/diagram-api/diagram-orchestration.ts

@@ -28,6 +28,7 @@ import architecture from '../diagrams/architecture/architectureDetector.js';
 import { registerLazyLoadedDiagrams } from './detectType.js';
 import { registerDiagram } from './diagramAPI.js';
 import { treemap } from '../diagrams/treemap/detector.js';
+import { usecase } from '../diagrams/usecase/usecaseDetector.js';
 import '../type.d.ts';
 
 let hasLoadedDiagrams = false;
@@ -101,6 +102,7 @@ export const addDiagrams = () => {
     xychart,
     block,
     radar,
-    treemap
+    treemap,
+    usecase
   );
 };

packages/mermaid/src/diagram-api/types.ts

@@ -3,6 +3,7 @@ import type * as d3 from 'd3';
 import type { SetOptional, SetRequired } from 'type-fest';
 import type { Diagram } from '../Diagram.js';
 import type { BaseDiagramConfig, MermaidConfig } from '../config.type.js';
+import type { DiagramOrientation } from '../diagrams/git/gitGraphTypes.js';
 
 export interface DiagramMetadata {
   title?: string;
@@ -35,7 +36,8 @@ export interface DiagramDB {
   getAccTitle?: () => string;
   setAccDescription?: (description: string) => void;
   getAccDescription?: () => string;
-
+  getDirection?: () => string | undefined;
+  setDirection?: (dir: DiagramOrientation) => void;
   setDisplayMode?: (title: string) => void;
   bindFunctions?: (element: Element) => void;
 }

packages/mermaid/src/diagrams/architecture/svgDraw.spec.ts

@@ -0,0 +1,48 @@
+import { describe } from 'vitest';
+import { draw } from './architectureRenderer.js';
+import { Diagram } from '../../Diagram.js';
+import { addDetector } from '../../diagram-api/detectType.js';
+import architectureDetector from './architectureDetector.js';
+import { ensureNodeFromSelector, jsdomIt } from '../../tests/util.js';
+
+const { id, detector, loader } = architectureDetector;
+
+addDetector(id, detector, loader); // Add architecture schemas to Mermaid
+
+describe('architecture diagram SVGs', () => {
+  jsdomIt('should add ids', async () => {
+    const svgNode = await drawDiagram(`
+      architecture-beta
+        group api(cloud)[API]
+
+        service db(database)[Database] in api
+        service disk1(disk)[Storage] in api
+        service disk2(disk)[Storage] in api
+        service server(server)[Server] in api
+
+        db:L -- R:server
+        disk1:T -- B:server
+        disk2:T -- B:db
+    `);
+
+    const nodesForGroup = svgNode.querySelectorAll(`#group-api`);
+    expect(nodesForGroup.length).toBe(1);
+
+    const serviceIds = [...svgNode.querySelectorAll(`[id^=service-]`)].map(({ id }) => id).sort();
+    expect(serviceIds).toStrictEqual([
+      'service-db',
+      'service-disk1',
+      'service-disk2',
+      'service-server',
+    ]);
+
+    const edgeIds = [...svgNode.querySelectorAll(`.edge[id^=L_]`)].map(({ id }) => id).sort();
+    expect(edgeIds).toStrictEqual(['L_db_server_0', 'L_disk1_server_0', 'L_disk2_db_0']);
+  });
+});
+
+async function drawDiagram(diagramText: string): Promise<Element> {
+  const diagram = await Diagram.fromText(diagramText, {});
+  await draw('NOT_USED', 'svg', '1.0.0', diagram);
+  return ensureNodeFromSelector('#svg');
+}

packages/mermaid/src/diagrams/architecture/svgDraw.ts

@@ -20,6 +20,7 @@ import {
   type ArchitectureJunction,
   type ArchitectureService,
 } from './architectureTypes.js';
+import { getEdgeId } from '../../utils.js';
 
 export const drawEdges = async function (
   edgesEl: D3Element,
@@ -91,7 +92,8 @@ export const drawEdges = async function (
 
         g.insert('path')
           .attr('d', `M ${startX},${startY} L ${midX},${midY} L${endX},${endY} `)
-          .attr('class', 'edge');
+          .attr('class', 'edge')
+          .attr('id', getEdgeId(source, target, { prefix: 'L' }));
 
         if (sourceArrow) {
           const xShift = isArchitectureDirectionX(sourceDir)
@@ -206,8 +208,9 @@ export const drawGroups = async function (
       if (data.type === 'group') {
         const { h, w, x1, y1 } = node.boundingBox();
 
-        groupsEl
-          .append('rect')
+        const groupsNode = groupsEl.append('rect');
+        groupsNode
+          .attr('id', `group-${data.id}`)
           .attr('x', x1 + halfIconSize)
           .attr('y', y1 + halfIconSize)
           .attr('width', w)
@@ -262,6 +265,7 @@ export const drawGroups = async function (
               ')'
           );
         }
+        db.setElementForId(data.id, groupsNode);
       }
     })
   );
@@ -342,9 +346,9 @@ export const drawServices = async function (
         );
     }
 
-    serviceElem.attr('class', 'architecture-service');
+    serviceElem.attr('id', `service-${service.id}`).attr('class', 'architecture-service');
 
-    const { width, height } = serviceElem._groups[0][0].getBBox();
+    const { width, height } = serviceElem.node().getBBox();
     service.width = width;
     service.height = height;
     db.setElementForId(service.id, serviceElem);

packages/mermaid/src/diagrams/er/parser/erDiagram.jison

@@ -66,12 +66,15 @@ accDescr\s*"{"\s*                                { this.begin("acc_descr_multili
 \}\|                            return 'ONE_OR_MORE';
 "one"                           return 'ONLY_ONE';
 "only one"                      return 'ONLY_ONE';
-"1"                             return 'ONLY_ONE';
+[0-9]+\.[0-9]+                  return 'DECIMAL_NUM';
+"1"(?=\s+[A-Za-z_"'])           return 'ONLY_ONE';
+"1"                             return 'ENTITY_ONE';
+[0-9]+                          return 'NUM';
 \|\|                            return 'ONLY_ONE';
 o\|                             return 'ZERO_OR_ONE';
 o\{                             return 'ZERO_OR_MORE';
 \|\{                            return 'ONE_OR_MORE';
-\s*u                            return 'MD_PARENT';
+u(?=[\.\-\|])                   return 'MD_PARENT';
 \.\.                            return 'NON_IDENTIFYING';
 \-\-                            return 'IDENTIFYING';
 "to"                            return 'IDENTIFYING';
@@ -80,13 +83,15 @@ o\{                             return 'ZERO_OR_MORE';
 \-\.                            return 'NON_IDENTIFYING';
 <style>([^\x00-\x7F]|\w|\-|\*)+ return 'STYLE_TEXT';
 <style>';'                      return 'SEMI';
-([^\x00-\x7F]|\w|\-|\*)+        return 'UNICODE_TEXT';
-[0-9]                           return 'NUM';
+([^\x00-\x7F]|\w|\-|\*|\.)+      return 'UNICODE_TEXT';
 .                               return yytext[0];
 <<EOF>>                         return 'EOF';
 
 /lex
 
+%left 'ONLY_ONE'
+%left 'ZERO_OR_ONE' 'ZERO_OR_MORE' 'ONE_OR_MORE' 'MD_PARENT'
+
 %start start
 %% /* language grammar */
 
@@ -228,6 +233,9 @@ styleComponent: STYLE_TEXT | NUM | COLON | BRKT;
 entityName
     : 'ENTITY_NAME'      { $$ = $1.replace(/"/g, ''); }
     | 'UNICODE_TEXT' { $$ = $1; }
+    | 'NUM' { $$ = $1; }
+    | 'DECIMAL_NUM' { $$ = $1; }
+    | 'ENTITY_ONE' { $$ = $1; }
     ;
 
 attributes

packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js

@@ -1001,4 +1001,90 @@ describe('when parsing ER diagram it...', function () {
       }
     );
   });
+
+  describe('syntax fixes for special characters and numbers', function () {
+    describe('standalone entity names', function () {
+      it('should allow number "1" as standalone entity', function () {
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER }|..|{ DELIVERY-ADDRESS : has\n1`);
+      });
+
+      it('should allow character "u" as standalone entity', function () {
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER }|..|{ DELIVERY-ADDRESS : has\nu`);
+      });
+
+      it('should allow decimal numbers as standalone entities', function () {
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER }|..|{ DELIVERY-ADDRESS : has\n2.5`);
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER }|..|{ DELIVERY-ADDRESS : has\n1.5`);
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER }|..|{ DELIVERY-ADDRESS : has\n0.1`);
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER }|..|{ DELIVERY-ADDRESS : has\n99.99`);
+      });
+    });
+
+    describe('entity names with attributes', function () {
+      it('should allow "u" as entity name with attributes', function () {
+        erDiagram.parser.parse(`erDiagram\nu {\nstring name\nint id\n}`);
+      });
+
+      it('should allow number "1" as entity name with attributes', function () {
+        erDiagram.parser.parse(`erDiagram\n1 {\nstring name\nint id\n}`);
+      });
+
+      it('should allow decimal numbers as entity names with attributes', function () {
+        erDiagram.parser.parse(`erDiagram\n2.5 {\nstring name\nint id\n}`);
+        erDiagram.parser.parse(`erDiagram\n1.5 {\nstring value\n}`);
+      });
+    });
+
+    describe('entity names in relationships', function () {
+      it('should allow "u" in relationships', function () {
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER ||--|| u : has`);
+        erDiagram.parser.parse(`erDiagram\nu ||--|| ORDER : places`);
+        erDiagram.parser.parse(`erDiagram\nu ||--|| v : connects`);
+      });
+
+      it('should allow numbers in relationships', function () {
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER ||--|| 1 : has`);
+        erDiagram.parser.parse(`erDiagram\n1 ||--|| ORDER : places`);
+        erDiagram.parser.parse(`erDiagram\n1 ||--|| 2 : connects`);
+      });
+
+      it('should allow decimal numbers in relationships', function () {
+        erDiagram.parser.parse(`erDiagram\nCUSTOMER ||--|| 2.5 : has`);
+        erDiagram.parser.parse(`erDiagram\n1.5 ||--|| ORDER : places`);
+        erDiagram.parser.parse(`erDiagram\n2.5 ||--|| 5.5 : connects`);
+      });
+    });
+
+    describe('mixed scenarios', function () {
+      it('should handle complex diagram with special entity names', function () {
+        erDiagram.parser.parse(
+          `erDiagram
+              CUSTOMER ||--o{ 1 : places
+              1 ||--|{ u : contains
+              u {
+                string name
+                int quantity
+              }
+              "2.5" ||--|| ORDER : processes
+              ORDER {
+                int id
+                date created
+              }
+        `
+        );
+      });
+
+      it('should handle attributes with numbers in names (but not starting)', function () {
+        erDiagram.parser.parse(
+          `erDiagram
+              ENTITY {
+                string name1
+                int value2
+                float point3_5
+              }
+        `
+        );
+      });
+    });
+  });
 });

packages/mermaid/src/diagrams/flowchart/flowDb.ts

@@ -962,7 +962,6 @@ You have to call mermaid.initialize.`
       case 'round':
         return 'roundedRect';
       case 'ellipse':
-        // @ts-expect-error -- Ellipses are broken, see https://github.com/mermaid-js/mermaid/issues/5976
         return 'ellipse';
       default:
         return vertex.type;

packages/mermaid/src/diagrams/gantt/ganttDb.js

@@ -268,7 +268,9 @@ const fixTaskDates = function (startTime, endTime, dateFormat, excludes, include
 
 const getStartDate = function (prevTime, dateFormat, str) {
   str = str.trim();
-
+  if ((dateFormat.trim() === 'x' || dateFormat.trim() === 'X') && /^\d+$/.test(str)) {
+    return new Date(Number(str));
+  }
   // Test for after
   const afterRePattern = /^after\s+(?<ids>[\d\w- ]+)/;
   const afterStatement = afterRePattern.exec(str);

packages/mermaid/src/diagrams/mindmap/mindmapDb.ts

@@ -37,6 +37,7 @@ export class MindmapDB {
   private nodes: MindmapNode[] = [];
   private count = 0;
   private elements: Record<number, D3Element> = {};
+  private baseLevel?: number;
   public readonly nodeType: typeof nodeType;
 
   constructor() {
@@ -54,6 +55,7 @@ export class MindmapDB {
     this.nodes = [];
     this.count = 0;
     this.elements = {};
+    this.baseLevel = undefined;
   }
 
   public getParent(level: number): MindmapNode | null {
@@ -72,6 +74,17 @@ export class MindmapDB {
   public addNode(level: number, id: string, descr: string, type: number): void {
     log.info('addNode', level, id, descr, type);
 
+    let isRoot = false;
+
+    if (this.nodes.length === 0) {
+      this.baseLevel = level;
+      level = 0;
+      isRoot = true;
+    } else if (this.baseLevel !== undefined) {
+      level = level - this.baseLevel;
+      isRoot = false;
+    }
+
     const conf = getConfig();
     let padding = conf.mindmap?.padding ?? defaultConfig.mindmap.padding;
 
@@ -92,6 +105,7 @@ export class MindmapDB {
       children: [],
       width: conf.mindmap?.maxNodeWidth ?? defaultConfig.mindmap.maxNodeWidth,
       padding,
+      isRoot,
     };
 
     const parent = this.getParent(level);
@@ -99,7 +113,7 @@ export class MindmapDB {
       parent.children.push(node);
       this.nodes.push(node);
     } else {
-      if (this.nodes.length === 0) {
+      if (isRoot) {
         this.nodes.push(node);
       } else {
         throw new Error(
@@ -204,8 +218,7 @@ export class MindmapDB {
     // Build CSS classes for the node
     const cssClasses = ['mindmap-node'];
 
-    // Add section-specific classes
-    if (node.level === 0) {
+    if (node.isRoot === true) {
       // Root node gets special classes
       cssClasses.push('section-root', 'section--1');
     } else if (node.section !== undefined) {

packages/mermaid/src/diagrams/mindmap/mindmapTypes.ts

@@ -15,6 +15,7 @@ export interface MindmapNode {
   icon?: string;
   x?: number;
   y?: number;
+  isRoot?: boolean;
 }
 
 export type FilledMindMapNode = RequiredDeep<MindmapNode>;

packages/mermaid/src/diagrams/sequence/parser/sequenceDiagram.jison

@@ -78,7 +78,7 @@ accDescr\s*"{"\s*                                { this.begin("acc_descr_multili
 "off"															return 'off';
 ","                                                             return ',';
 ";"                                                             return 'NEWLINE';
-[^+<\->\->:\n,;]+((?!(\-x|\-\-x|\-\)|\-\-\)))[\-]*[^\+<\->\->:\n,;]+)*             { yytext = yytext.trim(); return 'ACTOR'; }
+[^\/\\\+\()\+<\->\->:\n,;]+((?!(\-x|\-\-x|\-\)|\-\-\)|\-\|\\|\-\\|\-\/|\-\/\/|\-\|\/|\/\|\-|\\\|\-|\/\/\-|\\\\\-|\/\|\-|\-\-\|\\|\-\-|\(\)))[\-]*[^\+<\->\->:\n,;]+)*             { yytext = yytext.trim(); return 'ACTOR'; } //final_4.11
 "->>"                                                           return 'SOLID_ARROW';
 "<<->>"                                                           return 'BIDIRECTIONAL_SOLID_ARROW';
 "-->>"                                                          return 'DOTTED_ARROW';
@@ -89,10 +89,36 @@ accDescr\s*"{"\s*                                { this.begin("acc_descr_multili
 \-\-[x]                                                         return 'DOTTED_CROSS';
 \-[\)]                                                          return 'SOLID_POINT';
 \-\-[\)]                                                        return 'DOTTED_POINT';
+
+//normal-dotted
+\-\-\|\\                                                        return 'SOLID_ARROW_TOP_DOTTED';
+\-\-\|\/                                                        return 'SOLID_ARROW_BOTTOM_DOTTED';
+\-\-\\\\                                                        return 'STICK_ARROW_TOP_DOTTED';
+\-\-\/\/                                                        return 'STICK_ARROW_BOTTOM_DOTTED';
+
+//reverse-dotted
+\/\|\-\-                                                          return 'SOLID_ARROW_TOP_REVERSE_DOTTED';
+\\\|\-\-                                                          return 'SOLID_ARROW_BOTTOM_REVERSE_DOTTED';
+\/\/\-\-                                                          return 'STICK_ARROW_TOP_REVERSE_DOTTED';
+\\\\\-\-                                                          return 'STICK_ARROW_BOTTOM_REVERSE_DOTTED';
+
+//normal
+\-\|\\                                                          return 'SOLID_ARROW_TOP';
+\-\|\/                                                          return 'SOLID_ARROW_BOTTOM';
+\-\\\\                                                          return 'STICK_ARROW_TOP';
+\-\/\/                                                          return 'STICK_ARROW_BOTTOM';
+
+//reverse
+\/\|\-                                                          return 'SOLID_ARROW_TOP_REVERSE';
+\\\|\-                                                          return 'SOLID_ARROW_BOTTOM_REVERSE';
+\/\/\-                                                          return 'STICK_ARROW_TOP_REVERSE';
+\\\\\-                                                          return 'STICK_ARROW_BOTTOM_REVERSE';
+
 ":"(?:(?:no)?wrap:)?[^#\n;]*                                    return 'TXT';
 ":"                             								return 'TXT';
 "+"                                                             return '+';
 "-"                                                             return '-';
+"()"                                                            return '()';
 <<EOF>>                                                         return 'NEWLINE';
 .                                                               return 'INVALID';
 
@@ -304,6 +330,20 @@ signal
 	{ $$ = [$1,$4,{type: 'addMessage', from:$1.actor, to:$4.actor, signalType:$2, msg:$5},
 	             {type: 'activeEnd', signalType: yy.LINETYPE.ACTIVE_END, actor: $1.actor}
 	             ]}
+    | actor signaltype '()' actor text2
+	{ $$ = [$1,$4,{type: 'addMessage', from:$1.actor, to:$4.actor, signalType:$2, msg:$5, activate: true, centralConnection: yy.LINETYPE.CENTRAL_CONNECTION},
+	              {type: 'centralConnection', signalType: yy.LINETYPE.CENTRAL_CONNECTION, actor: $4.actor, }
+	             ]}
+    
+	| actor '()' signaltype actor text2
+	{ $$ = [$1,$4,{type: 'addMessage', from:$1.actor, to:$4.actor, signalType:$3, msg:$5, activate: false, centralConnection: yy.LINETYPE.CENTRAL_CONNECTION_REVERSE},
+	              {type: 'centralConnectionReverse', signalType: yy.LINETYPE.CENTRAL_CONNECTION_REVERSE, actor: $1.actor}
+	             ]}
+	| actor '()' signaltype '()' actor text2
+	{ $$ = [$1,$5,{type: 'addMessage', from:$1.actor, to:$5.actor, signalType:$3, msg:$6, activate: true, centralConnection: yy.LINETYPE.CENTRAL_CONNECTION_DUAL},
+	 			 {type: 'centralConnection', signalType: yy.LINETYPE.CENTRAL_CONNECTION, actor: $5.actor, },
+				 {type: 'centralConnectionReverse', signalType: yy.LINETYPE.CENTRAL_CONNECTION_REVERSE, actor: $1.actor}
+	             ]}
 	| actor signaltype actor text2
 	{ $$ = [$1,$3,{type: 'addMessage', from:$1.actor, to:$3.actor, signalType:$2, msg:$4}]}
 	;
@@ -337,7 +377,28 @@ signaltype
 	: SOLID_OPEN_ARROW  { $$ = yy.LINETYPE.SOLID_OPEN; }
 	| DOTTED_OPEN_ARROW { $$ = yy.LINETYPE.DOTTED_OPEN; }
 	| SOLID_ARROW       { $$ = yy.LINETYPE.SOLID; }
-	| BIDIRECTIONAL_SOLID_ARROW       { $$ = yy.LINETYPE.BIDIRECTIONAL_SOLID; }
+	
+	| SOLID_ARROW_TOP    { $$ = yy.LINETYPE.SOLID_TOP; }
+	| SOLID_ARROW_BOTTOM { $$ = yy.LINETYPE.SOLID_BOTTOM; }
+	| STICK_ARROW_TOP    { $$ = yy.LINETYPE.STICK_TOP; }
+	| STICK_ARROW_BOTTOM { $$ = yy.LINETYPE.STICK_BOTTOM; }
+
+	| SOLID_ARROW_TOP_DOTTED    { $$ = yy.LINETYPE.SOLID_TOP_DOTTED; }	
+	| SOLID_ARROW_BOTTOM_DOTTED { $$ = yy.LINETYPE.SOLID_BOTTOM_DOTTED; }
+	| STICK_ARROW_TOP_DOTTED    { $$ = yy.LINETYPE.STICK_TOP_DOTTED; }
+	| STICK_ARROW_BOTTOM_DOTTED { $$ = yy.LINETYPE.STICK_BOTTOM_DOTTED; }
+
+	| SOLID_ARROW_TOP_REVERSE    { $$ = yy.LINETYPE.SOLID_ARROW_TOP_REVERSE; }
+	| SOLID_ARROW_BOTTOM_REVERSE { $$ = yy.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE; }
+	| STICK_ARROW_TOP_REVERSE    { $$ = yy.LINETYPE.STICK_ARROW_TOP_REVERSE; }
+	| STICK_ARROW_BOTTOM_REVERSE { $$ = yy.LINETYPE.STICK_ARROW_BOTTOM_REVERSE; }
+
+	| SOLID_ARROW_TOP_REVERSE_DOTTED    { $$ = yy.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED; }
+	| SOLID_ARROW_BOTTOM_REVERSE_DOTTED { $$ = yy.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED; }
+	| STICK_ARROW_TOP_REVERSE_DOTTED    { $$ = yy.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED; }
+	| STICK_ARROW_BOTTOM_REVERSE_DOTTED { $$ = yy.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED; }
+
+  | BIDIRECTIONAL_SOLID_ARROW       { $$ = yy.LINETYPE.BIDIRECTIONAL_SOLID; }
 	| DOTTED_ARROW      { $$ = yy.LINETYPE.DOTTED; }
 	| BIDIRECTIONAL_DOTTED_ARROW      { $$ = yy.LINETYPE.BIDIRECTIONAL_DOTTED; }
 	| SOLID_CROSS       { $$ = yy.LINETYPE.SOLID_CROSS; }

packages/mermaid/src/diagrams/sequence/sequenceDb.ts

@@ -64,6 +64,30 @@ const LINETYPE = {
   PAR_OVER_START: 32,
   BIDIRECTIONAL_SOLID: 33,
   BIDIRECTIONAL_DOTTED: 34,
+
+  SOLID_TOP: 41,
+  SOLID_BOTTOM: 42,
+  STICK_TOP: 43,
+  STICK_BOTTOM: 44,
+
+  SOLID_ARROW_TOP_REVERSE: 45,
+  SOLID_ARROW_BOTTOM_REVERSE: 46,
+  STICK_ARROW_TOP_REVERSE: 47,
+  STICK_ARROW_BOTTOM_REVERSE: 48,
+
+  SOLID_TOP_DOTTED: 51,
+  SOLID_BOTTOM_DOTTED: 52,
+  STICK_TOP_DOTTED: 53,
+  STICK_BOTTOM_DOTTED: 54,
+
+  SOLID_ARROW_TOP_REVERSE_DOTTED: 55,
+  SOLID_ARROW_BOTTOM_REVERSE_DOTTED: 56,
+  STICK_ARROW_TOP_REVERSE_DOTTED: 57,
+  STICK_ARROW_BOTTOM_REVERSE_DOTTED: 58,
+
+  CENTRAL_CONNECTION: 59,
+  CENTRAL_CONNECTION_REVERSE: 60,
+  CENTRAL_CONNECTION_DUAL: 61,
 } as const;
 
 const ARROWTYPE = {
@@ -244,7 +268,8 @@ export class SequenceDB implements DiagramDB {
     idTo?: Message['to'],
     message?: { text: string; wrap: boolean },
     messageType?: number,
-    activate = false
+    activate = false,
+    centralConnection?: number
   ) {
     if (messageType === this.LINETYPE.ACTIVE_END) {
       const cnt = this.activationCount(idFrom ?? '');
@@ -271,6 +296,7 @@ export class SequenceDB implements DiagramDB {
       wrap: message?.wrap ?? this.autoWrap(),
       type: messageType,
       activate,
+      centralConnection: centralConnection ?? 0,
     });
     return true;
   }
@@ -563,6 +589,12 @@ export class SequenceDB implements DiagramDB {
         case 'activeStart':
           this.addSignal(param.actor, undefined, undefined, param.signalType);
           break;
+        case 'centralConnection':
+          this.addSignal(param.actor, undefined, undefined, param.signalType);
+          break;
+        case 'centralConnectionReverse':
+          this.addSignal(param.actor, undefined, undefined, param.signalType);
+          break;
         case 'activeEnd':
           this.addSignal(param.actor, undefined, undefined, param.signalType);
           break;
@@ -606,7 +638,14 @@ export class SequenceDB implements DiagramDB {
               this.state.records.lastDestroyed = undefined;
             }
           }
-          this.addSignal(param.from, param.to, param.msg, param.signalType, param.activate);
+          this.addSignal(
+            param.from,
+            param.to,
+            param.msg,
+            param.signalType,
+            param.activate,
+            param.centralConnection
+          );
           break;
         case 'boxStart':
           this.addBox(param.boxData);

packages/mermaid/src/diagrams/sequence/sequenceDiagram.spec.js

@@ -104,6 +104,7 @@ describe('more than one sequence diagram', () => {
       [
         {
           "activate": false,
+          "centralConnection": 0,
           "from": "Alice",
           "id": "0",
           "message": "Hello Bob, how are you?",
@@ -113,6 +114,7 @@ describe('more than one sequence diagram', () => {
         },
         {
           "activate": false,
+          "centralConnection": 0,
           "from": "Bob",
           "id": "1",
           "message": "I am good thanks!",
@@ -131,6 +133,7 @@ describe('more than one sequence diagram', () => {
       [
         {
           "activate": false,
+          "centralConnection": 0,
           "from": "Alice",
           "id": "0",
           "message": "Hello Bob, how are you?",
@@ -140,6 +143,7 @@ describe('more than one sequence diagram', () => {
         },
         {
           "activate": false,
+          "centralConnection": 0,
           "from": "Bob",
           "id": "1",
           "message": "I am good thanks!",
@@ -160,6 +164,7 @@ describe('more than one sequence diagram', () => {
       [
         {
           "activate": false,
+          "centralConnection": 0,
           "from": "Alice",
           "id": "0",
           "message": "Hello John, how are you?",
@@ -169,6 +174,7 @@ describe('more than one sequence diagram', () => {
         },
         {
           "activate": false,
+          "centralConnection": 0,
           "from": "John",
           "id": "1",
           "message": "I am good thanks!",
@@ -181,6 +187,254 @@ describe('more than one sequence diagram', () => {
   });
 });
 
+describe('Central Connection Parsing', () => {
+  describe('when parsing central connection syntax', () => {
+    it('should parse actor ()->>() actor syntax as CENTRAL_CONNECTION_DUAL', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()->>() Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(3); // addMessage + centralConnection + centralConnectionReverse
+
+      // Find the actual message (type: 'addMessage')
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL
+        activate: true,
+        type: 0, // SOLID (based on test output)
+      });
+    });
+
+    it('should parse actor ()-->>() actor syntax as CENTRAL_CONNECTION_DUAL', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()-->>() Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(3); // addMessage + centralConnection + centralConnectionReverse
+
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL
+        activate: true,
+        type: 1, // DOTTED (based on test output)
+      });
+    });
+
+    it('should parse actor ->>() actor syntax as CENTRAL_CONNECTION', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ->>() Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(2); // addMessage + centralConnection (no activation for this pattern)
+
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 59, // CENTRAL_CONNECTION
+        activate: true,
+        type: 0, // SOLID (based on actual parsing)
+      });
+    });
+
+    it('should parse actor ()-->> actor syntax as CENTRAL_CONNECTION_REVERSE', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()-->> Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(2); // addMessage + centralConnectionReverse
+
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 60, // CENTRAL_CONNECTION_REVERSE
+        activate: false,
+        type: 1, // DOTTED (based on test output)
+      });
+    });
+
+    it('should parse actor ()->> actor syntax as CENTRAL_CONNECTION_REVERSE', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()->> Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(2); // addMessage + centralConnectionReverse
+
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 60, // CENTRAL_CONNECTION_REVERSE
+        activate: false,
+        type: 0, // SOLID (based on test output)
+      });
+    });
+
+    it('should parse actor ()<<-->>() actor syntax as CENTRAL_CONNECTION_DUAL', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()<<-->>() Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(3); // addMessage + centralConnection + centralConnectionReverse
+
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL
+        activate: true,
+        type: 34, // BIDIRECTIONAL_DOTTED
+      });
+    });
+
+    it('should parse actor ()<<->>() actor syntax as CENTRAL_CONNECTION_DUAL', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()<<->>() Bob: Hello Bob, how are you?
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(3); // addMessage + centralConnection + centralConnectionReverse
+
+      const actualMessage = messages.find((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessage).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        message: 'Hello Bob, how are you?',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL
+        activate: true,
+        type: 33, // BIDIRECTIONAL_SOLID
+      });
+    });
+
+    it('should handle multiple central connection types in one diagram', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        participant Charlie
+        Alice ()->>() Bob: Message 1
+        Bob ()-->> Charlie: Message 2
+        Charlie ()<<-->>() Alice: Message 3
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(8); // 3 addMessages + 5 central connection markers
+
+      // Filter to get only the actual messages
+      const actualMessages = messages.filter((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessages).toHaveLength(3);
+
+      expect(actualMessages[0]).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL (()->>())
+      });
+
+      expect(actualMessages[1]).toMatchObject({
+        from: 'Bob',
+        to: 'Charlie',
+        centralConnection: 60, // CENTRAL_CONNECTION_REVERSE (()-->>)
+      });
+
+      expect(actualMessages[2]).toMatchObject({
+        from: 'Charlie',
+        to: 'Alice',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL (()<<-->>())
+      });
+    });
+
+    it('should handle central connections with different arrow types', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ()-x() Bob: Cross message
+        Alice ()--x() Bob: Dotted cross message
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(6); // 2 addMessages + 4 central connection markers
+
+      const actualMessages = messages.filter((msg) => msg.type !== undefined && msg.from && msg.to);
+      expect(actualMessages).toHaveLength(2);
+
+      expect(actualMessages[0]).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL (()-x())
+        type: 3, // SOLID_CROSS
+      });
+
+      expect(actualMessages[1]).toMatchObject({
+        from: 'Alice',
+        to: 'Bob',
+        centralConnection: 61, // CENTRAL_CONNECTION_DUAL (()--x())
+        type: 4, // DOTTED_CROSS
+      });
+    });
+
+    it('should not break existing parsing without central connections', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        Alice ->> Bob: Normal message
+        Bob -->> Alice: Normal dotted message
+        Alice -x Bob: Normal cross message
+      `);
+
+      const messages = diagram.db.getMessages();
+      expect(messages).toHaveLength(3);
+
+      messages.forEach((msg) => {
+        expect(msg.centralConnection).toBe(0); // No central connection
+      });
+
+      expect(messages[0].type).toBe(0); // SOLID (based on actual parsing)
+      expect(messages[1].type).toBe(1); // DOTTED (based on actual parsing)
+      expect(messages[2].type).toBe(3); // SOLID_CROSS
+    });
+  });
+});
+
 describe('when parsing a sequenceDiagram', function () {
   let diagram;
   beforeEach(async function () {
@@ -2058,6 +2312,36 @@ Bob->>Alice:Got it!
     expect(messages[0].from).toBe('Alice');
     expect(messages[0].to).toBe('Bob');
   });
+
+  it('1 should parse ', async () => {
+    const diagram = await Diagram.fromText(`
+    sequenceDiagram
+    actor Bob
+    actor Alice
+        Bob -|\\ Alice: Hello Alice, how are you?
+        Bob -|/ Alice: Hello Alice, how are you?
+        Bob -// Alice: Hello Alice, how are you?
+        Bob -\\\\ Alice: Hello Alice, how are you?
+        
+        Bob \\|- Alice: Hello Alice, how are you?
+        Bob /|- Alice: Hello Alice, how are you?
+        Bob //- Alice: Hello Alice, how are you?
+        Bob \\\\- Alice: Hello Alice, how are you?        
+    `);
+
+    const messages = diagram.db.getMessages();
+  });
+
+  it('2 should parse ', async () => {
+    const diagram = await Diagram.fromText(`
+    sequenceDiagram
+    actor Bob
+    actor Alice
+      Alice ()<<->>() Bob: hey?
+    `);
+
+    const messages = diagram.db.getMessages();
+  });
   describe('when parsing extended participant syntax', () => {
     it('should parse participants with different quote styles and whitespace', async () => {
       const diagram = await Diagram.fromText(`

packages/mermaid/src/diagrams/sequence/sequenceRenderer.ts

@@ -282,6 +282,49 @@ const drawNote = async function (elem: any, noteModel: NoteModel) {
   bounds.models.addNote(noteModel);
 };
 
+const drawCentralConnection = function (
+  elem: any,
+  msg: any,
+  msgModel: any,
+  diagObj: Diagram,
+  startx: number,
+  stopx: number,
+  lineStartY: number
+) {
+  const actors = diagObj.db.getActors();
+  const fromActor = actors.get(msg.from);
+  const toActor = actors.get(msg.to);
+  const fromCenter = fromActor.x + fromActor.width / 2;
+  const toCenter = toActor.x + toActor.width / 2;
+
+  const g = elem.append('g');
+
+  const drawCircle = (cx: number) => {
+    g.append('circle')
+      .attr('cx', cx)
+      .attr('cy', lineStartY)
+      .attr('r', 5)
+      .attr('width', 10)
+      .attr('height', 10);
+  };
+
+  const { CENTRAL_CONNECTION, CENTRAL_CONNECTION_REVERSE, CENTRAL_CONNECTION_DUAL } =
+    diagObj.db.LINETYPE;
+
+  switch (msg.centralConnection) {
+    case CENTRAL_CONNECTION:
+      drawCircle(toCenter);
+      break;
+    case CENTRAL_CONNECTION_REVERSE:
+      drawCircle(fromCenter);
+      break;
+    case CENTRAL_CONNECTION_DUAL:
+      drawCircle(fromCenter);
+      drawCircle(toCenter);
+      break;
+  }
+};
+
 const messageFont = (cnf) => {
   return {
     fontFamily: cnf.messageFontFamily,
@@ -367,7 +410,7 @@ async function boundMessage(_diagram, msgModel): Promise<number> {
  * @param lineStartY - The Y coordinate at which the message line starts
  * @param diagObj - The diagram object.
  */
-const drawMessage = async function (diagram, msgModel, lineStartY: number, diagObj: Diagram) {
+const drawMessage = async function (diagram, msgModel, lineStartY: number, diagObj: Diagram, msg) {
   const { startx, stopx, starty, message, type, sequenceIndex, sequenceVisible } = msgModel;
   const textDims = utils.calculateTextDimensions(message, messageFont(conf));
   const textObj = svgDrawCommon.getTextObj();
@@ -433,6 +476,9 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
     line.attr('y1', lineStartY);
     line.attr('x2', stopx);
     line.attr('y2', lineStartY);
+    if (hasCentralConnection(msg, diagObj)) {
+      drawCentralConnection(diagram, msg, msgModel, diagObj, startx, stopx, lineStartY);
+    }
   }
   // Make an SVG Container
   // Draw the line
@@ -441,7 +487,15 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
     type === diagObj.db.LINETYPE.DOTTED_CROSS ||
     type === diagObj.db.LINETYPE.DOTTED_POINT ||
     type === diagObj.db.LINETYPE.DOTTED_OPEN ||
-    type === diagObj.db.LINETYPE.BIDIRECTIONAL_DOTTED
+    type === diagObj.db.LINETYPE.BIDIRECTIONAL_DOTTED ||
+    type === diagObj.db.LINETYPE.SOLID_TOP_DOTTED ||
+    type === diagObj.db.LINETYPE.SOLID_BOTTOM_DOTTED ||
+    type === diagObj.db.LINETYPE.STICK_TOP_DOTTED ||
+    type === diagObj.db.LINETYPE.STICK_BOTTOM_DOTTED ||
+    type === diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED ||
+    type === diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED ||
+    type === diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED ||
+    type === diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED
   ) {
     line.style('stroke-dasharray', '3, 3');
     line.attr('class', 'messageLine1');
@@ -457,6 +511,51 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
   line.attr('stroke-width', 2);
   line.attr('stroke', 'none'); // handled by theme/css anyway
   line.style('fill', 'none'); // remove any fill colour
+
+  if (type === diagObj.db.LINETYPE.SOLID_TOP || type === diagObj.db.LINETYPE.SOLID_TOP_DOTTED) {
+    line.attr('marker-end', 'url(' + url + '#solidTopArrowHead)');
+  }
+  if (
+    type === diagObj.db.LINETYPE.SOLID_BOTTOM ||
+    type === diagObj.db.LINETYPE.SOLID_BOTTOM_DOTTED
+  ) {
+    line.attr('marker-end', 'url(' + url + '#solidBottomArrowHead)');
+  }
+  if (type === diagObj.db.LINETYPE.STICK_TOP || type === diagObj.db.LINETYPE.STICK_TOP_DOTTED) {
+    line.attr('marker-end', 'url(' + url + '#stickTopArrowHead)');
+  }
+  if (
+    type === diagObj.db.LINETYPE.STICK_BOTTOM ||
+    type === diagObj.db.LINETYPE.STICK_BOTTOM_DOTTED
+  ) {
+    line.attr('marker-end', 'url(' + url + '#stickBottomArrowHead)');
+  }
+
+  if (
+    type === diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE ||
+    type === diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED
+  ) {
+    line.attr('marker-start', 'url(' + url + '#solidBottomArrowHead)');
+  }
+  if (
+    type === diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE ||
+    type === diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED
+  ) {
+    line.attr('marker-start', 'url(' + url + '#solidTopArrowHead)');
+  }
+  if (
+    type === diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE ||
+    type === diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED
+  ) {
+    line.attr('marker-start', 'url(' + url + '#stickBottomArrowHead)');
+  }
+  if (
+    type === diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE ||
+    type === diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED
+  ) {
+    line.attr('marker-start', 'url(' + url + '#stickTopArrowHead)');
+  }
+
   if (type === diagObj.db.LINETYPE.SOLID || type === diagObj.db.LINETYPE.DOTTED) {
     line.attr('marker-end', 'url(' + url + '#arrowhead)');
   }
@@ -481,7 +580,18 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
       type === diagObj.db.LINETYPE.BIDIRECTIONAL_SOLID ||
       type === diagObj.db.LINETYPE.BIDIRECTIONAL_DOTTED;
 
-    if (isBidirectional) {
+    const isReverseArrowType =
+      type === diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE ||
+      type === diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED ||
+      type === diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE ||
+      type === diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED ||
+      type === diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE ||
+      type === diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED ||
+      type === diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE ||
+      type === diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED;
+
+    let x = 0;
+    if (isBidirectional || isReverseArrowType) {
       const SEQUENCE_NUMBER_RADIUS = 6;
 
       if (startx < stopx) {
@@ -489,6 +599,7 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
       } else {
         line.attr('x1', startx + SEQUENCE_NUMBER_RADIUS);
       }
+      x = 3.5;
     }
 
     diagram
@@ -498,7 +609,8 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
       .attr('x2', startx)
       .attr('y2', lineStartY)
       .attr('stroke-width', 0)
-      .attr('marker-start', 'url(' + url + '#sequencenumber)');
+      .attr('marker-start', 'url(' + url + '#sequencenumber)')
+      .attr('transform', `translate(-${x}, 0)`);
 
     diagram
       .append('text')
@@ -508,7 +620,8 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
       .attr('font-size', '12px')
       .attr('text-anchor', 'middle')
       .attr('class', 'sequenceNumber')
-      .text(sequenceIndex);
+      .text(sequenceIndex)
+      .attr('transform', `translate(-${x}, 0)`);
   }
 };
 
@@ -857,6 +970,10 @@ export const draw = async function (_text: string, id: string, _version: string,
   svgDraw.insertArrowCrossHead(diagram);
   svgDraw.insertArrowFilledHead(diagram);
   svgDraw.insertSequenceNumber(diagram);
+  svgDraw.insertSolidTopArrowHead(diagram);
+  svgDraw.insertSolidBottomArrowHead(diagram);
+  svgDraw.insertStickTopArrowHead(diagram);
+  svgDraw.insertStickBottomArrowHead(diagram);
 
   /**
    * @param msg - The message to draw.
@@ -897,6 +1014,12 @@ export const draw = async function (_text: string, id: string, _version: string,
       case diagObj.db.LINETYPE.ACTIVE_START:
         bounds.newActivation(msg, diagram, actors);
         break;
+      case diagObj.db.LINETYPE.CENTRAL_CONNECTION:
+        bounds.newActivation(msg, diagram, actors);
+        break;
+      case diagObj.db.LINETYPE.CENTRAL_CONNECTION_REVERSE:
+        bounds.newActivation(msg, diagram, actors);
+        break;
       case diagObj.db.LINETYPE.ACTIVE_END:
         activeEnd(msg, bounds.getVerticalPos());
         break;
@@ -1055,7 +1178,7 @@ export const draw = async function (_text: string, id: string, _version: string,
             createdActors,
             destroyedActors
           );
-          messagesToDraw.push({ messageModel: msgModel, lineStartY: lineStartY });
+          messagesToDraw.push({ messageModel: msgModel, lineStartY: lineStartY, msg });
           bounds.models.addMessage(msgModel);
         } catch (e) {
           log.error('error while drawing message', e);
@@ -1068,6 +1191,27 @@ export const draw = async function (_text: string, id: string, _version: string,
         diagObj.db.LINETYPE.SOLID_OPEN,
         diagObj.db.LINETYPE.DOTTED_OPEN,
         diagObj.db.LINETYPE.SOLID,
+
+        diagObj.db.LINETYPE.SOLID_TOP,
+        diagObj.db.LINETYPE.SOLID_BOTTOM,
+        diagObj.db.LINETYPE.STICK_TOP,
+        diagObj.db.LINETYPE.STICK_BOTTOM,
+
+        diagObj.db.LINETYPE.SOLID_TOP_DOTTED,
+        diagObj.db.LINETYPE.SOLID_BOTTOM_DOTTED,
+        diagObj.db.LINETYPE.STICK_TOP_DOTTED,
+        diagObj.db.LINETYPE.STICK_BOTTOM_DOTTED,
+
+        diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE,
+        diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE,
+        diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE,
+        diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE,
+
+        diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED,
+
         diagObj.db.LINETYPE.DOTTED,
         diagObj.db.LINETYPE.SOLID_CROSS,
         diagObj.db.LINETYPE.DOTTED_CROSS,
@@ -1087,7 +1231,7 @@ export const draw = async function (_text: string, id: string, _version: string,
   await drawActors(diagram, actors, actorKeys, false);
 
   for (const e of messagesToDraw) {
-    await drawMessage(diagram, e.messageModel, e.lineStartY, diagObj);
+    await drawMessage(diagram, e.messageModel, e.lineStartY, diagObj, e.msg);
   }
   if (conf.mirrorActors) {
     await drawActors(diagram, actors, actorKeys, true);
@@ -1461,12 +1605,85 @@ const buildNoteModel = async function (msg, actors, diagObj) {
   return noteModel;
 };
 
+// Central connection positioning constants
+const CENTRAL_CONNECTION_BASE_OFFSET = 4;
+const CENTRAL_CONNECTION_BIDIRECTIONAL_OFFSET = 6;
+
+/**
+ * Check if a message has central connection
+ * @param msg - The message object
+ * @param diagObj - The diagram object containing LINETYPE constants
+ * @returns True if the message has any type of central connection
+ */
+const hasCentralConnection = function (msg, diagObj) {
+  const { CENTRAL_CONNECTION, CENTRAL_CONNECTION_REVERSE, CENTRAL_CONNECTION_DUAL } =
+    diagObj.db.LINETYPE;
+  return [CENTRAL_CONNECTION, CENTRAL_CONNECTION_REVERSE, CENTRAL_CONNECTION_DUAL].includes(
+    msg.centralConnection
+  );
+};
+
+/**
+ * Calculate the positioning offset for central connection arrows
+ * @param msg - The message object
+ * @param diagObj - The diagram object containing LINETYPE constants
+ * @param isArrowToRight - Whether the arrow is pointing to the right
+ * @returns The offset to apply to startx position
+ */
+const calculateCentralConnectionOffset = function (msg, diagObj, isArrowToRight) {
+  const {
+    CENTRAL_CONNECTION_REVERSE,
+    CENTRAL_CONNECTION_DUAL,
+    BIDIRECTIONAL_SOLID,
+    BIDIRECTIONAL_DOTTED,
+  } = diagObj.db.LINETYPE;
+
+  let offset = 0;
+
+  if (
+    msg.centralConnection === CENTRAL_CONNECTION_REVERSE ||
+    msg.centralConnection === CENTRAL_CONNECTION_DUAL
+  ) {
+    offset += CENTRAL_CONNECTION_BASE_OFFSET;
+  }
+
+  if (
+    msg.centralConnection === CENTRAL_CONNECTION_DUAL &&
+    (msg.type === BIDIRECTIONAL_SOLID || msg.type === BIDIRECTIONAL_DOTTED)
+  ) {
+    offset += isArrowToRight ? 0 : -CENTRAL_CONNECTION_BIDIRECTIONAL_OFFSET;
+  }
+
+  return offset;
+};
+
 const buildMessageModel = function (msg, actors, diagObj) {
   if (
     ![
       diagObj.db.LINETYPE.SOLID_OPEN,
       diagObj.db.LINETYPE.DOTTED_OPEN,
       diagObj.db.LINETYPE.SOLID,
+
+      diagObj.db.LINETYPE.SOLID_TOP,
+      diagObj.db.LINETYPE.SOLID_BOTTOM,
+      diagObj.db.LINETYPE.STICK_TOP,
+      diagObj.db.LINETYPE.STICK_BOTTOM,
+
+      diagObj.db.LINETYPE.SOLID_TOP_DOTTED,
+      diagObj.db.LINETYPE.SOLID_BOTTOM_DOTTED,
+      diagObj.db.LINETYPE.STICK_TOP_DOTTED,
+      diagObj.db.LINETYPE.STICK_BOTTOM_DOTTED,
+
+      diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE,
+      diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE,
+      diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE,
+      diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE,
+
+      diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED,
+      diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED,
+      diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED,
+      diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED,
+
       diagObj.db.LINETYPE.DOTTED,
       diagObj.db.LINETYPE.SOLID_CROSS,
       diagObj.db.LINETYPE.DOTTED_CROSS,
@@ -1484,6 +1701,8 @@ const buildMessageModel = function (msg, actors, diagObj) {
   let startx = isArrowToRight ? fromRight : fromLeft;
   let stopx = isArrowToRight ? toLeft : toRight;
 
+  // Apply central connection positioning adjustments
+  startx += calculateCentralConnectionOffset(msg, diagObj, isArrowToRight);
   // As the line width is considered, the left and right values will be off by 2.
   const isArrowToActivation = Math.abs(toLeft - toRight) > 2;
 
@@ -1517,7 +1736,30 @@ const buildMessageModel = function (msg, actors, diagObj) {
      * Shorten the length of arrow at the end and move the marker forward (using refX) to have a clean arrowhead
      * This is not required for open arrows that don't have arrowheads
      */
-    if (![diagObj.db.LINETYPE.SOLID_OPEN, diagObj.db.LINETYPE.DOTTED_OPEN].includes(msg.type)) {
+    if (
+      ![
+        diagObj.db.LINETYPE.SOLID_OPEN,
+        diagObj.db.LINETYPE.DOTTED_OPEN,
+
+        diagObj.db.LINETYPE.STICK_TOP,
+        diagObj.db.LINETYPE.STICK_BOTTOM,
+
+        diagObj.db.LINETYPE.STICK_TOP_DOTTED,
+        diagObj.db.LINETYPE.STICK_BOTTOM_DOTTED,
+
+        diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED,
+
+        diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE,
+        diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE,
+
+        diagObj.db.LINETYPE.STICK_ARROW_TOP_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.STICK_ARROW_BOTTOM_REVERSE_DOTTED,
+
+        diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE,
+        diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE,
+      ].includes(msg.type)
+    ) {
       stopx += adjustValue(3);
     }
 
@@ -1525,9 +1767,14 @@ const buildMessageModel = function (msg, actors, diagObj) {
      * Shorten start position of bidirectional arrow to accommodate for second arrowhead
      */
     if (
-      [diagObj.db.LINETYPE.BIDIRECTIONAL_SOLID, diagObj.db.LINETYPE.BIDIRECTIONAL_DOTTED].includes(
-        msg.type
-      )
+      [
+        diagObj.db.LINETYPE.BIDIRECTIONAL_SOLID,
+        diagObj.db.LINETYPE.BIDIRECTIONAL_DOTTED,
+        diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE_DOTTED,
+        diagObj.db.LINETYPE.SOLID_ARROW_TOP_REVERSE,
+        diagObj.db.LINETYPE.SOLID_ARROW_BOTTOM_REVERSE,
+      ].includes(msg.type)
     ) {
       startx -= adjustValue(3);
     }

packages/mermaid/src/diagrams/sequence/svgDraw.js

@@ -1709,6 +1709,77 @@ const _drawMenuItemTextCandidateFunc = (function () {
   };
 })();
 
+/**
+ * Setup arrow head and define the marker. The result is appended to the svg.
+ *
+ * @param elem
+ */
+export const insertSolidTopArrowHead = function (elem) {
+  elem
+    .append('defs')
+    .append('marker')
+    .attr('id', 'solidTopArrowHead')
+    .attr('refX', 7.9)
+    .attr('refY', 7.25)
+    .attr('markerUnits', 'userSpaceOnUse')
+    .attr('markerWidth', 12)
+    .attr('markerHeight', 12)
+    .attr('orient', 'auto-start-reverse')
+    .append('path')
+    .attr('d', 'M 0 0 L 10 8 L 0 8 z'); // this is actual shape for arrowhead
+};
+
+export const insertSolidBottomArrowHead = function (elem) {
+  elem
+    .append('defs')
+    .append('marker')
+    .attr('id', 'solidBottomArrowHead')
+    .attr('refX', 7.9)
+    .attr('refY', 0.75)
+    .attr('markerUnits', 'userSpaceOnUse')
+    .attr('markerWidth', 12)
+    .attr('markerHeight', 12)
+    .attr('orient', 'auto-start-reverse')
+    .append('path')
+    .attr('d', 'M 0 0 L 10 0 L 0 8 z');
+};
+
+export const insertStickTopArrowHead = function (elem) {
+  elem
+    .append('defs')
+    .append('marker')
+    .attr('id', 'stickTopArrowHead')
+    .attr('refX', 7.5)
+    .attr('refY', 7)
+    .attr('markerUnits', 'userSpaceOnUse')
+    .attr('markerWidth', 12)
+    .attr('markerHeight', 12)
+    .attr('orient', 'auto-start-reverse')
+    .append('path')
+    .attr('d', 'M 0 0 L 7 7')
+    .attr('stroke', 'black')
+    .attr('stroke-width', 1.5)
+    .attr('fill', 'none');
+};
+
+export const insertStickBottomArrowHead = function (elem) {
+  elem
+    .append('defs')
+    .append('marker')
+    .attr('id', 'stickBottomArrowHead')
+    .attr('refX', 7.5)
+    .attr('refY', 0)
+    .attr('markerUnits', 'userSpaceOnUse')
+    .attr('markerWidth', 12)
+    .attr('markerHeight', 12)
+    .attr('orient', 'auto-start-reverse')
+    .append('path')
+    .attr('d', 'M 0 7 L 7 0')
+    .attr('stroke', 'black')
+    .attr('stroke-width', 1.5)
+    .attr('fill', 'none');
+};
+
 export default {
   drawRect,
   drawText,
@@ -1731,4 +1802,8 @@ export default {
   getNoteRect,
   fixLifeLineHeights,
   sanitizeUrl,
+  insertSolidTopArrowHead,
+  insertSolidBottomArrowHead,
+  insertStickTopArrowHead,
+  insertStickBottomArrowHead,
 };

packages/mermaid/src/diagrams/sequence/types.ts

@@ -35,6 +35,7 @@ export interface Message {
   type?: number;
   activate?: boolean;
   placement?: string;
+  centralConnection?: number;
 }
 
 export interface AddMessageParams {
@@ -50,6 +51,8 @@ export interface AddMessageParams {
     | 'destroyParticipant'
     | 'activeStart'
     | 'activeEnd'
+    | 'centralConnection'
+    | 'centralConnectionReverse'
     | 'addNote'
     | 'addLinks'
     | 'addALink'

packages/mermaid/src/diagrams/usecase/styles.ts

@@ -0,0 +1,87 @@
+const getStyles = (options: any) =>
+  `
+  .actor {
+    stroke: ${options.primaryColor};
+    fill: ${options.primaryColor};
+  }
+  
+  .actor-label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 14px;
+    font-weight: normal;
+  }
+  
+  .usecase-actor-shape line {
+    stroke: ${options.actorBorder};
+    fill: ${options.actorBkg};
+  }
+  .usecase-actor-shape circle, line {
+    stroke: ${options.actorBorder};
+    fill: ${options.actorBkg};
+    stroke-width: 2px;
+  }
+  
+  .usecase {
+    stroke: ${options.primaryColor};
+    fill: ${options.primaryColor};
+  }
+  
+  .usecase-label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 12px;
+    font-weight: normal;
+  }
+
+  /* Ellipse shape styling for use cases */
+  .usecase-element ellipse {
+    fill: ${options.mainBkg ?? '#ffffff'};
+    stroke: ${options.primaryColor};
+    stroke-width: 2px;
+  }
+
+  .usecase-element .label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 12px;
+    font-weight: normal;
+    text-anchor: middle;
+    dominant-baseline: central;
+  }
+
+  /* General ellipse styling */
+  .node ellipse {
+    fill: ${options.mainBkg ?? '#ffffff'};
+    stroke: ${options.nodeBorder ?? options.primaryColor};
+    stroke-width: 1px;
+  }
+  
+  .relationship {
+    stroke: ${options.lineColor};
+    fill: none;
+  }
+  
+  & .marker {
+    fill: ${options.lineColor};
+    stroke: ${options.lineColor};
+  }
+  
+  .relationship-label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 10px;
+    font-weight: normal;
+  }
+  
+  .nodeLabel, .edgeLabel {
+  color: ${options.classText};
+  }
+  .system-boundary {
+    fill: ${options.clusterBkg};
+    stroke: ${options.clusterBorder};
+    stroke-width: 1px;
+  }
+`;
+
+export default getStyles;

packages/mermaid/src/diagrams/usecase/usecase.spec.ts

@@ -0,0 +1,98 @@
+import { vi } from 'vitest';
+import { setSiteConfig } from '../../diagram-api/diagramAPI.js';
+import mermaidAPI from '../../mermaidAPI.js';
+import { Diagram } from '../../Diagram.js';
+import { addDiagrams } from '../../diagram-api/diagram-orchestration.js';
+
+beforeAll(async () => {
+  // Is required to load the useCase diagram
+  await Diagram.fromText('usecase\n actor TestActor');
+});
+
+/**
+ * UseCase diagrams require a basic d3 mock for rendering
+ */
+vi.mock('d3', () => {
+  const NewD3 = function (this: any) {
+    function returnThis(this: any) {
+      return this;
+    }
+    return {
+      append: function () {
+        return NewD3();
+      },
+      lower: returnThis,
+      attr: returnThis,
+      style: returnThis,
+      text: returnThis,
+      getBBox: function () {
+        return {
+          height: 10,
+          width: 20,
+        };
+      },
+    };
+  };
+
+  return {
+    select: function () {
+      return new (NewD3 as any)();
+    },
+
+    selectAll: function () {
+      return new (NewD3 as any)();
+    },
+
+    // TODO: In d3 these are CurveFactory types, not strings
+    curveBasis: 'basis',
+    curveBasisClosed: 'basisClosed',
+    curveBasisOpen: 'basisOpen',
+    curveBumpX: 'bumpX',
+    curveBumpY: 'bumpY',
+    curveBundle: 'bundle',
+    curveCardinalClosed: 'cardinalClosed',
+    curveCardinalOpen: 'cardinalOpen',
+    curveCardinal: 'cardinal',
+    curveCatmullRomClosed: 'catmullRomClosed',
+    curveCatmullRomOpen: 'catmullRomOpen',
+    curveCatmullRom: 'catmullRom',
+    curveLinear: 'linear',
+    curveLinearClosed: 'linearClosed',
+    curveMonotoneX: 'monotoneX',
+    curveMonotoneY: 'monotoneY',
+    curveNatural: 'natural',
+    curveStep: 'step',
+    curveStepAfter: 'stepAfter',
+    curveStepBefore: 'stepBefore',
+  };
+});
+// -------------------------------
+
+addDiagrams();
+
+/**
+ * @param conf - Configuration object
+ * @param key - Configuration key
+ * @param value - Configuration value
+ */
+function addConf(conf: any, key: any, value: any) {
+  if (value !== undefined) {
+    conf[key] = value;
+  }
+  return conf;
+}
+
+describe('UseCase diagram with ANTLR parser', () => {
+  it('should parse actors and use cases correctly', async () => {
+    const diagram = await Diagram.fromText(
+      `usecase
+      actor Developer1
+      actor Developer2
+      Developer1 --> a("Login System")
+      Developer2 --> b(Authentication)`
+    );
+
+    expect(diagram).toBeDefined();
+    expect(diagram.type).toBe('usecase');
+  });
+});

packages/mermaid/src/diagrams/usecase/usecaseDb.ts

@@ -0,0 +1,397 @@
+import { log } from '../../logger.js';
+import {
+  setAccTitle,
+  getAccTitle,
+  setDiagramTitle,
+  getDiagramTitle,
+  getAccDescription,
+  setAccDescription,
+  clear as commonClear,
+} from '../common/commonDb.js';
+import type {
+  UsecaseFields,
+  UsecaseDB,
+  Actor,
+  UseCase,
+  SystemBoundary,
+  Relationship,
+  ActorMetadata,
+  Direction,
+  ClassDef,
+} from './usecaseTypes.js';
+import { DEFAULT_DIRECTION, ARROW_TYPE } from './usecaseTypes.js';
+import type { RequiredDeep } from 'type-fest';
+import type { UsecaseDiagramConfig } from '../../config.type.js';
+import DEFAULT_CONFIG from '../../defaultConfig.js';
+import { getConfig as getGlobalConfig } from '../../diagram-api/diagramAPI.js';
+import type { LayoutData, Node, ClusterNode, Edge } from '../../rendering-util/types.js';
+
+export const DEFAULT_USECASE_CONFIG: Required<UsecaseDiagramConfig> = DEFAULT_CONFIG.usecase;
+
+export const DEFAULT_USECASE_DB: RequiredDeep<UsecaseFields> = {
+  actors: new Map(),
+  useCases: new Map(),
+  systemBoundaries: new Map(),
+  relationships: [],
+  classDefs: new Map(),
+  direction: DEFAULT_DIRECTION,
+  config: DEFAULT_USECASE_CONFIG,
+} as const;
+
+let actors = new Map<string, Actor>();
+let useCases = new Map<string, UseCase>();
+let systemBoundaries = new Map<string, SystemBoundary>();
+let relationships: Relationship[] = [];
+let classDefs = new Map<string, ClassDef>();
+let direction: Direction = DEFAULT_DIRECTION;
+const config: Required<UsecaseDiagramConfig> = structuredClone(DEFAULT_USECASE_CONFIG);
+
+const getConfig = (): Required<UsecaseDiagramConfig> => structuredClone(config);
+
+const clear = (): void => {
+  actors = new Map();
+  useCases = new Map();
+  systemBoundaries = new Map();
+  relationships = [];
+  classDefs = new Map();
+  direction = DEFAULT_DIRECTION;
+  commonClear();
+};
+
+// Actor management
+const addActor = (actor: Actor): void => {
+  if (!actor.id || !actor.name) {
+    throw new Error(
+      `Invalid actor: Actor must have both id and name. Received: ${JSON.stringify(actor)}`
+    );
+  }
+
+  if (!actors.has(actor.id)) {
+    actors.set(actor.id, actor);
+    log.debug(`Added actor: ${actor.id} (${actor.name})`);
+  } else {
+    log.debug(`Actor ${actor.id} already exists`);
+  }
+};
+
+const getActors = (): Map<string, Actor> => actors;
+
+const getActor = (id: string): Actor | undefined => actors.get(id);
+
+// UseCase management
+const addUseCase = (useCase: UseCase): void => {
+  if (!useCase.id || !useCase.name) {
+    throw new Error(
+      `Invalid use case: Use case must have both id and name. Received: ${JSON.stringify(useCase)}`
+    );
+  }
+
+  if (!useCases.has(useCase.id)) {
+    useCases.set(useCase.id, useCase);
+    log.debug(`Added use case: ${useCase.id} (${useCase.name})`);
+  } else {
+    log.debug(`Use case ${useCase.id} already exists`);
+  }
+};
+
+const getUseCases = (): Map<string, UseCase> => useCases;
+
+const getUseCase = (id: string): UseCase | undefined => useCases.get(id);
+
+// SystemBoundary management
+const addSystemBoundary = (systemBoundary: SystemBoundary): void => {
+  if (!systemBoundary.id || !systemBoundary.name) {
+    throw new Error(
+      `Invalid system boundary: System boundary must have both id and name. Received: ${JSON.stringify(systemBoundary)}`
+    );
+  }
+
+  if (!systemBoundaries.has(systemBoundary.id)) {
+    systemBoundaries.set(systemBoundary.id, systemBoundary);
+    log.debug(`Added system boundary: ${systemBoundary.name}`);
+  } else {
+    log.debug(`System boundary ${systemBoundary.id} already exists`);
+  }
+};
+
+const getSystemBoundaries = (): Map<string, SystemBoundary> => systemBoundaries;
+
+const getSystemBoundary = (id: string): SystemBoundary | undefined => systemBoundaries.get(id);
+
+// Relationship management
+const addRelationship = (relationship: Relationship): void => {
+  // Validate relationship structure
+  if (!relationship.id || !relationship.from || !relationship.to) {
+    throw new Error(
+      `Invalid relationship: Relationship must have id, from, and to fields. Received: ${JSON.stringify(relationship)}`
+    );
+  }
+
+  if (!relationship.type) {
+    throw new Error(
+      `Invalid relationship: Relationship must have a type. Received: ${JSON.stringify(relationship)}`
+    );
+  }
+
+  // Validate relationship type
+  const validTypes = ['association', 'include', 'extend'];
+  if (!validTypes.includes(relationship.type)) {
+    throw new Error(
+      `Invalid relationship type: ${relationship.type}. Valid types are: ${validTypes.join(', ')}`
+    );
+  }
+
+  // Validate arrow type if present
+  if (relationship.arrowType !== undefined) {
+    const validArrowTypes = [0, 1, 2, 3, 4, 5, 6]; // SOLID_ARROW, BACK_ARROW, LINE_SOLID, CIRCLE_ARROW, CROSS_ARROW
+    if (!validArrowTypes.includes(relationship.arrowType)) {
+      throw new Error(
+        `Invalid arrow type: ${relationship.arrowType}. Valid arrow types are: ${validArrowTypes.join(', ')}`
+      );
+    }
+  }
+
+  relationships.push(relationship);
+  log.debug(
+    `Added relationship: ${relationship.from} -> ${relationship.to} (${relationship.type})`
+  );
+};
+
+const getRelationships = (): Relationship[] => relationships;
+
+// ClassDef management
+const addClassDef = (classDef: ClassDef): void => {
+  if (!classDef.id) {
+    throw new Error(
+      `Invalid classDef: ClassDef must have an id. Received: ${JSON.stringify(classDef)}`
+    );
+  }
+
+  classDefs.set(classDef.id, classDef);
+  log.debug(`Added classDef: ${classDef.id}`);
+};
+
+const getClassDefs = (): Map<string, ClassDef> => classDefs;
+
+const getClassDef = (id: string): ClassDef | undefined => classDefs.get(id);
+
+/**
+ * Get compiled styles from class definitions
+ * Similar to flowchart's getCompiledStyles method
+ */
+const getCompiledStyles = (classNames: string[]): string[] => {
+  let compiledStyles: string[] = [];
+  for (const className of classNames) {
+    const cssClass = classDefs.get(className);
+    if (cssClass?.styles) {
+      compiledStyles = [...compiledStyles, ...(cssClass.styles ?? [])].map((s) => s.trim());
+    }
+  }
+  return compiledStyles;
+};
+
+// Direction management
+const setDirection = (dir: Direction): void => {
+  // Normalize TD to TB (same as flowchart)
+  if (dir === 'TD') {
+    direction = 'TB';
+  } else {
+    direction = dir;
+  }
+  log.debug('Direction set to:', direction);
+};
+
+const getDirection = (): Direction => direction;
+
+// Convert usecase diagram data to LayoutData format for unified rendering
+const getData = (): LayoutData => {
+  const globalConfig = getGlobalConfig();
+  const nodes: Node[] = [];
+  const edges: Edge[] = [];
+
+  // Convert actors to nodes
+  for (const actor of actors.values()) {
+    const classesArray = ['default', 'usecase-actor'];
+    const cssCompiledStyles = getCompiledStyles(classesArray);
+
+    // Determine which shape to use based on whether actor has an icon
+    const actorShape = actor.metadata?.icon ? 'usecaseActorIcon' : 'usecaseActor';
+
+    const node: Node = {
+      id: actor.id,
+      label: actor.name,
+      description: actor.description ? [actor.description] : undefined,
+      shape: actorShape, // Use icon shape if icon is present, otherwise stick figure
+      isGroup: false,
+      padding: 10,
+      look: globalConfig.look,
+      // Add metadata as data attributes for styling
+      cssClasses: `usecase-actor ${
+        actor.metadata && Object.keys(actor.metadata).length > 0
+          ? Object.entries(actor.metadata)
+              .map(([key, value]) => `actor-${key}-${value}`)
+              .join(' ')
+          : ''
+      }`.trim(),
+      cssStyles: actor.styles ?? [], // Direct styles
+      cssCompiledStyles, // Compiled styles from class definitions
+      // Pass actor metadata to the shape handler
+      metadata: actor.metadata,
+    } as Node & { metadata?: ActorMetadata };
+    nodes.push(node);
+  }
+
+  // Convert use cases to nodes
+  for (const useCase of useCases.values()) {
+    // Build CSS classes string
+    let cssClasses = 'usecase-element';
+    const classesArray = ['default', 'usecase-element'];
+    if (useCase.classes && useCase.classes.length > 0) {
+      cssClasses += ' ' + useCase.classes.join(' ');
+      classesArray.push(...useCase.classes);
+    }
+
+    // Get compiled styles from class definitions
+    const cssCompiledStyles = getCompiledStyles(classesArray);
+    const node: Node = {
+      id: useCase.id,
+      label: useCase.name,
+      description: useCase.description ? [useCase.description] : undefined,
+      shape: 'ellipse', // Use ellipse shape for use cases
+      isGroup: false,
+      padding: 10,
+      look: globalConfig.look,
+      cssClasses,
+      cssStyles: useCase.styles ?? [], // Direct styles
+      cssCompiledStyles, // Compiled styles from class definitions
+      // If use case belongs to a system boundary, set parentId
+      ...(useCase.systemBoundary && { parentId: useCase.systemBoundary }),
+    };
+    nodes.push(node);
+  }
+
+  // Convert system boundaries to group nodes
+  for (const boundary of systemBoundaries.values()) {
+    const classesArray = [
+      'default',
+      'system-boundary',
+      `system-boundary-${boundary.type ?? 'rect'}`,
+    ];
+    const cssCompiledStyles = getCompiledStyles(classesArray);
+
+    const node: ClusterNode & { boundaryType?: string } = {
+      id: boundary.id,
+      label: boundary.name,
+      shape: 'usecaseSystemBoundary', // Use custom usecase system boundary cluster shape
+      isGroup: true, // System boundaries are clusters (containers for other nodes)
+      padding: 20,
+      look: globalConfig.look,
+      cssClasses: `system-boundary system-boundary-${boundary.type ?? 'rect'}`,
+      cssStyles: boundary.styles ?? [], // Direct styles
+      cssCompiledStyles, // Compiled styles from class definitions
+      // Pass boundary type to the shape handler
+      boundaryType: boundary.type,
+    };
+    nodes.push(node);
+  }
+
+  // Convert relationships to edges
+  relationships.forEach((relationship, index) => {
+    // Determine arrow types based on relationship.arrowType
+    let arrowTypeEnd = 'none';
+    let arrowTypeStart = 'none';
+
+    switch (relationship.arrowType) {
+      case ARROW_TYPE.SOLID_ARROW: // -->
+        arrowTypeEnd = 'arrow_point';
+        break;
+      case ARROW_TYPE.BACK_ARROW: // <--
+        arrowTypeStart = 'arrow_point';
+        break;
+      case ARROW_TYPE.CIRCLE_ARROW: // --o
+        arrowTypeEnd = 'arrow_circle';
+        break;
+      case ARROW_TYPE.CROSS_ARROW: // --x
+        arrowTypeEnd = 'arrow_cross';
+        break;
+      case ARROW_TYPE.CIRCLE_ARROW_REVERSED: // o--
+        arrowTypeStart = 'arrow_circle';
+        break;
+      case ARROW_TYPE.CROSS_ARROW_REVERSED: // x--
+        arrowTypeStart = 'arrow_cross';
+        break;
+      case ARROW_TYPE.LINE_SOLID: // --
+        // Both remain 'none'
+        break;
+    }
+
+    const edge: Edge = {
+      id: relationship.id || `edge-${index}`,
+      start: relationship.from,
+      end: relationship.to,
+      source: relationship.from,
+      target: relationship.to,
+      label: relationship.label,
+      labelpos: 'c', // Center label position for proper dagre layout
+      type: relationship.type,
+      arrowTypeEnd,
+      arrowTypeStart,
+      classes: `relationship relationship-${relationship.type}`,
+      look: globalConfig.look,
+      thickness: 'normal',
+      pattern: 'solid',
+    };
+    edges.push(edge);
+  });
+
+  return {
+    nodes,
+    edges,
+    config: globalConfig,
+    // Additional properties that layout algorithms might expect
+    type: 'usecase',
+    layoutAlgorithm: 'dagre', // Default layout algorithm
+    direction: getDirection(), // Use the current direction setting
+    nodeSpacing: 50, // Default node spacing
+    rankSpacing: 50, // Default rank spacing
+    markers: ['arrow_point'], // Arrow point markers used in usecase diagrams
+  };
+};
+
+export const db: UsecaseDB = {
+  getConfig,
+
+  clear,
+  setDiagramTitle,
+  getDiagramTitle,
+  setAccTitle,
+  getAccTitle,
+  setAccDescription,
+  getAccDescription,
+
+  addActor,
+  getActors,
+  getActor,
+
+  addUseCase,
+  getUseCases,
+  getUseCase,
+
+  addSystemBoundary,
+  getSystemBoundaries,
+  getSystemBoundary,
+
+  addRelationship,
+  getRelationships,
+
+  addClassDef,
+  getClassDefs,
+  getClassDef,
+
+  // Direction management
+  setDirection,
+  getDirection,
+
+  // Add getData method for unified rendering
+  getData,
+};

packages/mermaid/src/diagrams/usecase/usecaseDetector.ts

@@ -0,0 +1,22 @@
+import type {
+  DiagramDetector,
+  DiagramLoader,
+  ExternalDiagramDefinition,
+} from '../../diagram-api/types.js';
+
+const id = 'usecase';
+
+const detector: DiagramDetector = (txt) => {
+  return /^\s*usecase/.test(txt);
+};
+
+const loader: DiagramLoader = async () => {
+  const { diagram } = await import('./usecaseDiagram.js');
+  return { id, diagram };
+};
+
+export const usecase: ExternalDiagramDefinition = {
+  id,
+  detector,
+  loader,
+};

packages/mermaid/src/diagrams/usecase/usecaseDiagram.ts

@@ -0,0 +1,12 @@
+import type { DiagramDefinition } from '../../diagram-api/types.js';
+import { parser } from './usecaseParser.js';
+import { db } from './usecaseDb.js';
+import { renderer } from './usecaseRenderer.js';
+import styles from './styles.js';
+
+export const diagram: DiagramDefinition = {
+  parser,
+  db,
+  renderer,
+  styles,
+};

packages/mermaid/src/diagrams/usecase/usecaseParser.ts

@@ -0,0 +1,188 @@
+// Import ANTLR parser from the parser package
+import { parse } from '@mermaid-js/parser';
+import { log } from '../../logger.js';
+import type { ParserDefinition } from '../../diagram-api/types.js';
+import { populateCommonDb } from '../common/populateCommonDb.js';
+import type {
+  UsecaseDB,
+  Actor,
+  UseCase,
+  SystemBoundary,
+  Relationship,
+  ArrowType,
+  ClassDef,
+} from './usecaseTypes.js';
+import { db } from './usecaseDb.js';
+
+// ANTLR parser result interface
+interface UsecaseParseResult {
+  actors: { id: string; name: string; metadata?: Record<string, string>; styles?: string[] }[];
+  useCases: {
+    id: string;
+    name: string;
+    nodeId?: string;
+    systemBoundary?: string;
+    classes?: string[];
+    styles?: string[];
+  }[];
+  systemBoundaries: {
+    id: string;
+    name: string;
+    useCases: string[];
+    type?: 'package' | 'rect';
+    styles?: string[];
+  }[];
+  relationships: {
+    id: string;
+    from: string;
+    to: string;
+    type: 'association' | 'include' | 'extend';
+    arrowType: number;
+    label?: string;
+  }[];
+  classDefs?: Map<string, { id: string; styles: string[] }>;
+  direction?: string;
+  accDescr?: string;
+  accTitle?: string;
+  title?: string;
+}
+
+/**
+ * Parse usecase diagram using ANTLR parser
+ */
+const parseUsecaseWithAntlr = async (input: string): Promise<UsecaseParseResult> => {
+  // Use the ANTLR parser from @mermaid-js/parser
+  const result = (await parse('usecase', input)) as UsecaseParseResult;
+  return result;
+};
+
+/**
+ * Populate the database with parsed ANTLR results
+ */
+const populateDb = (ast: UsecaseParseResult, db: UsecaseDB) => {
+  // Clear existing data
+  db.clear();
+
+  // Add actors (ANTLR result already has id, name, and metadata)
+  ast.actors.forEach((actorData) => {
+    const actor: Actor = {
+      id: actorData.id,
+      name: actorData.name,
+      metadata: actorData.metadata,
+      styles: actorData.styles,
+    };
+    db.addActor(actor);
+  });
+
+  // Add use cases (ANTLR result already has id, name, nodeId, systemBoundary, and classes)
+  ast.useCases.forEach((useCaseData) => {
+    const useCase: UseCase = {
+      id: useCaseData.id,
+      name: useCaseData.name,
+      nodeId: useCaseData.nodeId,
+      systemBoundary: useCaseData.systemBoundary,
+      classes: useCaseData.classes,
+      styles: useCaseData.styles,
+    };
+    db.addUseCase(useCase);
+  });
+
+  // Add system boundaries
+  if (ast.systemBoundaries) {
+    ast.systemBoundaries.forEach((boundaryData) => {
+      const systemBoundary: SystemBoundary = {
+        id: boundaryData.id,
+        name: boundaryData.name,
+        useCases: boundaryData.useCases,
+        type: boundaryData.type || 'rect', // default to 'rect' if not specified
+        styles: boundaryData.styles,
+      };
+      db.addSystemBoundary(systemBoundary);
+    });
+  }
+
+  // Add relationships (ANTLR result already has proper structure)
+  ast.relationships.forEach((relationshipData) => {
+    const relationship: Relationship = {
+      id: relationshipData.id,
+      from: relationshipData.from,
+      to: relationshipData.to,
+      type: relationshipData.type,
+      arrowType: relationshipData.arrowType as ArrowType,
+      label: relationshipData.label,
+    };
+    db.addRelationship(relationship);
+  });
+
+  // Add class definitions
+  if (ast.classDefs) {
+    ast.classDefs.forEach((classDefData) => {
+      const classDef: ClassDef = {
+        id: classDefData.id,
+        styles: classDefData.styles,
+      };
+      db.addClassDef(classDef);
+    });
+  }
+
+  // Set direction if provided
+  if (ast.direction) {
+    db.setDirection(ast.direction as any);
+  }
+
+  log.debug('Populated usecase database:', {
+    actors: ast.actors.length,
+    useCases: ast.useCases.length,
+    relationships: ast.relationships.length,
+    classDefs: ast.classDefs?.size ?? 0,
+    direction: ast.direction,
+  });
+};
+
+export const parser: ParserDefinition = {
+  parse: async (input: string): Promise<void> => {
+    log.debug('Parsing usecase diagram with ANTLR:', input);
+
+    try {
+      // Use our ANTLR parser
+      const ast: UsecaseParseResult = await parseUsecaseWithAntlr(input);
+      log.debug('ANTLR parsing result:', ast);
+
+      // Populate common database fields
+      populateCommonDb(ast as any, db);
+
+      // Populate the database with validation
+      populateDb(ast, db);
+
+      log.debug('Usecase diagram parsing completed successfully');
+    } catch (error) {
+      log.error('Error parsing usecase diagram:', error);
+
+      // Check if it's a UsecaseParseError from our ANTLR parser
+      if (
+        error &&
+        typeof error === 'object' &&
+        'name' in error &&
+        error.name === 'UsecaseParseError'
+      ) {
+        // Re-throw the detailed error for better error reporting
+        throw error;
+      }
+
+      // For other errors, wrap them in a generic error
+      const errorMessage = error instanceof Error ? error.message : 'Unknown error';
+      const wrappedError = new Error(`Failed to parse usecase diagram: ${errorMessage}`);
+
+      // Add hash property for consistency with other diagram types
+      (wrappedError as any).hash = {
+        text: input.split('\n')[0] || '',
+        token: 'unknown',
+        line: '1',
+        loc: { first_line: 1, last_line: 1, first_column: 1, last_column: 1 },
+        expected: ['valid usecase syntax'],
+      };
+
+      throw wrappedError;
+    }
+  },
+};

packages/mermaid/src/diagrams/usecase/usecaseRenderer.ts

@@ -0,0 +1,48 @@
+import type { DrawDefinition } from '../../diagram-api/types.js';
+import { log } from '../../logger.js';
+import { getDiagramElement } from '../../rendering-util/insertElementsForSize.js';
+import { getRegisteredLayoutAlgorithm, render } from '../../rendering-util/render.js';
+import { setupViewPortForSVG } from '../../rendering-util/setupViewPortForSVG.js';
+import { getConfig } from '../../diagram-api/diagramAPI.js';
+import utils from '../../utils.js';
+import type { UsecaseDB } from './usecaseTypes.js';
+
+/**
+ * Main draw function using unified rendering system
+ */
+const draw: DrawDefinition = async (_text, id, _version, diag) => {
+  log.info('Drawing usecase diagram (unified)', id);
+  const { securityLevel, usecase: conf, layout } = getConfig();
+
+  // The getData method provided in all supported diagrams is used to extract the data from the parsed structure
+  // into the Layout data format
+  const usecaseDb = diag.db as UsecaseDB;
+  const data4Layout = usecaseDb.getData();
+
+  // Create the root SVG - the element is the div containing the SVG element
+  const svg = getDiagramElement(id, securityLevel);
+
+  data4Layout.type = diag.type;
+  data4Layout.layoutAlgorithm = getRegisteredLayoutAlgorithm(layout);
+
+  data4Layout.nodeSpacing = 50; // Default node spacing
+  data4Layout.rankSpacing = 50; // Default rank spacing
+  data4Layout.markers = ['point', 'circle', 'cross']; // Support point, circle, and cross markers
+  data4Layout.diagramId = id;
+
+  log.debug('Usecase layout data:', data4Layout);
+
+  // Use the unified rendering system
+  await render(data4Layout, svg);
+
+  const padding = 8;
+  utils.insertTitle(
+    svg,
+    'usecaseDiagramTitleText',
+    0, // Default title top margin
+    usecaseDb.getDiagramTitle?.() ?? ''
+  );
+  setupViewPortForSVG(svg, padding, 'usecaseDiagram', conf?.useMaxWidth ?? false);
+};
+
+export const renderer = { draw };

packages/mermaid/src/diagrams/usecase/usecaseStyles.ts

@@ -0,0 +1,40 @@
+const getStyles = (options: any) =>
+  `
+  .actor {
+    stroke: ${options.primaryColor};
+    fill: ${options.primaryColor};
+  }
+  
+  .actor-label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 14px;
+    font-weight: normal;
+  }
+  
+  .usecase {
+    stroke: ${options.primaryColor};
+    fill: ${options.primaryColor};
+  }
+  
+  .usecase-label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 12px;
+    font-weight: normal;
+  }
+  
+  .relationship {
+    stroke: ${options.primaryColor};
+    fill: ${options.primaryColor};
+  }
+  
+  .relationship-label {
+    fill: ${options.primaryTextColor};
+    font-family: ${options.fontFamily};
+    font-size: 10px;
+    font-weight: normal;
+  }
+`;
+
+export default getStyles;

packages/mermaid/src/diagrams/usecase/usecaseTypes.ts

@@ -0,0 +1,113 @@
+import type { DiagramDB } from '../../diagram-api/types.js';
+import type { UsecaseDiagramConfig } from '../../config.type.js';
+import type { LayoutData } from '../../rendering-util/types.js';
+
+export type ActorMetadata = Record<string, string>;
+
+export interface Actor {
+  id: string;
+  name: string;
+  description?: string;
+  metadata?: ActorMetadata;
+  styles?: string[]; // Direct CSS styles applied to this actor
+}
+
+export interface UseCase {
+  id: string;
+  name: string;
+  description?: string;
+  nodeId?: string; // Optional node ID (e.g., 'a' in 'a(Go through code)')
+  systemBoundary?: string; // Optional reference to system boundary
+  classes?: string[]; // CSS classes applied to this use case
+  styles?: string[]; // Direct CSS styles applied to this use case
+}
+
+export type SystemBoundaryType = 'package' | 'rect';
+
+export interface SystemBoundary {
+  id: string;
+  name: string;
+  useCases: string[]; // Array of use case IDs within this boundary
+  type?: SystemBoundaryType; // Type of boundary rendering (default: 'rect')
+  styles?: string[]; // Direct CSS styles applied to this system boundary
+}
+
+// Arrow types for usecase diagrams (matching parser types)
+export const ARROW_TYPE = {
+  SOLID_ARROW: 0, // -->
+  BACK_ARROW: 1, // <--
+  LINE_SOLID: 2, // --
+  CIRCLE_ARROW: 3, // --o
+  CROSS_ARROW: 4, // --x
+  CIRCLE_ARROW_REVERSED: 5, // o--
+  CROSS_ARROW_REVERSED: 6, // x--
+} as const;
+
+export type ArrowType = (typeof ARROW_TYPE)[keyof typeof ARROW_TYPE];
+
+export interface Relationship {
+  id: string;
+  from: string;
+  to: string;
+  type: 'association' | 'include' | 'extend';
+  arrowType: ArrowType;
+  label?: string;
+}
+
+// Direction types for usecase diagrams
+export type Direction = 'TB' | 'TD' | 'BT' | 'RL' | 'LR';
+
+export const DEFAULT_DIRECTION: Direction = 'LR';
+
+export interface ClassDef {
+  id: string;
+  styles: string[];
+}
+
+export interface UsecaseFields {
+  actors: Map<string, Actor>;
+  useCases: Map<string, UseCase>;
+  systemBoundaries: Map<string, SystemBoundary>;
+  relationships: Relationship[];
+  classDefs: Map<string, ClassDef>;
+  direction: Direction;
+  config: Required<UsecaseDiagramConfig>;
+}
+
+export interface UsecaseDB extends DiagramDB {
+  getConfig: () => Required<UsecaseDiagramConfig>;
+
+  // Actor management
+  addActor: (actor: Actor) => void;
+  getActors: () => Map<string, Actor>;
+  getActor: (id: string) => Actor | undefined;
+
+  // UseCase management
+  addUseCase: (useCase: UseCase) => void;
+  getUseCases: () => Map<string, UseCase>;
+  getUseCase: (id: string) => UseCase | undefined;
+
+  // SystemBoundary management
+  addSystemBoundary: (systemBoundary: SystemBoundary) => void;
+  getSystemBoundaries: () => Map<string, SystemBoundary>;
+  getSystemBoundary: (id: string) => SystemBoundary | undefined;
+
+  // Relationship management
+  addRelationship: (relationship: Relationship) => void;
+  getRelationships: () => Relationship[];
+
+  // ClassDef management
+  addClassDef: (classDef: ClassDef) => void;
+  getClassDefs: () => Map<string, ClassDef>;
+  getClassDef: (id: string) => ClassDef | undefined;
+
+  // Direction management
+  setDirection: (direction: Direction) => void;
+  getDirection: () => Direction;
+
+  // Unified rendering support
+  getData: () => LayoutData;
+
+  // Utility methods
+  clear: () => void;
+}

packages/mermaid/src/docs/.vitepress/components/EditorSelectionModal.vue

@@ -40,105 +40,26 @@ const openSourceFeatures: Feature[] = [
   { iconUrl: '/icons/version-history.svg', featureName: 'Version history' },
 ];
 
-const playgroundFeatures: Feature[] = [
-  { iconUrl: '/icons/public.svg', featureName: 'Diagram stored in URL' },
-  { iconUrl: '/icons/terminal.svg', featureName: 'Code editor' },
-  { iconUrl: '/icons/whiteboard.svg', featureName: 'Whiteboard' },
+const editorColumns: EditorColumn[] = [
+  {
+    title: 'Mermaid Pro',
+    description: 'Unlock AI and real-time collaboration',
+    highlighted: true,
+    redBarText: 'Recommended',
+    proTrialButtonText: 'Start free trial',
+    proTrialUrl:
+      'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=2_editor_selection&utm_campaign=start_pro&redirect=%2Fapp%2Fuser%2Fbilling%2Fcheckout%3FisFromMermaid%3Dtrue',
+    features: mermaidChartFeatures,
+  },
+  {
+    title: 'Open Source',
+    description: 'Code only, no login',
+    buttonText: 'Start free',
+    redirectUrl: 'https://mermaid.live/edit',
+    features: openSourceFeatures,
+  },
 ];
 
-const editorColumnVariants: EditorColumn[][] = [
-  [
-    {
-      title: 'Playground',
-      description: 'Basic features, no login',
-      redirectUrl:
-        'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=3_editor_selection_A&utm_campaign=start_playground',
-      buttonText: 'Start free',
-      features: playgroundFeatures,
-    },
-    {
-      title: 'Free or Pro',
-      description: 'Advanced features, Free or Pro account',
-      proTrialUrl:
-        'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=3_editor_selection_A&utm_campaign=start_free',
-      proTrialButtonText: 'Start free',
-      highlighted: true,
-      redBarText: 'Best for collaboration',
-      features: mermaidChartFeatures,
-    },
-    {
-      title: 'Open Source',
-      description: 'Code only, no login',
-      redirectUrl: 'https://mermaid.live/edit',
-      buttonText: 'Start free',
-      features: openSourceFeatures,
-    },
-  ],
-  [
-    {
-      title: 'Mermaid Pro',
-      description: 'Unlock AI and real-time collaboration',
-      redirectUrl:
-        'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=editor_selection_B&utm_campaign=start_free',
-      buttonText: 'Start Free',
-      highlighted: true,
-      redBarText: 'Recommended',
-      proTrialButtonText: 'Start Pro trial',
-      proTrialUrl:
-        'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=editor_selection_B&utm_campaign=start_trial&redirect=%2Fapp%2Fuser%2Fbilling%2Fcheckout%3FisFromMermaid%3Dtrue',
-      features: mermaidChartFeatures,
-    },
-    {
-      title: 'Open Source',
-      description: 'Code only, no login',
-      buttonText: 'Start free',
-      redirectUrl: 'https://mermaid.live/edit',
-      isButtonMargined: true,
-      features: openSourceFeatures,
-    },
-  ],
-  [
-    {
-      title: 'Mermaid Pro',
-      description: 'Unlock AI and real-time collaboration',
-      highlighted: true,
-      redBarText: 'Recommended',
-      proTrialButtonText: 'Start free trial',
-      proTrialUrl:
-        'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=editor_selection_C&utm_campaign=start_trial&redirect=%2Fapp%2Fuser%2Fbilling%2Fcheckout%3FisFromMermaid%3Dtrue',
-      features: mermaidChartFeatures,
-    },
-    {
-      title: 'Open Source',
-      description: 'Code only, no login',
-      buttonText: 'Start free',
-      redirectUrl: 'https://mermaid.live/edit',
-      features: openSourceFeatures,
-    },
-  ],
-  [
-    {
-      title: 'Mermaid Pro',
-      description: 'Unlock AI and real-time collaboration',
-      highlighted: true,
-      redBarText: 'Recommended',
-      proTrialButtonText: 'Start free',
-      proTrialUrl:
-        'https://www.mermaidchart.com/app/sign-up?utm_source=mermaid_js&utm_medium=editor_selection_D&utm_campaign=start_free',
-      features: mermaidChartFeatures,
-    },
-    {
-      title: 'Open Source',
-      description: 'Code only, no login',
-      redirectUrl: 'https://mermaid.live/edit',
-      buttonText: 'Start free',
-      features: openSourceFeatures,
-    },
-  ],
-];
-
-const editorColumns = editorColumnVariants[Math.floor(Math.random() * editorColumnVariants.length)];
-
 const isVisible = ref(false);
 
 const handleMouseDown = (e: MouseEvent) => {

packages/mermaid/src/docs/.vitepress/theme/mermaid.ts

@@ -1,7 +1,13 @@
 import mermaid, { type MermaidConfig } from 'mermaid';
 import zenuml from '../../../../../mermaid-zenuml/dist/mermaid-zenuml.core.mjs';
+import tidyTreeLayout from '../../../../../mermaid-layout-tidy-tree/dist/mermaid-layout-tidy-tree.core.mjs';
+import layouts from '../../../../../mermaid-layout-elk/dist/mermaid-layout-elk.core.mjs';
 
-const init = mermaid.registerExternalDiagrams([zenuml]);
+const init = Promise.all([
+  mermaid.registerExternalDiagrams([zenuml]),
+  mermaid.registerLayoutLoaders(layouts),
+  mermaid.registerLayoutLoaders(tidyTreeLayout),
+]);
 mermaid.registerIconPacks([
   {
     name: 'logos',

packages/mermaid/src/docs/config/directives.md

@@ -17,7 +17,6 @@ While directives allow you to change most of the default configuration settings,
 Mermaid basically supports two types of configuration options to be overridden by directives.
 
 1. _General/Top Level configurations_ : These are the configurations that are available and applied to all the diagram. **Some of the most important top-level** configurations are:
-
    - theme
    - fontFamily
    - logLevel

packages/mermaid/src/docs/ecosystem/mermaid-chart.md

@@ -23,7 +23,6 @@ Try the Ultimate AI, Mermaid, and Visual Diagramming Suite by creating an accoun
 - **Plugins** - A plugin system for extending the functionality of Mermaid.
 
   Official Mermaid Chart plugins:
-
   - [Mermaid Chart GPT](https://chatgpt.com/g/g-684cc36f30208191b21383b88650a45d-mermaid-chart-diagrams-and-charts)
   - [Confluence](https://marketplace.atlassian.com/apps/1234056/mermaid-chart-for-confluence?hosting=cloud&tab=overview)
   - [Jira](https://marketplace.atlassian.com/apps/1234810/mermaid-chart-for-jira?tab=overview&hosting=cloud)

packages/mermaid/src/docs/news/announcements.md

@@ -33,13 +33,11 @@ The Mermaid Chart team is excited to introduce a new Visual Editor for Flowchart
 Learn more:
 
 - Visual Editor For Flowcharts
-
   - [Blog post](https://www.mermaidchart.com/blog/posts/mermaid-chart-releases-new-visual-editor-for-flowcharts)
 
   - [Demo video](https://www.youtube.com/watch?v=5aja0gijoO0)
 
 - Visual Editor For Sequence diagrams
-
   - [Blog post](https://www.mermaidchart.com/blog/posts/mermaid-chart-unveils-visual-editor-for-sequence-diagrams)
 
   - [Demo video](https://youtu.be/imc2u5_N6Dc)

packages/mermaid/src/docs/news/blog.md

@@ -1,5 +1,17 @@
 # Blog
 
+## [The Essential Guide to Mermaid Chart Plugin for VS Code [08/2025]](https://docs.mermaidchart.com/blog/posts/the-essential-guide-to-mermaid-chart-plugin-for-vs-code-08-2025)
+
+9/9/2025 • 5 mins
+
+Creating diagrams in VS Code has never been easier—the Mermaid VS Code plugin transforms text-based syntax into clear, professional visuals right inside your editor. With live previews, smart editing, and AI-powered diagram generation, it removes the friction from visualization so you can focus on coding.
+
+## [How to Create Perfect Flowcharts Using AI in 2025 Step-by-Step Guide](https://docs.mermaidchart.com/blog/posts/how-to-create-perfect-flowcharts-using-ai-in-2025-step-by-step-guide)
+
+7/22/2025 • 8 mins
+
+In 2025, AI tools make creating flowcharts faster and easier than ever. With Mermaid’s AI flowchart generator, you can turn plain text into clear, accurate diagrams in seconds. This guide walks through how it works and how to get the most out of it for technical and business workflows alike.
+
 ## [Mermaid introduces the Visual Editor for Entity Relationship diagrams](https://docs.mermaidchart.com/blog/posts/mermaid-introduces-the-visual-editor-for-entity-relationship-diagrams)
 
 7/15/2025 • 7 mins