Merge branch 'develop' of https://github.com/mermaid-js/mermaid into 6638-sequence-diagram-additional-messages

6637:Add support for new participant types in sequence diagrams

.changeset/crazy-loops-matter.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Handle arrows correctly when auto number is enabled

.changeset/hungry-baths-glow.md

@@ -0,0 +1,5 @@
+---
+'mermaid': minor
+---
+
+feat: Added support for new participant types (`actor`, `boundary`, `control`, `entity`, `database`, `collections`, `queue`) in `sequenceDiagram`.

.changeset/loud-results-melt.md

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

.github/workflows/e2e-timings.yml

@@ -58,7 +58,7 @@ jobs:
           echo "EOF" >> $GITHUB_OUTPUT
 
       - name: Commit and create pull request
-        uses: peter-evans/create-pull-request@1310d7dab503600742045e6fd4b84dda64352858
+        uses: peter-evans/create-pull-request@cb4d3bfce175d44325c6b7697f81e0afe8a79bdf
         with:
           add-paths: |
             cypress/timings.json

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

@@ -0,0 +1,659 @@
+import { imgSnapshotTest, renderGraph } from '../../helpers/util.ts';
+
+const looks = ['classic'];
+const participantTypes = [
+  { type: 'participant', display: 'participant' },
+  { type: 'actor', display: 'actor' },
+  { type: 'boundary', display: 'boundary' },
+  { type: 'control', display: 'control' },
+  { type: 'entity', display: 'entity' },
+  { type: 'database', display: 'database' },
+  { type: 'collections', display: 'collections' },
+  { type: 'queue', display: 'queue' },
+];
+
+const restrictedTypes = ['boundary', 'control', 'entity', 'database', 'collections', 'queue'];
+
+const interactionTypes = ['->>', '-->>', '->', '-->', '-x', '--x', '->>+', '-->>+'];
+
+const notePositions = ['left of', 'right of', 'over'];
+
+function getParticipantLine(name, type, alias) {
+  if (restrictedTypes.includes(type)) {
+    return `  participant ${name}@{ "type" : "${type}" }\n`;
+  } else if (alias) {
+    return `  participant ${name}@{ "type" : "${type}" } \n`;
+  } else {
+    return `  participant ${name}@{ "type" : "${type}" }\n`;
+  }
+}
+
+looks.forEach((look) => {
+  describe(`Sequence Diagram Tests - ${look} look`, () => {
+    it('should render all participant types', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      participantTypes.forEach((pt, index) => {
+        const name = `${pt.display}${index}`;
+        diagramCode += getParticipantLine(name, pt.type);
+      });
+      for (let i = 0; i < participantTypes.length - 1; i++) {
+        diagramCode += `  ${participantTypes[i].display}${i} ->> ${participantTypes[i + 1].display}${i + 1}: Message ${i}\n`;
+      }
+      imgSnapshotTest(diagramCode, { look, sequence: { diagramMarginX: 50, diagramMarginY: 10 } });
+    });
+
+    it('should render all interaction types', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      diagramCode += getParticipantLine('A', 'actor');
+      diagramCode += getParticipantLine('B', 'boundary');
+      interactionTypes.forEach((interaction, index) => {
+        diagramCode += `  A ${interaction} B: ${interaction} message ${index}\n`;
+      });
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render participant creation and destruction', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      participantTypes.forEach((pt, index) => {
+        const name = `${pt.display}${index}`;
+        diagramCode += getParticipantLine('A', pt.type);
+        diagramCode += getParticipantLine('B', pt.type);
+        diagramCode += `  create participant ${name}@{ "type" : "${pt.type}" }\n`;
+        diagramCode += `  A ->> ${name}: Hello ${pt.display}\n`;
+        if (index % 2 === 0) {
+          diagramCode += `  destroy ${name}\n`;
+        }
+      });
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render notes in all positions', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      diagramCode += getParticipantLine('A', 'actor');
+      diagramCode += getParticipantLine('B', 'boundary');
+      notePositions.forEach((position, index) => {
+        diagramCode += `  Note ${position} A: Note ${position} ${index}\n`;
+      });
+      diagramCode += `  A ->> B: Message with notes\n`;
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render parallel interactions', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      participantTypes.slice(0, 4).forEach((pt, index) => {
+        diagramCode += getParticipantLine(`${pt.display}${index}`, pt.type);
+      });
+      diagramCode += `  par Parallel actions\n`;
+      for (let i = 0; i < 3; i += 2) {
+        diagramCode += `    ${participantTypes[i].display}${i} ->> ${participantTypes[i + 1].display}${i + 1}: Message ${i}\n`;
+        if (i < participantTypes.length - 2) {
+          diagramCode += `    and\n`;
+        }
+      }
+      diagramCode += `  end\n`;
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render alternative flows', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      diagramCode += getParticipantLine('A', 'actor');
+      diagramCode += getParticipantLine('B', 'boundary');
+      diagramCode += `  alt Successful case\n`;
+      diagramCode += `    A ->> B: Request\n`;
+      diagramCode += `    B -->> A: Success\n`;
+      diagramCode += `  else Failure case\n`;
+      diagramCode += `    A ->> B: Request\n`;
+      diagramCode += `    B --x A: Failure\n`;
+      diagramCode += `  end\n`;
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render loops', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      participantTypes.slice(0, 3).forEach((pt, index) => {
+        diagramCode += getParticipantLine(`${pt.display}${index}`, pt.type);
+      });
+      diagramCode += `  loop For each participant\n`;
+      for (let i = 0; i < 3; i++) {
+        diagramCode += `    ${participantTypes[0].display}0 ->> ${participantTypes[1].display}1: Message ${i}\n`;
+      }
+      diagramCode += `  end\n`;
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render boxes around groups', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      diagramCode += `  box Group 1\n`;
+      participantTypes.slice(0, 3).forEach((pt, index) => {
+        diagramCode += `    ${getParticipantLine(`${pt.display}${index}`, pt.type)}`;
+      });
+      diagramCode += `  end\n`;
+      diagramCode += `  box rgb(200,220,255) Group 2\n`;
+      participantTypes.slice(3, 6).forEach((pt, index) => {
+        diagramCode += `    ${getParticipantLine(`${pt.display}${index}`, pt.type)}`;
+      });
+      diagramCode += `  end\n`;
+      diagramCode += `  ${participantTypes[0].display}0 ->> ${participantTypes[3].display}0: Cross-group message\n`;
+      imgSnapshotTest(diagramCode, { look });
+    });
+
+    it('should render with different font settings', () => {
+      let diagramCode = `sequenceDiagram\n`;
+      participantTypes.slice(0, 3).forEach((pt, index) => {
+        diagramCode += getParticipantLine(`${pt.display}${index}`, pt.type);
+      });
+      diagramCode += `  ${participantTypes[0].display}0 ->> ${participantTypes[1].display}1: Regular message\n`;
+      diagramCode += `  Note right of ${participantTypes[1].display}1: Regular note\n`;
+      imgSnapshotTest(diagramCode, {
+        look,
+        sequence: {
+          actorFontFamily: 'courier',
+          actorFontSize: 14,
+          messageFontFamily: 'Arial',
+          messageFontSize: 12,
+          noteFontFamily: 'times',
+          noteFontSize: 16,
+          noteAlign: 'left',
+        },
+      });
+    });
+  });
+});
+
+// Additional tests for specific combinations
+describe('Sequence Diagram Special Cases', () => {
+  it('should render complex sequence with all features', () => {
+    const diagramCode = `
+      sequenceDiagram
+        box rgb(200,220,255) Authentication
+          actor User
+          participant LoginUI@{ "type": "boundary" }
+          participant AuthService@{ "type": "control" }
+          participant UserDB@{ "type": "database" }
+        end
+
+        box rgb(200,255,220) Order Processing
+          participant Order@{ "type": "entity" }
+          participant OrderQueue@{ "type": "queue" }
+          participant AuditLogs@{ "type": "collections" }
+        end
+        
+        User ->> LoginUI: Enter credentials
+        LoginUI ->> AuthService: Validate
+        AuthService ->> UserDB: Query user
+        UserDB -->> AuthService: User data
+        alt Valid credentials
+          AuthService -->> LoginUI: Success
+          LoginUI -->> User: Welcome
+          
+          par Place order
+            User ->> Order: New order
+            Order ->> OrderQueue: Process
+            and
+            Order ->> AuditLogs: Record
+          end
+          
+          loop Until confirmed
+            OrderQueue ->> Order: Update status
+            Order -->> User: Notification
+          end
+        else Invalid credentials
+          AuthService --x LoginUI: Failure
+          LoginUI --x User: Retry
+        end
+    `;
+    imgSnapshotTest(diagramCode, {});
+  });
+
+  it('should render with wrapped messages and notes', () => {
+    const diagramCode = `
+      sequenceDiagram
+        participant A
+        participant B
+        
+        A ->> B: This is a very long message that should wrap properly in the diagram rendering
+        Note over A,B: This is a very long note that should also wrap properly when rendered in the diagram
+        
+        par Wrapped parallel
+          A ->> B: Parallel message 1<br>with explicit line break
+          and
+          B ->> A: Parallel message 2<br>with explicit line break
+        end
+        
+        loop Wrapped loop
+          Note right of B: This is a long note<br>in a loop
+          A ->> B: Message in loop
+        end
+    `;
+    imgSnapshotTest(diagramCode, { sequence: { wrap: true } });
+  });
+  describe('Sequence Diagram Rendering with Different Participant Types', () => {
+    it('should render a sequence diagram with various participant types', () => {
+      imgSnapshotTest(
+        `
+        sequenceDiagram
+          participant User@{ "type": "actor" }
+          participant AuthService@{ "type": "control" }
+          participant UI@{ "type": "boundary" }
+          participant OrderController@{ "type": "control" }
+          participant Product@{ "type": "entity" }
+          participant MongoDB@{ "type": "database" }
+          participant Products@{ "type": "collections" }
+          participant OrderQueue@{ "type": "queue" }
+          User ->> UI: Login request
+          UI ->> AuthService: Validate credentials
+          AuthService -->> UI: Authentication token
+          UI ->> OrderController: Place order
+          OrderController ->> Product: Check availability
+          Product -->> OrderController: Available
+          OrderController ->> MongoDB: Save order
+          MongoDB -->> OrderController: Order saved
+          OrderController ->> OrderQueue: Process payment
+          OrderQueue -->> User: Order confirmation
+      `
+      );
+    });
+
+    it('should render participant creation and destruction with different types', () => {
+      imgSnapshotTest(`
+      sequenceDiagram
+          participant Alice@{ "type" : "boundary" }
+          Alice->>Bob: Hello Bob, how are you ?
+          Bob->>Alice: Fine, thank you. And you?
+          create participant Carl@{ "type" : "control" }
+          Alice->>Carl: Hi Carl!
+          create actor D as Donald
+          Carl->>D: Hi!
+          destroy Carl
+          Alice-xCarl: We are too many
+          destroy Bob
+          Bob->>Alice: I agree
+      `);
+    });
+
+    it('should handle complex interactions between different participant types', () => {
+      imgSnapshotTest(
+        `
+     sequenceDiagram
+        box rgb(200,220,255) Authentication
+          participant User@{ "type": "actor" }
+          participant LoginUI@{ "type": "boundary" }
+          participant AuthService@{ "type": "control" }
+          participant UserDB@{ "type": "database" }
+        end
+
+        box rgb(200,255,220) Order Processing
+          participant Order@{ "type": "entity" }
+          participant OrderQueue@{ "type": "queue" }
+          participant AuditLogs@{ "type": "collections" }
+        end
+
+        User ->> LoginUI: Enter credentials
+        LoginUI ->> AuthService: Validate
+        AuthService ->> UserDB: Query user
+        UserDB -->> AuthService: User data
+
+        alt Valid credentials
+          AuthService -->> LoginUI: Success
+          LoginUI -->> User: Welcome
+
+          par Place order
+            User ->> Order: New order
+            Order ->> OrderQueue: Process
+            and
+            Order ->> AuditLogs: Record
+          end
+
+          loop Until confirmed
+            OrderQueue ->> Order: Update status
+            Order -->> User: Notification
+          end
+        else Invalid credentials
+          AuthService --x LoginUI: Failure
+          LoginUI --x User: Retry
+        end
+      `,
+        { sequence: { useMaxWidth: false } }
+      );
+    });
+
+    it('should render parallel processes with different participant types', () => {
+      imgSnapshotTest(
+        `
+       sequenceDiagram
+        participant Customer@{ "type": "actor" }
+        participant Frontend@{ "type": "participant" }
+        participant PaymentService@{ "type": "boundary" }
+        participant InventoryManager@{ "type": "control" }
+        participant Order@{ "type": "entity" }
+        participant OrdersDB@{ "type": "database" }
+        participant NotificationQueue@{ "type": "queue" }
+
+        Customer ->> Frontend: Place order
+        Frontend ->> Order: Create order
+        par Parallel Processing
+          Order ->> PaymentService: Process payment
+          and
+          Order ->> InventoryManager: Reserve items
+        end
+        PaymentService -->> Order: Payment confirmed
+        InventoryManager -->> Order: Items reserved
+        Order ->> OrdersDB: Save finalized order
+        OrdersDB -->> Order: Order saved
+        Order ->> NotificationQueue: Send confirmation
+        NotificationQueue -->> Customer: Order confirmation
+      `
+      );
+    });
+  });
+  it('should render different participant types with notes and loops', () => {
+    imgSnapshotTest(
+      `
+    sequenceDiagram
+    actor Admin
+    participant Dashboard
+    participant AuthService@{ "type" : "boundary" }
+    participant UserManager@{ "type" : "control" }
+    participant UserProfile@{ "type" : "entity" }
+    participant UserDB@{ "type" : "database" }
+    participant Logs@{ "type" : "database" }
+    
+    Admin ->> Dashboard: Open user management
+    loop Authentication check
+      Dashboard ->> AuthService: Verify admin rights
+      AuthService ->> Dashboard: Access granted
+    end
+    Dashboard ->> UserManager: List users
+    UserManager ->> UserDB: Query users
+    UserDB ->> UserManager: Return user data
+    Note right of UserDB: Encrypted data<br/>requires decryption
+    UserManager ->> UserProfile: Format profiles
+    UserProfile ->> UserManager: Formatted data
+    UserManager ->> Dashboard: Display users
+    Dashboard ->> Logs: Record access
+    Logs ->> Admin: Audit trail
+    `
+    );
+  });
+
+  it('should render different participant types with alternative flows', () => {
+    imgSnapshotTest(
+      `
+    sequenceDiagram
+      actor Client
+      participant MobileApp
+      participant CloudService@{ "type" : "boundary" }
+      participant DataProcessor@{ "type" : "control" }
+      participant Transaction@{ "type" : "entity" }
+      participant TransactionsDB@{ "type" : "database" }
+      participant EventBus@{ "type" : "queue" }
+      
+      Client ->> MobileApp: Initiate transaction
+      MobileApp ->> CloudService: Authenticate
+      alt Authentication successful
+        CloudService -->> MobileApp: Auth token
+        MobileApp ->> DataProcessor: Process data
+        DataProcessor ->> Transaction: Create transaction
+        Transaction ->> TransactionsDB: Save record
+        TransactionsDB -->> Transaction: Confirmation
+        Transaction ->> EventBus: Publish event
+        EventBus -->> Client: Notification
+      else Authentication failed
+        CloudService -->> MobileApp: Error
+        MobileApp -->> Client: Show error
+      end
+    `
+    );
+  });
+
+  it('should render different participant types with wrapping text', () => {
+    imgSnapshotTest(
+      `
+  sequenceDiagram
+      participant B@{ "type" : "boundary" }
+      participant C@{ "type" : "control" }
+      participant E@{ "type" : "entity" }
+      participant DB@{ "type" : "database" }
+      participant COL@{ "type" : "collections" }
+      participant Q@{ "type" : "queue" }
+    
+      FE ->> B: Another long message<br/>with explicit<br/>line breaks
+      B -->> FE: Response message that is also quite long and needs to wrap
+      FE ->> C: Process data
+      C ->> E: Validate
+      E -->> C: Validation result
+      C ->> DB: Save
+      DB -->> C: Save result
+      C ->> COL: Log
+      COL -->> Q: Forward
+      Q -->> LongNameUser: Final response with confirmation of all actions taken
+    `,
+      { sequence: { wrap: true } }
+    );
+  });
+
+  describe('Sequence Diagram - New Participant Types with Long Notes and Messages', () => {
+    it('should render long notes left of boundary', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+        participant Alice@{ "type" : "boundary" }
+        actor Bob
+        Alice->>Bob: Hola
+        Note left of Alice: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+        Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render wrapped long notes left of control', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "control" }
+      actor Bob
+      Alice->>Bob: Hola
+      Note left of Alice:wrap: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render long notes right of entity', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "entity" }
+      actor Bob
+      Alice->>Bob: Hola
+      Note right of Alice: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render wrapped long notes right of database', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "database" }
+      actor Bob
+      Alice->>Bob: Hola
+      Note right of Alice:wrap: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render long notes over collections', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "collections" }
+      actor Bob
+      Alice->>Bob: Hola
+      Note over Alice: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render wrapped long notes over queue', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "queue" }
+      actor Bob
+      Alice->>Bob: Hola
+      Note over Alice:wrap: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render notes over actor and boundary', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      actor Alice
+      participant Charlie@{ "type" : "boundary" }
+      note over Alice: Some note
+      note over Charlie: Other note
+    `,
+        {}
+      );
+    });
+
+    it('should render long messages from database to collections', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "database" }
+      participant Bob@{ "type" : "collections" }
+      Alice->>Bob: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render wrapped long messages from control to entity', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "control" }
+      participant Bob@{ "type" : "entity" }
+      Alice->>Bob:wrap: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+      Bob->>Alice: I'm short though
+    `,
+        {}
+      );
+    });
+
+    it('should render long messages from queue to boundary', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      participant Alice@{ "type" : "queue" }
+      participant Bob@{ "type" : "boundary" }
+      Alice->>Bob: I'm short
+      Bob->>Alice: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+    `,
+        {}
+      );
+    });
+
+    it('should render wrapped long messages from actor to database', () => {
+      imgSnapshotTest(
+        `
+      sequenceDiagram
+      actor Alice
+      participant Bob@{ "type" : "database" }
+      Alice->>Bob: I'm short
+      Bob->>Alice:wrap: Extremely utterly long line of longness which had previously overflown the actor box as it is much longer than what it should be
+    `,
+        {}
+      );
+    });
+  });
+
+  describe('svg size', () => {
+    it('should render a sequence diagram when useMaxWidth is true (default)', () => {
+      renderGraph(
+        `
+      sequenceDiagram
+        actor Alice
+        participant Bob@{ "type" : "boundary" }
+        participant John@{ "type" : "control" }
+        Alice ->> Bob: Hello Bob, how are you?
+        Bob-->>John: How about you John?
+        Bob--x Alice: I am good thanks!
+        Bob-x John: I am good thanks!
+        Note right of John: Bob thinks a long<br/>long time, so long<br/>that the text does<br/>not fit on a row.
+        Bob-->Alice: Checking with John...
+        alt either this
+          Alice->>John: Yes
+        else or this
+          Alice->>John: No
+        else or this will happen
+          Alice->John: Maybe
+        end
+        par this happens in parallel
+          Alice -->> Bob: Parallel message 1
+        and
+          Alice -->> John: Parallel message 2
+        end
+      `,
+        { sequence: { 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;$/);
+        const maxWidthValue = parseFloat(style.match(/[\d.]+/g).join(''));
+        expect(maxWidthValue).to.be.within(820 * 0.95, 820 * 1.05);
+      });
+    });
+
+    it('should render a sequence diagram when useMaxWidth is false', () => {
+      renderGraph(
+        `
+      sequenceDiagram
+        actor Alice
+        participant Bob@{ "type" : "boundary" }
+        participant John@{ "type" : "control" }
+        Alice ->> Bob: Hello Bob, how are you?
+        Bob-->>John: How about you John?
+        Bob--x Alice: I am good thanks!
+        Bob-x John: I am good thanks!
+        Note right of John: Bob thinks a long<br/>long time, so long<br/>that the text does<br/>not fit on a row.
+        Bob-->Alice: Checking with John...
+        alt either this
+          Alice->>John: Yes
+        else or this
+          Alice->>John: No
+        else or this will happen
+          Alice->John: Maybe
+        end
+        par this happens in parallel
+          Alice -->> Bob: Parallel message 1
+        and
+          Alice -->> John: Parallel message 2
+        end
+      `,
+        { sequence: { useMaxWidth: false } }
+      );
+      cy.get('svg').should((svg) => {
+        const width = parseFloat(svg.attr('width'));
+        expect(width).to.be.within(820 * 0.95, 820 * 1.05);
+        expect(svg).to.not.have.attr('style');
+      });
+    });
+  });
+});

cypress/integration/rendering/sequencediagram.spec.js

@@ -893,6 +893,17 @@ describe('Sequence diagram', () => {
         }
       );
     });
+
+    it('should handle bidirectional arrows with autonumber', () => {
+      imgSnapshotTest(`
+       sequenceDiagram
+       autonumber
+       participant A
+       participant B
+       A<<->>B: This is a bidirectional message
+       A->B: This is a normal message`);
+    });
+
     it('should support actor links and properties when not mirrored EXPERIMENTAL: USE WITH CAUTION', () => {
       //Be aware that the syntax for "properties" is likely to be changed.
       imgSnapshotTest(
@@ -1042,4 +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`
+      );
+    });
+  });
 });

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

@@ -10,7 +10,7 @@
 
 # Interface: ParseOptions
 
-Defined in: [packages/mermaid/src/types.ts:72](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L72)
+Defined in: [packages/mermaid/src/types.ts:84](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L84)
 
 ## Properties
 
@@ -18,7 +18,7 @@ Defined in: [packages/mermaid/src/types.ts:72](https://github.com/mermaid-js/mer
 
 > `optional` **suppressErrors**: `boolean`
 
-Defined in: [packages/mermaid/src/types.ts:77](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L77)
+Defined in: [packages/mermaid/src/types.ts:89](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L89)
 
 If `true`, parse will return `false` instead of throwing error when the diagram is invalid.
 The `parseError` function will not be called.

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

@@ -10,7 +10,7 @@
 
 # Interface: ParseResult
 
-Defined in: [packages/mermaid/src/types.ts:80](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L80)
+Defined in: [packages/mermaid/src/types.ts:92](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L92)
 
 ## Properties
 
@@ -18,7 +18,7 @@ Defined in: [packages/mermaid/src/types.ts:80](https://github.com/mermaid-js/mer
 
 > **config**: [`MermaidConfig`](MermaidConfig.md)
 
-Defined in: [packages/mermaid/src/types.ts:88](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L88)
+Defined in: [packages/mermaid/src/types.ts:100](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L100)
 
 The config passed as YAML frontmatter or directives
 
@@ -28,6 +28,6 @@ The config passed as YAML frontmatter or directives
 
 > **diagramType**: `string`
 
-Defined in: [packages/mermaid/src/types.ts:84](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L84)
+Defined in: [packages/mermaid/src/types.ts:96](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L96)
 
 The diagram type, e.g. 'flowchart', 'sequence', etc.

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

@@ -10,7 +10,7 @@
 
 # Interface: RenderResult
 
-Defined in: [packages/mermaid/src/types.ts:98](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L98)
+Defined in: [packages/mermaid/src/types.ts:110](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L110)
 
 ## Properties
 
@@ -18,7 +18,7 @@ Defined in: [packages/mermaid/src/types.ts:98](https://github.com/mermaid-js/mer
 
 > `optional` **bindFunctions**: (`element`) => `void`
 
-Defined in: [packages/mermaid/src/types.ts:116](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L116)
+Defined in: [packages/mermaid/src/types.ts:128](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L128)
 
 Bind function to be called after the svg has been inserted into the DOM.
 This is necessary for adding event listeners to the elements in the svg.
@@ -45,7 +45,7 @@ bindFunctions?.(div); // To call bindFunctions only if it's present.
 
 > **diagramType**: `string`
 
-Defined in: [packages/mermaid/src/types.ts:106](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L106)
+Defined in: [packages/mermaid/src/types.ts:118](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L118)
 
 The diagram type, e.g. 'flowchart', 'sequence', etc.
 
@@ -55,6 +55,6 @@ The diagram type, e.g. 'flowchart', 'sequence', etc.
 
 > **svg**: `string`
 
-Defined in: [packages/mermaid/src/types.ts:102](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L102)
+Defined in: [packages/mermaid/src/types.ts:114](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L114)
 
 The svg code for the rendered graph.

docs/syntax/sequenceDiagram.md

@@ -74,6 +74,126 @@ sequenceDiagram
     Bob->>Alice: Hi Alice
 ```
 
+### Boundary
+
+If you want to use the boundary symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "boundary" }
+    participant Bob
+    Alice->>Bob: Request from boundary
+    Bob->>Alice: Response to boundary
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice@{ "type" : "boundary" }
+    participant Bob
+    Alice->>Bob: Request from boundary
+    Bob->>Alice: Response to boundary
+```
+
+### Control
+
+If you want to use the control symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "control" }
+    participant Bob
+    Alice->>Bob: Control request
+    Bob->>Alice: Control response
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice@{ "type" : "control" }
+    participant Bob
+    Alice->>Bob: Control request
+    Bob->>Alice: Control response
+```
+
+### Entity
+
+If you want to use the entity symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "entity" }
+    participant Bob
+    Alice->>Bob: Entity request
+    Bob->>Alice: Entity response
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice@{ "type" : "entity" }
+    participant Bob
+    Alice->>Bob: Entity request
+    Bob->>Alice: Entity response
+```
+
+### Database
+
+If you want to use the database symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "database" }
+    participant Bob
+    Alice->>Bob: DB query
+    Bob->>Alice: DB result
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice@{ "type" : "database" }
+    participant Bob
+    Alice->>Bob: DB query
+    Bob->>Alice: DB result
+```
+
+### Collections
+
+If you want to use the collections symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "collections" }
+    participant Bob
+    Alice->>Bob: Collections request
+    Bob->>Alice: Collections response
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice@{ "type" : "collections" }
+    participant Bob
+    Alice->>Bob: Collections request
+    Bob->>Alice: Collections response
+```
+
+### Queue
+
+If you want to use the queue symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "queue" }
+    participant Bob
+    Alice->>Bob: Queue message
+    Bob->>Alice: Queue response
+```
+
+```mermaid
+sequenceDiagram
+    participant Alice@{ "type" : "queue" }
+    participant Bob
+    Alice->>Bob: Queue message
+    Bob->>Alice: Queue response
+```
+
 ### Aliases
 
 The actor can have a convenient identifier and a descriptive label.
@@ -209,7 +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                                          |
 | -------- | ---------------------------------------------------- |
@@ -224,6 +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**
+
+The following half-arrow types are now 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
+
+Mermaid sequence diagrams now 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:

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

@@ -14,7 +14,7 @@
 
 // Special states for recognizing aliases
 // A special state for grabbing text up to the first comment/newline
-%x ID ALIAS LINE
+%x ID ALIAS LINE CONFIG CONFIG_DATA
 
 %x acc_title
 %x acc_descr
@@ -28,6 +28,11 @@
 \%%(?!\{)[^\n]*                                                 /* skip comments */
 [^\}]\%\%[^\n]*                                                 /* skip comments */
 [0-9]+(?=[ \n]+)       											return 'NUM';
+<ID>\@\{                                                        { this.begin('CONFIG'); return 'CONFIG_START'; }
+<CONFIG>[^\}]+                                                  { return 'CONFIG_CONTENT'; }
+<CONFIG>\}                                                      { this.popState(); this.popState(); return 'CONFIG_END'; }
+<ID>[^\<->\->:\n,;@\s]+(?=\@\{)                                 { yytext = yytext.trim(); return 'ACTOR'; }
+<ID>[^\<->\->:\n,;@]+?([\-]*[^\<->\->:\n,;@]+?)*?(?=((?!\n)\s)+"as"(?!\n)\s|[#\n;]|$) { yytext = yytext.trim(); this.begin('ALIAS'); return 'ACTOR'; }
 "box"															{ this.begin('LINE'); return 'box'; }
 "participant"                                                   { this.begin('ID'); return 'participant'; }
 "actor"                                                   		{ this.begin('ID'); return 'participant_actor'; }
@@ -73,7 +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';
@@ -84,10 +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';
 
@@ -231,6 +262,8 @@ participant_statement
 	| 'participant_actor' actor 'AS' restOfLine 'NEWLINE' {$2.draw='actor'; $2.type='addParticipant';$2.description=yy.parseMessage($4); $$=$2;}
 	| 'participant_actor' actor 'NEWLINE' {$2.draw='actor'; $2.type='addParticipant'; $$=$2;}
 	| 'destroy' actor 'NEWLINE' {$2.type='destroyParticipant'; $$=$2;}
+    | 'participant' actor_with_config 'NEWLINE' {$2.draw='participant'; $2.type='addParticipant'; $$=$2;}
+
 	;
 
 note_statement
@@ -297,10 +330,41 @@ 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}]}
 	;
 
+actor_with_config
+    : ACTOR config_object
+      {
+        $$ = {
+          type: 'addParticipant',
+          actor: $1,
+          config: $2
+        };
+      }
+    ;
+
+config_object
+    : CONFIG_START CONFIG_CONTENT CONFIG_END
+      {
+        $$ = $2.trim();
+      }
+    ;
 // actor
 // 	: actor_participant
 // 	| actor_actor
@@ -313,6 +377,27 @@ signaltype
 	: SOLID_OPEN_ARROW  { $$ = yy.LINETYPE.SOLID_OPEN; }
 	| DOTTED_OPEN_ARROW { $$ = yy.LINETYPE.DOTTED_OPEN; }
 	| SOLID_ARROW       { $$ = yy.LINETYPE.SOLID; }
+	
+	| SOLID_ARROW_TOP    { $$ = 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; }

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

@@ -1,4 +1,5 @@
 import { getConfig } from '../../diagram-api/diagramAPI.js';
+import * as yaml from 'js-yaml';
 import type { DiagramDB } from '../../diagram-api/types.js';
 import { log } from '../../logger.js';
 import { ImperativeState } from '../../utils/imperativeState.js';
@@ -13,6 +14,7 @@ import {
   setDiagramTitle,
 } from '../common/commonDb.js';
 import type { Actor, AddMessageParams, Box, Message, Note } from './types.js';
+import type { ParticipantMetaData } from '../../types.js';
 
 interface SequenceState {
   prevActor?: string;
@@ -62,6 +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 = {
@@ -75,6 +101,17 @@ const PLACEMENT = {
   OVER: 2,
 } as const;
 
+export const PARTICIPANT_TYPE = {
+  ACTOR: 'actor',
+  BOUNDARY: 'boundary',
+  COLLECTIONS: 'collections',
+  CONTROL: 'control',
+  DATABASE: 'database',
+  ENTITY: 'entity',
+  PARTICIPANT: 'participant',
+  QUEUE: 'queue',
+} as const;
+
 export class SequenceDB implements DiagramDB {
   private readonly state = new ImperativeState<SequenceState>(() => ({
     prevActor: undefined,
@@ -119,9 +156,22 @@ export class SequenceDB implements DiagramDB {
     id: string,
     name: string,
     description: { text: string; wrap?: boolean | null; type: string },
-    type: string
+    type: string,
+    metadata?: any
   ) {
     let assignedBox = this.state.records.currentBox;
+    let doc;
+    if (metadata !== undefined) {
+      let yamlData;
+      // detect if shapeData contains a newline character
+      if (!metadata.includes('\n')) {
+        yamlData = '{\n' + metadata + '\n}';
+      } else {
+        yamlData = metadata + '\n';
+      }
+      doc = yaml.load(yamlData, { schema: yaml.JSON_SCHEMA }) as ParticipantMetaData;
+    }
+    type = doc?.type ?? type;
     const old = this.state.records.actors.get(id);
     if (old) {
       // If already set and trying to set to a new one throw error
@@ -218,7 +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 ?? '');
@@ -245,6 +296,7 @@ export class SequenceDB implements DiagramDB {
       wrap: message?.wrap ?? this.autoWrap(),
       type: messageType,
       activate,
+      centralConnection: centralConnection ?? 0,
     });
     return true;
   }
@@ -518,7 +570,7 @@ export class SequenceDB implements DiagramDB {
           });
           break;
         case 'addParticipant':
-          this.addActor(param.actor, param.actor, param.description, param.draw);
+          this.addActor(param.actor, param.actor, param.description, param.draw, param.config);
           break;
         case 'createParticipant':
           if (this.state.records.actors.has(param.actor)) {
@@ -527,7 +579,7 @@ export class SequenceDB implements DiagramDB {
             );
           }
           this.state.records.lastCreated = param.actor;
-          this.addActor(param.actor, param.actor, param.description, param.draw);
+          this.addActor(param.actor, param.actor, param.description, param.draw, param.config);
           this.state.records.createdActors.set(param.actor, this.state.records.messages.length);
           break;
         case 'destroyParticipant':
@@ -537,6 +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;
@@ -580,7 +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!",
@@ -2058,4 +2064,302 @@ 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(`
+  sequenceDiagram
+      participant Alice@{ "type" : "database" }
+      participant Bob@{ "type" : "database" }
+      participant Carl@{ type: "database" }
+      participant David@{ "type" : 'database' }
+      participant Eve@{ type: 'database' }
+      participant Favela@{ "type" : "database"    }
+      Bob->>+Alice: Hi Alice
+      Alice->>+Bob: Hi Bob
+    `);
+
+      const actors = diagram.db.getActors();
+
+      expect(actors.get('Alice').type).toBe('database');
+      expect(actors.get('Alice').description).toBe('Alice');
+
+      expect(actors.get('Bob').type).toBe('database');
+      expect(actors.get('Bob').description).toBe('Bob');
+
+      expect(actors.get('Carl').type).toBe('database');
+      expect(actors.get('Carl').description).toBe('Carl');
+
+      expect(actors.get('David').type).toBe('database');
+      expect(actors.get('David').description).toBe('David');
+
+      expect(actors.get('Eve').type).toBe('database');
+      expect(actors.get('Eve').description).toBe('Eve');
+
+      expect(actors.get('Favela').type).toBe('database');
+      expect(actors.get('Favela').description).toBe('Favela');
+
+      // Verify messages were parsed correctly
+      const messages = diagram.db.getMessages();
+      expect(messages.length).toBe(4); // 2 messages + 2 activation messages
+      expect(messages[0].from).toBe('Bob');
+      expect(messages[0].to).toBe('Alice');
+      expect(messages[0].message).toBe('Hi Alice');
+      expect(messages[2].from).toBe('Alice'); // Second message (index 2 due to activation)
+      expect(messages[2].to).toBe('Bob');
+      expect(messages[2].message).toBe('Hi Bob');
+    });
+
+    it('should parse mixed participant types with extended syntax', async () => {
+      const diagram = await Diagram.fromText(`
+    sequenceDiagram
+        participant lead
+        participant dsa@{ "type" : "queue" }
+        API->>+Database: getUserb
+        Database-->>-API: userb
+        dsa --> Database: hello
+`);
+
+      // Verify actors were created
+      const actors = diagram.db.getActors();
+
+      expect(actors.get('lead').type).toBe('participant');
+      expect(actors.get('lead').description).toBe('lead');
+
+      // Participant with extended syntax
+      expect(actors.get('dsa').type).toBe('queue');
+      expect(actors.get('dsa').description).toBe('dsa');
+
+      // Implicitly created actors (from messages)
+      expect(actors.get('API').type).toBe('participant');
+      expect(actors.get('API').description).toBe('API');
+
+      expect(actors.get('Database').type).toBe('participant');
+      expect(actors.get('Database').description).toBe('Database');
+
+      // Verify messages were parsed correctly
+      const messages = diagram.db.getMessages();
+      expect(messages.length).toBe(5); // 3 messages + 2 activation messages
+
+      // First message with activation
+      expect(messages[0].from).toBe('API');
+      expect(messages[0].to).toBe('Database');
+      expect(messages[0].message).toBe('getUserb');
+      expect(messages[0].activate).toBe(true);
+
+      // Second message with deactivation
+      expect(messages[2].from).toBe('Database');
+      expect(messages[2].to).toBe('API');
+      expect(messages[2].message).toBe('userb');
+
+      // Third message
+      expect(messages[4].from).toBe('dsa');
+      expect(messages[4].to).toBe('Database');
+      expect(messages[4].message).toBe('hello');
+    });
+
+    it('should fail for malformed JSON in participant definition', async () => {
+      const invalidDiagram = `
+    sequenceDiagram
+      participant D@{ "type: "entity" }
+      participant E@{ "type": "dat
+      abase }
+  `;
+
+      let error = false;
+      try {
+        await mermaidAPI.parse(invalidDiagram);
+      } catch (e) {
+        error = true;
+      }
+      expect(error).toBe(true);
+    });
+
+    it('should fail for missing colon separator', async () => {
+      const invalidDiagram = `
+    sequenceDiagram
+      participant C@{ "type" "control" }
+      C ->> C: action
+  `;
+
+      let error = false;
+      try {
+        await mermaidAPI.parse(invalidDiagram);
+      } catch (e) {
+        error = true;
+      }
+      expect(error).toBe(true);
+    });
+
+    it('should fail for missing closing brace', async () => {
+      const invalidDiagram = `
+    sequenceDiagram
+      participant E@{ "type": "entity"
+      E ->> E: process
+  `;
+
+      let error = false;
+      try {
+        await mermaidAPI.parse(invalidDiagram);
+      } catch (e) {
+        error = true;
+      }
+      expect(error).toBe(true);
+    });
+  });
+  describe('participant type parsing', () => {
+    it('should parse boundary participant', async () => {
+      const diagram = await Diagram.fromText(`
+          sequenceDiagram
+          participant boundary@{ "type" : "boundary" }
+          boundary->boundary: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('boundary').type).toBe('boundary');
+      expect(actors.get('boundary').description).toBe('boundary');
+    });
+
+    it('should parse control participant', async () => {
+      const diagram = await Diagram.fromText(`
+        sequenceDiagram
+         participant C@{ "type" : "control" }
+        C->C: test
+        `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('C').type).toBe('control');
+      expect(actors.get('C').description).toBe('C');
+    });
+
+    it('should parse entity participant', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant E@{ "type" : "entity" }
+      E->E: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('E').type).toBe('entity');
+      expect(actors.get('E').description).toBe('E');
+    });
+
+    it('should parse database participant', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant D@{ "type" : "database" }
+      D->D: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('D').type).toBe('database');
+      expect(actors.get('D').description).toBe('D');
+    });
+
+    it('should parse collections participant', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant L@{ "type" : "collections" }
+      L->L: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('L').type).toBe('collections');
+      expect(actors.get('L').description).toBe('L');
+    });
+
+    it('should parse queue participant', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant Q@{ "type" : "queue" }
+      Q->Q: test 
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('Q').type).toBe('queue');
+      expect(actors.get('Q').description).toBe('Q');
+    });
+  });
+
+  describe('participant type parsing', () => {
+    it('should parse actor participant', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant A@{ "type" : "queue" }
+      A->A: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('A').type).toBe('queue');
+      expect(actors.get('A').description).toBe('A');
+    });
+
+    it('should parse participant participant', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant P@{ "type" : "database" }
+      P->P: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('P').type).toBe('database');
+      expect(actors.get('P').description).toBe('P');
+    });
+
+    it('should parse boundary using actor keyword', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+        participant Alice@{ "type" : "collections" }
+        participant Bob@{ "type" : "control" }
+        Alice->>Bob: Hello Bob, how are you?
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('Alice').type).toBe('collections');
+      expect(actors.get('Bob').type).toBe('control');
+      expect(actors.get('Bob').description).toBe('Bob');
+    });
+
+    it('should parse control using participant keyword', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant C@{ "type" : "control" }
+      C->C: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('C').type).toBe('control');
+      expect(actors.get('C').description).toBe('C');
+    });
+
+    it('should parse entity using actor keyword', async () => {
+      const diagram = await Diagram.fromText(`
+      sequenceDiagram
+      participant E@{ "type" : "entity" }
+      E->E: test
+      `);
+      const actors = diagram.db.getActors();
+      expect(actors.get('E').type).toBe('entity');
+      expect(actors.get('E').description).toBe('E');
+    });
+  });
 });

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

@@ -10,6 +10,7 @@ import assignWithDepth from '../../assignWithDepth.js';
 import utils from '../../utils.js';
 import { configureSvgSize } from '../../setupGraphViewbox.js';
 import type { Diagram } from '../../Diagram.js';
+import { PARTICIPANT_TYPE } from './sequenceDb.js';
 
 let conf = {};
 
@@ -281,6 +282,44 @@ 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 [fromLeft] = activationBounds(msg.from, actors);
+  const [toLeft] = activationBounds(msg.to, actors);
+  const isArrowToRight = fromLeft <= toLeft;
+
+  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);
+  };
+
+  if (msg.centralConnection === diagObj.db.LINETYPE.CENTRAL_CONNECTION) {
+    const cx = isArrowToRight ? stopx + 5 : stopx - 8;
+    drawCircle(cx);
+  } else if (msg.centralConnection === diagObj.db.LINETYPE.CENTRAL_CONNECTION_REVERSE) {
+    const cx = isArrowToRight ? startx - 5 : stopx + 8;
+    drawCircle(cx);
+  } else if (msg.centralConnection === diagObj.db.LINETYPE.CENTRAL_CONNECTION_DUAL) {
+    const offset = isArrowToRight ? 5 : -5;
+    drawCircle(stopx + offset);
+    drawCircle(startx - offset);
+  }
+};
+
 const messageFont = (cnf) => {
   return {
     fontFamily: cnf.messageFontFamily,
@@ -366,7 +405,7 @@ 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();
@@ -432,6 +471,9 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
     line.attr('y1', lineStartY);
     line.attr('x2', stopx);
     line.attr('y2', lineStartY);
+    if (msg.centralConnection) {
+      drawCentralConnection(diagram, msg, msgModel, diagObj, startx, stopx, lineStartY);
+    }
   }
   // Make an SVG Container
   // Draw the line
@@ -440,7 +482,15 @@ 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');
@@ -456,6 +506,51 @@ 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)');
   }
@@ -476,7 +571,42 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
 
   // add node number
   if (sequenceVisible || conf.showSequenceNumbers) {
-    line.attr('marker-start', 'url(' + url + '#sequencenumber)');
+    const isBidirectional =
+      type === diagObj.db.LINETYPE.BIDIRECTIONAL_SOLID ||
+      type === diagObj.db.LINETYPE.BIDIRECTIONAL_DOTTED;
+
+    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) {
+        line.attr('x1', startx + 2 * SEQUENCE_NUMBER_RADIUS);
+      } else {
+        line.attr('x1', startx + SEQUENCE_NUMBER_RADIUS);
+      }
+      x = 3.5;
+    }
+
+    diagram
+      .append('line')
+      .attr('x1', startx)
+      .attr('y1', lineStartY)
+      .attr('x2', startx)
+      .attr('y2', lineStartY)
+      .attr('stroke-width', 0)
+      .attr('marker-start', 'url(' + url + '#sequencenumber)')
+      .attr('transform', `translate(-${x}, 0)`);
+
     diagram
       .append('text')
       .attr('x', startx)
@@ -485,7 +615,8 @@ const drawMessage = async function (diagram, msgModel, lineStartY: number, diagO
       .attr('font-size', '12px')
       .attr('text-anchor', 'middle')
       .attr('class', 'sequenceNumber')
-      .text(sequenceIndex);
+      .text(sequenceIndex)
+      .attr('transform', `translate(-${x}, 0)`);
   }
 };
 
@@ -724,11 +855,19 @@ function adjustCreatedDestroyedData(
       msgModel.startx = msgModel.startx - adjustment;
     }
   }
+  const actorArray = [
+    PARTICIPANT_TYPE.ACTOR,
+    PARTICIPANT_TYPE.CONTROL,
+    PARTICIPANT_TYPE.ENTITY,
+    PARTICIPANT_TYPE.DATABASE,
+  ];
 
   // if it is a create message
   if (createdActors.get(msg.to) == index) {
     const actor = actors.get(msg.to);
-    const adjustment = actor.type == 'actor' ? ACTOR_TYPE_WIDTH / 2 + 3 : actor.width / 2 + 3;
+    const adjustment = actorArray.includes(actor.type)
+      ? ACTOR_TYPE_WIDTH / 2 + 3
+      : actor.width / 2 + 3;
     receiverAdjustment(actor, adjustment);
     actor.starty = lineStartY - actor.height / 2;
     bounds.bumpVerticalPos(actor.height / 2);
@@ -737,7 +876,7 @@ function adjustCreatedDestroyedData(
   else if (destroyedActors.get(msg.from) == index) {
     const actor = actors.get(msg.from);
     if (conf.mirrorActors) {
-      const adjustment = actor.type == 'actor' ? ACTOR_TYPE_WIDTH / 2 : actor.width / 2;
+      const adjustment = actorArray.includes(actor.type) ? ACTOR_TYPE_WIDTH / 2 : actor.width / 2;
       senderAdjustment(actor, adjustment);
     }
     actor.stopy = lineStartY - actor.height / 2;
@@ -747,7 +886,9 @@ function adjustCreatedDestroyedData(
   else if (destroyedActors.get(msg.to) == index) {
     const actor = actors.get(msg.to);
     if (conf.mirrorActors) {
-      const adjustment = actor.type == 'actor' ? ACTOR_TYPE_WIDTH / 2 + 3 : actor.width / 2 + 3;
+      const adjustment = actorArray.includes(actor.type)
+        ? ACTOR_TYPE_WIDTH / 2 + 3
+        : actor.width / 2 + 3;
       receiverAdjustment(actor, adjustment);
     }
     actor.stopy = lineStartY - actor.height / 2;
@@ -824,6 +965,10 @@ 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.
@@ -864,6 +1009,12 @@ 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;
@@ -1022,7 +1173,7 @@ 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);
@@ -1035,6 +1186,27 @@ 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,
@@ -1054,7 +1226,7 @@ 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);
@@ -1065,10 +1237,11 @@ export const draw = async function (_text: string, id: string, _version: string,
   for (const box of bounds.models.boxes) {
     box.height = bounds.getVerticalPos() - box.y;
     bounds.insert(box.x, box.y, box.x + box.width, box.height);
-    box.startx = box.x;
-    box.starty = box.y;
-    box.stopx = box.startx + box.width;
-    box.stopy = box.starty + box.height;
+    const boxPadding = conf.boxMargin * 2;
+    box.startx = box.x - boxPadding;
+    box.starty = box.y - boxPadding * 0.25;
+    box.stopx = box.startx + box.width + 2 * boxPadding;
+    box.stopy = box.starty + box.height + boxPadding * 0.75;
     box.stroke = 'rgb(0,0,0, 0.5)';
     svgDraw.drawBox(diagram, box, conf);
   }
@@ -1333,6 +1506,9 @@ async function calculateActorMargins(
       return (total += actors.get(aKey).width + (actors.get(aKey).margin || 0));
     }, 0);
 
+    const standardBoxPadding = conf.boxMargin * 8;
+    totalWidth += standardBoxPadding;
+
     totalWidth -= 2 * conf.boxTextMargin;
     if (box.wrap) {
       box.name = utils.wrapLabel(box.name, totalWidth - 2 * conf.wrapPadding, textFont);
@@ -1430,6 +1606,27 @@ const buildMessageModel = function (msg, actors, diagObj) {
       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,
@@ -1447,6 +1644,12 @@ const buildMessageModel = function (msg, actors, diagObj) {
   let startx = isArrowToRight ? fromRight : fromLeft;
   let stopx = isArrowToRight ? toLeft : toRight;
 
+  if (
+    msg.centralConnection === diagObj.db.LINETYPE.CENTRAL_CONNECTION_REVERSE ||
+    msg.centralConnection === diagObj.db.LINETYPE.CENTRAL_CONNECTION_DUAL
+  ) {
+    startx += 4;
+  }
   // As the line width is considered, the left and right values will be off by 2.
   const isArrowToActivation = Math.abs(toLeft - toRight) > 2;
 
@@ -1480,7 +1683,30 @@ 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);
     }
 
@@ -1488,9 +1714,14 @@ 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/styles.js

@@ -12,6 +12,11 @@ const getStyles = (options) =>
   .actor-line {
     stroke: ${options.actorLineColor};
   }
+  
+  .innerArc {
+    stroke-width: 1.5;
+    stroke-dasharray: none;
+  }
 
   .messageLine0 {
     stroke-width: 1.5;
@@ -115,6 +120,7 @@ const getStyles = (options) =>
     fill: ${options.actorBkg};
     stroke-width: 2px;
   }
+
 `;
 
 export default getStyles;

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

@@ -415,6 +415,600 @@ const drawActorTypeParticipant = function (elem, actor, conf, isFooter) {
   return height;
 };
 
+/**
+ * Draws an actor in the diagram with the attached line
+ *
+ * @param {any} elem - The diagram we'll draw to.
+ * @param {any} actor - The actor to draw.
+ * @param {any} conf - DrawText implementation discriminator object
+ * @param {boolean} isFooter - If the actor is the footer one
+ */
+const drawActorTypeCollections = function (elem, actor, conf, isFooter) {
+  const actorY = isFooter ? actor.stopy : actor.starty;
+  const center = actor.x + actor.width / 2;
+  const centerY = actorY + actor.height;
+
+  const boxplusLineGroup = elem.append('g').lower();
+  var g = boxplusLineGroup;
+
+  if (!isFooter) {
+    actorCnt++;
+    if (Object.keys(actor.links || {}).length && !conf.forceMenus) {
+      g.attr('onclick', popupMenuToggle(`actor${actorCnt}_popup`)).attr('cursor', 'pointer');
+    }
+    g.append('line')
+      .attr('id', 'actor' + actorCnt)
+      .attr('x1', center)
+      .attr('y1', centerY)
+      .attr('x2', center)
+      .attr('y2', 2000)
+      .attr('class', 'actor-line 200')
+      .attr('stroke-width', '0.5px')
+      .attr('stroke', '#999')
+      .attr('name', actor.name);
+
+    g = boxplusLineGroup.append('g');
+    actor.actorCnt = actorCnt;
+
+    if (actor.links != null) {
+      g.attr('id', 'root-' + actorCnt);
+    }
+  }
+
+  const rect = svgDrawCommon.getNoteRect();
+  var cssclass = 'actor';
+  if (actor.properties?.class) {
+    cssclass = actor.properties.class;
+  } else {
+    rect.fill = '#eaeaea';
+  }
+  if (isFooter) {
+    cssclass += ` ${BOTTOM_ACTOR_CLASS}`;
+  } else {
+    cssclass += ` ${TOP_ACTOR_CLASS}`;
+  }
+  rect.x = actor.x;
+  rect.y = actorY;
+  rect.width = actor.width;
+  rect.height = actor.height;
+  rect.class = cssclass;
+  rect.name = actor.name;
+
+  // DRAW STACKED RECTANGLES
+  const offset = 6;
+  const shadowRect = {
+    ...rect,
+    x: rect.x + (isFooter ? -offset : -offset),
+    y: rect.y + (isFooter ? +offset : +offset),
+    class: 'actor',
+  };
+  const rectElem = drawRect(g, rect); // draw main rectangle on top
+  drawRect(g, shadowRect);
+  actor.rectData = rect;
+
+  if (actor.properties?.icon) {
+    const iconSrc = actor.properties.icon.trim();
+    if (iconSrc.charAt(0) === '@') {
+      svgDrawCommon.drawEmbeddedImage(g, rect.x + rect.width - 20, rect.y + 10, iconSrc.substr(1));
+    } else {
+      svgDrawCommon.drawImage(g, rect.x + rect.width - 20, rect.y + 10, iconSrc);
+    }
+  }
+
+  _drawTextCandidateFunc(conf, hasKatex(actor.description))(
+    actor.description,
+    g,
+    rect.x - offset,
+    rect.y + offset,
+    rect.width,
+    rect.height,
+    { class: `actor ${ACTOR_BOX_CLASS}` },
+    conf
+  );
+
+  let height = actor.height;
+  if (rectElem.node) {
+    const bounds = rectElem.node().getBBox();
+    actor.height = bounds.height;
+    height = bounds.height;
+  }
+
+  return height;
+};
+
+const drawActorTypeQueue = function (elem, actor, conf, isFooter) {
+  const actorY = isFooter ? actor.stopy : actor.starty;
+  const center = actor.x + actor.width / 2;
+  const centerY = actorY + actor.height;
+
+  const boxplusLineGroup = elem.append('g').lower();
+  let g = boxplusLineGroup;
+
+  if (!isFooter) {
+    actorCnt++;
+    if (Object.keys(actor.links || {}).length && !conf.forceMenus) {
+      g.attr('onclick', popupMenuToggle(`actor${actorCnt}_popup`)).attr('cursor', 'pointer');
+    }
+    g.append('line')
+      .attr('id', 'actor' + actorCnt)
+      .attr('x1', center)
+      .attr('y1', centerY)
+      .attr('x2', center)
+      .attr('y2', 2000)
+      .attr('class', 'actor-line 200')
+      .attr('stroke-width', '0.5px')
+      .attr('stroke', '#999')
+      .attr('name', actor.name);
+
+    g = boxplusLineGroup.append('g');
+    actor.actorCnt = actorCnt;
+
+    if (actor.links != null) {
+      g.attr('id', 'root-' + actorCnt);
+    }
+  }
+
+  const rect = svgDrawCommon.getNoteRect();
+  let cssclass = 'actor';
+  if (actor.properties?.class) {
+    cssclass = actor.properties.class;
+  } else {
+    rect.fill = '#eaeaea';
+  }
+
+  if (isFooter) {
+    cssclass += ` ${BOTTOM_ACTOR_CLASS}`;
+  } else {
+    cssclass += ` ${TOP_ACTOR_CLASS}`;
+  }
+
+  rect.x = actor.x;
+  rect.y = actorY;
+  rect.width = actor.width;
+  rect.height = actor.height;
+  rect.class = cssclass;
+  rect.name = actor.name;
+
+  // Cylinder dimensions
+  const ry = rect.height / 2;
+  const rx = ry / (2.5 + rect.height / 50);
+
+  // Cylinder base group
+  const cylinderGroup = g.append('g');
+  const cylinderArc = g.append('g');
+
+  // Main cylinder body
+  cylinderGroup
+    .append('path')
+    .attr(
+      'd',
+      `M ${rect.x},${rect.y + ry}
+    a ${rx},${ry} 0 0 0 0,${rect.height}
+    h ${rect.width - 2 * rx}
+    a ${rx},${ry} 0 0 0 0,-${rect.height}
+    Z
+  `
+    )
+    .attr('class', cssclass);
+  cylinderArc
+    .append('path')
+    .attr(
+      'd',
+      `M ${rect.x},${rect.y + ry}
+      a ${rx},${ry} 0 0 0 0,${rect.height}`
+    )
+    .attr('stroke', '#666')
+    .attr('stroke-width', '1px')
+    .attr('class', cssclass);
+
+  cylinderGroup.attr('transform', `translate(${rx}, ${-(rect.height / 2)})`);
+  cylinderArc.attr('transform', `translate(${rect.width - rx}, ${-rect.height / 2})`);
+
+  actor.rectData = rect;
+
+  if (actor.properties?.icon) {
+    const iconSrc = actor.properties.icon.trim();
+    const iconX = rect.x + rect.width - 20;
+    const iconY = rect.y + 10;
+    if (iconSrc.charAt(0) === '@') {
+      svgDrawCommon.drawEmbeddedImage(g, iconX, iconY, iconSrc.substr(1));
+    } else {
+      svgDrawCommon.drawImage(g, iconX, iconY, iconSrc);
+    }
+  }
+
+  _drawTextCandidateFunc(conf, hasKatex(actor.description))(
+    actor.description,
+    g,
+    rect.x,
+    rect.y,
+    rect.width,
+    rect.height,
+    { class: `actor ${ACTOR_BOX_CLASS}` },
+    conf
+  );
+
+  let height = actor.height;
+  const lastPath = cylinderGroup.select('path:last-child');
+  if (lastPath.node()) {
+    const bounds = lastPath.node().getBBox();
+    actor.height = bounds.height;
+    height = bounds.height;
+  }
+
+  return height;
+};
+
+const drawActorTypeControl = function (elem, actor, conf, isFooter) {
+  const actorY = isFooter ? actor.stopy : actor.starty;
+  const center = actor.x + actor.width / 2;
+  const centerY = actorY + 75;
+
+  const line = elem.append('g').lower();
+
+  if (!isFooter) {
+    actorCnt++;
+    line
+      .append('line')
+      .attr('id', 'actor' + actorCnt)
+      .attr('x1', center)
+      .attr('y1', centerY)
+      .attr('x2', center)
+      .attr('y2', 2000)
+      .attr('class', 'actor-line 200')
+      .attr('stroke-width', '0.5px')
+      .attr('stroke', '#999')
+      .attr('name', actor.name);
+
+    actor.actorCnt = actorCnt;
+  }
+  const actElem = elem.append('g');
+  let cssClass = ACTOR_MAN_FIGURE_CLASS;
+  if (isFooter) {
+    cssClass += ` ${BOTTOM_ACTOR_CLASS}`;
+  } else {
+    cssClass += ` ${TOP_ACTOR_CLASS}`;
+  }
+  actElem.attr('class', cssClass);
+  actElem.attr('name', actor.name);
+
+  const rect = svgDrawCommon.getNoteRect();
+  rect.x = actor.x;
+  rect.y = actorY;
+  rect.fill = '#eaeaea';
+  rect.width = actor.width;
+  rect.height = actor.height;
+  rect.class = 'actor';
+
+  const cx = actor.x + actor.width / 2;
+  const cy = actorY + 30;
+  const r = 18;
+
+  actElem
+    .append('defs')
+    .append('marker')
+    .attr('id', 'filled-head-control')
+    .attr('refX', 11)
+    .attr('refY', 5.8)
+    .attr('markerWidth', 20)
+    .attr('markerHeight', 28)
+    .attr('orient', '172.5')
+    .append('path')
+    .attr('d', 'M 14.4 5.6 L 7.2 10.4 L 8.8 5.6 L 7.2 0.8 Z');
+
+  // Draw the base circle
+  actElem
+    .append('circle')
+    .attr('cx', cx)
+    .attr('cy', cy)
+    .attr('r', r)
+    .attr('fill', '#eaeaf7')
+    .attr('stroke', '#666')
+    .attr('stroke-width', 1.2);
+
+  // Draw looping arrow as arc path
+  actElem
+    .append('line')
+    .attr('marker-end', 'url(#filled-head-control)')
+    .attr('transform', `translate(${cx}, ${cy - r})`);
+
+  const bounds = actElem.node().getBBox();
+  actor.height = bounds.height + 2 * (conf?.sequence?.labelBoxHeight ?? 0);
+
+  _drawTextCandidateFunc(conf, hasKatex(actor.description))(
+    actor.description,
+    actElem,
+    rect.x,
+    rect.y + r + (isFooter ? 5 : 10),
+    rect.width,
+    rect.height,
+    { class: `actor ${ACTOR_MAN_FIGURE_CLASS}` },
+    conf
+  );
+
+  return actor.height;
+};
+
+const drawActorTypeEntity = function (elem, actor, conf, isFooter) {
+  const actorY = isFooter ? actor.stopy : actor.starty;
+  const center = actor.x + actor.width / 2;
+  const centerY = actorY + 75;
+
+  const line = elem.append('g').lower();
+
+  const actElem = elem.append('g');
+  let cssClass = ACTOR_MAN_FIGURE_CLASS;
+  if (isFooter) {
+    cssClass += ` ${BOTTOM_ACTOR_CLASS}`;
+  } else {
+    cssClass += ` ${TOP_ACTOR_CLASS}`;
+  }
+  actElem.attr('class', cssClass);
+  actElem.attr('name', actor.name);
+
+  const rect = svgDrawCommon.getNoteRect();
+  rect.x = actor.x;
+  rect.y = actorY;
+  rect.fill = '#eaeaea';
+  rect.width = actor.width;
+  rect.height = actor.height;
+  rect.class = 'actor';
+
+  const cx = actor.x + actor.width / 2;
+  const cy = actorY + (!isFooter ? 25 : 10);
+  const r = 18;
+
+  actElem
+    .append('circle')
+    .attr('cx', cx)
+    .attr('cy', cy)
+    .attr('r', r)
+    .attr('width', actor.width)
+    .attr('height', actor.height);
+
+  actElem
+    .append('line')
+    .attr('x1', cx - r)
+    .attr('x2', cx + r)
+    .attr('y1', cy + r)
+    .attr('y2', cy + r)
+    .attr('stroke', '#333')
+    .attr('stroke-width', 2);
+
+  const bounds = actElem.node().getBBox();
+  actor.height = bounds.height + (conf?.sequence?.labelBoxHeight ?? 0);
+
+  if (!isFooter) {
+    actorCnt++;
+    line
+      .append('line')
+      .attr('id', 'actor' + actorCnt)
+      .attr('x1', center)
+      .attr('y1', centerY)
+      .attr('x2', center)
+      .attr('y2', 2000)
+      .attr('class', 'actor-line 200')
+      .attr('stroke-width', '0.5px')
+      .attr('stroke', '#999')
+      .attr('name', actor.name);
+
+    actor.actorCnt = actorCnt;
+  }
+
+  _drawTextCandidateFunc(conf, hasKatex(actor.description))(
+    actor.description,
+    actElem,
+    rect.x,
+    rect.y + (!isFooter ? (cy + r - actorY) / 2 : (cy - actorY + r - 5) / 2),
+    rect.width,
+    rect.height,
+    { class: `actor ${ACTOR_MAN_FIGURE_CLASS}` },
+    conf
+  );
+
+  if (!isFooter) {
+    actElem.attr('transform', `translate(${0}, ${r / 2})`);
+  } else {
+    actElem.attr('transform', `translate(${0}, ${r / 2})`);
+  }
+
+  return actor.height;
+};
+
+const drawActorTypeDatabase = function (elem, actor, conf, isFooter) {
+  const actorY = isFooter ? actor.stopy : actor.starty;
+  const center = actor.x + actor.width / 2;
+  const centerY = actorY + actor.height + 2 * conf.boxTextMargin;
+
+  const boxplusLineGroup = elem.append('g').lower();
+  let g = boxplusLineGroup;
+
+  if (!isFooter) {
+    actorCnt++;
+    if (Object.keys(actor.links || {}).length && !conf.forceMenus) {
+      g.attr('onclick', popupMenuToggle(`actor${actorCnt}_popup`)).attr('cursor', 'pointer');
+    }
+    g.append('line')
+      .attr('id', 'actor' + actorCnt)
+      .attr('x1', center)
+      .attr('y1', centerY)
+      .attr('x2', center)
+      .attr('y2', 2000)
+      .attr('class', 'actor-line 200')
+      .attr('stroke-width', '0.5px')
+      .attr('stroke', '#999')
+      .attr('name', actor.name);
+
+    g = boxplusLineGroup.append('g');
+    actor.actorCnt = actorCnt;
+
+    if (actor.links != null) {
+      g.attr('id', 'root-' + actorCnt);
+    }
+  }
+
+  const rect = svgDrawCommon.getNoteRect();
+
+  let cssclass = 'actor';
+  if (actor.properties?.class) {
+    cssclass = actor.properties.class;
+  } else {
+    rect.fill = '#eaeaea';
+  }
+
+  if (isFooter) {
+    cssclass += ` ${BOTTOM_ACTOR_CLASS}`;
+  } else {
+    cssclass += ` ${TOP_ACTOR_CLASS}`;
+  }
+
+  rect.x = actor.x;
+  rect.y = actorY;
+  rect.width = actor.width;
+  rect.height = actor.height;
+  rect.class = cssclass;
+  rect.name = actor.name;
+
+  // Cylinder dimensions
+  rect.x = actor.x;
+  rect.y = actorY;
+  const w = rect.width / 4;
+  const h = rect.width / 4;
+  const rx = w / 2;
+  const ry = rx / (2.5 + w / 50);
+
+  // Cylinder base group
+  const cylinderGroup = g.append('g');
+
+  const d = `
+  M ${rect.x},${rect.y + ry}
+  a ${rx},${ry} 0 0 0 ${w},0
+  a ${rx},${ry} 0 0 0 -${w},0
+  l 0,${h - 2 * ry}
+  a ${rx},${ry} 0 0 0 ${w},0
+  l 0,-${h - 2 * ry}
+`;
+  // Draw the main cylinder body
+  cylinderGroup
+    .append('path')
+    .attr('d', d)
+    .attr('fill', '#eaeaea')
+    .attr('stroke', '#000')
+    .attr('stroke-width', 1)
+    .attr('class', cssclass);
+
+  if (!isFooter) {
+    cylinderGroup.attr('transform', `translate(${w * 1.5}, ${(rect.height + ry) / 4})`);
+  } else {
+    cylinderGroup.attr('transform', `translate(${w * 1.5}, ${rect.height / 4 - 2 * ry})`);
+  }
+  actor.rectData = rect;
+  _drawTextCandidateFunc(conf, hasKatex(actor.description))(
+    actor.description,
+    g,
+    rect.x,
+    rect.y + (!isFooter ? (rect.height + ry) / 2 : (rect.height + h) / 4),
+    rect.width,
+    rect.height,
+    { class: `actor ${ACTOR_BOX_CLASS}` },
+    conf
+  );
+
+  const lastPath = cylinderGroup.select('path:last-child');
+  if (lastPath.node()) {
+    const bounds = lastPath.node().getBBox();
+    actor.height = bounds.height + (conf.sequence.labelBoxHeight ?? 0);
+  }
+
+  return actor.height;
+};
+
+const drawActorTypeBoundary = function (elem, actor, conf, isFooter) {
+  const actorY = isFooter ? actor.stopy : actor.starty;
+  const center = actor.x + actor.width / 2;
+  const centerY = actorY + 80;
+  const radius = 30;
+  const line = elem.append('g').lower();
+
+  if (!isFooter) {
+    actorCnt++;
+    line
+      .append('line')
+      .attr('id', 'actor' + actorCnt)
+      .attr('x1', center)
+      .attr('y1', centerY)
+      .attr('x2', center)
+      .attr('y2', 2000)
+      .attr('class', 'actor-line 200')
+      .attr('stroke-width', '0.5px')
+      .attr('stroke', '#999')
+      .attr('name', actor.name);
+
+    actor.actorCnt = actorCnt;
+  }
+  const actElem = elem.append('g');
+  let cssClass = ACTOR_MAN_FIGURE_CLASS;
+  if (isFooter) {
+    cssClass += ` ${BOTTOM_ACTOR_CLASS}`;
+  } else {
+    cssClass += ` ${TOP_ACTOR_CLASS}`;
+  }
+  actElem.attr('class', cssClass);
+  actElem.attr('name', actor.name);
+
+  const rect = svgDrawCommon.getNoteRect();
+  rect.x = actor.x;
+  rect.y = actorY;
+  rect.fill = '#eaeaea';
+  rect.width = actor.width;
+  rect.height = actor.height;
+  rect.class = 'actor';
+
+  actElem
+    .append('line')
+    .attr('id', 'actor-man-torso' + actorCnt)
+    .attr('x1', actor.x + actor.width / 2 - radius * 2.5)
+    .attr('y1', actorY + 10)
+    .attr('x2', actor.x + actor.width / 2 - 15)
+    .attr('y2', actorY + 10);
+
+  actElem
+    .append('line')
+    .attr('id', 'actor-man-arms' + actorCnt)
+    .attr('x1', actor.x + actor.width / 2 - radius * 2.5)
+    .attr('y1', actorY + 0) // starting Y
+    .attr('x2', actor.x + actor.width / 2 - radius * 2.5)
+    .attr('y2', actorY + 20); // ending Y (26px long, adjust as needed)
+
+  actElem
+    .append('circle')
+    .attr('cx', actor.x + actor.width / 2)
+    .attr('cy', actorY + 10)
+    .attr('r', radius);
+
+  const bounds = actElem.node().getBBox();
+  actor.height = bounds.height + (conf.sequence.labelBoxHeight ?? 0);
+
+  _drawTextCandidateFunc(conf, hasKatex(actor.description))(
+    actor.description,
+    actElem,
+    rect.x,
+    rect.y + (!isFooter ? radius / 2 + 3 : radius / 2 - 4),
+    rect.width,
+    rect.height,
+    { class: `actor ${ACTOR_MAN_FIGURE_CLASS}` },
+    conf
+  );
+
+  if (!isFooter) {
+    actElem.attr('transform', `translate(0,${radius / 2 + 7})`);
+  } else {
+    actElem.attr('transform', `translate(0,${radius / 2 + 7})`);
+  }
+
+  return actor.height;
+};
+
 const drawActorTypeActor = function (elem, actor, conf, isFooter) {
   const actorY = isFooter ? actor.stopy : actor.starty;
   const center = actor.x + actor.width / 2;
@@ -516,6 +1110,18 @@ export const drawActor = async function (elem, actor, conf, isFooter) {
       return await drawActorTypeActor(elem, actor, conf, isFooter);
     case 'participant':
       return await drawActorTypeParticipant(elem, actor, conf, isFooter);
+    case 'boundary':
+      return await drawActorTypeBoundary(elem, actor, conf, isFooter);
+    case 'control':
+      return await drawActorTypeControl(elem, actor, conf, isFooter);
+    case 'entity':
+      return await drawActorTypeEntity(elem, actor, conf, isFooter);
+    case 'database':
+      return await drawActorTypeDatabase(elem, actor, conf, isFooter);
+    case 'collections':
+      return await drawActorTypeCollections(elem, actor, conf, isFooter);
+    case 'queue':
+      return await drawActorTypeQueue(elem, actor, conf, isFooter);
   }
 };
 
@@ -1103,6 +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,
@@ -1125,4 +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/docs/syntax/sequenceDiagram.md

@@ -46,6 +46,78 @@ sequenceDiagram
     Bob->>Alice: Hi Alice
 ```
 
+### Boundary
+
+If you want to use the boundary symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "boundary" }
+    participant Bob
+    Alice->>Bob: Request from boundary
+    Bob->>Alice: Response to boundary
+```
+
+### Control
+
+If you want to use the control symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "control" }
+    participant Bob
+    Alice->>Bob: Control request
+    Bob->>Alice: Control response
+```
+
+### Entity
+
+If you want to use the entity symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "entity" }
+    participant Bob
+    Alice->>Bob: Entity request
+    Bob->>Alice: Entity response
+```
+
+### Database
+
+If you want to use the database symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "database" }
+    participant Bob
+    Alice->>Bob: DB query
+    Bob->>Alice: DB result
+```
+
+### Collections
+
+If you want to use the collections symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "collections" }
+    participant Bob
+    Alice->>Bob: Collections request
+    Bob->>Alice: Collections response
+```
+
+### Queue
+
+If you want to use the queue symbol for a participant, use the JSON configuration syntax as shown below.
+
+```mermaid-example
+sequenceDiagram
+    participant Alice@{ "type" : "queue" }
+    participant Bob
+    Alice->>Bob: Queue message
+    Bob->>Alice: Queue response
+```
+
 ### Aliases
 
 The actor can have a convenient identifier and a descriptive label.
@@ -144,7 +216,11 @@ 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                                          |
 | -------- | ---------------------------------------------------- |
@@ -159,6 +235,49 @@ 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**
+
+The following half-arrow types are now 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
+
+Mermaid sequence diagrams now 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!
+```
+
 ## Activations
 
 It is possible to activate and deactivate an actor. (de)activation can be dedicated declarations:

packages/mermaid/src/mermaid.spec.ts

@@ -207,7 +207,7 @@ describe('when using mermaid and ', () => {
         [Error: Parse error on line 2:
         ...equenceDiagramAlice:->Bob: Hello Bob, h...
         ----------------------^
-        Expecting 'SOLID_OPEN_ARROW', 'DOTTED_OPEN_ARROW', 'SOLID_ARROW', 'BIDIRECTIONAL_SOLID_ARROW', 'DOTTED_ARROW', 'BIDIRECTIONAL_DOTTED_ARROW', 'SOLID_CROSS', 'DOTTED_CROSS', 'SOLID_POINT', 'DOTTED_POINT', got 'TXT']
+        Expecting '()', 'SOLID_OPEN_ARROW', 'DOTTED_OPEN_ARROW', 'SOLID_ARROW', 'SOLID_ARROW_TOP', 'SOLID_ARROW_BOTTOM', 'STICK_ARROW_TOP', 'STICK_ARROW_BOTTOM', 'SOLID_ARROW_TOP_DOTTED', 'SOLID_ARROW_BOTTOM_DOTTED', 'STICK_ARROW_TOP_DOTTED', 'STICK_ARROW_BOTTOM_DOTTED', 'SOLID_ARROW_TOP_REVERSE', 'SOLID_ARROW_BOTTOM_REVERSE', 'STICK_ARROW_TOP_REVERSE', 'STICK_ARROW_BOTTOM_REVERSE', 'SOLID_ARROW_TOP_REVERSE_DOTTED', 'SOLID_ARROW_BOTTOM_REVERSE_DOTTED', 'STICK_ARROW_TOP_REVERSE_DOTTED', 'STICK_ARROW_BOTTOM_REVERSE_DOTTED', 'BIDIRECTIONAL_SOLID_ARROW', 'DOTTED_ARROW', 'BIDIRECTIONAL_DOTTED_ARROW', 'SOLID_CROSS', 'DOTTED_CROSS', 'SOLID_POINT', 'DOTTED_POINT', got 'TXT']
       `);
     });
 

packages/mermaid/src/types.ts

@@ -13,6 +13,18 @@ export interface NodeMetaData {
   ticket?: string;
 }
 
+export interface ParticipantMetaData {
+  type?:
+    | 'actor'
+    | 'participant'
+    | 'boundary'
+    | 'control'
+    | 'entity'
+    | 'database'
+    | 'collections'
+    | 'queue';
+}
+
 export interface EdgeMetaData {
   animation?: 'fast' | 'slow';
   animate?: boolean;