diff --git a/V10-BreakingChanges.md b/V10-BreakingChanges.md
index bd9110d1a..e3322a3a1 100644
--- a/V10-BreakingChanges.md
+++ b/V10-BreakingChanges.md
@@ -1,5 +1,25 @@
-# A collection of updates that change the behaviour
+# A collection of updates that change the behavior
+
+## Async
+
+`init`, `parse`, `render` are now async.
 
 ## Lazy loading and asynchronisity
 
 - Invalid dates are rendered as syntax error instead of returning best guess or the current date
+
+## ParseError is removed
+
+```js
+//< v10.0.0
+mermaid.parse(text, parseError);
+
+//>= v10.0.0
+await mermaid.parse(text).catch(parseError);
+// or
+try {
+  await mermaid.parse(text);
+} catch (err) {
+  parseError(err);
+}
+```
diff --git a/docs/config/setup/interfaces/mermaidAPI.RenderResult.md b/docs/config/setup/interfaces/mermaidAPI.RenderResult.md
new file mode 100644
index 000000000..b95b0acff
--- /dev/null
+++ b/docs/config/setup/interfaces/mermaidAPI.RenderResult.md
@@ -0,0 +1,78 @@
+> **Warning**
+>
+> ## THIS IS AN AUTOGENERATED FILE. DO NOT EDIT.
+>
+> ## Please edit the corresponding file in [/packages/mermaid/src/docs/config/setup/interfaces/mermaidAPI.RenderResult.md](../../../../packages/mermaid/src/docs/config/setup/interfaces/mermaidAPI.RenderResult.md).
+
+# Interface: RenderResult
+
+[mermaidAPI](../modules/mermaidAPI.md).RenderResult
+
+Function that renders an svg with a graph from a chart definition. Usage example below.
+
+```javascript
+mermaidAPI.initialize({
+  startOnLoad: true,
+});
+$(function () {
+  const graphDefinition = 'graph TB\na-->b';
+  const cb = function (svgGraph) {
+    console.log(svgGraph);
+  };
+  mermaidAPI.render('id1', graphDefinition, cb);
+});
+```
+
+**`Param`**
+
+The id for the SVG element (the element to be rendered)
+
+**`Param`**
+
+The text for the graph definition
+
+**`Param`**
+
+Callback which is called after rendering is finished with the svg code as in param.
+
+**`Param`**
+
+HTML element where the svg will be inserted. (Is usually element with the .mermaid class)
+If no svgContainingElement is provided then the SVG element will be appended to the body.
+Selector to element in which a div with the graph temporarily will be
+inserted. If one is provided a hidden div will be inserted in the body of the page instead. The
+element will be removed when rendering is completed.
+
+## Properties
+
+### bindFunctions
+
+• `Optional` **bindFunctions**: (`element`: `Element`) => `void`
+
+#### Type declaration
+
+▸ (`element`): `void`
+
+##### Parameters
+
+| Name      | Type      |
+| :-------- | :-------- |
+| `element` | `Element` |
+
+##### Returns
+
+`void`
+
+#### Defined in
+
+[mermaidAPI.ts:382](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L382)
+
+---
+
+### svg
+
+• **svg**: `string`
+
+#### Defined in
+
+[mermaidAPI.ts:381](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L381)
diff --git a/docs/config/setup/modules/mermaidAPI.md b/docs/config/setup/modules/mermaidAPI.md
index 2cdeb597a..f75dd85c7 100644
--- a/docs/config/setup/modules/mermaidAPI.md
+++ b/docs/config/setup/modules/mermaidAPI.md
@@ -6,6 +6,10 @@
 
 # Module: mermaidAPI
 
+## Interfaces
+
+- [RenderResult](../interfaces/mermaidAPI.RenderResult.md)
+
 ## References
 
 ### default
@@ -20,13 +24,13 @@ Renames and re-exports [mermaidAPI](mermaidAPI.md#mermaidapi)
 
 #### Defined in
 
-[mermaidAPI.ts:75](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L75)
+[mermaidAPI.ts:71](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L71)
 
 ## Variables
 
 ### mermaidAPI
 
-• `Const` **mermaidAPI**: `Readonly`<{ `defaultConfig`: `MermaidConfig` = configApi.defaultConfig; `getConfig`: () => `MermaidConfig` = configApi.getConfig; `getSiteConfig`: () => `MermaidConfig` = configApi.getSiteConfig; `globalReset`: () => `void` ; `initialize`: (`options`: `MermaidConfig`) => `void` ; `parse`: (`text`: `string`, `parseError?`: `ParseErrorFunction`) => `Promise`<`boolean`> ; `parseDirective`: (`p`: `any`, `statement`: `string`, `context`: `string`, `type`: `string`) => `void` ; `render`: (`id`: `string`, `text`: `string`, `cb?`: (`svgCode`: `string`, `bindFunctions?`: (`element`: `Element`) => `void`) => `void`, `svgContainingElement?`: `Element`) => `Promise`<`string`> ; `reset`: () => `void` ; `setConfig`: (`conf`: `MermaidConfig`) => `MermaidConfig` = configApi.setConfig; `updateSiteConfig`: (`conf`: `MermaidConfig`) => `MermaidConfig` = configApi.updateSiteConfig }>
+• `Const` **mermaidAPI**: `Readonly`<{ `defaultConfig`: `MermaidConfig` = configApi.defaultConfig; `getConfig`: () => `MermaidConfig` = configApi.getConfig; `getSiteConfig`: () => `MermaidConfig` = configApi.getSiteConfig; `globalReset`: () => `void` ; `initialize`: (`options`: `MermaidConfig`) => `void` ; `parse`: (`text`: `string`, `parseOptions?`: { `silent?`: `boolean` }) => `Promise`<`boolean` | `void`> ; `parseDirective`: (`p`: `any`, `statement`: `string`, `context`: `string`, `type`: `string`) => `void` ; `render`: (`id`: `string`, `text`: `string`, `svgContainingElement?`: `Element`) => `Promise`<[`RenderResult`](../interfaces/mermaidAPI.RenderResult.md)> ; `reset`: () => `void` ; `setConfig`: (`conf`: `MermaidConfig`) => `MermaidConfig` = configApi.setConfig; `updateSiteConfig`: (`conf`: `MermaidConfig`) => `MermaidConfig` = configApi.updateSiteConfig }>
 
 ## mermaidAPI configuration defaults
 
@@ -90,7 +94,7 @@ mermaid.initialize(config);
 
 #### Defined in
 
-[mermaidAPI.ts:671](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L671)
+[mermaidAPI.ts:666](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L666)
 
 ## Functions
 
@@ -121,7 +125,7 @@ Return the last node appended
 
 #### Defined in
 
-[mermaidAPI.ts:278](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L278)
+[mermaidAPI.ts:289](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L289)
 
 ---
 
@@ -147,7 +151,7 @@ the cleaned up svgCode
 
 #### Defined in
 
-[mermaidAPI.ts:229](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L229)
+[mermaidAPI.ts:240](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L240)
 
 ---
 
@@ -173,7 +177,7 @@ the string with all the user styles
 
 #### Defined in
 
-[mermaidAPI.ts:158](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L158)
+[mermaidAPI.ts:169](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L169)
 
 ---
 
@@ -196,7 +200,7 @@ the string with all the user styles
 
 #### Defined in
 
-[mermaidAPI.ts:206](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L206)
+[mermaidAPI.ts:217](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L217)
 
 ---
 
@@ -223,7 +227,7 @@ with an enclosing block that has each of the cssClasses followed by !important;
 
 #### Defined in
 
-[mermaidAPI.ts:142](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L142)
+[mermaidAPI.ts:153](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L153)
 
 ---
 
@@ -243,7 +247,7 @@ with an enclosing block that has each of the cssClasses followed by !important;
 
 #### Defined in
 
-[mermaidAPI.ts:122](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L122)
+[mermaidAPI.ts:133](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L133)
 
 ---
 
@@ -263,7 +267,7 @@ with an enclosing block that has each of the cssClasses followed by !important;
 
 #### Defined in
 
-[mermaidAPI.ts:93](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L93)
+[mermaidAPI.ts:104](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L104)
 
 ---
 
@@ -289,7 +293,7 @@ Put the svgCode into an iFrame. Return the iFrame code
 
 #### Defined in
 
-[mermaidAPI.ts:257](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L257)
+[mermaidAPI.ts:268](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L268)
 
 ---
 
@@ -314,4 +318,4 @@ Remove any existing elements from the given document
 
 #### Defined in
 
-[mermaidAPI.ts:328](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L328)
+[mermaidAPI.ts:339](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/mermaidAPI.ts#L339)
diff --git a/packages/mermaid/src/Diagram.ts b/packages/mermaid/src/Diagram.ts
index 1f68e52ba..3a0818854 100644
--- a/packages/mermaid/src/Diagram.ts
+++ b/packages/mermaid/src/Diagram.ts
@@ -3,26 +3,24 @@ import { log } from './logger';
 import { getDiagram, registerDiagram } from './diagram-api/diagramAPI';
 import { detectType, getDiagramLoader } from './diagram-api/detectType';
 import { extractFrontMatter } from './diagram-api/frontmatter';
-import { isDetailedError } from './utils';
-import type { DetailedError } from './utils';
+import { UnknownDiagramError } from './errors';
+import { DetailedError } from './utils';
 
 export type ParseErrorFunction = (err: string | DetailedError | unknown, hash?: any) => void;
-
 export class Diagram {
   type = 'graph';
   parser;
   renderer;
   db;
-  private detectTypeFailed = false;
-  constructor(public txt: string, parseError?: ParseErrorFunction) {
+  private detectError?: UnknownDiagramError;
+  constructor(public text: string) {
+    this.text += '\n';
     const cnf = configApi.getConfig();
-    this.txt = txt;
     try {
-      this.type = detectType(txt, cnf);
+      this.type = detectType(text, cnf);
     } catch (e) {
-      this.handleError(e, parseError);
       this.type = 'error';
-      this.detectTypeFailed = true;
+      this.detectError = e as UnknownDiagramError;
     }
     const diagram = getDiagram(this.type);
     log.debug('Type ' + this.type);
@@ -46,44 +44,19 @@ export class Diagram {
       diagram.init(cnf);
       log.info('Initialized diagram ' + this.type, cnf);
     }
-    this.txt += '\n';
-
-    this.parse(this.txt, parseError);
+    this.parse();
   }
 
-  parse(text: string, parseError?: ParseErrorFunction): boolean {
-    if (this.detectTypeFailed) {
-      return false;
+  parse() {
+    if (this.detectError) {
+      throw this.detectError;
     }
-    try {
-      text = text + '\n';
-      this.db.clear?.();
-      this.parser.parse(text);
-      return true;
-    } catch (error) {
-      this.handleError(error, parseError);
-    }
-    return false;
+    this.db.clear?.();
+    this.parser.parse(this.text);
   }
 
-  handleError(error: unknown, parseError?: ParseErrorFunction) {
-    // Is this the correct way to access mermaid's parseError()
-    // method ? (or global.mermaid.parseError()) ?
-
-    if (parseError === undefined) {
-      // No mermaid.parseError() handler defined, so re-throw it
-      throw error;
-    }
-
-    if (isDetailedError(error)) {
-      // Handle case where error string and hash were
-      // wrapped in object like`const error = { str, hash };`
-      parseError(error.str, error.hash);
-      return;
-    }
-
-    // Otherwise, assume it is just an error string and pass it on
-    parseError(error as string);
+  async render(id: string, version: string) {
+    await this.renderer.draw(this.text, id, version, this);
   }
 
   getParser() {
@@ -95,10 +68,7 @@ export class Diagram {
   }
 }
 
-export const getDiagramFromText = (
-  txt: string,
-  parseError?: ParseErrorFunction
-): Diagram | Promise<Diagram> => {
+export const getDiagramFromText = async (txt: string): Promise<Diagram> => {
   const type = detectType(txt, configApi.getConfig());
   try {
     // Trying to find the diagram
@@ -106,19 +76,12 @@ export const getDiagramFromText = (
   } catch (error) {
     const loader = getDiagramLoader(type);
     if (!loader) {
-      throw new Error(`Diagram ${type} not found.`);
+      throw new UnknownDiagramError(`Diagram ${type} not found.`);
     }
-    // TODO: Uncomment for v10
-    // // Diagram not available, loading it
-    // const { diagram } = await loader();
-    // registerDiagram(type, diagram, undefined, diagram.injectUtils);
-    // // new diagram will try getDiagram again and if fails then it is a valid throw
-    return loader().then(({ diagram }) => {
-      registerDiagram(type, diagram, undefined);
-      return new Diagram(txt, parseError);
-    });
+    // Diagram not available, loading it
+    // new diagram will try getDiagram again and if fails then it is a valid throw
+    const { id, diagram } = await loader();
+    registerDiagram(id, diagram);
   }
-  return new Diagram(txt, parseError);
+  return new Diagram(txt);
 };
-
-export default Diagram;
diff --git a/packages/mermaid/src/diagram-api/detectType.ts b/packages/mermaid/src/diagram-api/detectType.ts
index b75e914fb..3c9237e5b 100644
--- a/packages/mermaid/src/diagram-api/detectType.ts
+++ b/packages/mermaid/src/diagram-api/detectType.ts
@@ -7,6 +7,7 @@ import type {
   ExternalDiagramDefinition,
 } from './types';
 import { frontMatterRegex } from './frontmatter';
+import { UnknownDiagramError } from '../errors';
 
 const directive = /%{2}{\s*(?:(\w+)\s*:|(\w+))\s*(?:(\w+)|((?:(?!}%{2}).|\r?\n)*))?\s*(?:}%{2})?/gi;
 const anyComment = /\s*%%.*\n/gm;
@@ -44,7 +45,7 @@ export const detectType = function (text: string, config?: MermaidConfig): strin
     }
   }
 
-  throw new Error(`No diagram type detected for text: ${text}`);
+  throw new UnknownDiagramError(`No diagram type detected for text: ${text}`);
 };
 
 export const registerLazyLoadedDiagrams = (...diagrams: ExternalDiagramDefinition[]) => {
diff --git a/packages/mermaid/src/diagram-api/types.ts b/packages/mermaid/src/diagram-api/types.ts
index d60019577..081136563 100644
--- a/packages/mermaid/src/diagram-api/types.ts
+++ b/packages/mermaid/src/diagram-api/types.ts
@@ -18,6 +18,7 @@ export interface DiagramDb {
   setDiagramTitle?: (title: string) => void;
   getAccTitle?: () => string;
   getAccDescription?: () => string;
+  bindFunctions?: (element: Element) => void;
 }
 
 export interface DiagramDefinition {
diff --git a/packages/mermaid/src/diagrams/class/classRenderer-v2.js b/packages/mermaid/src/diagrams/class/classRenderer-v2.js
index d95c29fd5..b7e538583 100644
--- a/packages/mermaid/src/diagrams/class/classRenderer-v2.js
+++ b/packages/mermaid/src/diagrams/class/classRenderer-v2.js
@@ -348,19 +348,6 @@ export const setConf = function (cnf) {
  */
 export const draw = function (text, id, _version, diagObj) {
   log.info('Drawing class - ', id);
-  // diagObj.db.clear();
-  // const parser = diagObj.db.parser;
-  // parser.yy = classDb;
-
-  // Parse the graph definition
-  // try {
-  // parser.parse(text);
-  // } catch (err) {
-  // log.debug('Parsing failed');
-  // }
-
-  // Fetch the default direction, use TD if none was found
-  //let dir = 'TD';
 
   const conf = getConfig().flowchart;
   const securityLevel = getConfig().securityLevel;
@@ -384,15 +371,6 @@ export const draw = function (text, id, _version, diagObj) {
       return {};
     });
 
-  // let subG;
-  // const subGraphs = flowDb.getSubGraphs();
-  // log.info('Subgraphs - ', subGraphs);
-  // for (let i = subGraphs.length - 1; i >= 0; i--) {
-  //   subG = subGraphs[i];
-  //   log.info('Subgraph - ', subG);
-  //   flowDb.addVertex(subG.id, subG.title, 'group', undefined, subG.classes);
-  // }
-
   // Fetch the vertices/nodes and edges/links from the parsed graph definition
   const classes = diagObj.db.getClasses();
   const relations = diagObj.db.getRelations();
diff --git a/packages/mermaid/src/diagrams/sequence/sequenceRenderer.ts b/packages/mermaid/src/diagrams/sequence/sequenceRenderer.ts
index e4ce05350..acee7bbe5 100644
--- a/packages/mermaid/src/diagrams/sequence/sequenceRenderer.ts
+++ b/packages/mermaid/src/diagrams/sequence/sequenceRenderer.ts
@@ -2,15 +2,12 @@
 import { select, selectAll } from 'd3';
 import svgDraw, { drawText, fixLifeLineHeights } from './svgDraw';
 import { log } from '../../logger';
-// import { parser } from './parser/sequenceDiagram';
 import common from '../common/common';
-// import sequenceDb from './sequenceDb';
 import * as configApi from '../../config';
 import assignWithDepth from '../../assignWithDepth';
 import utils from '../../utils';
 import { configureSvgSize } from '../../setupGraphViewbox';
-import Diagram from '../../Diagram';
-import { convert } from '../../tests/util';
+import { Diagram } from '../../Diagram';
 
 let conf = {};
 
diff --git a/packages/mermaid/src/errors.ts b/packages/mermaid/src/errors.ts
new file mode 100644
index 000000000..e3650c5a9
--- /dev/null
+++ b/packages/mermaid/src/errors.ts
@@ -0,0 +1,6 @@
+export class UnknownDiagramError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = 'UnknownDiagramError';
+  }
+}
diff --git a/packages/mermaid/src/mermaid.ts b/packages/mermaid/src/mermaid.ts
index 540e0368e..c4499bbc3 100644
--- a/packages/mermaid/src/mermaid.ts
+++ b/packages/mermaid/src/mermaid.ts
@@ -7,7 +7,7 @@ import dedent from 'ts-dedent';
 import { MermaidConfig } from './config.type';
 import { log } from './logger';
 import utils from './utils';
-import { mermaidAPI } from './mermaidAPI';
+import { mermaidAPI, RenderResult } from './mermaidAPI';
 import { registerLazyLoadedDiagrams } from './diagram-api/detectType';
 import type { ParseErrorFunction } from './Diagram';
 import { isDetailedError } from './utils';
@@ -44,10 +44,8 @@ export type { MermaidConfig, DetailedError, ExternalDiagramDefinition, ParseErro
  */
 const init = async function (
   config?: MermaidConfig,
-  // eslint-disable-next-line no-undef
   nodes?: string | HTMLElement | NodeListOf<HTMLElement>,
-  // eslint-disable-next-line @typescript-eslint/ban-types
-  callback?: Function
+  callback?: (id: string) => unknown
 ) {
   try {
     await initThrowsErrors(config, nodes, callback);
@@ -125,8 +123,7 @@ const loadExternalDiagrams = async (...diagrams: ExternalDiagramDefinition[]) =>
 const initThrowsErrors = async function (
   config?: MermaidConfig,
   nodes?: string | HTMLElement | NodeListOf<HTMLElement>,
-  // eslint-disable-next-line @typescript-eslint/ban-types
-  callback?: Function
+  callback?: (id: string) => unknown
 ) {
   const conf = mermaidAPI.getConfig();
 
@@ -188,20 +185,14 @@ const initThrowsErrors = async function (
       log.debug('Detected early reinit: ', init);
     }
     try {
-      await mermaidAPI.render(
-        id,
-        txt,
-        (svgCode: string, bindFunctions?: (el: Element) => void) => {
-          element.innerHTML = svgCode;
-          if (callback !== undefined) {
-            callback(id);
-          }
-          if (bindFunctions) {
-            bindFunctions(element);
-          }
-        },
-        element
-      );
+      const { svg, bindFunctions } = await mermaidAPI.render(id, txt, element);
+      element.innerHTML = svg;
+      if (callback) {
+        callback(id);
+      }
+      if (bindFunctions) {
+        bindFunctions(element);
+      }
     } catch (error) {
       handleError(error, errors, mermaid.parseError);
     }
@@ -296,15 +287,24 @@ const executeQueue = async () => {
 };
 
 /**
- * @param txt - The mermaid code to be parsed.
+ * Parse the text and validate the syntax.
+ * @param text - The mermaid diagram definition.
+ * @param parseOptions - Options for parsing.
+ * @returns true if the diagram is valid, false otherwise if parseOptions.silent is true.
+ * @throws Error if the diagram is invalid and parseOptions.silent is false.
  */
-const parse = (txt: string): Promise<boolean> => {
+const parse = async (
+  text: string,
+  parseOptions?: {
+    silent?: boolean;
+  }
+): Promise<boolean | void> => {
   return new Promise((resolve, reject) => {
     // This promise will resolve when the mermaidAPI.render call is done.
     // It will be queued first and will be executed when it is first in line
     const performCall = () =>
       new Promise((res, rej) => {
-        mermaidAPI.parse(txt, mermaid.parseError).then(
+        mermaidAPI.parse(text, parseOptions).then(
           (r) => {
             // This resolves for the promise for the queue handling
             res(r);
@@ -313,6 +313,7 @@ const parse = (txt: string): Promise<boolean> => {
           },
           (e) => {
             log.error('Error parsing', e);
+            mermaid.parseError?.(e);
             rej(e);
             reject(e);
           }
@@ -323,18 +324,13 @@ const parse = (txt: string): Promise<boolean> => {
   });
 };
 
-const render = (
-  id: string,
-  text: string,
-  cb?: (svgCode: string, bindFunctions?: (element: Element) => void) => void,
-  container?: Element
-): Promise<string> => {
+const render = (id: string, text: string, container?: Element): Promise<RenderResult> => {
   return new Promise((resolve, reject) => {
     // This promise will resolve when the mermaidAPI.render call is done.
     // It will be queued first and will be executed when it is first in line
     const performCall = () =>
       new Promise((res, rej) => {
-        mermaidAPI.render(id, text, cb, container).then(
+        mermaidAPI.render(id, text, container).then(
           (r) => {
             // This resolves for the promise for the queue handling
             res(r);
@@ -343,6 +339,7 @@ const render = (
           },
           (e) => {
             log.error('Error parsing', e);
+            mermaid.parseError?.(e);
             rej(e);
             reject(e);
           }
@@ -355,7 +352,6 @@ const render = (
 
 const mermaid: {
   startOnLoad: boolean;
-  diagrams: any;
   parseError?: ParseErrorFunction;
   mermaidAPI: typeof mermaidAPI;
   parse: typeof parse;
@@ -368,7 +364,6 @@ const mermaid: {
   setParseErrorHandler: typeof setParseErrorHandler;
 } = {
   startOnLoad: true,
-  diagrams: {},
   mermaidAPI,
   parse,
   render,
diff --git a/packages/mermaid/src/mermaidAPI.ts b/packages/mermaid/src/mermaidAPI.ts
index 275ec656b..5a71bb08e 100644
--- a/packages/mermaid/src/mermaidAPI.ts
+++ b/packages/mermaid/src/mermaidAPI.ts
@@ -17,11 +17,7 @@ import { compile, serialize, stringify } from 'stylis';
 import { version } from '../package.json';
 import * as configApi from './config';
 import { addDiagrams } from './diagram-api/diagram-orchestration';
-import classDb from './diagrams/class/classDb';
-import flowDb from './diagrams/flowchart/flowDb';
-import ganttDb from './diagrams/gantt/ganttDb';
-import Diagram, { getDiagramFromText } from './Diagram';
-import type { ParseErrorFunction } from './Diagram';
+import { Diagram, getDiagramFromText } from './Diagram';
 import errorRenderer from './diagrams/error/errorRenderer';
 import { attachFunctions } from './interactionDb';
 import { log, setLogLevel } from './logger';
@@ -37,7 +33,7 @@ import { parseDirective } from './directiveUtils';
 
 // diagram names that support classDef statements
 const CLASSDEF_DIAGRAMS = ['graph', 'flowchart', 'flowchart-v2', 'stateDiagram', 'stateDiagram-v2'];
-
+const MAX_TEXTLENGTH = 50_000;
 const MAX_TEXTLENGTH_EXCEEDED_MSG =
   'graph TB;a[Maximum text size in diagram exceeded];style a fill:#faa';
 
@@ -74,16 +70,34 @@ interface DiagramStyleClassDef {
 // @ts-ignore Could replicate the type definition in d3. This also makes it possible to use the untyped info from the js diagram files.
 export type D3Element = any;
 
-// ----------------------------------------------------------------------------
-
 /**
+ * Parse the text and validate the syntax.
  * @param text - The mermaid diagram definition.
- * @param parseError - If set, handles errors.
+ * @param parseOptions - Options for parsing.
+ * @returns true if the diagram is valid, false otherwise if parseOptions.silent is true.
+ * @throws Error if the diagram is invalid and parseOptions.silent is false.
  */
-async function parse(text: string, parseError?: ParseErrorFunction): Promise<boolean> {
+
+async function parse(
+  text: string,
+  parseOptions?: {
+    silent?: boolean;
+  }
+): Promise<boolean | void> {
   addDiagrams();
-  const diagram = await getDiagramFromText(text, parseError);
-  return diagram.parse(text, parseError);
+  let error;
+  try {
+    const diagram = await getDiagramFromText(text);
+    diagram.parse();
+  } catch (err) {
+    error = err;
+  }
+  if (parseOptions?.silent) {
+    return error === undefined;
+  }
+  if (error) {
+    throw error;
+  }
 }
 
 /**
@@ -366,12 +380,16 @@ export const removeExistingElements = (
  * @returns Returns the rendered element as a string containing the SVG definition.
  */
 
+export interface RenderResult {
+  svg: string;
+  bindFunctions?: (element: Element) => void;
+}
+
 const render = async function (
   id: string,
   text: string,
-  cb?: (svgCode: string, bindFunctions?: (element: Element) => void) => void,
   svgContainingElement?: Element
-): Promise<string> {
+): Promise<RenderResult> {
   addDiagrams();
 
   configApi.reset();
@@ -387,8 +405,7 @@ const render = async function (
   log.debug(config);
 
   // Check the maximum allowed text size
-  // TODO: Remove magic number
-  if (text.length > (config?.maxTextSize ?? 50000)) {
+  if (text.length > (config?.maxTextSize ?? MAX_TEXTLENGTH)) {
     text = MAX_TEXTLENGTH_EXCEEDED_MSG;
   }
 
@@ -453,11 +470,10 @@ const render = async function (
   // Create the diagram
 
   // Important that we do not create the diagram until after the directives have been included
-  let diag;
+  let diag: Diagram;
   let parseEncounteredException;
 
   try {
-    // diag = new Diagram(text);
     diag = await getDiagramFromText(text);
   } catch (error) {
     diag = new Diagram('error');
@@ -510,7 +526,7 @@ const render = async function (
   root.select(`[id="${id}"]`).selectAll('foreignobject > *').attr('xmlns', XMLNS_XHTML_STD);
 
   // Fix for when the base tag is used
-  let svgCode = root.select(enclosingDivID_selector).node().innerHTML;
+  let svgCode: string = root.select(enclosingDivID_selector).node().innerHTML;
 
   log.debug('config.arrowMarkerAbsolute', config.arrowMarkerAbsolute);
   svgCode = cleanUpSvgCode(svgCode, isSandboxed, evaluate(config.arrowMarkerAbsolute));
@@ -526,27 +542,6 @@ const render = async function (
     });
   }
 
-  // -------------------------------------------------------------------------------
-  // Do any callbacks (cb = callback)
-  if (cb !== undefined) {
-    switch (graphType) {
-      case 'flowchart':
-      case 'flowchart-v2':
-        cb(svgCode, flowDb.bindFunctions);
-        break;
-      case 'gantt':
-        cb(svgCode, ganttDb.bindFunctions);
-        break;
-      case 'class':
-      case 'classDiagram':
-        cb(svgCode, classDb.bindFunctions);
-        break;
-      default:
-        cb(svgCode);
-    }
-  } else {
-    log.debug('CB = undefined!');
-  }
   attachFunctions();
 
   // -------------------------------------------------------------------------------
@@ -561,7 +556,10 @@ const render = async function (
     throw parseEncounteredException;
   }
 
-  return svgCode;
+  return {
+    svg: svgCode,
+    bindFunctions: diag.db.bindFunctions,
+  };
 };
 
 /**