@mermanjs/web-editor

Parser-backed diagnostics, symbols, and editor intelligence for browser-based Mermaid editors. Use retained sessions from a dedicated module Worker when the editor benefits from an isolated runtime.

Version 0.10.0 uses Web transport API 10, facts schema 3, and Options JSON schema 3. Keep the facade, generated glue, and WASM at the same exact version and source revision. Check the host installation guide for verified versions and channel availability.

Published 0.10.0-alpha.2 retains Web transport API 9. Version 0.10.0-alpha.1 retains Web transport API 8, facts schema 2, and Options JSON schema 3. Upgrade all package assets together and update facts consumers for the source appearance changes.

Quick start

npm install --save-exact @mermanjs/[email protected]

import { createEditorSession, initMerman } from "@mermanjs/web-editor";

await initMerman();

const session = createEditorSession(
  `flowchart TD
  A -->`,
  1,
  "file:///diagram.mmd",
);

try {
  const diagnostics = session.diagnostics();
  const symbols = session.searchDocumentSymbols("A");
  console.log({ diagnostics, symbols });
} finally {
  session.dispose();
}

For one-shot queries without retained state, use functions such as editorSearchDocumentSymbols(source, query, uri). Search remains scoped to the supplied document; it does not scan a workspace.

Scope and lifecycle

The package includes analysis and editor workflows but no callable SVG or ASCII rendering. Load it only in a browser main thread or Web Worker. Dispose every retained session, and terminate a Worker after failure, replacement, or application teardown.

See the browser package guide for runtime lifecycle, resource policy, package selection, and source-checkout development. See the current changelog for changes and upgrade actions.