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Mermaid Chart

Developer toolsby Mermaid Chart Inc
Open in ChatGPTOpen in ClaudeWebsite
Launched Apr 14, 2026 on ChatGPT

Validates Mermaid syntax, renders diagrams as high-quality SVG, and displays them instantly in an interactive UI where users can preview, zoom, and iterate in real time.

5ChatGPT Tools
1Claude Tools
Mermaid Chart IncDeveloper
Developer toolsCategory

Use Cases

designproductivity

Available Tools

Display Mermaid diagram

display_mermaid
Full Description

Use this tool to display a Mermaid diagram in an interactive UI widget.

  • The widget renders the diagram directly in the browser using the Mermaid library — no external service required.
  • The widget shows the diagram code, a "Copy Code" button, and the rendered diagram.
  • If the diagram has a syntax error, the widget will show the error and offer a repair option.

Tips:

  • Always prefer this tool over using code blocks.
  • Use documentID when updating an existing diagram that already has a documentID.
Parameters (2 required, 1 optional)
Required
diagramCodestring

The Mermaid diagram code to display

titlestring

Title for the diagram

Optional
documentIDstring

Must be provided when updating an existing diagram that already has a documentID. Should be omitted when creating a new diagram from scratch.

List Personal Diagrams

list_personal_diagrams
Full Description

Lists the user's saved Mermaid diagrams from their Mermaid.ai account.

Repair Mermaid Diagram

repair_diagram
Full Description

Use this tool to repair an invalid Mermaid diagram:

  • The tool will attempt to fix the syntax error and render the corrected diagram to a UI widget.
  • Provide the broken diagram code and the error message from the previous validation attempt.
Parameters (2 required)
Required
codestring

The invalid Mermaid diagram code to repair

errorstring

The error message from diagram validation

Save diagram to user's account

save_diagram
Full Description

Use this tool to save the diagram to the user's account. The tool will save the diagram and return the updated diagram information.

Parameters (1 required, 1 optional)
Required
diagramCodestring

The Mermaid diagram code to save

Optional
titlestring

Optional title for the diagram

Update diagram in user's account

update_diagram
Full Description

Use this tool to update the diagram in the user's account. The tool will update the diagram and return the updated diagram information.

Parameters (2 required, 1 optional)
Required
diagramCodestring

The updated Mermaid diagram code

documentIDstring

The ID of the document to update

Optional
titlestring

Optional new title for the diagram

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