Mermaid Chart

No. We opened an anonymous handshake on 2026-08-18 and the server returned its tool definition with no credential and no authentication challenge. The connector renders diagrams your assistant writes; it never reaches your Mermaid Chart account, your saved diagrams or your projects. Account features live on separate Mermaid servers that this endpoint does not expose.

No. The single tool is annotated read-only and non-destructive, and its schema accepts only diagram code and an optional title. There is no save, update, list or delete call anywhere in the surface. Mermaid documents saving and listing on two other servers, each at a different URL you would have to add yourself.

In your client, not on the server. The server validates the code and returns rendered SVG and PNG plus a live-edit link, then points the client at a widget resource. Claude fetches that widget and draws the diagram, the Copy Code button and the repair link. A client without MCP Apps support shows the returned data as plain content.

The tool reports the failure rather than throwing it away. Its output carries an error or validationError field, and Mermaid's documentation says the widget then offers a link to repair the diagram in Mermaid Live. The v1 connector does not repair syntax itself; the repair is a link you follow, not a tool call.

Every type the Mermaid library parses, because the server validates the code rather than a fixed list. Mermaid's own example prompts name flowcharts, sequence diagrams, class diagrams and state diagrams, and the tool returns a diagramType field naming what it detected. The connector's limit is Mermaid syntax itself, not a shorter allowlist.

Mermaid publishes no price for this endpoint, and we make no claim about one. The connector needs no account, so no plan gate applies at the point of rendering. Mermaid Chart is a paid product with a published pricing page, and the account features documented on its other MCP servers plainly require an account; check mermaid.ai/web/pricing for what a plan covers.

Anthropic's directory declares this connector works with Claude only — not Claude Code, not Claude Desktop, not the API. That is narrower than most entries in this catalogue. The endpoint is a standard streamable-HTTP MCP server and answered our anonymous handshake, but the interactive widget depends on MCP Apps support in the client.