MCP
Hosted MCP at /mcp, plus a local stdio server.
The hosted MCP endpoint is https://agentic-mermaid.dev/mcp: stateless streamable HTTP (JSON-RPC over POST, no sessions). Hosted tools: execute, describe_sdk, render_svg, render_ascii, render_png, verify, describe, mutate, and build. Call describe_sdk for one family's compact signatures or exact mutation fields; pass format: "facts" to describe for deterministic semantic read-back. Successful deterministic pure-tool results may be reused by a private server-side compute cache for up to 24 hours; execute, mutate, and build bypass it. The JSON-RPC response itself is always cache-control: no-store, and x-agentic-mermaid-compute-cache reports reuse. Inputs are capped at 64KB, and Code Mode execute runs in an isolated on-demand Worker with network access disabled and a CPU budget.
The local MCP tools are execute, describe_sdk, render_png, and describe. Multi-step parse/narrow/mutate/verify workflows run inside execute(code); local describe_sdk returns version-matched mutation schemas and describe supports format: "facts". For file/URL PNG artifacts, diagrams beyond the hosted caps, or offline use, run the installed package locally: npx --no-install agentic-mermaid mcp.
Privacy: every hosted tool call sends your diagram source (or Code Mode code) to this site’s server. For diagrams that must not leave your machine, use the library, the CLI, or the local stdio server — the pipeline is fully local and needs no network.
Response framing: the hosted /mcp endpoint always replies with plain application/json — no SSE data: framing — so scripts can parse the body directly. The local HTTP transport’s /sse + /message pair delivers responses as SSE events on the open stream; script writers who want unframed JSON should POST to its /rpc endpoint instead.