Agentic Mermaid is an MCP server with 9 tools an agent can call, among them build, describe, describe_sdk. It answers at https://agentic-mermaid.dev/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 6 of 6 times since 11 September 2026; the last check, on 21 October 2026, succeeded.
Render, verify, describe, and safely edit Mermaid diagrams through MCP.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
build | Author a new Mermaid diagram from blank by folding a list of structured ops over an empty diagram of `family`. The declarative counterpart to hand-writing source. Returns the same envelope as `mutate`: { ok, family, source, verify } or { ok Inputs: family, ops |
describe | Describe a Mermaid diagram. format=text returns { ok, text } with one or two summary sentences; format=json returns { ok, tree } with the AX tree; format=facts returns { ok, facts } with deterministic semantic fact lines for machine checkin Inputs: source, format |
describe_sdk | Return version-matched mutation operations for one diagram family. Use detail=signatures for the compact op menu or detail=fields (default) for exact field types, required flags, enum values, defaults, and constraints. Call this before buil Inputs: family, detail |
execute | Run JavaScript in an isolated sandbox; return a value. One call composes edits. Submit JavaScript; declaration types are guidance. No promises, async/await, dynamic import, or type annotations. Hosted note: execute runs in an on-demand isol Inputs: code, timeoutMs |
mutate | Apply a list of structured edit ops to an existing Mermaid `source` and return the edited diagram. This is the declarative counterpart to `execute`: plain JSON in, plain JSON out, no sandbox. Prefer it for straightforward edits; reserve `ex Inputs: source, ops |
render_ascii | Render a Mermaid source string to text. Returns { ok, text }. useAscii true → plain ASCII (+,-,|); false/absent → Unicode box drawing (┌,─,│). targetWidth sets a hard terminal display-cell bound; impossible bounds return a typed error. |
render_png | Rasterize a Mermaid source string to PNG. Returns { ok, png_base64 }. Hosted rendering uses resvg-wasm with bundled fonts; bytes may differ from the local napi renderer, so hosted PNG is a convenience surface, not part of the byte-determini |
render_svg | Render a Mermaid source string to themeable SVG. Returns { ok, svg }. Layout is deterministic: identical input produces identical geometry. The hosted boundary forces security:'strict' and embedFontImport:false. |
verify | Parse and verify a Mermaid diagram without rendering it. Returns { ok, family, summary, warnings, layout: { bounds, nodes, edges } } for valid diagrams and { ok: false, errors } for parse failures. `family` is the detected diagram family an Inputs: source |
Every block below points at https://agentic-mermaid.dev/mcp. Pick your client and copy.
claude mcp add --transport http agentic-mermaid https://agentic-mermaid.dev/mcp
{
"mcpServers": {
"agentic-mermaid": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://agentic-mermaid.dev/mcp"]
}
}
}{
"mcpServers": {
"agentic-mermaid": {
"url": "https://agentic-mermaid.dev/mcp"
}
}
}{
"servers": {
"agentic-mermaid": {
"type": "http",
"url": "https://agentic-mermaid.dev/mcp"
}
}
}{
"context_servers": {
"agentic-mermaid": {
"url": "https://agentic-mermaid.dev/mcp"
}
}
}{
"mcpServers": {
"agentic-mermaid": {
"serverUrl": "https://agentic-mermaid.dev/mcp"
}
}
}{
"mcpServers": {
"agentic-mermaid": {
"url": "https://agentic-mermaid.dev/mcp"
}
}
}name: Agentic Mermaid
version: 0.0.1
schema: v1
mcpServers:
- name: Agentic Mermaid
type: streamable-http
url: https://agentic-mermaid.dev/mcp{
"mcpServers": {
"agentic-mermaid": {
"httpUrl": "https://agentic-mermaid.dev/mcp"
}
}
}{
"mcpServers": {
"agentic-mermaid": {
"type": "http",
"url": "https://agentic-mermaid.dev/mcp"
}
}
}{
"mcpServers": {
"agentic-mermaid": {
"url": "https://agentic-mermaid.dev/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fagentic-mermaid.dev%2Fmcp&type=streamable_http&id=agentic-mermaid&name=Agentic%20Mermaid
It answered our last check on 21 October 2026 in 575 ms. Over 6 checks since 11 September 2026 it answered 6. Status here comes from Neuronto's own probes, not from the publisher.
9, as returned by the server's own tools/list on 13 September 2026: build, describe, describe_sdk, execute, mutate, render_ascii, render_png, render_svg, and 1 more.
It answered our last check on 21 October 2026 in 575 ms. Over 6 checks since 11 September 2026 it answered 6.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://agentic-mermaid.dev/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: io.github.adewale. Endpoint host: agentic-mermaid.dev. ARD identifier: urn:air:io.github.adewale:mcp:agentic-mermaid.
First indexed 10 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.