Agentic Mermaid

adewale/agentic-mermaid

Render, verify, describe, and safely edit Mermaid diagrams through MCP.

GitHub stars: 69
tools: 9
transport: STDIO, HTTP
last updated: Nov 2, 2026

View on GitHub

Install

From registry metadata

$ npx add-mcp https://agentic-mermaid.dev/mcp --name agentic-mermaid

Run in your terminal. add-mcp asks which agents to add it to (Claude Code, Codex, Cursor and more). Add -g to install it for every project.

Review the command, arguments and environment values before installing. MCP servers run with your local permissions.

Other ways

Claude Code

$ claude mcp add --transport http agentic-mermaid https://agentic-mermaid.dev/mcp

Run in your terminal. Add --scope user to make it available in every project.

Tools

Verified live · 9 tools

Verified live against the running server on Nov 6, 2026.

Parameters* required

code*string

JavaScript to execute; mermaid.* SDK is global.

timeoutMsinteger

Optional CPU-time budget (default 5000ms, max 30000ms).

describe_sdkReturn version-matched mutation operations for one diagram family, or use capability=resolved-scene for painted geometry, runtime limits and typed errors. Use detail=signatures for the compact op menu or detail=fields (default) for exact field types, required flags, enum value...3 params

Return version-matched mutation operations for one diagram family, or use capability=resolved-scene for painted geometry, runtime limits and typed errors. Use detail=signatures for the compact op menu or detail=fields (default) for exact field types, required flags, enum value...

Parameters* required

capabilitystring

Read-only rendering capability; use instead of family.one of resolved-scene

detailstring

signatures for a compact menu; fields for the complete schema (default).one of signatures · fields

familystring

Diagram family whose mutation operations are needed.one of flowchart · state · sequence · timeline · class · er

render_svgRender 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.2 params

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.

Parameters* required

optionsobject

Shared advanced RenderOptions object. Styles accept a registered Look (crisp, hand-drawn, excalidraw, pen-and-ink, freehand, watercolor, blueprint, look:tufte, accessible-high-contrast, patent-draw...

source*string

Mermaid source.

render_asciiRender 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.4 params

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.

Parameters* required

optionsobject

Shared advanced RenderOptions object, including style/palette/config/security.

source*string

Mermaid source.

targetWidthinteger

Hard maximum line width in terminal display cells.

useAsciiboolean

true = ASCII characters, false = Unicode (default).

render_pngRasterize 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-determinism contract. For file/URL artifacts u...6 params

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-determinism contract. For file/URL artifacts u...

Parameters* required

backgroundstring

Portable basic color or hex color painted behind the raster artifact.

fitToobject

Exactly one output width or height constraint.

minLabelPxnumber

Legibility floor in effective px: the render warns (BELOW_READABLE_SIZE) when fitTo/scale rasterizes the smallest configured text below it. 0 disables.default: 9

optionsobject

Shared advanced RenderOptions object.

scalenumber

Positive output scale used when no fitTo constraint is supplied.default: 2

source*string

Mermaid source.

verifyParse and verify source, structure, and renderability. This runs the graphical pipeline. 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 and `su...1 params

Parse and verify source, structure, and renderability. This runs the graphical pipeline. 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 and `su...

Parameters* required

source*string

Mermaid source.

describeDescribe 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 checking (for example edge A -> B : label, m...2 params

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 checking (for example edge A -> B : label, m...

Parameters* required

formatstring

text (default), json AX tree, or facts semantic read-back.one of text · json · facts

source*string

Mermaid source.

mutateApply 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 `execute` for logic the ops don't expres...3 params

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 `execute` for logic the ops don't expres...

Parameters* required

modestring

Source-preserving mode edits owned source ranges without regenerating unsupported syntax.one of structured · source-preservingdefault: structured

ops*array

Non-empty ordered list of edit ops; each is { kind, ...fields }.

source*string

Mermaid source to edit.

buildAuthor 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:false, family, opIndex, error }. Cal...2 params

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:false, family, opIndex, error }. Cal...

Parameters* required

family*string

Diagram family to author (one of: zenuml, eventmodeling, flowchart, state, sequence, timeline, class, er, journey, architecture, xychart, pie, quadrant, gantt, mindmap, gitgraph, radar, sankey, c4,...

ops*array

Non-empty ordered list of ops; each is { kind, ...fields }.

Readme

Agentic Mermaid

Beautiful diagrams, made with your agent.

Agentic Mermaid helps coding agents create styled diagrams from Mermaid source and edit existing diagrams through typed operations. Export SVG or PNG for documents, and ASCII or Unicode for terminal review.

It is forked from lukilabs/beautiful-mermaid. Published on npm as agentic-mermaid; the GitHub repository is adewale/agentic-mermaid; the live site is agentic-mermaid.dev.

A login flow with credential validation, an MFA decision, two retry paths, session creation and a dashboard, rendered in the hand-drawn style

A login flow with MFA, rendered directly by Agentic Mermaid. Mermaid source · Style and reproduction command

Live Demo & Samples · Live Editor

Ask your coding agent:

View the full README on GitHub

Details

Repository: github.com/adewale/agentic-mermaid
Website: agentic-mermaid.dev
Categories: AI & LLM Tools, Design & Creative
Package: agentic-mermaid
Transport: STDIO, HTTP
Registry: MCP registry, active
Tools verified: Nov 6, 2026

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