Who it is for
Anyone writing Mermaid diagrams for documentation, design notes, or README files.
Overview
What Mermaid Chart does
Mermaid Chart takes diagram code, checks that the syntax parses, and renders the result as SVG. The output appears in an interactive panel where a diagram can be previewed, zoomed, and revised without leaving the conversation.
The validation step is the practical part. Mermaid syntax fails in ways that are hard to spot by eye, and a checked render answers clearly whether a diagram is well formed before it goes into a document or a pull request.
Sample requests in the listing cover a web application architecture diagram, a sequence diagram for a login flow, and a flowchart for subscription access logic, which is roughly the range of shapes Mermaid gets used for in engineering documentation.
What stands out
Syntax validation runs ahead of rendering, so a malformed diagram gets caught instead of pasted into a document.
Availability
Where Mermaid Chart is listed
Mermaid Chart Inc ships this on both marketplaces: Mermaid Chart is listed in the Claude connectors directory and in the ChatGPT apps directory, under the same publisher domain.
Only 392 of the 3,150 products in this directory are listed in both marketplaces. One MCP server can serve both surfaces; what differs is each platform's listing and review process.
ChatGPT listing
In the ChatGPT apps directory
- Developer
- Mermaid Chart Inc
- Filed under
- Developer Tools
- Listed since
- June 2026
- Authentication
- Authenticates when installed
- Website
- mermaidchart.com
- Policies published
- Privacy policy · Terms of service
- Official listing
- Open in ChatGPT
- Snapshot
- August 2026
Example prompts from the listing
- Create a Mermaid diagram showing a modern web app architecture
- Generate a Mermaid sequence diagram for user login
- Create a Mermaid flowchart for subscription access logic
Claude listing
In the Claude connectors directory
Mermaid Chart publishes 1 tool to Claude, a deliberately narrow surface; only 0.7% of the 1,253 Claude-listed connectors expose fewer.
The median Claude-listed connector filed under Creative & Design publishes 9, so this one sits 8 tools below its bucket's median, 14th of 17.
It falls in the 1-3 tools band, which holds 16.4% of the Claude directory.
Measured against the live endpoint
A direct call to the endpoint returned 1 tools, matching the 1 the listing publishes. Probed 2026-08-07.
Tools the server actually returns
validate_and_render_mermaid_diagram
Mermaid Chart publishes a remote MCP endpoint. Claude connects to it over HTTP; there is nothing to install locally.
Every connector in the Claude directory is remote, all 1,253 of them, so transport is not a differentiator there.
- Publisher
- Mermaid Chart Inc
- Verification
- Verified partner (37.8% of the Claude directory)
- Filed under
- Creative & Design
- Endpoint
-
https://chatgpt.mermaid.ai/anthropic/mcp - Documentation
- Publisher setup docs
- Published tools
- 1 · 1-3 tools band
- Depth rank in Creative & Design
- 14 of 17
- Snapshot
- August 2026
Mermaid Chart carries partner verification in the Claude directory, which 474 of 1,253 listings do (37.8%). That is a review step past self-publishing, not an Anthropic-built server.
In the publisher's words
How Mermaid Chart Inc describes it
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.
Quoted from the connector's own Claude directory listing as captured in August 2026. Node8 did not write it and does not vouch for it.
Nearby
Other Creative & Design connectors
Alpix
Shared pixel canvas painted with an AI
ChatGPT
Coffee & Contracts
Real estate social content library, calendar and Instagram metrics
Claude
Figma
Design-to-code work between Figma files and a codebase
Claude · ChatGPT
Flipsnack
Interactive flipbook publishing with engagement analytics
ChatGPT
InstaSite Builder
Website generation from a written prompt
ChatGPT
Macaly
Generate, iterate on and deploy web apps through Macaly
Claude
This is an independent catalogue entry compiled by Node8 from Mermaid Chart's public marketplace listings as they stood in August 2026. Listing facts come from the marketplaces; the comparisons against the rest of the directory and any live-endpoint measurements are Node8's. Node8 is not affiliated with Mermaid Chart Inc, and inclusion here is not an endorsement.
Want your company reachable inside ChatGPT and Claude?
Node8 builds MCP servers end to end: deciding which tools are worth exposing, the authentication and permission model, the review submissions, and the onboarding that gets them used. One server serves ChatGPT, Claude, and Microsoft Copilot.