Claude Mermaid Chart connectorWhat Claude can do in your Mermaid Chart account.
The Claude Mermaid Chart connector exposes 7 tools. 3 read or display diagrams, 4 act on your Mermaid.ai account: saving, overwriting, repairing and signing in. Below: what Claude draws, what it keeps for you, and which step burns AI credits.
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What it changes when you document a system
Describe a flow to Claude and the diagram shows up inside the conversation, in an interactive panel where the Mermaid library draws it on your side. The directory sheet confirms this connector displays an interface inside the chat. With a Mermaid.ai account signed in, the result can also be stored with your saved diagrams, listed later or reopened from its link.
A readable chart from one sentence. Ask for the user sign-up flow; Claude writes the Mermaid syntax and display_mermaid renders it in the panel.
A broken diagram brought back. A teammate's sequence diagram no longer renders: repair_diagram attempts an AI fix, spending AI credits only when the repair succeeds.
Your saved work, found again and kept current. list_personal_diagrams shows what you have stored, get_diagram_by_url opens the one you hold a link to, and update_diagram replaces its content with the new version.
Save or overwrite, on purpose. save_diagram creates a new document on every call and leaves the others alone, while update_diagram writes over an existing one, which Mermaid flags as destructive. Saying which of the two you want avoids losing a version.
What Claude will not do: store, list or update anything unless you are signed in to Mermaid.ai. Nothing runs on its own either; no diagram regenerates when your code or docs change. That kind of hands-off refresh belongs to an automation tool, a different job, and the Integrations hub covers that side.
The vocabulary in one minute
Five terms to know before you connect Mermaid Chart.
- Connector
- The link you set up once between Claude and a service you use, so Claude can use it while it answers you.
- Tool
- One named capability the connector hands to Claude. Claude decides which ones it needs; the directory sheet lists every one.
- Authorization
- Mermaid.ai's own sign-in screen, where you give Claude access to your account. Granted once per person, taken back the same way.
- Approval
- The confirmation Claude waits for in the chat before carrying out something that changes your account.
- MCP
- The shared standard behind connectors; it is what lets an assistant such as Claude talk to an outside service.
Connect Mermaid Chart to Claude in three steps
- 01
Open the connector list
In Claude, go to Customize, then Connectors, and find Mermaid Chart. On a Team or Enterprise workspace, an Owner or Primary Owner must enable it before each member can connect.
- 02
Start the connection
Click Connect on its row, then sign in to your Mermaid.ai account in the window the service opens itself. If the link breaks later, hit Disconnect and connect again.
- 03
Read the authorization
Go through the authorization screen before you approve. It is Mermaid.ai's screen, not Claude's, and it defines what the access covers. You can also revoke it later from your Mermaid.ai account.
All 7 tools, grouped by what they do
Mermaid Chart gives Claude 7 tools: 3 that read your account, 4 that change something in it.
Two groups: what Claude displays or looks up, and what it does in your Mermaid.ai account. Tool names stay exactly as Claude shows them.
- 3 read
- 4 write
What Claude reads or displays (3)
3 toolsThree tools that show or consult diagrams without touching your account.
display_mermaid
Shows a Mermaid diagram in an interactive panel inside the conversation, drawn client-side by the Mermaid library. Mermaid tags it as read-only: nothing is stored in your account.
list_personal_diagrams
Retrieves the diagrams stored in your Mermaid.ai account. Mermaid notes it requires authentication, so it only answers once you are signed in.
get_diagram_by_url
Takes a Mermaid Chart URL and returns the title and code of that diagram from your account.. It needs you signed in.
What Claude does in your account (4)
4 toolsFour tools that act on your Mermaid.ai account. No source describes their confirmation, so the general rule below applies.
save_diagram
Approval: see the ruleStores a fresh diagram in your Mermaid.ai account, once you are signed in. Each call adds a separate document and leaves existing ones alone.
update_diagram
Approval: see the ruleWrites over the data of a diagram already in your account. Mermaid flags it as destructive: the previous version is overwritten.
repair_diagram
Approval: see the ruleAttempts an AI fix of invalid Mermaid code. It requires sign-in, and a successful repair spends AI credits.
sign_in
Approval: see the ruleKicks off sign-in to your Mermaid.ai account and opens an authenticated session. Without it, the tools that store, list or repair will not respond.
What Claude checks with you first
By default, Claude pauses and asks for your go-ahead before each action it takes on an account for you. The request appears in the chat, right when it matters.
For Mermaid Chart, no source describes a confirmation tied to a particular tool, so that default rule covers saving, updating and repairing. On Team and Enterprise workspaces, owners decide whether members may let some actions through without being asked every time, and they can cap a connector for the whole organisation, keeping display open and shutting writes. Claude only ever holds the rights of your own Mermaid.ai account.
Which plans it's available on
None of the 819 sheets in the official directory shows plan availability. For a given connector, that information is not published anywhere.
The general rule is sourced: remote connectors are open to all users on Claude, Cowork, Claude Desktop and mobile. On Team and Enterprise, an Owner or Primary Owner enables the connector for the organisation before members connect. This connector's sheet lists Claude as its supported surface. For the current status, the connector's sheet in the official directory is the reference.
Where this connector stops
A connector is not an automation. Claude calls these tools while it answers you: no diagram updates itself when your code moves on.
Only the publisher documents this connector; neither Claude's help centre nor Anthropic's developer docs cover it, and two of its sources disagree on the tool list (details below): Mermaid's v2 docs describe seven tools, while the server at the sheet's address listed a single one when queried on 1 October 2026. The directory badge is not a security audit, and Anthropic does not guarantee a publisher's tools behave as described, so connect what you know.
Which tools does the Mermaid Chart connector give Claude?
- Mermaid docs, "Claude MCP App v2", matching the directory sheet ↗undatedSeven tools: display, list, save, update, repair, sign in and open by link.
- Tool list published by the server at the sheet's address ↗October 2026A single tool that validates a diagram and renders it in a panel.
What this page followsThe v2 docs and the sheet agree on seven tools; the server queried at the sheet's address in October 2026 announces just one. We do not pick a side for you: what Claude can do in your account is the list the connector's sheet shows there.
Need help connecting Mermaid Chart to Claude?
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