mermaid-mcp

MCP server for Mermaid diagram validation and rendering

CommunityDegradedNo sign-inGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    MCP server for Mermaid diagram validation and rendering

    How to connect

    How to connect mermaid-mcp to Claude

    The server address to paste into Claude settings:

    https://mcp.mermaidchart.com/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect mermaid-mcp to ChatGPT

    The server address to paste into ChatGPT settings:

    https://mcp.mermaidchart.com/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect mermaid-mcp to Cursor

    The server address to paste into Cursor settings:

    https://mcp.mermaidchart.com/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (25)

    Raw names from tools/list. Only developers need these.

    validate_and_render_mermaid_diagramSIMPLE RENDER TOOL - Renders Mermaid diagrams directly (Mermaid automatically validates during rendering). If successful, returns diagram image. If Mermaid validation fails, returns error details for fixing. One tool, one call, simple workflow.
    get_diagram_titleGenerate a descriptive title for a Mermaid diagram based on its content. This tool analyzes the diagram structure and content to suggest an appropriate title.
    get_diagram_summaryGenerate a concise summary for a Mermaid diagram based on its content. This tool provides prompts for the LLM to generate a brief summary (2-4 sentences) highlighting the primary flow, key decisions, and outcomes.
    search_mermaid_iconsSearch for available Mermaid icons by provider or name. Returns icons in ready-to-use format with provider prefixes (e.g., 'aws:arch-amazon-ec2'). PERFORMANCE TIP: For faster searches, start with limit=10 and specific queries. If no suitable icons found, increase limit and retry. Supports AWS, Azure, GCP, and FontAwesome icon sets.
    get_mermaid_syntax_documentGet comprehensive syntax documentation and examples for a specific Mermaid diagram type. Returns the official Mermaid.js documentation with syntax rules, examples, and usage instructions for the requested diagram type.
    list_toolsLists all available MCP servers and their tools in the workspace.
    list_reposList GitHub repositories for the authenticated user, or for an organization when `org` is set. REQUIRES: `Github-Token` header (HTTP) or `GITHUB_TOKEN` / `GH_TOKEN` in the server environment.
    list_mermaid_filesList .mmd Mermaid files in a GitHub repository (code search with tree fallback). REQUIRES: `Github-Token` header (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    read_mermaid_fileRead a single .mmd file from a GitHub repository. Only paths ending in .mmd are allowed. REQUIRES: `Github-Token` header (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    create_prCreate a new branch (git ref), one commit from the base tree with your file changes, then open a pull request in the same repository. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN with `contents: write` (and no existing branch with the same `headBranch` name).
    push_fileCreate or update a single file on a given branch in a GitHub repository. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN with contents write access.
    list_pullsList pull requests for a GitHub repository. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    list_branchesList or resolve branch names. **List mode (default):** one `GET /repos/.../branches?per_page=100&page=1` — at most 100 names, A–Z sorted in the response; `has_more` if a full page was returned. **Resolve mode:** set `branch_name` for a single `GET` branch (404 if missing). At most one GitHub API call. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    list_issuesList issues for a repository (excludes pull requests). REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    create_issueCreate an issue in a GitHub repository. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN with issues write if creating issues in private repos.
    get_issue_commentsList comments on an issue by issue number. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    get_pull_commentsGet all pull request comments: both issue/PR thread comments and inline review comments, with a `type` of `issue_thread` or `review` per item. REQUIRES: `Github-Token` (HTTP) or GITHUB_TOKEN / GH_TOKEN.
    generate_ticket_dependency_treeGenerate a Mermaid flowchart that visualises Jira issue dependency links for a project. Each node shows the ticket key, summary, and status, and is a clickable link to the ticket. Dashed nodes represent issues linked from outside the current filter set.
    generate_jira_kanban_boardGenerate a Mermaid kanban board from Jira issues. Issues are grouped into columns by their current status and ordered by workflow stage (To Do → In Progress → Done). Each card shows the issue summary and is a clickable link to the ticket, with optional assignee and priority badges.
    generate_ticket_diagramGenerate a Mermaid flowchart centred on a single Jira ticket. Fetches the ticket's subtasks, parent, issue links, and recent comments in one call. The focal ticket is highlighted in indigo; subtasks are grouped in a subgraph; issue links use colour-coded arrows (red thick = blocks, cyan dashed = relates to); comments appear in a rose subgraph.
    generate_ticket_timelineGenerate a Mermaid diagram showing the history of a single Jira ticket using its changelog. Two views are available: - **state**: stateDiagram-v2 showing all status transitions with dates and authors, nodes coloured by status category. - **timeline** (default): Mermaid timeline grouped by month, showing status changes, assignee changes, priority changes, sprint moves, and resolutions.
    get_notion_page_mermaid_diagramsExtract all Mermaid code blocks from a Notion page. Returns block ID, diagram code, and optional caption for each block.
    get_notion_mermaid_diagram_by_block_idRetrieve a single Mermaid diagram block by its block ID. Returns the diagram code and optional caption.
    update_notion_mermaid_diagramUpdate the Mermaid source code (and optional caption) of an existing mermaid code block by its block ID.
    insert_notion_mermaid_diagramAppend a Mermaid diagram as a code block to a Notion page. The block is added at the end of the page content.