Line9

ai.line9Published by line9.aiOfficial publisherv0.4.4Updated Oct 24, 2026

Render Mermaid with Line9 layout in your assistant.

VerifiedStreamable HTTPWeb executableDeveloper ToolsMedia & Design

Overview

AI-generated overview

A remote MCP server that lets an assistant render Mermaid diagrams with Line9's layout engine and browse the user's published Line9 diagrams.

What you can do
Render Mermaid source into diagrams using Line9's layout, with flowcharts and sequence diagrams getting Line9 layout and other kinds flagged as using Mermaid's own layout, returning a short verdict on the result. List the diagrams published in the user's Line9 workspaces with name, visibility, version, last update and permalink. Fetch a published diagram's current Mermaid source by name or slug and show it rendered, with a line9 frontmatter block that should be kept when editing.
When to use it
Useful when an assistant writes or changes Mermaid and the user should see the rendered result, or when the user wants to find, open and edit diagrams already published in their Line9 workspace.
Requirements
A remote endpoint at mcp.line9.ai over streamable HTTP; no packages, environment variables or headers are declared. Listing and fetching published diagrams require Line9 sign-in.
Before you install
The server can read the user's Line9 workspace contents, including diagram names, visibility and source. Editing a fetched diagram means keeping its line9 frontmatter block so Line9 recognises it rather than creating a new diagram. Sign-in is required for workspace tools, so account access is involved.

Installation

In SourceWeft

  1. Open Line9 in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/ai.line9%2Fdiagrams/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "line9": {
      "type": "http",
      "url": "https://mcp.line9.ai/mcp"
    }
  }
}

Tools

3

render_diagram

Render diagram

Render Mermaid source with Line9's layout engine. Call this whenever you write or change Mermaid and the user should see the result. Flowcharts and sequence diagrams get Line9's layout; other Mermaid kinds are rendered with Mermaid's own layout and flagged as such. Returns a short verdict — kind, size, warnings, or a parse error with its line and column — plus an "Open in Line9" link. On a parse error, fix the named line and call again. Assistants that support MCP Apps show the diagram in a panel; there, do not paste the SVG or repeat the source in your reply. In an assistant with no panel (a terminal or editor), reply with the verdict line and the `open_url` link — that link is the only way the user sees the diagram. Write flowcharts as `flowchart LR` unless the user asks for top-to-bottom; chat panels are wide and short. No sign-in needed; renders carry a small Line9 mark unless the user is signed in to Line9 Pro. Set theme, orientation, spacing and legend in the source itself (`line9:` frontmatter; `flowchart LR`), never as arguments. This connector cannot publish or save. To publish, the user opens the diagram in Line9 (the `open_url` link) and publishes there — not with the Line9 CLI.

Parametersplansourcerequired

list_diagrams

List my diagrams

List the diagrams published in the user's Line9 workspace(s): name, visibility, version, last update and permalink. Use it to find a diagram before `get_diagram`. Requires Line9 sign-in.

Parameterslimitquery

get_diagram

Get a diagram

Fetch a published diagram's current Mermaid source by name or slug, and show it rendered. The returned source is stamped with the diagram's identity — keep the `line9:` frontmatter block when you edit it so that Line9 recognises the diagram when it is opened and published there instead of creating a new one. Requires Line9 sign-in. This connector cannot publish or save. To publish, the user opens the diagram in Line9 (the `open_url` link) and publishes there — not with the Line9 CLI.

Parametersdiagramrequired

Version history

2
  1. v0.4.4LatestSep 18, 2026
  2. v0.4.3Sep 17, 2026

Score

72% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts

    Publish an icon in the registry entry.

  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.