CodePic

AI agent draws editable hand-drawn diagrams (flowchart, ER, architecture) via MCP, not static images

CommunityOnlineAPI key requiredGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    An API key from the service settings is required

    AI agent draws editable hand-drawn diagrams (flowchart, ER, architecture) via MCP, not static images

    How to connect

    How to connect CodePic to Claude

    The server address to paste into Claude settings:

    https://codepic.cc/api/mcp/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 CodePic to ChatGPT

    The server address to paste into ChatGPT settings:

    https://codepic.cc/api/mcp/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 CodePic to Cursor

    The server address to paste into Cursor settings:

    https://codepic.cc/api/mcp/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 (7)

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

    get_shape_docsReturn the full CodePic shape reference — all element types, their fields, data payloads, and JSON examples. Call get_shape_catalog first for concise shape selection and container capabilities; use this tool when you need complete fields or type-specific data (e.g. select options, triangle direction, callout tail). No authentication required.
    get_shape_catalogReturn compact machine-readable shape metadata for planning a diagram: semantic tags, geometry family, container support, recommended padding, default size, and MCP availability. Use this before create_diagram when choosing shapes or containers. Unlike get_shape_docs, this tool is concise and filterable.
    list_templatesList all available CodePic diagram templates. Use this ONLY when the user has explicitly asked to browse, list, or pick from templates (e.g. "show me templates", "列出模板"). Do NOT call this as a preparatory step when the user just described a diagram they want — in that case go straight to `create_diagram`. Discovering slugs here is only meaningful before a user-confirmed `create_from_template` call.
    create_from_templateCreate a new CodePic diagram from a predefined template. Requires API Key authentication. Returns a public view URL and edit URL. **STRICT USAGE RULE — READ BEFORE CALLING:** Only call this tool when the user has **explicitly** asked to use a template. Explicit signals include phrases like: "use a template", "from template", "用模板", "从模板创建", "list templates and pick one", or the user directly naming/selecting a template slug. If the user merely describes a diagram they want (e.g. "draw an A/B test flowchart", "帮我画一个登录流程", "给我做一个系统架构图"), **DO NOT** call this tool. Call `create_diagram` instead and build the diagram from the user's description. Never silently substitute a template for a described diagram — the user will get a generic result that does not match what they asked for. When responding to the user, present the returned URL as a clickable markdown link (e.g. `[Open in CodePic →](URL)`) so the user can click it directly in their AI client (Cursor / Claude / etc.).
    create_diagramCreate a custom CodePic hand-drawn style diagram by specifying nodes and edges. Requires API Key authentication. Returns a public view URL. **THIS IS THE DEFAULT TOOL FOR ANY USER-DESCRIBED DIAGRAM.** Whenever the user describes a diagram they want ("draw an A/B test flowchart", "帮我画一个登录流程", "a system architecture with a load balancer and 3 servers", etc.), build it here from their description. Do NOT fall back to `create_from_template` / `list_templates` unless the user explicitly asked for a template. When responding to the user, present the returned URL as a clickable markdown link (e.g. `[Open in CodePic →](URL)`) so the user can click it directly in their AI client (Cursor / Claude / etc.). **Container nesting (IMPORTANT — use whenever possible):** - Set `parentId` on a node to nest it inside another node. ANY node type can be a container. - The parent automatically becomes draggable-as-a-group and users can keep dropping elements into it. - Call `get_shape_catalog` with tag `container-capable` to choose among native structural containers and adaptive semantic shapes such as rectangles, circles, ellipses, diamonds, cylinders, and hexagons. - Parent bounds are expanded automatically using the selected shape's title and outline safe area. - Use absolute canvas coordinates for all nodes — child coordinates are auto-converted to parent-relative. - Set node `name`, `description`, and `tags` when later MCP/Agent reads need stable business semantics beyond visible text. - **Rule**: whenever 2+ nodes logically belong to the same module / component / region, create a container node first and set `parentId` on each child. **Design tips for beautiful diagrams:** - Use semantic types: `button-primary` for CTA buttons (auto blue), `diamond` for decisions - Pick a color palette and apply it consistently — light fill + darker stroke of the same hue: • Blue: fillColor #e3f2fd / #bbdefb, strokeColor #1565c0, fontColor #1565c0 (or #ffffff on dark fill) • Green: fillCo
    get_diagramFetch the current state of an existing CodePic diagram. Returns a compact summary of all elements with their IDs, types, positions, and parent-child relationships. Use this before update_diagram when you need to: add nested children to existing containers, make targeted edits to specific elements, or understand the current structure. Requires API Key authentication.
    update_diagramUpdate an existing CodePic diagram. You can rename it, replace all nodes/edges, or add/remove individual nodes and edges. Requires API Key authentication. When responding to the user, present the returned URL as a clickable markdown link (e.g. `[Open in CodePic →](URL)`) so the user can click it directly in their AI client (Cursor / Claude / etc.).