# Composer 

> Use this tool when you need to design, visualize, and evolve software architecture diagrams directly from your IDE, and integrate with AI coding agents for real-time collaboration. It solves problems such as creating and modifying interactive architecture diagrams, adding services, databases, queues, and connections, and provides inputs like diagram management, read, write, plan, and verify tools, with outputs like updated diagrams and API definitions. Use Composer when working on complex software projects that require collaborative design and development.

Canonical page: https://skillsregistry.net/skills/oliver-charles-rene-grabner-hju9-composer  
JSON: https://api.skillsregistry.net/v1/skills/oliver-charles-rene-grabner-hju9-composer

## Description

<p align="center">
  <img src="https://github.com/OliverGrabner/composer-mcp/raw/main/demo.gif" alt="Composer demo" />
</p>

<p align="center">
  <img src="https://usecomposer.com/logo_warm_trio_no_bg.svg" width="14" alt="Composer logo" />
  <strong>Composer MCP Server</strong>
</p>

<p align="center">
  Give your AI coding agent an architecture canvas.<br/>
  Design, visualize, and evolve software architecture diagrams - right from your IDE.
</p>

<p align="center">
  <a href="https://www.npmjs.com/package/@usecomposer/mcp"><img src="https://img.shields.io/npm/v/@usecomposer/mcp?color=D27754&label=npm" alt="npm version" /></a>
  <a href="https://opensource.org/licenses/MIT"><img src="https://img.shields.io/badge/license-MIT-blue.svg" alt="MIT License" /></a>
  <a href="https://modelcontextprotocol.io"><img src="https://img.shields.io/badge/MCP-compatible-green.svg" alt="MCP Compatible" /></a>
</p>

---

**Composer** is a visual system design tool that lets AI coding agents create and modify interactive architecture diagrams through [MCP (Model Context Protocol)](https://modelcontextprotocol.io). Your agent gets tools to add services, databases, queues, and connections, and you get a live canvas at [usecomposer.com](https://usecomposer.com) that updates in real-time.

```
Your IDE  <-->  MCP Server (this package)  <-->  Composer API  <-->  Your Diagram
```

## Getting Started

### Connect your IDE

**Claude Code:**

```bash
claude mcp add --transport http composer https://mcp.usecomposer.com
```

**Cursor** — create `.cursor/mcp.json` in your project root:

```json
{
  "mcpServers": {
    "composer": {
      "type": "http",
      "url": "https://mcp.usecomposer.com"
    }
  }
}
```

Your browser will open for authorization on first use.

<details>
<summary><strong>Claude Code</strong></summary>

```bash
claude mcp add --transport http composer https://mcp.usecomposer.com
```

</details>

<details>
<summary><strong>Cursor</strong></summary>

Create `.cursor/mcp.json` in your project root:

```json
{
  "mcpServers": {
    "composer": {
      "type": "http",
      "url": "https://mcp.usecomposer.com"
    }
  }
}
```

</details>

<details>
<summary><strong>Codex</strong></summary>

```bash
codex mcp add composer -- npx -y @usecomposer/mcp --stdio
```

</details>

<details>
<summary><strong>VS Code (Copilot Chat)</strong></summary>

Create `.vscode/mcp.json` in your project root:

```json
{
  "servers": {
    "composer": {
      "type": "http",
      "url": "https://mcp.usecomposer.com"
    }
  }
}
```

</details>

<details>
<summary><strong>VS Code (Cline)</strong></summary>

Open Cline sidebar > Settings (gear icon) > MCP Servers > Add Remote Server:

```json
{
  "mcpServers": {
    "composer": {
      "type": "http",
      "url": "https://mcp.usecomposer.com"
    }
  }
}
```

</details>

<details>
<summary><strong>VS Code (Continue)</strong></summary>

Add to `.continue/config.yaml`:

```yaml
mcpServers:
  - name: composer
    url: https://mcp.usecomposer.com
```

</details>

<details>
<summary><strong>Windsurf</strong></summary>

Add to `~/.codeium/windsurf/mcp_config.json`:

```json
{
  "mcpServers": {
    "composer": {
      "serverUrl": "https://mcp.usecomposer.com"
    }
  }
}
```

> **Note:** Windsurf uses `"serverUrl"` instead of `"url"`.

</details>

<details>
<summary><strong>OpenCode</strong></summary>

Create `opencode.json` in your project root:

```json
{
  "mcp": {
    "composer": {
      "type": "remote",
      "url": "https://mcp.usecomposer.com"
    }
  }
}
```

</details>

## Tools

### Diagram Management

| Tool | Description |
|------|-------------|
| `list_diagrams` | List all your diagrams. Call this first to find which diagram to work on |
| `create_diagram` | Create a new diagram and auto-select it for this session |
| `select_diagram` | Select which diagram to work on for this session |
| `rename_diagram` | Rename the currently selected diagram |

> **Note:** Call `list_diagrams` then `select_diagram` (or `create_diagram`) before using other tools.

### Read

| Tool | Description |
|------|-------------|
| `get_graph` | Get the full architecture diagram - all nodes and edges |
| `get_node` | Get details for a single node including connected edges |
| `search_graph` | Search nodes and edges by keyword |
| `get_screenshot` | Get a PNG thumbnail of the diagram from the last auto-save |

### Write

| Tool | Description |
|------|-------------|
| `upsert_node` | Create or update a node (service, database, queue, etc.) |
| `upsert_edge` | Create or update a connection between two nodes |
| `define_api` | Define API endpoints on a backend service node |
| `delete_element` | Delete a node or edge from the diagram |
| `link_path` | Link a node to a file or folder in your codebase |

### Plan & Verify

| Tool | Description |
|------|-------------|
| `verify_diagram` | Check for issues like missing endpoints or orphaned nodes |
| `plan_import` | Step-by-step workflow for importing an existing codebase |
| `get_guide` | Reference guide for node types, protocols, and best practices |

### Node Types

`client` · `frontend` · `backend` · `database` · `cache` · `queue` · `storage` · `external`

### Edge Protocols

`REST` · `gRPC` · `GraphQL` · `WebSocket` · `TCP` · `UDP` · `async` · `event` · `internal`

## Example Prompts

Once connected, try asking your AI agent:

| Prompt | What it does |
|--------|-------------|
| *"Import this codebase into Composer"* | Scans your repo and builds the architecture diagram |
| *"Create a new Composer diagram called Backend Architecture"* | Creates and auto-selects a new diagram |
| *"Add a Redis cache between the API and the database in Composer"* | Adds a new node and edges to the diagram |
| *"Add analytics monitoring to the Composer diagram"* | Adds observability nodes and connections |
| *"Update the APIs I defined in Composer"* | Refreshes endpoint definitions on backend nodes |
| *"Verify my Composer diagram"* | Checks for missing endpoints, orphaned nodes, etc. |
| *"Link each Composer node to its source code"* | Associates diagram nodes with file paths |

## How It Works

Authentication is handled via OAuth 2.1 — your browser opens for a one-time consent flow, and you're connected. Tool calls are proxied to the Composer API at `mcp.usecomposer.com`. Your diagram data lives on Composer's servers. The MCP server itself is stateless.

Changes made through MCP are immediately visible on the [Composer canvas](https://usecomposer.com) via real-time WebSocket sync.

## Development

```bash
git clone https://github.com/olivergrabner/composer-mcp
cd composer-mcp
npm install
npm run dev        # Watch mode (rebuilds on change)
npm run build      # Production build
```

## Links

- [Composer](https://usecomposer.com) - the visual architecture canvas
- [MCP Protocol](https://modelcontextprotocol.io) - Model Context Protocol spec
- [Issues](https://github.com/olivergrabner/composer-mcp/issues) - bug reports and feature requests

## License

MIT

## Trust

- **Trust score (0–1):** 0.50
- **Verification tier:** unverified

## Facts

- **Version:** 1.0.0
- **Skill type:** atomic
- **Execution layer:** container
- **Runtime environment:** vm
- **Category:** database
- **Updated:** 2026-04-27

## Source

- **Source listing:** [Smithery](https://smithery.ai/server/oliver-charles-rene-grabner-hju9/composer)
- **Repository:** <https://github.com/OliverGrabner/composer-mcp>

## Use it

Resolve this record through the SkillsRegistry MCP server (no auth, read-only):

```
claude mcp add --transport http --scope user skillsregistry https://api.skillsregistry.net/mcp
```

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_skill",
    "arguments": {
      "slug": "oliver-charles-rene-grabner-hju9-composer"
    }
  }
}
```

REST: `GET https://api.skillsregistry.net/v1/skills/oliver-charles-rene-grabner-hju9-composer` · pull for local use: `GET https://api.skillsregistry.net/v1/skills/oliver-charles-rene-grabner-hju9-composer/pull`

---
SkillsRegistry indexes agent skills from public registries and GitHub. Skills we have analysed are scanned with Circle-IR and scored on six dimensions; each listing states its scan coverage. More: https://skillsregistry.net/llms.txt