Affinity MCP Bridge

A standalone MCP stdio bridge for Affinity by Canva's local MCP server.

This lets MCP clients connect to Affinity without depending on Claude Desktop's installed extension path, such as:

C:\Users\<you>\AppData\Roaming\Claude\Claude Extensions\...

The bridge starts as a normal stdio MCP server, then forwards tools, resources, and prompts to Affinity's local SSE server.

Requirements

• Node.js 20 or newer.
• Affinity by Canva 3.2 or newer.
• Affinity running with Settings > Model Context Protocol > Enable MCP server turned on.
• Restart Affinity after enabling the MCP server.

By default, the bridge connects to:

http://localhost:6767/sse

You can override it with AFFINITY_MCP_SSE_URL.

Use From GitHub

Clone the repository and install dependencies:

git clone https://github.com/andre-carbajal/affinity-mcp-bridge.git
cd affinity-mcp-bridge
npm install

Then configure your MCP client to run src/index.js with Node.

Claude Desktop

{
  "mcpServers": {
    "affinity": {
      "command": "node",
      "args": ["/absolute/path/to/affinity-mcp-bridge/src/index.js"],
      "env": {
        "AFFINITY_MCP_SSE_URL": "http://localhost:6767/sse"
      }
    }
  }
}

On Windows, use forward slashes or escaped backslashes:

{
  "mcpServers": {
    "affinity": {
      "command": "C:/Program Files/nodejs/node.exe",
      "args": ["C:/Users/you/path/to/affinity-mcp-bridge/src/index.js"],
      "env": {
        "AFFINITY_MCP_SSE_URL": "http://localhost:6767/sse"
      }
    }
  }
}

Codex config.toml

[mcp_servers.affinity]
command = "C:/Program Files/nodejs/node.exe"
args = ["C:/absolute/path/to/affinity-mcp-bridge/src/index.js"]
startup_timeout_sec = 30

[mcp_servers.affinity.env]
AFFINITY_MCP_SSE_URL = "http://localhost:6767/sse"

Optional Global Install

You can also install from GitHub globally:

npm install -g github:andre-carbajal/affinity-mcp-bridge

Then find the global package path:

npm root -g

Use that path with node, for example:

<npm-root-global>/affinity-mcp-bridge/src/index.js

For Windows MCP clients, calling node with the JS file path is more reliable than launching npm's .cmd wrapper directly.

Tools

The bridge exposes:

• affinity_status: local diagnostic tool that checks whether Affinity MCP is reachable.
• All tools reported by Affinity's upstream MCP server, when Affinity is running.

Typical upstream tools include script execution, rendering the current spread/selection, SDK documentation access, and Affinity script-library operations.

Troubleshooting

If affinity_status says the bridge cannot connect:

1. Open Affinity by Canva.
2. Enable Settings > Model Context Protocol > Enable MCP server.
3. Restart Affinity.
4. Check whether another local app is occupying port 6767.

On Windows, you can check the port owner with:

Get-NetTCPConnection -LocalPort 6767 | ForEach-Object {
  Get-Process -Id $_.OwningProcess
}

If another app owns 127.0.0.1:6767 but Affinity owns ::1:6767, keep the default http://localhost:6767/sse; do not force 127.0.0.1.

Development

npm install
npm run check
npm run smoke

npm run smoke starts the bridge and lists MCP tools. If Affinity is not reachable, it should still list affinity_status.

License

MIT