composio-byo

Composio BYO

Use this skill when the user wants to connect Composio, add SaaS tools through Composio, or troubleshoot Composio MCP access.

This is a bring-your-own Composio setup. The user owns their Composio account, API key, auth configs, connected accounts, quotas, and billing. Cetus should not use a shared Composio account or shared API key for this plugin.

What the User Needs

Ask the user for these values, or help them find them in their Composio dashboard:

• Composio MCP URL, usually shaped like https://backend.composio.dev/v3/mcp/...?...
• Composio project API key, sent as the x-api-key header
• A short server name, such as Composio, Composio Gmail, or Composio Work

The user must authenticate the required Composio toolkits before using them. Composio creates connected accounts and stores the third-party credentials in the user's Composio project.

Add to Cetus

Use Settings -> MCP, or the manage_mcp tool if available, with:

{
  "name": "Composio",
  "transport": "http",
  "url": "https://backend.composio.dev/v3/mcp/YOUR_SERVER_ID?user_id=YOUR_USER_ID",
  "headers": {
    "x-api-key": "YOUR_COMPOSIO_API_KEY"
  },
  "enabled": true
}

After saving, test the MCP server. A successful test should list the tools that the Composio server exposes. Start a new conversation before relying on newly added tools, because Cetus freezes MCP configuration per conversation.

Creating a Composio MCP URL

Composio supports creating MCP servers from the dashboard or SDK. For a single toolkit, Composio's documented flow is:

1. Create an auth config for the toolkit, such as Gmail, Linear, Notion, Slack, or GitHub.
2. Create an MCP server configuration with the toolkit and allowed tools.
3. Generate a user-specific MCP URL for a user_id.
4. Connect using the generated MCP URL and an x-api-key header.

Example shape from Composio docs:

URL: https://backend.composio.dev/v3/mcp/YOUR_SERVER_ID?user_id=YOUR_USER_ID
Header: x-api-key: YOUR_COMPOSIO_API_KEY