Connect Trillet over MCP

Trillet ships an official Model Context Protocol server. Point an MCP client at it and your assistant can build agents, write call flows, wire in-call API tools, attach knowledge bases, buy and bind phone numbers, run workflows, and read real call transcripts — without you leaving the chat.

The server exposes 77 tools. Every tool is annotated read-only or destructive, and the destructive ones refuse to run without an explicit confirm: true.

Before you start

You need two values from your Trillet workspace.

Choose a route

There are two ways to connect. They expose the same tools.

If your client supports remote MCP servers with custom headers, use the hosted server. Otherwise use the local route — it is not a lesser option, just a different transport.

Hosted server

POST https://mcp.trillet.ai/mcp

Streamable HTTP, MCP protocol revision 2025-06-18. Authentication is two headers:

If your client lets you set a URL but only one header, you can pass the workspace id as a query parameter instead:

https://mcp.trillet.ai/mcp?workspace=<your workspace id>

The workspace id is not a secret, so it is safe in a URL. The API key is accepted only in the Authorization header — never in the query string — so it stays out of browser history and server logs.

Claude Code

claude mcp add --transport http trillet https://mcp.trillet.ai/mcp \
  --header "Authorization: Bearer YOUR_API_KEY" \
  --header "X-Trillet-Workspace-Id: YOUR_WORKSPACE_ID"

Then confirm it is live:

claude mcp list

Any HTTP client

A raw request, to verify connectivity or to wire up a client we have not documented:

curl -X POST https://mcp.trillet.ai/mcp \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "X-Trillet-Workspace-Id: YOUR_WORKSPACE_ID" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2025-06-18",
      "capabilities": {},
      "clientInfo": { "name": "my-client", "version": "1.0.0" }
    }
  }'

A successful response carries an Mcp-Session-Id header. Send it on every subsequent request.

Local server (stdio)

The same server, published on npm as @trillet-ai/mcp. It reads both credentials from environment variables and talks to the Trillet API directly.

{
  "mcpServers": {
    "trillet": {
      "command": "npx",
      "args": ["-y", "@trillet-ai/mcp@latest"],
      "env": {
        "TRILLET_API_KEY": "YOUR_API_KEY",
        "TRILLET_WORKSPACE_ID": "YOUR_WORKSPACE_ID"
      }
    }
  }
}

ChatGPT and the connector directories

Trillet is not currently installable from the ChatGPT connector UI, the Claude connector directory, or any other one-click MCP directory.

Those surfaces discover and authorise a server through OAuth. The Trillet MCP server authenticates with a static API key and does not implement OAuth — there is no /.well-known/oauth-protected-resource or /.well-known/oauth-authorization-server endpoint to discover, so the directories have nothing to connect to.

In practice:

• ChatGPT — not supported today. The connector dialog has no field for a custom header, so the workspace id cannot be supplied. Even with the ?workspace= query parameter above, whether you can set a bearer token at all depends on your ChatGPT release. We do not recommend this path.
• Claude connector directory — Trillet is not listed. Use the Claude Code or Claude Desktop setup above instead; both are fully supported.
• Everything else — if the client can set custom headers, the hosted endpoint works. If it can run a command, the stdio package works.

Agencies and multiple workspaces

Every tool accepts an optional workspace_id argument that overrides the connection's default workspace for that one call. One connection can therefore operate across several client workspaces, as long as your API key's user is a member of each.

Ask your assistant to "list the agents in workspace <id>" and it will pass the override through.

What you can do

Tools that cost money or change the world

These are annotated destructive and will not run unless the call includes confirm: true, so your assistant has to ask you first:

trillet_start_outbound_call (places a real call) · trillet_purchase_phone_number (bills the workspace) · trillet_run_workflow (real run, real side effects) · trillet_register_external_number · and every delete tool.

Troubleshooting

Security

• The API key and workspace id are read from headers or environment variables and are never logged.
• The API key is never accepted in a URL, so it cannot leak through browser history, referrers, or access logs.
• trillet_list_secrets always returns masked values.
• Tools with real-world or irreversible effects are annotated destructive and gated behind confirm: true.
• Revoke a key at any time from Settings → Developer → API Keys. Revocation takes effect immediately on both routes.

Getting help