Generic / custom client

What are the connection details?

How do I connect Generic / custom client?

1. 1

   Create a production API key

   Open https://www.unitpost.com → Settings → API keys → create a scoped key. Copy the full pk_live_… value (shown once). In every snippet below, replace pk_live_YOUR_KEY with that value.

   Must be production. Keys from unitpost.dev only work on the dev API. This MCP URL is production (mcp.unitpost.com) — a .dev key returns 401 Invalid API key on tool calls even if the server appears connected.

2. 2

   Point the client at Unitpost

   Configure a streamable-HTTP MCP server with these values:

   Server URL	https://mcp.unitpost.com/mcp
   Transport	Streamable HTTP
   Auth header	Authorization: Bearer pk_live_YOUR_KEY
   Tools	one per API operation (emails_send, campaigns_send, …)

3. 3

   Send the Authorization header

   On every MCP request, send Authorization: Bearer pk_live_YOUR_KEY (replace the placeholder; keep Bearer ).

   Grant only the scopes the agent needs (e.g. emails:send for emails_send). Prefer a revocable key dedicated to the agent.

4. 4

   Discover tools

   The server advertises one tool per API operation (emails_send, campaigns_send, domains_verify, …). A write's body maps to the API request body.

5. 5

   Verify

   Call a read tool (e.g. list domains). A 401 Invalid API key usually means a .dev key or a missing Bearer prefix — recreate the key on www.unitpost.com and retry.

Every MCP call uses the same pipeline as the REST API (scopes, rate limits, suppression, tracking, webhooks). Full tool list: /api/v1/openapi.json.