> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lupin.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP server

> Give Claude and Cursor a Lupin inbox.

# MCP

`POST /mcp` speaks JSON-RPC (stateless) with bearer auth — point any MCP
client at it:

```json theme={null}
{ "jsonrpc": "2.0", "id": 1, "method": "initialize" }
{ "jsonrpc": "2.0", "id": 2, "method": "tools/list" }
{ "jsonrpc": "2.0", "id": 3, "method": "tools/call",
  "params": { "name": "send_message",
    "arguments": { "inbox_id": "in_…", "to": ["u@e.com"], "subject": "Hi" } } }
```

Tools: `list_inboxes`, `create_inbox`, `list_threads`, `search_threads`,
`get_thread`, `list_emails`, `send_email`, `reply_to_email`,
`create_draft`, `list_domains`, `query_usage`. Everything runs inside the
caller's organization — keys scope exactly like REST.