DEVELOPERS / AGENTS

MCP for agents

Give an agent narrowly scoped tools for listing, reading, sending, and replying to mailbox conversations.

Endpoint and authentication

Startup Mail exposes a stateless Streamable HTTP MCP endpoint at:

EXAMPLE

https://api.startupmail.dev/mcp

Use the same Bearer API key as the REST API. Available tools are determined when the connection is created from that key’s scopes.

Configure a client

The exact configuration format depends on the MCP client. A typical HTTP entry needs the URL and authorization header:

EXAMPLE

{
  "startupmail": {
    "type": "http",
    "url": "https://api.startupmail.dev/mcp",
    "headers": {
      "Authorization": "Bearer ${STARTUPMAIL_API_KEY}"
    }
  }
}

Do not paste a production key into a configuration file that will be committed or shared. Prefer environment-variable interpolation supported by your client.

Available tools

Tool	Required scope	Purpose
`list_mailboxes`	`mailboxes:read`	See addresses available to the key
`list_threads`	`mail:read`	List recent threads for a mailbox and label
`get_thread`	`mail:read`	Read a thread with messages and attachment metadata
`send_email`	`mail:send`	Start a conversation from an accessible mailbox
`reply_to_message`	`mail:send`	Continue a thread from a specific message

Permission an agent safely

Create a dedicated key for one agent or workload. Start with read-only scopes, add mail:send only when the workflow needs it, and keep human approval around ambiguous or high-impact sends.