API & MCP — overview
Two ways to drive Mailbo from outside: the REST API for code, the MCP server for AI clients like Claude.
Mailbo exposes two surfaces for programmatic control:
| Surface | When to use it | How auth works |
|---|---|---|
REST API (/api/v1/*) | Backend code, CLI scripts, server-to-server integrations. | Authorization: Bearer mb_… on every request. |
MCP server (/api/mcp) | AI clients like Claude Code, Claude Desktop, Cursor — anything speaking Model Context Protocol. | Same mb_… key, same Authorization header. |
Both run off the same workspace API keys and the same authorization scopes (read, write). Anything you can do in the UI you can do here — create contacts, tag them, build sequences, launch automations, fire events.
Get a key
- Settings → API keys → Create key. Pick scopes (defaults to read + write). Copy the key once — only its hash is stored.
- Or Settings → MCP connection to get a key plus ready-to-paste snippets for Claude clients.
Keep the key secret. Anyone with it has full workspace access. Revoke from Settings → API keys if it leaks.
Base URL
https://mailbo.io/api/v1
https://mailbo.io/api/mcp
Quick test
curl https://mailbo.io/api/v1/me \
-H "Authorization: Bearer mb_YOUR_KEY"
Returns your workspace and scopes. If you get 401 Invalid or revoked token, the key is wrong or revoked.
Where to go next
- REST API reference — every endpoint with short descriptions.
- Connect Claude to Mailbo (MCP) — Claude Code / Desktop / other clients.
- MCP tools reference — all 34 MCP tools.
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Last updated 6/23/2026← More in API & MCP Reference