Connect Claude (or any MCP client) to Mailbo

Mailbo runs a Streamable HTTP MCP server at /api/mcp. Any client that speaks Model Context Protocol can connect to it with an API key.

1. Get a key

Open Settings → MCP connection in Mailbo. Click Create key (or paste one you already have). Copy the mb_… value.

The MCP page shows ready-to-paste snippets for each client below, with your key already filled in.

2. Claude Code (CLI)

claude mcp add --transport http --scope user mailbo https://mailbo.io/api/mcp \
  --header "Authorization: Bearer mb_YOUR_KEY"

Verify:

claude mcp list

You should see mailbo with a green check.

3. Claude Desktop

Edit the config file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Add (or merge) this block:

{
  "mcpServers": {
    "mailbo": {
      "url": "https://mailbo.io/api/mcp",
      "headers": { "Authorization": "Bearer mb_YOUR_KEY" }
    }
  }
}

Restart Claude Desktop.

4. Other MCP clients (Cursor, custom agents, …)

Any Streamable-HTTP MCP client needs just two values:

5. Test the connection

Open Claude and ask:

Use mailbo to show me my workspace summary.

You should see a tool call to mailbo returning your contact count, tags, lists, sequences, and recent purchases. If you get an auth error, your key is wrong, revoked, or copy-pasted with a leading space.

6. Update / revoke

• Rotate the key: create a new one on the same page, run claude mcp remove mailbo then re-add with the new key, or edit the desktop config and restart.
• Revoke: Settings → API keys → Revoke. The MCP connection stops working immediately.

Next: MCP tools reference — every tool the LLM can call.