Set up AgentInbox with Cursor

Give your Cursor AI agent a real email address in under two minutes. Connect AgentInbox as an MCP server and start sending and receiving emails from Composer.

Prerequisites

1. Cursor IDE installed — version 0.45+ required for MCP support.
2. A project open in Cursor (MCP servers are configured per-project or globally).

Add via Cursor Settings

The fastest way to get started — no config files needed.

Open Cursor Settings (Cmd + , on macOS)
Navigate to the MCP section in the sidebar
Click Add new MCP server
Fill in the fields:
Field Value
Name agentinbox
Transport HTTP
URL https://mcp.agentinbox.sh/mcp
Click Save — the server appears in your MCP list

Or add via .cursor/mcp.json

Prefer config-as-code? Create a .cursor/mcp.json file in your project root:

.cursor/mcp.json

{
  "mcpServers": {
    "agentinbox": {
      "url": "https://mcp.agentinbox.sh/mcp",
      "transport": "http"
    }
  }
}

Save the file and restart Cursor. The server will be picked up automatically.

Authentication

AgentInbox uses OAuth with auto-approve — no passwords, no signup forms.

On first use, a browser tab opens briefly for OAuth authorization
The authorization auto-approves instantly — no manual action needed
The browser tab closes and Cursor stores the token locally
Your agent is assigned a permanent email address (e.g. agent-b4a0@agent-mail.agentinbox.sh)
All future connections reuse the stored credentials — fully automatic

Tip: Same credentials always map to the same agent identity and email address. No configuration needed.

Using AgentInbox in Cursor

Open Composer in Agent mode and ask your agent to use email. Here are some examples:

“Send an email to hello@example.com introducing yourself”

“Check my inbox for new emails”

“What's my email address?”

Cursor will automatically invoke the right AgentInbox tool — send_email, get_emails, or get_inbox_address — based on your prompt.

Alternative: API key

If you prefer token-based auth (no browser popup), pass an API key in your MCP config:

.cursor/mcp.json

{
  "mcpServers": {
    "agentinbox": {
      "url": "https://mcp.agentinbox.sh/mcp",
      "transport": "http",
      "headers": {
        "Authorization": "Bearer sk-your-api-key"
      }
    }
  }
}

Replace sk-your-api-key with your actual key. No browser popup required — fully headless.

Pricing

AgentInbox offers a generous free tier to get started.

Plan	Price	Emails
Free	Free	500 / month
Pro	$5 / month	10,000 / month

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Field	Value
Name	agentinbox
Transport	HTTP
URL	https://mcp.agentinbox.sh/mcp