Send an email

Send an email

Sends one email from a verified domain to up to 50 recipients, now or at a scheduled time, and returns its ID.

Note: Pass an Idempotency-Key header (--idempotency-key on the CLI) so a retry never sends it twice; keys expire after 24 hours.

Set up

Use the first option your agent supports.

MCP (official, remote)

Add this server to your agent's MCP settings, then sign in when asked.

{ "mcpServers": { "resend": { "url": "https://mcp.resend.com/mcp" } } }

Call the MCP tool send-email.

Server URL: https://mcp.resend.com/mcp

CLI (official)

Install the command, then confirm it runs.

npm install -g resend-cli
resend --version

Run resend emails send.

Set $RESEND_API_KEY in your environment first (get a key: https://resend.com/api-keys).

API (official)

• Base URL: https://api.resend.com
• Endpoint: POST /emails
• Auth: send the header Authorization: Bearer $RESEND_API_KEY
• Get a key: https://resend.com/api-keys
• Docs: https://resend.com/docs/api-reference/introduction

Before anything else, confirm access with the cheapest read-only call, like a list or a search. Never send or change anything to test access.

Rules

• Ask the user before anything that sends messages, costs money, or changes data, and say how many records it touches. One approval covers a batch the user has seen.
• Never print API keys.