Resend
Email API for developers, with broadcasts, contacts and event-triggered automations.
Updated Sep 30, 2026
Overview
Resend is an email API for developers. It sends transactional email and
marketing broadcasts from your verified domains, keeps contacts in segments
with topic subscriptions, and runs automations that custom events start. The
hosted MCP server, the resend CLI and the REST API each cover the whole
platform.
The MCP server signs in with OAuth; an agent that can't open a browser can
send an API key as a Bearer token instead. Direct API requests must also send
a User-Agent header, and a team gets 10 requests per second by default.
Workflows
Workflows that use Resend's tools.
TContributed by thedogwiththedataonitWin back canceled customers with an offer for why they leftReads why each Stripe subscription was canceled, sorts the reason with Jev, and emails a win-back offer that fits it with Resend.
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R- TContributed by thedogwiththedataonitInvite NPS promoters with specific praise to a case study
Pulls 9s and 10s from your Typeform NPS survey, picks promoters whose praise names a result with Jev, and emails each a case-study invite.
TTR - TContributed by thedogwiththedataonitRecover failed payments before the subscription cancels
Finds past-due Stripe subscriptions, emails each customer a link to pay with Resend, and posts the largest amounts to Slack.
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Tools
What agents can reach at Resend.
- Add a contact to a segment
Adds an existing contact, found by ID or email address, to a segment that broadcasts can target.
- Create a broadcast
Creates a marketing email to every subscribed contact in one segment, saved as a draft or, with send set to true, sent or scheduled at once.
- Create a contact
Adds a contact with an email address and optional name, custom properties, segments and topic subscriptions, and returns its ID.
- Get email metrics
Returns the account's delivery and engagement counts and rates, such as sent, delivered, open, click, bounce and unsubscribe, for a date range as totals or by period, domain, email or broadcast.
- List a broadcast's clicked links
Returns the links people clicked in a broadcast, most clicked first, with total clicks and the number of people who clicked each.
- List a broadcast's recipients
Returns the people a broadcast reached for one event, such as everyone who opened, clicked, bounced or unsubscribed, with their contact ID and, for clicks, the links they clicked.
- 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.
- Send an event
Sends a named event for one contact, by contact ID or email address, and starts every automation that event triggers.