Resend
EmailSend transactional email through Resend from any workflow. Agents send single or batch emails, schedule and cancel sends, verify domains, and manage audiences, contacts, and broadcasts across 29 actions.
What This Integration Enables
Deliverability is a reputation your domain earns one send at a time and loses in a single bad afternoon. Resend treats sending as infrastructure, domains with DNS verification, scoped API keys, delivery events per email, and FlowRunner agents run the operation on top of it: single transactional sends with attachments and scheduling, batch fan-outs of up to 100 independent emails, audience and contact management, and full broadcast lifecycle from draft to sent. - Transactional flow: receipts, resets, and alerts sent from workflows, scheduled in natural language when timing matters - Batch fan-out: up to 100 tailored, independent emails in one call for survey follow-ups and notification bursts - List hygiene: contacts created, updated, and unsubscribed based on what delivery events actually report - Broadcast lifecycle: drafts created and updated by agents, sent only after review - Infrastructure management: domains registered and verified, tracking and TLS configured, keys provisioned and revoked The asymmetry that shapes the [human-in-the-loop](/concepts/human-in-the-loop) design: a single email that goes wrong is an apology, a broadcast that goes wrong is a reputation event. Agents draft everything; the mass send waits for a person.
Without FlowRunner
With FlowRunner
Use Case Scenarios
Onboarding email that starts the moment the user exists
A new record in [Airtable](/integrations/airtable) fires the onboarding flow. Send Email delivers a personalized welcome with the workspace guide attached, tagged for analytics, and Create Contact files the person into the onboarding audience. Three days later a scheduled Send Email follows up, unless the delivery event on the first message came back bounced, in which case Update Contact flips the subscription status and the follow-up never fires. The sequence behaves like a lifecycle tool, but it lives in the same workflow that provisioned the account, with the same audit trail.
A hundred personalized follow-ups in one call
Survey responses land from [Typeform](/integrations/typeform). The agent composes a tailored reply for each respondent, referencing their answers, and ships the whole set through Send Batch Emails as independent messages in a single call. Responses that flagged churn risk skip the batch and route to a human owner instead, with a drafted personal note. The mechanical hundred get handled by the machine; the five that matter get handled by a person who was told exactly why.
The newsletter pipeline with a review gate where it counts
Each week the agent assembles the product update from the changelog, builds the HTML with FIRST_NAME personalization and the unsubscribe link, and runs Create Broadcast against the subscriber audience. The marketing lead gets the rendered draft and the live audience count from Get Audience, edits through Update Broadcast if needed, and approves. Send Broadcast schedules the delivery, and the confirmation posts to [Slack](/integrations/slack). List cleanup runs continuously in the background: complained addresses get unsubscribed through Update Contact, and the audience the next broadcast targets is already the clean one.
Human-in-Loop Highlight
Send Broadcast delivers to an entire audience with one call, and delivered email cannot be recalled. A broken personalization variable, a stale segment, or a subject line that reads differently at scale lands in thousands of inboxes under your verified domain, and the spam complaints that follow damage deliverability for every transactional email that domain sends afterward, receipts and password resets included. So no FlowRunner agent sends a broadcast on its own judgment: drafts are built and updated by machine, reviewed by a person with the rendered content and audience count in front of them, and scheduled only on approval. Delete Domain sits behind the same gate for a blunter reason: removing a verified sending domain stops every workflow that sends from it, instantly, and re-verification is not instant. The infrastructure that took weeks to warm up does not get modified by reflex.
Agent Capabilities
29 actionsEmails
5- Send Email Sends a transactional email with up to 50 recipients, CC and BCC, reply-to, custom headers, analytics tags, natural-language or ISO 8601 scheduling, and attachments from FlowRunner files or remote URLs up to 40 MB.
- Get Email Retrieves a sent or scheduled email with its content and last delivery event: delivered, bounced, or complained. The feedback loop for list hygiene.
- Update Email Reschedules a not-yet-sent email to a new delivery time.
- Cancel Scheduled Email Cancels a scheduled email before it sends, the undo that exists only until delivery.
- Send Batch Emails Sends up to 100 fully independent emails in one call, each with its own sender, recipients, subject, and content. No attachments, tags, or scheduling in batch mode.
Domains
6- Create Domain Registers a sending domain and returns the SPF, DKIM, and MX records to add at your DNS provider.
- List Domains Lists sending domains with verification status and region.
- Get Domain Retrieves a domain with per-record DNS status, the checklist for finishing verification.
- Verify Domain Triggers asynchronous DNS verification once the records are in place.
- Update Domain Configures click tracking, open tracking, and TLS enforcement for a domain.
- Delete Domain Permanently removes a sending domain, stopping all sends from its addresses. Human-gated.
API Keys
3- Create API Key Creates a Full Access or Sending Access key, optionally restricted to one domain. The token is visible only at creation.
- List API Keys Lists keys by name and creation time; token values are never returned.
- Delete API Key Permanently revokes a key; anything still using it loses access immediately.
Audiences
4- Create Audience Creates a named contact list that broadcasts target.
- List Audiences Lists audiences with IDs and names.
- Get Audience Retrieves one audience, the count check before a send.
- Delete Audience Permanently deletes an audience and every contact in it. Cannot be undone.
Contacts
5- Create Contact Adds a contact to an audience with email, name, and subscription status.
- List Contacts Lists an audience's contacts with subscription status.
- Get Contact Retrieves one contact by ID or email.
- Update Contact Updates a contact's name or subscription status, the write behind automated list hygiene.
- Delete Contact Permanently removes a contact from an audience.
Broadcasts
6- Create Broadcast Creates a draft marketing email targeting an audience, with personalization variables and the required unsubscribe link. Nothing sends until Send Broadcast.
- List Broadcasts Lists broadcasts with status: draft, scheduled, or sent.
- Get Broadcast Retrieves a broadcast's sender, subject, audience, and scheduling detail.
- Update Broadcast Edits a draft's audience, content, subject, or sender; sent broadcasts are immutable.
- Send Broadcast Sends a draft to its audience, immediately or scheduled. The mass send this page's human gate exists for.
- Delete Broadcast Deletes a draft broadcast; scheduled and sent ones cannot be deleted.
Frequently Asked Questions
What can FlowRunner do with Resend?
FlowRunner agents can run Send Email, Get Email, and Update Email in Resend, plus 26 more actions.
Does connecting Resend to FlowRunner require OAuth?
No. Resend connects to FlowRunner with an API key, no OAuth flow required.
Can Resend trigger a FlowRunner workflow automatically?
Resend doesn't currently expose triggers in FlowRunner. It connects as an action step inside workflows started by another trigger.
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