Resend

email 62 tools available

The universal API for sending emails.

About this integration

Connect Resend to Definable to triage inboxes, draft and queue follow-ups, classify and route incoming threads. Personas call Resend's 62 tools directly from chat or scheduled flows. Hand off to an email persona to triage, draft, and route — with you in the loop on every outbound.

Connect Resend to Definable and it becomes a set of typed tools your agents plan with — triggered by events, run on schedules, or invoked mid-conversation. Every write is checked by the verifier before it lands.

Auth OAuth2 · 2 clicks

Tools 62 exposed

Plans All, incl. Free

Data Never trained on

Resend · in workflows

What teams actually run.

Three patterns teams run with Resend on day one. Each one is a plain-English prompt — no canvas, no glue code — and you can remix them into anything.

Inbox triage

│ Read incoming threads

│ Classify by intent + urgency

└ Draft replies for review

Auto-follow-up

│ Detect emails awaiting reply for 3+ days

│ Draft contextual nudges

└ Queue for one-click send

Lead capture

│ Listen for inbound from a form alias

│ Extract details

└ Push to the CRM

62 tools available

The Resend toolbox.

Every Resend capability your agents can call, each with a typed schema the planner reads. The router picks the right tool per step; the verifier checks the result.

Add Contact To Segment

Add an existing contact to a segment in Resend. Use when you need to organize contacts into specific segments for targeted communication.

Cancel Email

Cancel a scheduled email.

Create API Key

Create a new API key to authenticate communications with Resend. Use when you need to generate a new authentication token for API access.

Create Audience

Create a list of contacts.

Create Contact

Create a contact in Resend.

Create Contact Property

Tool to create a new contact property in Resend. Use when you need to define custom fields for contacts.

Create Contact V2

Tool to create a new contact in Resend. Use when you need to add a contact to Resend without specifying an audience.

Create Domain

Create a domain through the Resend Email API. The domain is created in a pending/unverified state and cannot be used for sending emails until DNS verification is completed.

Create Template

Tool to create a new email template in Resend. Use when you need to define reusable email templates with optional variables.

Create Topic

Tool to create a new topic to segment your audience. Use when you need to create a topic for organizing contacts by interests or preferences.

Create Webhook

Tool to create a webhook to receive real-time notifications about email events. Use when you need to set up automated notifications for email status changes.

Delete API Key

Remove an existing API key from Resend. Use when you need to revoke or delete an API key.

Delete Audience

Remove an existing audience.

Delete Contact

Delete a contact in Resend.

Delete Contact By ID

Tool to remove an existing contact by its ID. Use when you need to delete a contact directly without specifying an audience.

Delete Contact Property

Remove an existing contact property from Resend.

Delete Domain

Delete a domain through the Resend Email API. Deletion is irreversible; ensure no active email traffic or DNS configurations depend on the domain before calling.

Delete Segment

Remove an existing segment. Use when you need to permanently delete a segment by its ID.

Delete Template

Remove an existing template. Use this action when you need to delete a template from Resend.

Delete Topic

Tool to remove an existing topic in Resend. Use when you need to delete a topic.

Delete Webhook

Remove an existing webhook. Use this to delete a webhook configuration when you no longer need to receive event notifications at that endpoint.

Duplicate Template

Duplicate an existing template through the Resend Email API. Use when you need to create a copy of an existing template.

Get Contact

Tool to retrieve a single contact from Resend by ID or email. Use when you need to get details of a specific contact using the global contacts endpoint.

Get Contact Property

Tool to retrieve a single contact property from Resend. Use when you need to get details about a specific contact property by its ID.

Get Email Attachment

Retrieve a single attachment from a sent email. Use when you need to access attachment metadata and download URL.

Get Segment

Retrieve a single segment by its ID. Use when you need to get detailed information about a specific segment.

Get Template

Retrieve a single template by ID or alias from Resend. Use when you need to view template details.

Get Topic

Tool to retrieve a single topic by its ID in Resend. Use when you need to fetch details of a specific topic.

Get Webhook

Retrieve a single webhook for the authenticated user. Use this to get details about a specific webhook configuration including its endpoint, subscribed events, and signing secret.

List All Contacts

Tool to retrieve a list of all contacts from Resend. Use when you need to fetch contacts across all audiences with optional pagination.

List API Keys

Tool to retrieve a list of API keys for the authenticated user. Use when you need to view all API keys associated with the account, including pagination support for large result sets.

List Audiences

List all audiences.

List Broadcasts

Tool to retrieve a list of broadcasts. Use when you need to fetch all broadcasts or paginate through them.

List Contact Properties

Tool to retrieve a list of contact properties from Resend. Use when you need to view available contact property definitions.

List Contacts

List contacts in Resend.

List Contact Segments

Retrieve a list of segments that a contact is part of. Use when you need to determine which segments a specific contact belongs to.

List Contact Topics

Retrieve a list of topic subscriptions for a contact in Resend. Use when you need to check which topics a specific contact is subscribed to.

List Domains

List all domains. Use the returned domain IDs as inputs for tools like RESEND_VERIFY_DOMAIN that require a domain_id.

List Email Attachments

Tool to retrieve a list of attachments from a sent email. Use when you need to get information about files attached to an email sent via Resend.

List Emails

Tool to retrieve a list of emails sent by your team. Use when you need to fetch outbound emails from your account. Supports pagination with limit, after, and before parameters.

List Received Emails

Tool to retrieve a list of received emails for the authenticated user. Use when you need to fetch incoming emails from the receiving endpoint.

List Segments

Tool to retrieve a list of segments from Resend. Use when you need to view all available segments for audience management.

List Templates

Tool to retrieve a list of templates from Resend. Use when you need to get all available templates with optional pagination support.

List Topics

Tool to retrieve a list of topics for the authenticated user. Use when you need to fetch available topics with optional pagination support.

List Webhooks

Retrieve a list of webhooks for the authenticated user. Use this to view all configured webhooks with their endpoints, event types, and status.

Publish Template

Publish a template through the Resend Email API. Use when you need to make a template publicly available.

Remove Contact From Segment

Remove an existing contact from a segment. Use when you need to disassociate a contact from a specific segment.

Retrieve Audience

Retrieve a single audience.

Retrieve Contact

Retrieve a contact in Resend.

Retrieve Domain

Retrieve a single domain.

Retrieve Email

Retrieve a single email.

Send Batch Emails

Trigger up to 100 batch emails at once. Use when you need to send multiple emails in a single API request.

Send Email

Send an email using Resend. Confirm recipients and content with the user before invoking — sends are irreversible. All recipients must be listed explicitly via `to`, `cc`, or `bcc`; audience-based sending is unsupported. Render HTML or plain text externally before passing via `html` or `text`.

Update Broadcast

Update an existing broadcast in Resend. Use when you need to modify broadcast details like name, subject, content, or recipients.

Update Contact

Tool to update an existing contact in Resend by ID or email. Use when you need to modify contact details such as name or subscription status.

Update Contact Property

Update an existing contact property in Resend. Only the fallback_value can be updated; the key and type fields cannot be changed after creation.

Update Domain

Update an existing domain.

Update Email

Update a scheduled email.

Update Template

Tool to update an existing email template in Resend. Use when you need to modify template properties such as name, subject, HTML content, or variables.

Update Topic

Tool to update an existing topic in Resend. Use when you need to modify the name of a topic.

Update Webhook

Tool to update an existing webhook configuration. Use when you need to modify the endpoint URL, change event subscriptions, or enable/disable a webhook.

Verify Domain

Verify a domain through the Resend Email API. DNS records must fully propagate before verification succeeds; avoid immediate retries after DNS setup.

See it run

One prompt, start to finish.

A real prompt, the Resend tools it calls, and what comes back. This is the whole interface — describe the outcome, agents handle the rest.

❯

Run a real Resend task end-to-end — plan it, execute across the API, and hand back a verified result.

resend.add_contact_to_segment Add an existing contact to a segment in Resend. Use when you need to organize contacts int

resend.cancel_email Cancel a scheduled email.

resend.create_api_key Create a new API key to authenticate communications with Resend. Use when you need to gene · verified

done

Done. Resend responded across 3 calls, the verifier signed off, and the result is logged with every payload.

Pairs well with Resend

Connect Resend to your stack with Workflow

AI-native automation between Resend and 82+ other tools — built, run, and self-healed by Workflow.

All integrations →

Resend + ActiveCampaign

FAQ · Resend

Questions, answered.

What teams ask before connecting Resend.

01 What can I automate with Resend on Definable?

Anything Resend exposes through its API. Common email workflows on Definable include triage inboxes, draft and queue follow-ups, classify and route incoming threads. Personas can call any of the 62 Resend tools directly, then chain the result into another integration without you writing code.

02 How does Resend authentication work?

Resend uses API_KEY on Definable. You connect once from the integrations page, scoped to the permissions you choose, and from then on any persona that has the integration enabled can act on your behalf. Tokens are encrypted at rest and rotated automatically.

03 Is the Resend integration included in my Definable plan?

Yes — every Definable plan, including Starter, includes access to all 62 Resend tools. You only need a separate Resend subscription if Resend itself charges per seat or per API call.

04 Is using Resend through Definable secure?

Every call from a persona to Resend is logged with the user, persona, prompt, and response. Tokens never leave Definable's secrets vault, scopes are configurable per persona, and you can revoke access at any time from the integration page.

05 How do I get started with Resend on Definable?

Sign up for Definable, open the integrations page, find Resend, and connect via OAuth or API key. You can immediately attach Resend to any persona and start running workflows. The free Starter plan includes 5,000 credits/month.

06 What Resend actions does Definable expose?

Definable exposes all 62 Resend actions as callable tools — including `Add Contact To Segment`, `Cancel Email`, `Create API Key`, plus 59 more. Each tool gets a typed parameter schema so personas know exactly how to call it.