Resend Block

The Resend block sends transactional and marketing emails through the Resend API. It supports HTML and plain text content, CC/BCC, reply-to, scheduled delivery, tags, custom headers, attachments, batch sending, and email retrieval or cancellation. Reach for it whenever a workflow needs to send or manage email.

Overview

When to Use

• Send transactional emails (welcome, password reset, receipts) from a workflow
• Deliver AI-generated content as an HTML email to one or many recipients
• Schedule emails for future delivery (up to 30 days out)
• Send personalized emails in bulk with a single batch request
• Look up the status and details of a previously sent email
• Cancel a scheduled email before it goes out

Configuration

API Key

Your Resend API key (starts with re_). Required for every action. Stored as a password field.

Action

Dropdown selecting the operation: Send Email (send), Batch Send (batch), Get Email (get), or Cancel Scheduled Email (cancel). Defaults to send. The remaining fields are conditionally shown based on this choice.

Send Email Fields

For the send action: From (verified-domain sender, required), To (recipients, comma-separated, required), Subject (required), HTML Body, and an advanced Plain Text Body. Advanced extras include CC, BCC, Reply-To, Schedule At (ISO 8601 or natural language), Tags (JSON), Custom Headers (JSON), and Attachments (JSON, max 40MB total).

Batch Send Fields

For the batch action: Emails (Batch), a JSON array of email objects (each with from, to, subject, and html/text). Supports the AI Wand to generate the array.

Get / Cancel Fields

For the get and cancel actions: Email ID, the id returned from a previous send.

Inputs & Outputs

• Inputs: apiKey (string), action (string), from (string), to (string), subject (string), html (string), text (string), cc (string), bcc (string), replyTo (string), scheduledAt (string), headers (string, JSON), tags (string, JSON), attachments (string, JSON), emails (string, JSON), emailId (string)
• Outputs: id (string), ids (json), email (json), status (string), error (string)

Tools

• Resend Send Email (resend_send) — Sends a single email via the Resend API. Accepts apiKey, from, to, subject, and optional html, text, cc, bcc, replyTo, scheduledAt, headers, tags, and attachments. Returns id, status, and error.
• Resend Batch Send (resend_batch) — Sends multiple emails in a single Resend API call. Accepts apiKey and emails (a JSON array of email objects). Returns ids (array of created email IDs) and error.
• Resend Get Email (resend_get) — Retrieves full details of a previously sent email by its ID. Accepts apiKey and emailId. Returns email (JSON object with full email details) and error.
• Resend Cancel Email (resend_cancel) — Cancels a scheduled (not-yet-delivered) email by its ID. Accepts apiKey and emailId. Returns status and error.

YAML Example

resend_1:
  type: resend
  name: "Resend"
  inputs:
    apiKey: "{{variable.resendApiKey}}"
    action: "send"
    from: "Your Name <you@yourdomain.com>"
    to: "recipient@example.com"
    subject: "Welcome aboard"
    html: "{{agent_1.content}}"
  connections:
    outgoing:
      - target: next-block-id