resend-skills_skill

Overview

This skill helps you send transactional and bulk emails via the Resend API using Python. It supports single sends (attachments, scheduling) and batch sends (up to 100 distinct emails) and includes production-ready guidance on idempotency, retries, and deliverability. Use it to integrate welcome messages, receipts, password resets, notifications, and bulk notifications into your app.

How this skill works

The skill chooses between two Resend endpoints: POST /emails for single transactional sends and POST /emails/batch for multi-email batches. It validates required fields, applies idempotency keys to prevent duplicates, implements retry/backoff for transient errors, and recommends webhook verification to track delivery events. It also provides guidance for chunking large sends and configuring deliverability settings like SPF/DKIM/DMARC.

When to use it

• Send a single transactional message that needs attachments or scheduling.
• Dispatch multiple distinct emails in one request to reduce API calls (<=100 emails).
• Implement password resets, welcome flows, order confirmations, or receipts.
• Run bulk notifications or announcements where per-email content differs.
• Streamline large sends by chunking into multiple batch requests.

Best practices

• Always set idempotency keys (format: event/entity or batch-event/batch-id) and reuse them only for identical payloads.
• Retry only on 429 or 500 with exponential backoff (1s, 2s, 4s…), max 3–5 attempts.
• Pre-validate batches (required fields, email format, <=100 items) because one invalid email fails the whole batch.
• Verify webhook signatures before processing events and handle email.delivered, bounced, and complained events.
• Ensure domain authentication (SPF, DKIM, DMARC), include plain-text bodies, and avoid no-reply addresses for better deliverability.

Example use cases

• Send a welcome email with attachments and scheduled send using POST /emails.
• Send a batch of personalized order confirmations for up to 100 orders in one request.
• Chunk and parallelize a 1,000-email notification by splitting into 10 batch requests with unique idempotency keys.
• Track delivery status with webhooks and remove bounced addresses from your lists automatically.
• Use templates for repeatable content and pass case-sensitive template variables from your application.