migrate-sendgrid

name	migrate-sendgrid
description	Use when migrating SendGrid email integration to Resend - detects @sendgrid/mail, sgMail, sendgrid-ruby, sendgrid-go, sendgrid-java, sendgrid-php, or SENDGRID_API_KEY patterns.
license	MIT
metadata	{"author":"resend","version":"1.0.0","homepage":"https://resend.com/migrate/sendgrid","source":"https://github.com/resend/resend-migration-skills"}
inputs	[{"name":"RESEND_API_KEY","description":"Resend API key. Get yours at https://resend.com/api-keys","required":true}]

Migrate from SendGrid to Resend

Overview

Resend is a modern email platform for developers. This skill covers migrating SendGrid integrations to Resend across all supported SDKs.

Automated tool: resend.com/migrate/sendgrid — paste SendGrid code and get Resend code instantly.

Detection Patterns

Code is SendGrid if it contains any of: @sendgrid/mail, sendgrid, SendGrid, SENDGRID, sgMail, sg.client, sendgrid-ruby, sendgrid-go, sendgrid-java, sendgrid-php

Migration Checklist

• Verify domain in Resend Domains (SPF/DKIM/DMARC)
• Create API key at resend.com/api-keys
• Replace env var: SENDGRID_API_KEY → RESEND_API_KEY
• Replace SDK (see SDK Examples)
• Map webhook events (see Webhooks)
• Update SMTP config if used (see SMTP)
• Review feature differences (see Feature Mapping)

Key Differences at a Glance

Aspect	SendGrid	Resend
API endpoint	https://api.sendgrid.com/v3/mail/send	https://api.resend.com/emails
Auth header	Authorization: Bearer $SENDGRID_API_KEY	Authorization: Bearer $RESEND_API_KEY
Batch send	sgMail.sendMultiple()	resend.batch.send()
Response	[response, body]	{ data, error }
Idempotency	Not supported	Idempotency-Key header or SDK option
Rate limit info	Error only	IETF-standard response headers
Rust SDK	No official SDK	resend-rs available
Templates	Dynamic templates (templateId)	React Email components or html
Tracking	Per-email trackingSettings	Configured per-domain in dashboard
Unsubscribe groups	asm field	Resend Topics (topic_id)
IP pools	ipPoolName field	Account-level in dashboard

Quick Reference

Reference	Use When
SDK Examples	Converting code for Node.js, Python, Ruby, Go, PHP, Java, .NET, Elixir, cURL
SMTP	Updating SMTP hostname, port, credentials
Webhooks	Mapping SendGrid event types to Resend event types
Feature Mapping	Templates, tracking, unsubscribe groups, idempotency

Dashboard Concepts

SendGrid	Resend
Sender Authentication	Domains page
Activity	Emails page
Dashboard (stats)	Metrics page
Event Webhook	Webhooks page

Common Mistakes

Mistake	Fix
asm has "no equivalent" in Resend	It does — use topic_id field + Resend Topics. See Feature Mapping
Webhook unsubscribe maps to email.unsubscribed	That event doesn't exist. Use contact.updated. See Webhooks
sendAt: unixTimestamp copied over	Resend uses ISO 8601 string: scheduledAt: new Date(...).toISOString()
Expecting [response, body] from resend.emails.send()	Resend returns { data, error }
Looking for a CLI migration tool	The tool is a web UI: resend.com/migrate/sendgrid — no CLI
sgMail.sendMultiple() replaced by passing array to to field	Wrong — to array sends one email to multiple recipients. resend.batch.send() sends multiple different emails in one call
dropped SendGrid event has no Resend equivalent	Monitor email.bounced and email.delivery_delayed instead. See Webhooks
Resend SMTP only supports ports 465 and 587	Resend also supports 2465 (SMTPS) and 2587 (STARTTLS) as alternatives. See SMTP
Forgot to rename env var	SENDGRID_API_KEY → RESEND_API_KEY

Resources

• Full migration guide
• Resend API reference
• React Email — component-based email templates
• Resend Broadcasts — for marketing/newsletter campaigns