Skill

migrate-sendgrid

Name: migrate-sendgrid
Author: Resend

migrate SendGrid integrations to Resend

Published by Resend Updated Apr 6

Covers SendGrid Resend Migration Email

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.

SKILL.md

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

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SkillTagsUpdated

resend-migrate
migrate email providers to Resend
EmailMigrationResendSendGrid
Apr 6

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