Emailactive

Resend API

Email infrastructure built for developers and coding agents.

Resend provides REST APIs, SDKs, webhooks, a CLI, and MCP integrations for sending and receiving transactional email, managing contacts, and running marketing email workflows.

Last checked Aug 15, 2026 11 primary sources Agent tasks not tested yet

Editorial verdict

What we know before manual testing

A particularly complete email API for modern developer workflows, with unusually strong official support for coding agents. Manual task testing is still required before we assign an agent-readiness verdict.

Verified facts

Integration overview

Sourced from Resend documentation and checked on Aug 15, 2026.

AuthenticationBearer API key + OAuth 2.1 with PKCE

Free access3,000 transactional emails per month, capped at 100 per day

OpenAPI Available

Official SDKs10

Webhooks Available

Default limit5 requests per second per team; increases available by request

Common jobs

What developers use Resend for

01Send transactional email

02Receive and process inbound email

03Track delivery, bounce, and complaint events

04Manage contacts and marketing broadcasts

05Let coding agents operate email workflows

Agent readiness

Strong official support, independent test pending

Not tested yet

MCP server Available

Official CLI Available

llms.txt Available

Non-interactive auth Available

Documented client support

What remains unverified

We have not yet measured setup time, first-call success, manual corrections, task completion, or recovery from errors in any agent client.

Decision guide

Where Resend fits

Best for

Product teams sending transactional and lifecycle email
TypeScript and multi-language applications that prefer official SDKs
Teams that want CLI, MCP, and machine-readable documentation

Strengths

Broad official SDK coverage plus an OpenAPI repository
Scoped API keys and OAuth for delegated integrations
Documented test addresses, structured errors, webhooks, and idempotency

Watch for

A verified domain is required before sending broadly
The free plan is capped at 100 transactional emails per day
The default API rate limit is five requests per second per team
The API does not currently expose a formal versioning system

Access and integration

Implementation details

Base URL: https://api.resend.com
Protocols: REST, HTTPS, Webhooks, SMTP
Credential scope: API keys support full or sending-only access; OAuth supports emails:send or full_access
Testing: Test addresses simulate delivery, bounce, complaint, and suppression events
Pricing: Monthly volume for transactional email; contact-based plans for marketing email
Resources: Pricing Status Changelog GitHub