Introduction

Relay is transactional email as a plain HTTPS API — no SDK to install or keep updated. Send from any language in a single request.

Every request authenticates with an API key as a Bearer token and talks to https://api.relay.dev. Relay validates the payload, rate-limits per tenant, checks your suppression list, and hands the message to AWS SES from the edge — then streams delivery, bounce, and complaint events to your signed webhooks.

Prefer a machine-readable reference? The full OpenAPI spec is published for you.

Quickstart

Create an API key in the console, then send your first email:

curl https://api.relay.dev/v1/email \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "you@yourdomain.com",
    "to": ["ada@lovelace.io"],
    "subject": "Welcome to Acme",
    "html_body": "<h1>You are in.</h1>"
  }'

You'll get a 202 with a message_id and watch it move in your activity feed. Next: Authentication → Send an email.