Story

Relay is an SMS API I built because integrating Twilio for a simple verification flow took me an unreasonable amount of time. The API is a single POST endpoint. You sign up, get an API key, and send a real SMS in under 2 minutes.

Tech stack: Express.js API, AWS End User Messaging for delivery, PostgreSQL (Supabase), Redis rate limiting. SDKs for JS/TS, Python, and Go.

Currently US/Canada only. Starting at $19/mo with 1,500 messages included. We handle 10DLC compliance and carrier registration.

One thing that might interest HN: AI agents can create accounts and start sending via POST /v1/accounts/autonomous. No human verification required. Trust levels auto-upgrade based on delivery quality.

Also released sms-dev as a free local dev tool (npm install -g @relay-works/sms-dev) for testing SMS flows without sending real messages.

Docs: docs.relay.works | Site: relay.works