I built this because I was working on an AI agent that needed to create
accounts on various websites, but kept getting stuck at phone verification.
Existing SMS APIs (Twilio Verify, etc.) are designed for YOU to verify
YOUR users. I needed the opposite - my agent needed to receive OTPs.
So I built Agent OTP:
POST /api/v1/numbers/rent → Get a phone number
POST /api/v1/numbers/{n}/wait-for-otp → Wait for SMS (with timeout)
DELETE /api/v1/numbers/{n} → Release when done
That's basically it. The agent gets a number, uses it to sign up somewhere,
waits for the OTP, and releases the number.
Stack: FastAPI + PostgreSQL on Railway, Twilio for SMS, LemonSqueezy for
payments. Landing page on Cloudflare Pages.
Pricing: 5 free OTPs/month, then $9/50, $29/200, $49/500.
Site: https://agentotp.angletech.io
Docs: https://agentotp.angletech.io/docs/
Happy to answer questions about the implementation or the surprisingly
annoying edge cases with SMS delivery timing.