Build and Test an OTP Flow in the Sandbox (No Charges)

OTP (one-time passcode) is the most common SMS use case. Here's how to build and test a complete OTP flow in the sandbox before spending a cent.

1. Generate and send

curl "https://sms.esmsafrica.io/api/messages/send" \
  -H "Authorization: Bearer esms_test_..." \
  -d '{"to":"+254712341234","text":"Your code is 482910","sender_id":"eSMSAfrica"}'

You get a realistic response with the segment count and a test_… id. Tip: our OTP templates let you send just the code and we wrap it in an approved template.

2. Handle delivery

A delivered webhook arrives moments later ("livemode":false). Wire your UI to react to it — mark the code as sent, start your resend timer.

3. Rehearse the unhappy paths

Use magic numbers to test what your app does when things go wrong:

• …0000 — the SMS is undelivered; show a "resend" option.
• …0009 — insufficient balance (HTTP 402); alert your ops team.

4. Go live

Swap in your live key. Same code, real delivery, billed per segment. See the full sandbox docs to finish up.