Key Takeaways
- Pre-launch checklist for Free SMS server: prove path within 1 device, 300 SMS lifetime, and 300 contacts.
- Free is a canary lane — not production OTP at scale and not free carrier SMS.
- Sends pause when the platform SMS allowance is exhausted. Upgrade before launch traffic.
- Keep OTP templates, keys, and overnight phone ops on the list.
- 300 SMS lifetime · 300 contacts · 1 device max
Pre-launch checklist for Free SMS server is the go/no-go list before you burn the lifetime SMS cap on real users. Limits that force upgrade · Pricing. Docs: Developer Center.
300 SMS lifetime · 300 contacts · 1 device max. You fund the SIM.
Check the phone before you check the marketing site.
What “pre-launch Free” means
Prove pairing, send, DLR, and a webhook with staff numbers. Do not promise customers Unlimited SMS or monthly Free refills.
If your launch plan needs more than one handset or more than 300 platform SMS, upgrade before go-live — not after the pause.
Pre-launch checklist
| Item | Pass criteria |
|---|---|
| Device paired | last-seen fresh; charger + RF OK |
| Staff SMS | Accept + DLR; body correct |
| Webhook | HMAC verified; event id unique |
| OTP template | Boring, branded, hashed server-side |
| Keys | Env only; staging key for canaries |
| Ceiling math | Launch fits under 1 / 300 / 300 or paid plan ready |
| STOP (if lists) | Opt-out path documented |
1 / 300 / 300 ceilings
1 device, 300 SMS lifetime, 300 contacts. On Free and Developer, sending pauses when you use the plan SMS allowance rather than silently billing aggregator-style overage. Upgrade or request a custom allowance to continue.
Handset readiness
OEM battery exceptions, spare cable, prepaid funded. Overnight uptime.
API and DLR canaries
Persist message id; never mark login on HTTP accept alone. DLR · OTP.
Next steps
Run the table once with two people; sign the go/no-go before public traffic. Downloads.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- SMS API documentationLive endpoint reference
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
- download the Android gateway appGet the APK
