Turn your Android phone into a programmable SMS gateway
Send and receive SMS through a clean REST API. Two-way inbox, campaigns, signed webhooks, and a human-sounding AI auto-reply on your own free Gemini key. No per-message fee.
More than a send endpoint.
All included during early access, because your phone does the heavy lifting.
Two-way inbox
Every SMS sent and received, with delivery status, refreshing every 15 seconds.
Campaigns
Up to 10,000 recipients with {{first_name}}-style variables, scheduling and pause.
AI auto-reply
Bring your own free Gemini key. Replies sound like you, not a bot.
Multi-phone, multi-SIM
Pair as many phones as you like and choose the SIM. No per-phone fee.
Signed webhooks
HMAC-signed events with five automatic retries and a delivery log.
Test mode
Build your integration with simulated delivery before a single real SMS goes out.
Team members
Invite owners and members into one shared workspace.
Scheduling & working hours
Schedule campaigns, and keep AI replies as drafts during your working hours.
24-hour retention
Message text goes after 30 minutes, the record after a day. Less to leak.
One HTTP call to your first SMS.
A plain JSON REST API that works from any language, copy-paste examples for seven of them, and signed webhooks so your app hears back the moment a reply lands.
- Idempotent sends with request_id
- Cursor pagination on every list
- HMAC-signed webhooks with retries
- Request builder in the docs — no account needed
// Node.js 18+ (built-in fetch)
const res = await fetch("https://api.99billingsolutions.com/v1/messages/send", {
method: "POST",
headers: {
"x-api-key": process.env.SMS_BRIDGE_KEY,
"Content-Type": "application/json",
},
body: JSON.stringify({
from_number: "+15550100001",
to_number: "+15550100002",
content: "Your order #A12 has shipped",
}),
});
const body = await res.json();
if (!res.ok) throw new Error(`${body.error_code}: ${body.message}`);
console.log(body.data.id, body.data.status);How it works
Three steps. Done in under a minute.
- 1
Sign up
Create a free account. No card, no phone number required to start.
- 2
Pair your phone
Install the SMS Bridge Android app and scan the QR code in the portal.
- 3
Send & receive
Hit the REST API from any language. Watch the inbox update live.
Straight comparison.
Your phone's normal SMS plan applies. Competitor prices from their public websites, September 2026.
| Feature | SMS Bridge | httpSMS | Twilio |
|---|---|---|---|
| Cost per message | None — your SIM plan | Plan quota | Per message + fees |
| Paid entry price | Free in early access | $10 / mo for 5,000 | ≈ $8+ per 1,000 |
| Sender number | Your own SIM | Your own SIM | Rented number |
| AI auto-reply | Yes (your Gemini key) | No | Build it yourself |
| Message text deleted | Within 24 h | No | No |
Built for businesses that text
Home services
Send booking confirmations and “on my way” texts from the office phone customers already know, with no per-message fee.
Online stores
Ask cash-on-delivery buyers to reply YES before you ship, and let the AI answer “where is my order?” after hours.
Clinics
Appointment reminders from your own number, with message text deleted from our servers within 24 hours.
Frequently asked questions
- Is it really free?
- Yes, during early access everything is free. We charge nothing per message — your phone's SIM plan is the only cost. Optional paid add-ons are planned, but everything available today stays free.
- Does it work on iPhone?
- No. iOS does not let apps send SMS on their own. The phone app is Android only (Android 7.0 or newer). You can use the portal and API from any device.
- How many SMS can one phone send?
- Android limits apps to roughly 30 SMS per 30 minutes, so SMS Bridge sends at most 25 per 30 minutes per phone — about 1,200 a day. Pair more phones to send more; five phones is about 6,000 a day.
- Can I change the sender number?
- The sender is always the SIM in the paired phone. Pair several phones and choose which one sends with from_number; on dual-SIM phones you can pick the SIM.
- How does the AI auto-reply stay free?
- You bring your own Gemini API key from Google AI Studio, and Google's free tier is enough for most small businesses. Your key is stored encrypted and is only used to call Gemini for your own messages.
- What happens to my messages?
- Message bodies are blanked 30 minutes after they settle and the rows are deleted after 24 hours. If you need a permanent record, forward them to your own system with a webhook.
Ready to send your first SMS?
Free forever. No credit card. Bring your own phone and — if you like — your own Gemini key.
Get started