Quickstart

Send your first SMS in under five minutes. No card, no sales call: a test key works instantly against the sandbox.

1. Get a key

Create a free account at the console. A sandbox tenant is provisioned automatically with a test key (ssms_sk_test_...) and a sandbox number. The key is shown once, so copy it. Sign-up ends with an optional step to verify your cell (you can also do it later in Settings). If you just signed up in this browser, your key and phone are already in the snippets below.

Test keys simulate. The message ends up delivered, but no text is sent to any phone, and the response says so: "simulated": true. The one exception is your own verified phone: send to it and a test key hands the text to a carrier for real ("simulated": false). See Sandbox.

2. Send a message

to and body are the whole request. from is optional: a test key sends from your sandbox number.

curl -X POST https://api.jointextkit.com/v1/messages \
  -H "Authorization: Bearer ssms_sk_test_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+15005550006",
    "body": "Hello from TextKit"
  }'

3. Read the response

{
  "id": "msg_a1B2c3D4e5F6g7H8",
  "object": "message",
  "to": "+15005550006",
  "from": "+15005550100",
  "body": "Hello from TextKit",
  "direction": "outbound",
  "status": "delivered",
  "test": true,
  "simulated": true,
  "created_at": "2026-08-06T16:20:00.000Z"
}

Fetch it back anytime with GET /v1/messages/{id}, and watch the delivery lifecycle in GET /v1/events (message.sent, then message.delivered). The message's timeline shows each step with its timestamp.

4. Simulate a reply

curl -X POST https://api.jointextkit.com/v1/test/inbound \
  -H "Authorization: Bearer ssms_sk_test_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+15005550100",
    "from": "+14155550132",
    "body": "Hey, got your message!"
  }'

The inbound message lands in GET /v1/messages and emits a message.received event, exactly what a real inbound SMS will do in live mode.

5. Go live

When you're ready to send real SMS from real numbers, add a number and register your business from the console. We verify your business (someone authorized to act for it signs for it) and file your registration with the carriers. Until the carriers approve it, your number can text only your own verified numbers; after that, it can text anyone who opted in. See going live.