# Track a customer event

Source: https://joinsimplesms.com/docs/api/track/event
Index: https://joinsimplesms.com/llms.txt

`POST /v1/track`

Records something a person did in your app and starts or advances the automations listening for it. Pass phone, user_id, or both; a call with both links them so later events need only user_id. Test keys reach sandbox automations, live keys live ones. Supports Idempotency-Key. 100 calls per 10 seconds per key. Scope: automations. (GET /events is the webhook event log, a different thing.)

Send your API key as a bearer token: `Authorization: Bearer ssms_sk_...`. Test keys run this endpoint against the [sandbox](/docs/sandbox); see [Authentication](/docs/authentication) for key modes and scopes.

## Headers

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `Idempotency-Key` | string | No | At most 255 characters. |

## Request body

JSON (`Content-Type: application/json`).

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `event` | string | Yes | Letters, digits, and _ . : - At most 64 characters. Example: `trial_started`. |
| `user_id` | string | No | At most 128 characters. Example: `123`. |
| `phone` | string | No | Example: `+14155550132`. |
| `properties` | object | No | Up to 20 scalar values; usable as merge fields and in conditions. |

## Responses

| Status | Meaning | Body |
| --- | --- | --- |
| 201 | Recorded | `TrackedEvent` |
| 401 | Missing, malformed, or revoked API key | `Error` |
| 402 | Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged | `Error` |
| 429 | Rate limit or quota exceeded | `Error` |

### 201: `TrackedEvent` fields

| Field | Type | Description |
| --- | --- | --- |
| `id` | string | Example: `tev_a1B2c3D4e5F6g7H8`. |
| `object` | `tracked_event` |  |
| `event` | string |  |
| `user_id` | string | Nullable. |
| `phone` | string | Null when user_id is not linked to a number yet (nothing could start). Nullable. |
| `properties` | object |  |
| `test` | boolean |  |
| `runs_started` | array of string | Ids of the runs this event started. |
| `runs_notified` | integer | Runs in progress for this person that recorded the event. |
| `created_at` | string (date-time) |  |

## Errors

| Status | When |
| --- | --- |
| 401 | Missing, malformed, or revoked API key |
| 402 | Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged |
| 429 | Rate limit or quota exceeded |

Every error has the same JSON shape, and `request_id` matches the `X-Request-Id` response header. [Errors](/docs/errors) lists every code and what to do about it.

```json
{
  "error": {
    "code": "invalid_request",
    "message": "What went wrong, in plain words.",
    "param": "the_field",
    "request_id": "req_a1B2c3D4e5F6g7H8"
  }
}
```

## Idempotency

Send an `Idempotency-Key` header to make retries safe. For 24 hours the same key with the same body replays the original successful response (with `Idempotent-Replayed: true`); the same key with a different body returns 409. A failed request releases its key.

## Examples

### curl

```bash
curl -X POST "https://api.joinsimplesms.com/v1/track" \
  -H "Authorization: Bearer $SIMPLESMS_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 6f1c2f0e-order-1042" \
  -d '{
  "event": "trial_started",
  "user_id": "123",
  "phone": "+14155550132",
  "properties": {
    "plan": "pro"
  }
}'
```

### Node.js

```javascript
import { SimpleSMS } from 'joinsimplesms'; // npm install joinsimplesms

const sms = new SimpleSMS(process.env.SIMPLESMS_API_KEY);

await sms.events.track({
  event: 'order_placed',
  phone: '+14155550132',
  properties: { order_id: 'A-1042' },
});
```

### Python

```python
import os
from joinsimplesms import SimpleSMS  # pip install joinsimplesms

client = SimpleSMS(os.environ["SIMPLESMS_API_KEY"])

client.events.track(
    "order_placed",
    phone="+14155550132",
    properties={"order_id": "A-1042"},
)
```

## Related

- Guide: [Automations](/docs/automations)
- [All tracked events endpoints](/docs/api#track)
- [API reference](/docs/api)