> ## Documentation Index
> Fetch the complete documentation index at: https://docs.famulor.io/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.famulor.io/feedback

```json
{
  "path": "/en/api-reference/sms/send",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# Send SMS

> Send an SMS message using your phone number

This endpoint allows you to send SMS messages via your purchased phone numbers. The SMS is sent through Twilio, and the costs are automatically deducted from your account balance.

### Request Body

<ParamField body="from" type="integer" required>
  The ID of your phone number from which the SMS will be sent (must be SMS-capable)
</ParamField>

<ParamField body="to" type="string" required>
  The recipient's phone number in international format (e.g., "+4915123456789")
</ParamField>

<ParamField body="body" type="string" required>
  The SMS message content (max. 300 characters)
</ParamField>

### Response Fields

<ResponseField name="message" type="string">
  Success message confirming that the SMS was sent
</ResponseField>

<ResponseField name="data" type="object">
  Additional data about the sent SMS
</ResponseField>

### Error Responses

<ResponseField name="400 Bad Request" type="object">
  <Expandable title="Error Details">
    <ResponseField name="message" type="string">
      Error message describing the issue (invalid phone number, insufficient balance, etc.)
    </ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="500 Internal Server Error" type="object">
  <Expandable title="Server Error">
    <ResponseField name="message" type="string">
      Error message indicating a failure in sending the SMS
    </ResponseField>

    <ResponseField name="error" type="string">
      Detailed error information
    </ResponseField>
  </Expandable>
</ResponseField>

### Notes

* The sender phone number must belong to the authenticated user
* The sender phone number must be SMS-capable
* The phone number subscription must be active (not expired)
* Sufficient account balance is required to cover SMS costs
* Phone numbers are automatically formatted to E.164 format
* SMS costs vary depending on the destination country and are charged per segment
* Long messages can be split into multiple segments, increasing the cost
* The recipient phone number must comply with international standards

<CodeGroup>
  ```bash cURL theme={null}
  curl -X POST "https://app.famulor.de/api/user/sms" \
    -H "Authorization: Bearer YOUR_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "from": 12345,
      "to": "+4915123456789",
      "body": "Hello! This is a test SMS from Famulor."
    }'
  ```

  ```javascript JavaScript theme={null}
  const response = await fetch("https://app.famulor.de/api/user/sms", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: "Bearer YOUR_API_KEY",
    },
    body: JSON.stringify({
      from: 12345,
      to: "+4915123456789",
      body: "Hello! This is a test SMS from Famulor.",
    }),
  });

  const data = await response.json();
  ```

  ```python Python theme={null}
  import requests

  payload = {
      "from": 12345,
      "to": "+4915123456789",
      "body": "Hello! This is a test SMS from Famulor.",
  }

  response = requests.post(
      "https://app.famulor.de/api/user/sms",
      headers={
          "Content-Type": "application/json",
          "Authorization": "Bearer YOUR_API_KEY",
      },
      json=payload,
      timeout=10,
  )

  print(response.json())
  ```
</CodeGroup>

<ResponseExample>
  ```json 200 Sent Successfully theme={null}
  {
    "message": "SMS sent successfully",
    "data": {
      "sms_id": "SMS_67890",
      "from": "+4912345678",
      "to": "+4915123456789",
      "body": "Hello! This is a test SMS from Famulor.",
      "segments": 1,
      "cost": 0.05,
      "currency": "EUR",
      "status": "sent"
    }
  }
  ```

  ```json 400 Invalid Request theme={null}
  {
    "message": "Invalid phone number format"
  }
  ```

  ```json 400 Insufficient Balance theme={null}
  {
    "message": "Insufficient balance to send SMS"
  }
  ```

  ```json 400 Phone Number Not SMS-Capable theme={null}
  {
    "message": "Phone number is not SMS-capable"
  }
  ```

  ```json 400 Phone Number Not Found theme={null}
  {
    "message": "From number not found"
  }
  ```

  ```json 500 Server Error theme={null}
  {
    "message": "Failed to send SMS",
    "error": "Twilio service temporarily unavailable"
  }
  ```
</ResponseExample>

<Tip>
  Related pages: [Introduction](/en/api-reference/introduction) and [Authentication Guide](/en/developers/authentication-guide), and [API Integration Examples](/en/developers/api-integration-examples).
</Tip>