# Create a customer

Source: https://jointextkit.com/docs/api/customers/create
Index: https://jointextkit.com/llms.txt

`POST /v1/customers`

A business you send on behalf of. Assign numbers to it and its messages, verifications, events and usage carry its id. Optional; nothing requires customers.

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.

## Request body

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

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `name` | string | No | At most 200 characters. Nullable. |
| `external_id` | string | No | Your id for them; unique per account At most 200 characters. Nullable. |
| `metadata` | object | No | Up to 50 string values |

## Responses

| Status | Meaning | Body |
| --- | --- | --- |
| 201 | The customer | `Customer` |
| 400 | Invalid request | `Error` |
| 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` |
| 409 | external_id already used | `Error` |
| 429 | Rate limit or quota exceeded | `Error` |

### 201: `Customer` fields

| Field | Type | Description |
| --- | --- | --- |
| `id` | string | Example: `cus_a1B2c3D4e5F6g7`. |
| `object` | `customer` |  |
| `name` | string | Nullable. |
| `external_id` | string | Nullable. |
| `metadata` | object |  |
| `created_at` | string (date-time) |  |
| `updated_at` | string (date-time) |  |
| `phone_numbers` | array of string | Only on retrieve |

## Errors

| Status | When |
| --- | --- |
| 400 | Invalid request |
| 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 |
| 409 | external_id already used |
| 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"
  }
}
```

## Examples

### Node.js

```javascript
import { TextKit } from 'jointextkit'; // npm install jointextkit

const sms = new TextKit(process.env.TEXTKIT_API_KEY);

const customer = await sms.customers.create({ name: 'Acme Dental', externalId: 'acct_42' });

console.log(customer.id);
```

### PHP

```php
<?php

$ch = curl_init('https://api.jointextkit.com/v1/customers');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . getenv('TEXTKIT_API_KEY'),
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode((object) []),
]);

$data = json_decode(curl_exec($ch), true);
```

### Python

```python
import os
from jointextkit import TextKit  # pip install jointextkit

client = TextKit(os.environ["TEXTKIT_API_KEY"])

customer = client.customers.create(name="Acme Dental", external_id="acct_42")

print(customer["id"])
```

### Ruby

```ruby
require "net/http"
require "json"

uri = URI("https://api.jointextkit.com/v1/customers")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer #{ENV["TEXTKIT_API_KEY"]}"
req["Content-Type"] = "application/json"
req.body = {}.to_json

res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |http| http.request(req) }
data = JSON.parse(res.body)
```

### Go

```go
package main

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"
)

func main() {
	body := strings.NewReader(`{}`)
	req, _ := http.NewRequest("POST", "https://api.jointextkit.com/v1/customers", body)
	req.Header.Set("Authorization", "Bearer "+os.Getenv("TEXTKIT_API_KEY"))
	req.Header.Set("Content-Type", "application/json")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	data, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(data))
}
```

### Rust

```rust
// cargo add reqwest --features blocking,json
// cargo add serde_json
use serde_json::json;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let key = std::env::var("TEXTKIT_API_KEY")?;
    let res = reqwest::blocking::Client::new()
        .post("https://api.jointextkit.com/v1/customers")
        .bearer_auth(key)
        .json(&json!({}))
        .send()?
        .error_for_status()?;
    let data: serde_json::Value = res.json()?;
    println!("{data}");
    Ok(())
}
```

### Java

```java
import java.net.URI;
import java.net.http.*;

public class Main {
    public static void main(String[] args) throws Exception {
        var request = HttpRequest.newBuilder(URI.create("https://api.jointextkit.com/v1/customers"))
            .header("Authorization", "Bearer " + System.getenv("TEXTKIT_API_KEY"))
            .header("Content-Type", "application/json")
            .method("POST", HttpRequest.BodyPublishers.ofString("""
                {}
                """))
            .build();

        var response = HttpClient.newHttpClient().send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode() + " " + response.body());
    }
}
```

### .NET

```csharp
using System.Net.Http.Headers;
using System.Text;

var http = new HttpClient();
http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
    "Bearer", Environment.GetEnvironmentVariable("TEXTKIT_API_KEY"));

var body = new StringContent("""
    {}
    """, Encoding.UTF8, "application/json");
var res = await http.PostAsync("https://api.jointextkit.com/v1/customers", body);
res.EnsureSuccessStatusCode();

var data = await res.Content.ReadAsStringAsync();
```

### cURL

```bash
curl -X POST "https://api.jointextkit.com/v1/customers" \
  -H "Authorization: Bearer $TEXTKIT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{}'
```

## Related

- Guide: [Customers](/docs/customers)
- [All customers endpoints](/docs/api#customers)
- [API reference](/docs/api)