> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> STT). Lightning v2 and lightning-large are deprecated; mention them
> only when the user is migrating away from them. The Smallest AI voice
> agent platform is what wraps these models into hosted agents.

# Create audience with CSV upload

POST https://api.smallest.ai/atoms/v1/audience
Content-Type: multipart/form-data

Create a new audience by uploading a CSV file containing phone numbers.
Only CSV text files are accepted — binary files will produce malformed data.

**Additional 400 cases:**
- Duplicate phone numbers in the CSV: `"Some phone numbers in your CSV already exist in this audience. Please remove duplicate entries and try again."`
- Member limit exceeded: `"Audience cannot exceed X members"`


Reference: https://docs.smallest.ai/api-reference/voice-agents/audience/create-audience-with-csv-upload

## Authentication

- `Authorization` header (bearer token, required) — API key from the console ApiKey collection, sent as Bearer token. Also accepts session cookies for browser-based auth.

## Request

### Body (multipart/form-data)

This endpoint expects a multipart form containing a file.

- `name` (string, required) — The name of the audience
- `description` (string, optional) — Optional description of the audience
- `phoneNumberColumnName` (string, required) — The name of the column in the CSV that contains phone numbers
- `identifierColumnName` (string, optional) — The name of the column in the CSV that contains identifiers (e.g., names)
- `file` (file, required) — CSV file containing phone numbers and identifiers (max 5MB)

## Response

### 200

Audience created successfully

- `status` (boolean, optional)
- `data` (AudiencePostResponsesContentApplicationJsonSchemaData, optional)

## Errors

### 400 Bad Request Error

Bad request

- `status` (boolean, optional)
- `errors` (list of string, optional)

### 401 Unauthorized Error

Unauthorized access

- `status` (boolean, optional)
- `errors` (list of string, optional)

### 500 Internal Server Error

Internal server error

- `status` (boolean, optional)
- `errors` (list of string, optional)

## Types

### AudiencePostResponsesContentApplicationJsonSchemaData

- `_id` (string, optional) — The unique identifier for the audience
- `name` (string, optional) — The name of the audience
- `description` (string, optional) — The description of the audience
- `phoneNumberColumnName` (string, optional) — The name of the column in the CSV that contains phone numbers
- `identifierColumnName` (string, optional) — The name of the column in the CSV that contains identifiers
- `organization` (string, optional) — The organization ID
- `createdBy` (string, optional) — The user ID who created the audience
- `createdAt` (datetime, optional) — The date and time when the audience was created
- `updatedAt` (datetime, optional) — The date and time when the audience was last updated

## Examples

**Request**

```json
{
  "file": "<file: audience_template.csv>",
  "name": "test_audience",
  "phoneNumberColumnName": "phoneNumber"
}
```

**Response**

```json
{
  "status": true,
  "data": {
    "_id": "60d0fe4f5311236168a109ca",
    "name": "My Customer List",
    "description": "List of customers for marketing campaign",
    "phoneNumberColumnName": "phoneNumber",
    "identifierColumnName": "Name",
    "organization": "60d0fe4f5311236168a109cb",
    "createdBy": "60d0fe4f5311236168a109cc",
    "createdAt": "2025-01-15T10:30:00.000Z",
    "updatedAt": "2025-01-15T10:30:00.000Z"
  }
}
```

**SDK Code**

```python
import requests

url = "https://api.smallest.ai/atoms/v1/audience"

files = { "file": "open('audience_template.csv', 'rb')" }
payload = {
    "description": ,
    "identifierColumnName": ,
    "name": "test_audience",
    "phoneNumberColumnName": "phoneNumber"
}
headers = {"Authorization": "Bearer <token>"}

response = requests.post(url, data=payload, files=files, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.smallest.ai/atoms/v1/audience';
const form = new FormData();
form.append('description', '');
form.append('file', 'audience_template.csv');
form.append('identifierColumnName', '');
form.append('name', 'test_audience');
form.append('phoneNumberColumnName', 'phoneNumber');

const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

options.body = form;

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

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

func main() {

	url := "https://api.smallest.ai/atoms/v1/audience"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"description\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"audience_template.csv\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"identifierColumnName\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"name\"\r\n\r\ntest_audience\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"phoneNumberColumnName\"\r\n\r\nphoneNumber\r\n-----011000010111000001101001--\r\n")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.smallest.ai/atoms/v1/audience")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"description\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"audience_template.csv\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"identifierColumnName\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"name\"\r\n\r\ntest_audience\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"phoneNumberColumnName\"\r\n\r\nphoneNumber\r\n-----011000010111000001101001--\r\n"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.smallest.ai/atoms/v1/audience")
  .header("Authorization", "Bearer <token>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"description\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"audience_template.csv\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"identifierColumnName\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"name\"\r\n\r\ntest_audience\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"phoneNumberColumnName\"\r\n\r\nphoneNumber\r\n-----011000010111000001101001--\r\n")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.smallest.ai/atoms/v1/audience', [
  'multipart' => [
    [
        'name' => 'file',
        'filename' => 'audience_template.csv',
        'contents' => null
    ],
    [
        'name' => 'name',
        'contents' => 'test_audience'
    ],
    [
        'name' => 'phoneNumberColumnName',
        'contents' => 'phoneNumber'
    ]
  ]
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.smallest.ai/atoms/v1/audience");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddParameter("undefined", "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"description\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"audience_template.csv\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"identifierColumnName\"\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"name\"\r\n\r\ntest_audience\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"phoneNumberColumnName\"\r\n\r\nphoneNumber\r\n-----011000010111000001101001--\r\n", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "Bearer <token>"]
let parameters = [
  [
    "name": "description",
    "value": 
  ],
  [
    "name": "file",
    "fileName": "audience_template.csv"
  ],
  [
    "name": "identifierColumnName",
    "value": 
  ],
  [
    "name": "name",
    "value": "test_audience"
  ],
  [
    "name": "phoneNumberColumnName",
    "value": "phoneNumber"
  ]
]

let boundary = "---011000010111000001101001"

var body = ""
var error: NSError? = nil
for param in parameters {
  let paramName = param["name"]!
  body += "--\(boundary)\r\n"
  body += "Content-Disposition:form-data; name=\"\(paramName)\""
  if let filename = param["fileName"] {
    let contentType = param["content-type"]!
    let fileContent = String(contentsOfFile: filename, encoding: String.Encoding.utf8)
    if (error != nil) {
      print(error as Any)
    }
    body += "; filename=\"\(filename)\"\r\n"
    body += "Content-Type: \(contentType)\r\n\r\n"
    body += fileContent
  } else if let paramValue = param["value"] {
    body += "\r\n\r\n\(paramValue)"
  }
}

let request = NSMutableURLRequest(url: NSURL(string: "https://api.smallest.ai/atoms/v1/audience")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```