> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://developers.synthesia.io/docs/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://developers.synthesia.io/docs/_mcp/server.

# List a localization's locales

GET https://developers.synthesia.io/api/localizations/{localization_id}/locales

**Required scope:** [`localization:read`](https://developers.synthesia.io/docs/scopes) (in Studio: Localization (read))

Reference: https://developers.synthesia.io/docs/api-reference/localization/list-localization-locales

## Authentication

- `Authorization` header (bearer token, required) — Your Synthesia API key. * Send it as `Authorization: Bearer <key>`; a bare key also works. * An endpoint that needs a scope names it in its description; [Scopes](https://developers.synthesia.io/docs/scopes) lists them all. * A `:write` scope also satisfies the same resource's `:read`. * Without the scope, the request fails with a 403 `insufficient_scope`.

## Request

### Path parameters

- `localization_id` (string, required) — The localization id, prefixed `l10n_…`.

### Query parameters

- `limit` (integer, optional, default: 20) — Items per page.
- `cursor` (string, optional, nullable) — The `nextCursor` of the previous page. Omit for the first page.

## Response

### 200

Successful Response

- `data` (list of Locale, required)
- `nextCursor` (string, required, nullable)

## Errors

### 400 Bad Request Error

The id is malformed, or it is a translation, which is not supported yet (validation_error).

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 401 Unauthorized Error

Unauthenticated

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 403 Forbidden Error

Insufficiently scoped or forbidden

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 404 Not Found Error

The localization does not exist, or you cannot see it (not_found).

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 429 Too Many Requests Error

Rate limited

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 500 Internal Server Error

Internal error

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 503 Service Unavailable Error

Service unavailable

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### 504 Gateway Timeout Error

Upstream timeout

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

## Types

### Locale

- `id` (string, required) — The locale's id. Starts with `locale_`.
- `status` (enum, required) — `processing` while the video is made, then `completed` or `failed`.
  - Allowed values: `queued`, `processing`, `completed`, `failed`, `canceled`
- `error` (Problem, required, nullable) — Why the locale failed. Branch on its `code`: `moderation` or `processing_error`. More codes may be added. Null unless the status is `failed`.
- `videoId` (string, required) — The localized video's id. Starts with `vid_`.
- `language` (string, required) — BCP 47 language code.
- `mode` (string, required) — How the locale is made: `dubbing`. More modes may be added; ignore values you don't recognize.
- `visibility` (enum, required, nullable) — Null until the locale completes.
  - Allowed values: `private`, `public`
- `createdAt` (datetime, required, nullable) — Null until the locale completes.
- `download` (string, required, nullable) — Time-limited URL of the video. Null until the locale completes.
- `thumbnail` (LocaleThumbnail, required, nullable) — Null until the locale completes.
- `captions` (LocaleCaptions, required, nullable) — Null until the locale completes.
- `done` (boolean, required) — True once `status` is terminal, whatever the outcome. Poll until it is true, then read `status`.

### Problem

An error response in RFC 9457 Problem Details format.

- `type` (string, required) — A URL identifying the error class — documentation, not a contract: branch on `code`, never parse `type`.
- `title` (string, required) — A human-readable summary of the error class.
- `status` (integer, required) — The HTTP status code, repeated from the response.
- `code` (string, required) — The stable, machine-readable error code to branch on. New codes may appear; treat an unknown one by its `status`.
- `detail` (string, optional, nullable) — Human-readable specifics; the wording may change without notice.
- `features` (list of string, optional, nullable) — On `feature_not_in_plan` only: the plan features this request needs.
- `instance` (string, optional, nullable) — The request path that produced the error.
- `requestId` (string, optional, nullable) — Identifies the request in Synthesia's logs (also the `Request-Id` header); quote it when contacting support.

### LocaleThumbnail

- `image` (string, required, nullable) — Time-limited URL of the thumbnail image.
- `gif` (string, required, nullable) — Time-limited URL of the animated thumbnail.

### LocaleCaptions

- `srt` (string, required, nullable) — Time-limited URL of the SRT captions.
- `vtt` (string, required, nullable) — Time-limited URL of the WebVTT captions.

## Examples

**Response**

```json
{
  "data": [
    {
      "id": "string",
      "status": "queued",
      "error": {
        "type": "string",
        "title": "string",
        "status": 1,
        "code": "string",
        "detail": "string",
        "features": [
          "string"
        ],
        "instance": "string",
        "requestId": "string"
      },
      "videoId": "string",
      "language": "es-ES",
      "mode": "dubbing",
      "visibility": "private",
      "createdAt": "2024-01-15T09:30:00Z",
      "download": "string",
      "thumbnail": {
        "image": "string",
        "gif": "string"
      },
      "captions": {
        "srt": "string",
        "vtt": "string"
      },
      "done": true
    }
  ],
  "nextCursor": "string"
}
```

**SDK Code**

```python
import requests

url = "https://developers.synthesia.io/api/localizations/localization_id/locales"

headers = {"Authorization": "Bearer <token>"}

response = requests.get(url, headers=headers)

print(response.json())
```

```javascript
const url = 'https://developers.synthesia.io/api/localizations/localization_id/locales';
const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

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"
	"net/http"
	"io"
)

func main() {

	url := "https://developers.synthesia.io/api/localizations/localization_id/locales"

	req, _ := http.NewRequest("GET", url, nil)

	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://developers.synthesia.io/api/localizations/localization_id/locales")

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

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

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.get("https://developers.synthesia.io/api/localizations/localization_id/locales")
  .header("Authorization", "Bearer <token>")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://developers.synthesia.io/api/localizations/localization_id/locales', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://developers.synthesia.io/api/localizations/localization_id/locales");
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://developers.synthesia.io/api/localizations/localization_id/locales")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers

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()
```