# ElevenLabs TTS V4 Turbo

AUDIOelevenlabs-tts-v4-turbo

**Eleven v4 Turbo** is the faster ElevenLabs text-to-speech tier. It generates speech from a chosen voice with inline audio tags, stability and similarity controls, and IPA pronunciation in forward slashes. Supports language selection, text normalization, and an optional seed. Best when you want v4 delivery at a lower character cost.

Best for

Lower-cost expressive voiceovers, High-volume narration with audio tags

POST

/v2/workspaces/{workspace\_id}/base-models/elevenlabs-tts-v4-turbo/inferences

```bash
curl --request POST \
  --url https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "prompt": "a knight standing in a snowy forest"
}'
```

```python
import requests


url = "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences"


payload = { "prompt": "a knight standing in a snowy forest" }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}


response = requests.post(url, json=payload, headers=headers)


print(response.json())
```

```js
const url = 'https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"prompt":"a knight standing in a snowy forest"}'
};


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.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences"


  payload := strings.NewReader("{\n  \"prompt\": \"a knight standing in a snowy forest\"\n}")


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


  req.Header.Add("Authorization", "Bearer <token>")
  req.Header.Add("Content-Type", "application/json")


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


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


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


}
```

```php
<?php


$curl = curl_init();


curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'prompt' => 'a knight standing in a snowy forest'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);


$response = curl_exec($curl);
$err = curl_error($curl);


curl_close($curl);


if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}
```

```java
OkHttpClient client = new OkHttpClient();


MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{\n  \"prompt\": \"a knight standing in a snowy forest\"\n}");
Request request = new Request.Builder()
  .url("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences")
  .post(body)
  .addHeader("Authorization", "Bearer <token>")
  .addHeader("Content-Type", "application/json")
  .build();


Response response = client.newCall(request).execute();
```

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


url = URI("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences")


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


request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"prompt\": \"a knight standing in a snowy forest\"\n}"


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

```csharp
var client = new RestClient("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/elevenlabs-tts-v4-turbo/inferences");
var request = new RestRequest("", Method.Post);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"prompt\": \"a knight standing in a snowy forest\"\n}", ParameterType.RequestBody);
var response = client.Execute(request);
```

* Layer API

## Authorizations

* **[bearerAuth](/docs/v2/rest-api#bearerauth)**
* **[oauth2](/docs/v2/rest-api#oauth2)**

## Parameters

### Path Parameters

**workspace\_id**

required

_Workspace Id_

Id of the workspace that owns the resource.

string format: uuid

Id of the workspace that owns the resource.

### Query Parameters

**session\_name**

_Session Name_

Organize this run under a named session. A new session is created if none matches.

string

nullable

Organize this run under a named session. A new session is created if none matches.

### Header Parameters

**Idempotency-Key**

string

<= 255 characters

Opaque key making a retry of this request return the first result. A 2xx response is replayed for 24 hours with `Idempotent-Replayed: true`. A 4xx releases the key. A 5xx, or a request still running, holds the key for 120 seconds, during which a retry gets 409; after that a retry executes again. The key covers the method, path, query, and byte-identical body it was first used with; reusing it for a different request is rejected with 422\. Protection is best effort: if the key store is unavailable, or a record is lost early, a retry can execute again even after an earlier 409\. See the Idempotency section of the API description.

## Request Bodyrequired

_ElevenLabs TTS V4 Turbo_object

**prompt**

required

_Prompt_

The text the voice speaks.

string

<= 5000 characters

**seed**

_Seed_

The starting point for the model’s randomness. The same seed and settings give the same result.

_Advanced field._

integer

nullable

**stability**

_Stability_

How steady the voice stays. Lower is more expressive, higher more consistent.

_Advanced field._

number

default: 0.5 <= 1 multiple of 0.01

**similarity\_boost**

_Similarity boost_

How closely the voice keeps to the original speaker.

_Advanced field._

number

default: 0.75 <= 1 multiple of 0.01

**text\_normalization**

_Text normalization_

Spell out numbers, dates and abbreviations as words before speaking them.

_Advanced field._

string

default: AUTO

Allowed values: AUTO ON OFF

**prompt\_language**

_Speech language_

The language the voice speaks in.

_Advanced field._

string

nullable

##### Example

```json
{
  "prompt": "a knight standing in a snowy forest"
}
```

## Responses

### 202

Successful Response

_ExecuteForgeOutput_object

**inference\_id**

required

_Inference Id_

Unique identifier for this forge run.

string format: uuid

**status**

required

_InferenceStatus_

Current status: IN\_PROGRESS.

string

Allowed values: in\_progress complete failed cancelled deleted

**estimated\_price\_creative\_units**

_Estimated Price Creative Units_

Estimated price in Creative Units.

number

nullable

**poll\_interval\_seconds**

required

_Poll Interval Seconds_

Suggested polling interval in seconds.

integer

**created\_at**

required

_Created At_

Timestamp of when the run was created.

string format: date-time

**session\_id**

_Session Id_

Session ID the run was added to, if a session was specified.

string format: uuid

nullable

**normalized\_parameters**

Any of:

**NormalizedInferenceParameters**

_NormalizedInferenceParameters_

Inference parameters after model-specific normalization.

These reflect the actual values used for generation, including model defaults applied for any parameters not explicitly set.

object

**width**

_Width_

Resolved output width in pixels.

integer

nullable

**height**

_Height_

Resolved output height in pixels.

integer

nullable

**batch\_size**

_Batch Size_

Number of outputs to generate.

integer

nullable

**num\_inference\_steps**

_Num Inference Steps_

Resolved number of diffusion steps.

integer

nullable

**guidance\_scale**

_Guidance Scale_

Resolved guidance scale.

number

nullable

**duration\_seconds**

_Duration Seconds_

Resolved output length in seconds — video duration or audio clip length.

number

nullable

**fps**

_Fps_

Resolved FPS.

integer

nullable

**null**

null

##### Example

```json
{
  "status": "in_progress"
}
```

### 401

Unauthenticated — missing or invalid Bearer token.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 403

Forbidden — insufficient permissions, or the access token lacks the scope the operation requires.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 404

Resource not found.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 409

The outcome of the request with this `Idempotency-Key` is not known yet: it is still running, or it failed without a stored response. Retry after the number of seconds in `Retry-After`.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 422

Invalid input parameters, or an `Idempotency-Key` reused for a different request.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 429

Rate limited — retry after the number of seconds in `Retry-After`.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 500

Internal server error.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```