Gemini 3.1 Flash TTS

AUDIOgemini-3.1-flash-tts

Gemini 3.1 Flash TTS from Google is a next-generation text-to-speech model offering best-in-class controllability and expressiveness. It introduces 200+ audio tags that let you steer vocal style, pace, and delivery using natural language commands embedded directly in the text input. Supporting 70+ languages with native multi-speaker dialogue, it achieved an Elo score of 1,211 on the Artificial Analysis TTS leaderboard. All generated audio is watermarked with SynthID for responsible AI identification.

POST

/v2/workspaces/{workspace_id}/base-models/gemini-3.1-flash-tts/inferences

curl --request POST \
  --url https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/inferences \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "prompt": "a knight standing in a snowy forest"
}'

import requests

url = "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/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())

const url = 'https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/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);
}

package main

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

func main() {

  url := "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/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

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/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;
}

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/gemini-3.1-flash-tts/inferences")
  .post(body)
  .addHeader("Authorization", "Bearer <token>")
  .addHeader("Content-Type", "application/json")
  .build();

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

require 'uri'
require 'net/http'

url = URI("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/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

var client = new RestClient("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/gemini-3.1-flash-tts/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);

Authorizations

bearerAuth

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

Any of:

string
null

string

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

Request Body^required

application/json

Gemini 3.1 Flash TTS

object

prompt

required

Prompt

string

temperature

Temperature

Advanced field.

number

default: 1 <= 2 multiple of 0.05

style_instructions

Style Instructions

Advanced field.

string

prompt_language

Speech language

Advanced field.

string

nullable

Example

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

Responses

202

Successful Response

application/json

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

Any of:

number
null

number

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

Any of:

string
null

string format: uuid

normalized_parameters

Any of:

NormalizedInferenceParameters
null

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

Any of:

integer
null

integer

height

Any of:

integer
null

integer

batch_size

Any of:

integer
null

integer

num_inference_steps

Any of:

integer
null

integer

guidance_scale

Any of:

number
null

number

duration_seconds

Any of:

number
null

number

fps

Any of:

integer
null

integer

Example

{
  "status": "in_progress"
}

401

Unauthenticated — missing or invalid Bearer token.

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

required

string

Example

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

403

Forbidden — insufficient permissions.

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

required

string

Example

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

404

Resource not found.

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

required

string

Example

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

422

Invalid input parameters.

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

required

string

Example

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

429

Rate limited — too many concurrent requests.

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

required

string

Example

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

500

Internal server error.

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

required

string

Example

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

Gemini 3.1 Flash TTS

Authorizations

Parameters

Path Parameters

Query Parameters

Request Bodyrequired

Example

Responses

202

Example

401

Example

403

Example

404

Example

422

Example

429

Example

500

Example

Request Body^required