Text-to-Speech (TTS) Service User Guide¶

Welcome! This guide will help you quickly get started with the Language Server Text-to-Speech (TTS) API. You’ll learn how to convert text into speech using a simple API call, understand the required parameters, and see example requests and responses.

Supported Providers: Azure, Google, Sarvam, and Open Source (Indic-Parler)

Quickstart¶

Get your API key from your admin or dashboard.
Choose your provider (Azure, Google, Sarvam, or Karya Local).
Prepare your text and language code (see supported languages below).
Send a POST request to the TTS endpoint with the required headers and form data.
Download your audio from the response URLs.

1. Request Headers¶

Include these headers in every request:

Accept: application/json
X-API-Key: YOUR_API_KEY      # Replace with your actual API key
Content-Type: multipart/form-data

2. Request Body: Form Data¶

Send the request body as multipart/form-data with a field named payload_data (see below for structure).

Synchronous TTS:

The synchronous endpoint processes your text in real time and returns audio URLs in the response.

3. Endpoint¶

URL: https://language-server-url/v1/task/text-to-speech
Method: POST

4. Example Request (cURL)¶

curl -X POST 'https://language-server-url/v1/task/text-to-speech' \
  -H 'accept: application/json' \
  -H 'X-API-Key: YOUR_API_KEY' \
  -H 'Content-Type: multipart/form-data' \
  -F 'payload_data={
    "user_email": "your_email@example.com",
    "project_name": "Individual",
    "provider": "AZURE",
    "models": ["NEURAL"],
    "task_name": "my_first_tts_task_unique_001",
    "datapoints": {
      "datapoint 1": {"text": "नमस्ते, यह एक परीक्षण है।", "speed": "1.0x", "lang": "hi-IN"}
    }
  }'

5. `payload_data` Structure¶

This is a JSON string containing your task and datapoints. Example:

{
  "user_email": "your_email@example.com",
  "project_name": "your_project_name",
  "task_name": "my_first_tts_task_unique_001",
  "provider": "AZURE",
  "models": ["NEURAL"],
  "datapoints": {
    "datapoint 1": {
      "text": "नमस्ते, यह एक परीक्षण है।",
      "speed": "1.0x",
      "lang": "hi-IN"
    },
    "datapoint 2": {
      "text": "This is a test for English audio generation.",
      "speed": "1.2x",
      "lang": "en-IN"
    }
  }
}

Important: The models field is mandatory. It must be a non-empty list of model names (e.g., ["default"]). Omitting this field or leaving it empty will result in an error.

You can add as many datapoints as you need.

Required Fields in `payload_data`¶

Field	Description	Type
`user_email`	Your registered email address	string
`project_name`	Name of your project	string
`task_name`	A unique name for the task (must not be reused)	string
`provider`	Backend provider (see table below)	string
`models`	Required. List of model names to use (e.g., `["NEURAL"]`).	list of strings
`datapoints`	Dictionary of datapoint objects. Each key (e.g., `"datapoint 1"`) is a unique identifier.	dict

Provider & Model Mapping¶

Provider	`provider` value	Required `models` value	Notes
Azure	`"AZURE"`	`["NEURAL"]`	Commercial. Only the model name `NEURAL` is supported.
Google	`"GOOGLE"`	`["WAVENET"]` or `["STANDARD"]`	Commercial. Use `["WAVENET"]` for premium, `["STANDARD"]` for basic.
Sarvam	`"SARVAM"`	`["BULBULV2"]`	Commercial. Only `BULBULV2` is supported.
Karya Local (Indic-Parler)	`"KARYA_LOCAL"`	`["INDIC_PARLER"]`	Open Source. Only `INDIC_PARLER` is supported.

Tip: For personal use, set project_name to "Individual".

Available Models for Each Provider¶

Azure¶

Set models to ["neural"] (the only supported model for Azure TTS).

Google¶

Set models to either ["WAVENET"] (premium) or ["STANDARD"] (basic).

Sarvam¶

Set models to ["BULBULV2"] (the only supported model).

Karya Local (Indic-Parler)¶

Set models to ["INDIC_PARLER"] (the only supported model).

Warning: Leaving models as ["default"] or omitting it will not work. You must specify the correct model for your provider as shown above.

Note: - If a model exists but is currently unserviceable (e.g., due to downtime or errors), the system will fall back to the most basic model for that provider.

Each datapoint must include:

Field	Description	Type
`text`	Text to convert to speech	string
`speed`	Playback speed (e.g., `"1.0x"`, `"1.2x"`)	string
`lang`	Language code (see below)	string

About the `models` Field¶

The models field is required for all TTS requests.
It must be a non-empty list of model names. For most providers, use ["NEURAL"].
If you omit this field or provide an empty list, your request will be rejected.
The available model names may vary by provider. See the Provider & Model Mapping table above for details.

Supported Languages¶

Language	Code
Assamese	`as-IN`
Bengali	`bn-IN`
English (India)	`en-IN`
Gujarati	`gu-IN`
Hindi	`hi-IN`
Kannada	`kn-IN`
Malayalam	`ml-IN`
Marathi	`mr-IN`
Odia	`or-IN`
Punjabi	`pa-IN`
Tamil	`ta-IN`
Telugu	`te-IN`
Urdu	`ur-IN`

Note: Not all providers support every language above.

6. Example Response¶

On success, you’ll get a JSON response with audio URLs:

{
  "task_id": "your_task_id",
  "status": "COMPLETED",
  "result": {
    "user_email": "your_email@example.com",
    "project_name": "your_project_name",
    "task_name": "my_first_tts_task_unique_001",
    "provider": "AZURE",
    "models": ["NEURAL"],
    "datapoints": {
      "datapoint 1": {
        "text": "नमस्ते, यह एक परीक्षण है।",
        "speed": "1.0x",
        "lang": "hi-IN",
        "saas_url": "https://<storage_account_name>.blob.core.windows.net/audio-output1/..."
      }
    }
  }
}

Field Descriptions:

Field	Description
`task_id`	Unique task identifier
`status`	Task status (`PENDING`, `COMPLETED`, `FAILED`)
`saas_url`	Temporary download link for the audio file

Warning: Download your audio files within 24 hours. Links expire after that.

7. Response & Error Codes¶

Code	Description
200	Request successful
404	Missing or invalid parameters
500	Internal server error