> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sunbird.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Speech to Text

> Speech-to-Text endpoint. Accepts an uploaded audio file. Replaces /stt, /stt_from_gcs, /org/stt, and /modal/stt.



## OpenAPI

````yaml api-reference/openapi.json POST /tasks/audio/transcriptions
openapi: 3.1.0
info:
  title: Sunbird AI API
  description: >

    Welcome to the Sunbird AI API documentation. The Sunbird AI API provides
    access to

    Sunbird's language models and AI services for Ugandan languages.


    ## Supported Languages

    **English**, **Acholi**, **Ateso**, **Luganda**, **Lugbara**,
    **Runyankole**, **Swahili**

    and **20+** more Ugandan languages supported via sunflower.


    ## Getting Started

    You can checkout the [usage guide](https://salt.sunbird.ai/API/) for a full
    tutorial.


    For quickstart tutorials, visit our

    [GitHub
    repository](https://github.com/SunbirdAI/sunbird-ai-api/blob/main/docs/tutorial.md)


    ### Authentication


    #### Signing Up

    If you don't already have an account, use the `/auth/register` endpoint to
    create one.


    #### Getting an Access Token

    Authentication is done via a Bearer token. Use the `/auth/token` endpoint to
    get your

    access token. This token lasts for 7 days.


    Use the `Authorize` button below to login and access the protected
    endpoints.


    ## API Endpoints


    ### Translation

    - **`POST /tasks/translate`** - Translate text between 32 Ugandan and East
    African
      languages using the Sunflower model. Languages are accepted as ISO codes (`lug`)
      or full names (`Luganda`); `source_language` is optional (auto-detected when
      omitted). Translation works between any pair of supported languages.

    ### Language Detection

    - **`POST /tasks/language_id`** - Auto-detect the language of text input
      (supports Acholi, Ateso, English, Luganda, Lugbara, Runyankole)

    ### Speech-to-Text (STT)

    - **`POST /tasks/audio/transcriptions`** - STT endpoint (OpenAI-style).
      - Accepts an uploaded audio file (`audio`) or a GCS object (`gcs_blob_name`).
      - `platform`: `modal` (default, Whisper large-v3) or `runpod`.
      - RunPod options: `adapter` (language adapter), `whisper`, `recognise_speakers`
        (diarization), and the `org` organization workflow.
      - `language`: 3-letter code (e.g. `eng`, `lug`) or full name; improves accuracy.
        Supports WAV, MP3, OGG, M4A, and more. Auto-detects when omitted.
      - **Deprecated** → use `POST /tasks/audio/transcriptions`:
        - `POST /tasks/stt`, `POST /tasks/stt_from_gcs`, `POST /tasks/org/stt`,
          `POST /tasks/modal/stt`

    ### Text-to-Speech (TTS)

    - **`POST /tasks/audio/speech`** - single-synthesis endpoint.
      - `model`: `orpheus-3b-tts` (default) or `spark-tts`; `platform`: `modal` or `runpod`.
      - `voice`: speaker tag/name. `response_mode`: `url` (default), `stream`, or `both`
        (`stream`/`both` require `spark-tts` on `modal`).
      - Orpheus tuning: `language`, `temperature`, `top_p`, `repetition_penalty`,
        `max_tokens`, `seed`. Returns a signed GCP Storage URL.
    - **`POST /tasks/audio/speech/batch`** - Batch synthesis (orpheus-3b-tts
    only), 1-128 items.

    - **`GET /tasks/voice/speakers`** - List voices for a `model` (optional
    orpheus `language`).
      - **orpheus-3b-tts** covers 20 African languages: Acholi (`ach`), Afrikaans (`afr`),
        English (`eng`), Ewe (`ewe`), Fulah (`ful`), Hausa (`hau`), Igbo (`ibo`), Kikuyu (`kik`),
        Kinyarwanda (`kin`), Lugbara (`lgg`), Lingala (`lin`), Luganda (`lug`), Luo (`luo`),
        Runyankole (`nyn`), Sesotho (`sot`), Swahili (`swa`), Ateso (`teo`), Setswana (`tsn`),
        Xhosa (`xho`), Yoruba (`yor`). A few (`lgg`, `sot`, `tsn`) are in the training mix but
        expose no individual voice IDs yet. Full per-speaker catalog: see the
        [tutorial](https://github.com/SunbirdAI/sunbird-ai-api/blob/main/docs/tutorial.md)
        or call `GET /tasks/voice/speakers`.
    - **`GET /tasks/audio/speech/url`** - Refresh an expired signed URL for a
    stored audio object.
      - **Deprecated** → superseded by the new endpoints above:
        - `POST /tasks/modal/tts`, `POST /tasks/runpod/tts`,
          `POST /tasks/modal/orpheus/tts` → `POST /tasks/audio/speech`
        - `POST /tasks/modal/tts/stream` → `/tasks/audio/speech` (`response_mode=stream`)
        - `POST /tasks/modal/tts/stream-with-url` → `/tasks/audio/speech` (`response_mode=both`)
        - `POST /tasks/modal/orpheus/tts/batch` → `POST /tasks/audio/speech/batch`
        - `GET /tasks/modal/tts/speakers`, `GET /tasks/modal/orpheus/speakers`,
          `GET /tasks/modal/orpheus/speakers/{language}` → `GET /tasks/voice/speakers`
        - `GET /tasks/modal/tts/refresh-url` → `GET /tasks/audio/speech/url`

    ### Inference (Sunflower Chat)

    - **`POST /tasks/chat/completions`** - OpenAI-compatible chat completions
    (Sunflower model).
      Supports single instructions, multi-turn conversations, and SSE streaming (`stream: true`).
      Use model `Sunbird/Sunflower-14B`.
      - **Deprecated** → superseded by the unified endpoint above:
        - `POST /tasks/sunflower_inference` → `POST /tasks/chat/completions`
        - `POST /tasks/sunflower_simple` → `POST /tasks/chat/completions` (send the instruction as a single user message)

    ### File Upload

    - **`POST /tasks/generate-upload-url`** - Generate signed URLs for direct
    client uploads to GCP Storage
      - Supports audio files, images, and other content types
      - Includes path traversal protection and input validation
      - Returns temporary signed URL valid for 30 minutes

    ### WhatsApp Integration (Webhooks)

    - **`POST /tasks/webhook`** - Handle incoming WhatsApp Business API messages

    - **`GET /tasks/webhook`** - Verify webhook endpoint ownership for WhatsApp


    ### Legacy Endpoints

    - **`POST /tasks/summarise`** - *(Deprecated)* Anonymized text summarization
    (use Sunflower inference instead)


    ## Rate Limiting

    API endpoints are rate-limited to ensure fair usage. Authentication is
    required for most endpoints.
  version: 0.1.0
servers:
  - url: https://api.sunbird.ai
security: []
tags:
  - name: Authentication Endpoints
    description: >-
      Operations for authentication, including user registration and login. Get
      access tokens to use protected endpoints.
  - name: Speech-to-Text
    description: >-
      Convert speech audio to text. The /tasks/audio/transcriptions endpoint
      accepts an uploaded file or a GCS object, routes to the Modal or RunPod
      backend, and supports optional speaker diarization for Acholi, Ateso,
      English, Luganda, Lugbara, and Runyankole.
  - name: Text-to-Speech
    description: >-
      Synthesize speech from text. Endpoints for single (/tasks/audio/speech)
      and batch (/tasks/audio/speech/batch) synthesis across the orpheus-3b-tts
      and spark-tts models, plus voice listing (/tasks/voice/speakers) and
      signed-URL refresh (/tasks/audio/speech/url). Returns signed GCS audio
      URLs.
  - name: Translation
    description: >-
      Translate text using the Sunflower model. Supports 32 languages (e.g.
      Luganda, Acholi, Ateso, Lugbara, Runyankole, Swahili, Kinyarwanda)
      accepted as ISO codes or full names; source language is optional and
      translation works between any supported pair.
  - name: Language
    description: >-
      Language identification and detection. Automatically detect the language
      of text input from supported languages.
  - name: Chat
    description: >-
      OpenAI-compatible chat completions powered by the Sunflower model.
      Supports single instructions, multi-turn conversations, and SSE streaming.
  - name: Upload
    description: >-
      File upload utilities. Generate signed URLs for direct client uploads to
      GCP Storage with security validation.
  - name: Webhooks
    description: >-
      WhatsApp Business API webhook integration. Handle incoming messages and
      verify webhook endpoints for WhatsApp chatbot functionality.
paths:
  /tasks/audio/transcriptions:
    post:
      tags:
        - Speech-to-Text
      summary: Transcribe audio (STT endpoint)
      description: >-
        Speech-to-Text endpoint. Accepts an uploaded audio file. Replaces /stt,
        /stt_from_gcs, /org/stt, and /modal/stt.
      operationId: create_transcription_tasks_audio_transcriptions_post
      requestBody:
        content:
          multipart/form-data:
            schema:
              $ref: >-
                #/components/schemas/Body_create_transcription_tasks_audio_transcriptions_post
        required: true
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/STTTranscript'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      security:
        - OAuth2PasswordBearer: []
components:
  schemas:
    Body_create_transcription_tasks_audio_transcriptions_post:
      properties:
        language:
          $ref: '#/components/schemas/SttbLanguage'
          description: Target language code.
          default: lug
        audio:
          type: string
          format: binary
          title: Audio
          description: Audio file to transcribe.
      type: object
      required:
        - language
      title: Body_create_transcription_tasks_audio_transcriptions_post
    STTTranscript:
      properties:
        audio_transcription:
          anyOf:
            - type: string
            - type: 'null'
          title: Audio Transcription
          description: The transcribed text from the audio
        diarization_output:
          anyOf:
            - additionalProperties: true
              type: object
            - type: 'null'
          title: Diarization Output
          description: Speaker diarization data
        formatted_diarization_output:
          anyOf:
            - type: string
            - type: 'null'
          title: Formatted Diarization Output
          description: Human-readable diarization output
        audio_transcription_id:
          anyOf:
            - type: integer
            - type: 'null'
          title: Audio Transcription Id
          description: Database ID of the saved transcription
        audio_url:
          anyOf:
            - type: string
            - type: 'null'
          title: Audio Url
          description: URL or path to the processed audio file
        language:
          anyOf:
            - type: string
            - type: 'null'
          title: Language
          description: The language code used for transcription
        was_audio_trimmed:
          anyOf:
            - type: boolean
            - type: 'null'
          title: Was Audio Trimmed
          description: Whether the audio was trimmed to max duration
          default: false
        original_duration_minutes:
          anyOf:
            - type: number
            - type: 'null'
          title: Original Duration Minutes
          description: Original duration in minutes if audio was trimmed
      type: object
      title: STTTranscript
      description: |-
        Response model for speech-to-text transcription results.

        This model represents the output of an STT transcription request,
        including the transcribed text, diarization data, and metadata.

        Attributes:
            audio_transcription: The transcribed text from the audio.
            diarization_output: Speaker diarization data as a dictionary.
            formatted_diarization_output: Human-readable diarization output.
            audio_transcription_id: Database ID of the saved transcription.
            audio_url: URL or path to the processed audio file.
            language: The language code used for transcription.
            was_audio_trimmed: Whether the audio was trimmed to max duration.
            original_duration_minutes: Original duration if audio was trimmed.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    SttbLanguage:
      type: string
      enum:
        - ach
        - teo
        - eng
        - lug
        - lgg
        - nyn
        - swa
        - kin
        - xog
        - myx
      default: eng
      title: SttbLanguage
      description: |-
        Supported languages for Speech-to-Text transcription.

        This enum defines the language codes supported by the STT service.
        Each value represents an ISO 639-3 language code.

        Attributes:
            acholi: Acholi language (ach).
            ateso: Ateso language (teo).
            english: English language (eng).
            luganda: Luganda language (lug).
            lugbara: Lugbara language (lgg).
            runyankole: Runyankole language (nyn).
            swahili: Swahili language (swa).
            kinyarwanda: Kinyarwanda language (kin).
            lusoga: Lusoga language (xog).
            lumasaba: Lumasaba language (myx).
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError
  securitySchemes:
    OAuth2PasswordBearer:
      type: oauth2
      flows:
        password:
          scopes: {}
          tokenUrl: /auth/token

````