> ## 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. # Text to Speech > Text-to-Speech endpoint. Routes by model (orpheus-3b-tts | spark-tts). Returns a signed audio URL (response_mode='url'). Replaces /tasks/modal/tts, /tasks/runpod/tts, and /tasks/modal/orpheus/tts. ## OpenAPI ````yaml api-reference/openapi.json POST /tasks/audio/speech 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/speech: post: tags: - Text-to-Speech summary: Generate speech (TTS endpoint) description: >- Text-to-Speech endpoint. Routes by model (orpheus-3b-tts | spark-tts). Returns a signed audio URL (response_mode='url'). Replaces /tasks/modal/tts, /tasks/runpod/tts, and /tasks/modal/orpheus/tts. operationId: create_speech_tasks_audio_speech_post requestBody: content: application/json: schema: $ref: '#/components/schemas/SpeechRequest' required: true responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/SpeechResponse' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' security: - OAuth2PasswordBearer: [] components: schemas: SpeechRequest: properties: text: type: string minLength: 1 title: Text description: Text to synthesize. model: $ref: '#/components/schemas/TTSModel' description: TTS model. default: orpheus-3b-tts voice: anyOf: - type: string - type: 'null' title: Voice description: >- Voice/speaker. spark-tts: SpeakerID name (e.g. 'luganda_female') or id (e.g. '248'); orpheus-3b-tts: catalog tag (e.g. 'salt_lug_0001'). response_mode: $ref: '#/components/schemas/TTSResponseMode' description: >- url (signed URL), stream (raw audio), or both (SSE). stream/both require model='spark-tts' on platform='modal'. default: url language: anyOf: - type: string - type: 'null' title: Language description: orpheus only (ISO 639-3). max_tokens: anyOf: - type: integer - type: 'null' title: Max Tokens description: orpheus only. seed: anyOf: - type: integer - type: 'null' title: Seed description: orpheus only. max_new_audio_tokens: anyOf: - type: integer - type: 'null' title: Max New Audio Tokens description: runpod-spark only. type: object required: - text title: SpeechRequest description: |- Text-to-speech request. Some fields apply only to specific model/platform combinations; the SpeechService validates combinations and returns 400 on a mismatch. example: language: eng max_tokens: 1200 model: orpheus-3b-tts response_mode: url seed: 42 text: I am a nurse who takes care of many people. voice: salt_eng_0001 SpeechResponse: properties: audio_url: type: string title: Audio Url description: Signed URL to the generated audio. model: type: string title: Model description: Model used. voice: type: string title: Voice description: Resolved voice/speaker. audio_url_expires_at: anyOf: - type: string format: date-time - type: 'null' title: Audio Url Expires At language: anyOf: - type: string - type: 'null' title: Language sample_rate: anyOf: - type: integer - type: 'null' title: Sample Rate duration_seconds: anyOf: - type: number - type: 'null' title: Duration Seconds request_id: anyOf: - type: string - type: 'null' title: Request Id timings_ms: anyOf: - additionalProperties: true type: object - type: 'null' title: Timings Ms type: object required: - audio_url - model - voice title: SpeechResponse description: Normalized response for response_mode='url' across all providers. HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError TTSModel: type: string enum: - orpheus-3b-tts - spark-tts title: TTSModel description: Supported TTS models for the TTS endpoint. TTSResponseMode: type: string enum: - url - stream - both title: TTSResponseMode description: |- Response mode for the TTS endpoint. Attributes: URL: Return only the signed URL after generation completes STREAM: Stream audio chunks directly to the client BOTH: Stream audio chunks AND return a signed URL at the end 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 ````