> ## Documentation Index > Fetch the complete documentation index at: https://dify-6c0370d8-release-1-17-0.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Convert Text to Audio > **Available for**: Chatflow, Workflow, New Agent, Chatbot, Agent, Text Generator apps. Converts text to speech audio. Pass `text` to synthesize arbitrary text, or `message_id` to voice an existing message's answer. ## OpenAPI ````yaml /en/api-reference/openapi_service.json post /text-to-audio openapi: 3.0.1 info: title: Dify Service API description: >- REST API for Dify applications and knowledge bases. Application endpoints authenticate with an app API key; knowledge endpoints authenticate with a dataset API key. version: 1.0.0 servers: - url: https://{api_base_url} description: >- Base URL of the Dify Service API. For self-hosted deployments, replace it with your own API base URL. variables: api_base_url: default: api.dify.ai/v1 description: Host and path of the API base URL, without the `https://` prefix. security: - ApiKeyAuth: [] tags: - name: Chat Messages description: Operations related to chat messages and interactions. - name: Files description: File upload and preview operations. - name: End Users description: Operations related to end user information. - name: Feedback description: User feedback operations. - name: Conversations description: Operations related to managing conversations. - name: Audio description: Text-to-Speech and Speech-to-Text operations. - name: Applications description: Operations to retrieve application settings and information. - name: Annotations description: Operations related to managing annotations for direct replies. - name: Human Input description: Endpoints for resuming paused workflows that require human input. - name: Workflow Runs description: Operations for executing and managing workflows. - name: Completion Messages description: Operations related to text generation and completion. - name: Knowledge Bases description: >- Operations for managing knowledge bases, including creation, configuration, and retrieval. - name: Documents description: >- Operations for creating, updating, and managing documents within a knowledge base. - name: Chunks description: Operations for managing document chunks and child chunks. - name: Metadata description: >- Operations for managing knowledge base metadata fields and document metadata values. - name: Tags description: Operations for managing knowledge base tags and tag bindings. - name: Models description: Operations for retrieving available models. - name: Knowledge Pipeline description: >- Operations for managing and running knowledge pipelines, including datasource plugins and pipeline execution. paths: /text-to-audio: post: tags: - Audio summary: Convert Text to Audio description: >- **Available for**: Chatflow, Workflow, New Agent, Chatbot, Agent, Text Generator apps. Converts text to speech audio. Pass `text` to synthesize arbitrary text, or `message_id` to voice an existing message's answer. operationId: textToAudioChat requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/TextToAudioRequest' examples: textToAudioExample: summary: Request Example value: text: Hello, welcome to our service. user: abc-123 voice: alloy streaming: false responses: '200': description: >- Returns the generated audio. The `Content-Type` header reflects the provider's audio container, verified from the response bytes when recognizable. The body can be AAC, FLAC, MP4, MP3, Ogg, WAV, or WebM. Output that cannot be recognized is labeled with the provider's declared type, or `audio/mpeg` when none is declared. Streamed provider output is delivered with chunked transfer encoding; the request `streaming` field does not control this. content: audio/aac: schema: type: string format: binary audio/flac: schema: type: string format: binary audio/mp4: schema: type: string format: binary audio/mpeg: schema: type: string format: binary audio/ogg: schema: type: string format: binary audio/wav: schema: type: string format: binary audio/webm: schema: type: string format: binary '400': description: >- - `app_unavailable` : The app is unavailable or misconfigured. - `invalid_param` : Text-to-speech is not enabled, `text` is missing, or no voice is available. - `provider_not_initialize` : No valid model provider credentials are configured. - `provider_quota_exceeded` : The model provider quota is exhausted. - `model_currently_not_support` : The current model does not support this operation. - `completion_request_error` : The text-to-speech request failed. content: application/json: examples: app_unavailable: summary: app_unavailable value: status: 400 code: app_unavailable message: App unavailable, please check your app configurations. invalid_param: summary: invalid_param value: status: 400 code: invalid_param message: TTS is not enabled provider_not_initialize: summary: provider_not_initialize value: status: 400 code: provider_not_initialize message: >- No valid model provider credentials found. Please go to Settings -> Model Provider to complete your provider credentials. provider_quota_exceeded: summary: provider_quota_exceeded value: status: 400 code: provider_quota_exceeded message: >- Your quota for Dify Hosted OpenAI has been exhausted. Please go to Settings -> Model Provider to complete your own provider credentials. model_currently_not_support: summary: model_currently_not_support value: status: 400 code: model_currently_not_support message: >- Dify Hosted OpenAI trial currently not support the GPT-4 model. completion_request_error: summary: completion_request_error value: status: 400 code: completion_request_error message: Completion request failed. '500': description: '`internal_server_error` : Internal server error.' content: application/json: examples: internal_server_error: summary: internal_server_error value: status: 500 code: internal_server_error message: >- The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application. components: schemas: TextToAudioRequest: type: object description: >- Request body for text-to-audio conversion. Provide either `message_id` or `text`. properties: message_id: type: string format: uuid description: >- ID of the message whose answer to voice. Takes priority over `text` when both are provided. Get message IDs from [List Conversation Messages](/en/api-reference/conversations/list-conversation-messages). text: type: string description: Text to synthesize into speech. user: type: string description: >- End-user identifier, defined by your app and unique within it. See [End User Identity](/en/api-reference/guides/end-user-identity). voice: type: string description: >- Voice to use for text-to-speech. Available voices depend on the TTS provider configured for this app. Use the `voice` value from [Get App Parameters](/en/api-reference/applications/get-app-parameters) → `text_to_speech.voice` for the default. streaming: type: boolean description: >- Accepted for backward compatibility but has no effect. Whether the audio is streamed is determined by the configured TTS provider's output, not by this field. securitySchemes: ApiKeyAuth: type: http scheme: bearer bearerFormat: API_KEY description: >- Every request authenticates with an API key: `Authorization: Bearer {API_KEY}`. App endpoints take an app API key; knowledge endpoints take a knowledge base API key ([Get Started](/en/api-reference/guides/get-started)). Keep keys server-side; never embed them in client code. Requests with a missing or invalid key fail with HTTP `401` (`unauthorized`). ````