> ## Documentation Index > Fetch the complete documentation index at: https://enterprise-docs.dify.ai/llms.txt > Use this file to discover all available pages before exploring further. # Convert Text to Audio > **Available for**: Chatflow, Workflow, 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/3.11.x/develop/api/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. Replace it with your deployment's API endpoint. variables: api_base_url: default: api.example.com/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, 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 file. The `Content-Type` header is set to the audio MIME type (e.g., `audio/wav`, `audio/mp3`). When the configured TTS provider returns a stream, the audio is delivered as `audio/mpeg` with chunked transfer encoding; the request `streaming` field does not control this. content: audio/mpeg: 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. - `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. 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/3.11.x/develop/api/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/3.11.x/develop/api/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/3.11.x/develop/api/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/3.11.x/develop/api/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`). ````