> ## Documentation Index > Fetch the complete documentation index at: https://assemblyai.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # List models (OpenRouter) > The models of the OpenAI-compatible route in the provider document format of [OpenRouter](https://openrouter.ai): one entry per language that has voices, named `assemblyai-tts-`, with the voices (each by its library slug, such as `aai-jane`), output formats, input limit and data centers of each. It is public: no credential is needed, and a credential that is sent is not checked. `HEAD` answers with the same headers and no body. The answer may be cached for 5 minutes (`Cache-Control: public, max-age=300`). ## OpenAPI ````yaml api-reference/specs/streaming-tts-speech.yaml GET /v1/openrouter/models openapi: 3.0.3 info: title: AssemblyAI Streaming TTS HTTP API description: >- HTTP API of Streaming Text-to-Speech: send a text in one `POST` and read the speech back as the response body. The audio streams while it is synthesized, so the first bytes arrive long before the last; with `"stream": false` the whole clip arrives at once. `POST /v1/speech/events` streams the audio as server-sent events with word timings, and `POST /v1/openai/audio/speech` takes the request shape of the OpenAI speech API, so OpenAI SDKs and the frameworks built on them work by changing their base URL. See the [Quickstart](/tts/getting-started/quickstart) for a first request and [OpenAI compatibility](/tts/openai-compatibility) for the OpenAI-compatible route. Voices, models, audio formats and text handling are those of the [Streaming TTS WebSocket API](/tts/connect-parameters). Every error the native routes answer has the JSON body described under `ErrorResponse`, and every error of the OpenAI-compatible routes the body described under `OpenAIErrorResponse`; see [HTTP API basics](/tts/api-reference/http-api/overview). version: 1.0.0 termsOfService: https://www.assemblyai.com/legal/terms-of-service contact: name: API Support email: support@assemblyai.com url: https://www.assemblyai.com/docs/ servers: - url: https://tts.us.assemblyai.com description: US data zone x-fern-server-name: US - url: https://tts.eu.assemblyai.com description: EU data zone x-fern-server-name: EU security: - apiKey: [] tags: - name: Speech description: Text to speech in one request. - name: OpenAI compatibility description: The route and the models documents for OpenAI-shaped clients. paths: /v1/openrouter/models: get: tags: - OpenAI compatibility summary: List models (OpenRouter) description: >- The models of the OpenAI-compatible route in the provider document format of [OpenRouter](https://openrouter.ai): one entry per language that has voices, named `assemblyai-tts-`, with the voices (each by its library slug, such as `aai-jane`), output formats, input limit and data centers of each. It is public: no credential is needed, and a credential that is sent is not checked. `HEAD` answers with the same headers and no body. The answer may be cached for 5 minutes (`Cache-Control: public, max-age=300`). operationId: ListOpenRouterModels responses: '200': description: OK. headers: Cache-Control: $ref: '#/components/headers/Cache-Control-Public' content: application/json: schema: $ref: '#/components/schemas/OpenRouterModelList' '404': $ref: '#/components/responses/OpenAINotFound' '405': $ref: '#/components/responses/OpenAIMethodNotAllowed' security: [] components: headers: Cache-Control-Public: description: '`public, max-age=300`.' schema: type: string X-Request-Id: description: >- The request's id, a UUID, on every response, errors and the answer to a browser's CORS preflight included. It is the `id` of the `Begin` event and the `request_id` of an error body. Quote it in support requests. schema: type: string Allow: description: The methods the path answers, such as `OPTIONS, POST`. schema: type: string schemas: OpenRouterModelList: type: object properties: data: type: array items: $ref: '#/components/schemas/OpenRouterModel' OpenRouterModel: type: object additionalProperties: true description: One language's entry, in OpenRouter's provider document format. properties: schema_version: type: string id: type: string description: '`assemblyai-tts-`, a name the `model` field accepts.' name: type: string created: type: integer description: type: string input_modalities: type: array items: type: object additionalProperties: true description: The text input, with its length limit (5,000 characters). output_modalities: type: array items: type: object additionalProperties: true description: >- The speech output, with its voices, output formats, pricing and capacity. datacenters: type: array items: type: object additionalProperties: true deployment_region: type: string is_ready: type: boolean OpenAIErrorResponse: type: object required: - error description: The body of every error of the OpenAI-compatible routes. properties: error: $ref: '#/components/schemas/OpenAIError' OpenAIError: type: object required: - message - type - code - request_id - retryable properties: message: type: string description: What went wrong, written for people. type: type: string description: >- The OpenAI error type: `invalid_request_error`, `authentication_error`, `permission_error`, `insufficient_quota`, `rate_limit_error`, `server_error` or `service_unavailable_error`. param: type: string nullable: true description: The field the error is about, or `null`. code: type: string description: The same code the native routes answer, such as `invalid_parameter`. request_id: type: string description: The request's id, also in the `X-Request-Id` header. retryable: type: boolean description: Whether the same request can succeed when you retry it later. retry_after_seconds: type: integer nullable: true description: Seconds to wait before retrying; `null` when there is no hint. responses: OpenAINotFound: description: >- Type `invalid_request_error`, code `not_found`: a path the API does not serve, an unknown path or a documented one with a trailing slash. Paths are exact; nothing redirects. headers: X-Request-Id: $ref: '#/components/headers/X-Request-Id' content: application/json: schema: $ref: '#/components/schemas/OpenAIErrorResponse' OpenAIMethodNotAllowed: description: >- Type `invalid_request_error`, code `method_not_allowed`: a method the path does not answer; `Allow` lists the ones it does. headers: X-Request-Id: $ref: '#/components/headers/X-Request-Id' Allow: $ref: '#/components/headers/Allow' content: application/json: schema: $ref: '#/components/schemas/OpenAIErrorResponse' securitySchemes: apiKey: type: apiKey in: header name: Authorization description: >- Your AssemblyAI API key, or a temporary token, in the `Authorization` header. The raw key works directly; a `Bearer ` prefix is also accepted, which is what OpenAI SDKs send. Send exactly one `Authorization` header. The HTTP routes read the credential from this header only. ````