> ## Documentation Index > Fetch the complete documentation index at: https://phaseo.app/docs/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Phaseo Gateway base URL: https://api.phaseo.app/v1. Send `Authorization: Bearer $PHASEO_API_KEY` with every request. > Model IDs look like `provider/model`, for example `openai/gpt-6-astra`. Do not guess IDs: list them with `GET /v1/models` or check https://phaseo.app/models. `phaseo/free` routes to an available free model and needs no wallet balance. > For new text integrations prefer `POST /v1/responses`. `POST /v1/chat/completions` (OpenAI format) and `POST /v1/messages` (Anthropic format) suit existing code. > The full API contract is https://phaseo.app/docs/openapi/v1/openapi.yaml. Official SDKs: `@phaseo/sdk` (TypeScript) and `phaseo` (Python), plus Go, C#, PHP, Ruby and Rust. > Search these docs over MCP at https://phaseo.app/docs/mcp, and install Phaseo skills with `npx skills add https://phaseo.app/docs`. If a page is wrong or out of date, report it with the MCP `submit_feedback` tool. > Manage Phaseo accounts with the `phaseo` CLI (`npm install -g @phaseo/cli`, then `phaseo login` or `phaseo login --device-code`), the `/v1` Management API or the MCP server at `https://mcp.phaseo.app/mcp?access=manage`. Do not send users to the dashboard for account tasks. A person is still needed for sign-up, approving a sign-in, paying the first top-up on the checkout link that `phaseo credits add` returns when no card is saved, confirming each saved-card top-up from the emailed link, and account security (password, MFA, passkeys). Create API keys with `phaseo keys create --name --json`; never guess one. Credit top-ups need `phaseo login --scopes billing:write` first. Task map: https://phaseo.app/docs/v1/developers/manage-from-an-agent.md. # Create speech > Generate TTS audio from text using the specified voice and format. ## Voice Mapping `voice` is normalized by provider with an internal alias map: * `openai`: common voices (for example `alloy`, `ash`, `ballad`, `coral`, `echo`, `fable`, `onyx`, `nova`, `sage`, `shimmer`, `verse`, `cedar`, `marin`). * `google` (AI Studio / Gemini TTS): canonical prebuilt voices: `Zephyr`, `Puck`, `Charon`, `Kore`, `Fenrir`, `Leda`, `Orus`, `Aoede`, `Callirrhoe`, `Autonoe`, `Enceladus`, `Iapetus`, `Umbriel`, `Algieba`, `Despina`, `Erinome`, `Algenib`, `Rasalgethi`, `Laomedeia`, `Achernar`, `Alnilam`, `Schedar`, `Gacrux`, `Pulcherrima`, `Achird`, `Zubenelgenubi`, `Vindemiatrix`, `Sadachbia`, `Sadaltager`, `Sulafat`. * `elevenlabs`: common public starter voices are mapped (for example `rachel`, `domi`, `bella`, `antoni`, `elli`, `josh`, `arnold`, `adam`, `sam`). For `eleven-labs/eleven-v4` and `eleven-labs/eleven-v4-turbo`, pass any 20-character ElevenLabs voice library ID, including a custom clone. Set `config.elevenlabs.voice_settings.stability` and `similarity_boost` as needed. Eleven v4 does not support `speed` or `voice_settings.style`. If a provided `voice` is not valid for the routed provider/model mapping, the request returns `400 invalid_request_error` with `param: "voice"`. ## Provider Overrides You can still pass provider-native voice settings: * ElevenLabs: `config.elevenlabs.voice_id` / `config.elevenlabs.voice` / `config.elevenlabs.voiceName` * Google: `config.google.voice_name` / `config.google.voiceName` Top-level `voice` should be your default for portability. ## Voice Samples * OpenAI: [openai.fm](https://www.openai.fm/) * Google TTS voice examples: [Gemini text-to-speech docs](https://ai.google.dev/gemini-api/docs/speech-generation#voices) * ElevenLabs voice library: [ElevenLabs Voice Library](https://elevenlabs.io/voice-library) ## OpenAPI ````yaml openapi/v1/openapi.yaml POST /audio/speech openapi: 3.0.3 info: title: Phaseo Gateway API description: >- A gateway API for accessing various AI models with OpenAI-compatible endpoints. version: 1.0.0 contact: name: Phaseo url: https://phaseo.app email: danielbutler500@gmail.com servers: - url: https://api.phaseo.app/v1 description: Global routing security: - BearerAuth: [] tags: - name: Gateway description: Core Phaseo Gateway operations. paths: /audio/speech: post: tags: - Gateway summary: Generate speech description: Generates audio from the input text. operationId: createSpeech requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/AudioSpeechRequest' responses: '200': description: Audio file content: audio/mpeg: schema: type: string format: binary components: schemas: AudioSpeechRequest: type: object required: - model - input properties: model: type: string models: $ref: '#/components/schemas/ModelFallbacks' input: type: string voice: type: string speed: type: number minimum: 0.25 maximum: 4 format: type: string enum: - mp3 - wav - ogg - aac provider: $ref: '#/components/schemas/ProviderRoutingOptions' config: type: object additionalProperties: true properties: elevenlabs: type: object additionalProperties: true properties: voice_id: type: string language_code: type: string output_format: type: string voice_settings: type: object additionalProperties: true properties: stability: type: number similarity_boost: type: number ModelFallbacks: type: array minItems: 1 maxItems: 25 items: type: string minLength: 1 description: >- Optional ordered fallback models tried after `model`. `model` is required and is always the primary model. When an attempt fails with `429`, `500`, `502`, `503`, or `504`, the next entry is tried; other errors are returned unchanged. Accepts up to 25 model IDs or presets; duplicates and entries equal to `model` are ignored. Each attempt is validated, logged, and billed as its own request, and the response `model` field and routing trace show the model that served the request. Streaming requests fall back only before the first byte, and video and music jobs fall back only at submission. Batch, realtime, and council requests reject `models`. Fallbacks set on a dynamic route take precedence, and `phaseo/auto` cannot be combined with `models`. example: - anthropic/claude-sonnet-5-5 - google/gemini-2.5-flash ProviderRoutingOptions: type: object description: Provider routing preferences for gateway selection. properties: order: type: array items: type: string only: type: array items: type: string ignore: type: array items: type: string include_alpha: type: boolean description: Include alpha providers in routing (off by default). allow_fallbacks: type: boolean nullable: true description: Allow fallback to another eligible provider after failure. require_parameters: type: boolean nullable: true description: Require provider support for requested parameters before routing. required_execution_region: type: string nullable: true description: Restrict routing to providers with the requested execution region. required_data_region: type: string nullable: true description: Restrict routing to providers with the requested data region. require_zero_data_retention: type: boolean nullable: true description: Restrict routing to providers that support zero data retention. data_collection: type: string nullable: true description: >- `allow` (the default) filters nothing. `deny` is not supported yet and returns 400 unsupported_routing_filter. enum: - allow - deny zdr: type: boolean nullable: true enforce_distillable_text: type: boolean nullable: true description: >- `false` (the default) filters nothing. `true` is not supported yet and returns 400 unsupported_routing_filter. quantizations: type: array nullable: true items: type: string sort: oneOf: - type: string - type: object additionalProperties: true description: >- Rank providers for this request, for example by price, latency, or throughput. max_price: type: object properties: prompt: oneOf: - type: number - type: string completion: oneOf: - type: number - type: string image: oneOf: - type: number - type: string audio: oneOf: - type: number - type: string request: oneOf: - type: number - type: string preferred_min_throughput: oneOf: - type: number - type: object additionalProperties: type: number preferred_max_latency: oneOf: - type: number - type: object additionalProperties: type: number securitySchemes: BearerAuth: type: http scheme: bearer description: Bearer token authentication ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.