> ## Documentation Index
> Fetch the complete documentation index at: https://phidatainc-studio-tools-doc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Responses

> Access multiple AI models through a unified, stateless API.

[OpenRouter's Responses API (Beta)](https://openrouter.ai/docs/api/reference/responses/overview) provides an OpenAI-compatible interface for accessing multiple AI models through a unified, stateless API. It is designed as a drop-in replacement for OpenAI's Responses API with enhanced capabilities including reasoning, tool calling, and web search integration.

For details, see examples in `cookbook/90_models/openrouter/responses`.

| Example                                                                      | Description                                                                                   |
| ---------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
| [Basic](/examples/models/openrouter/responses/basic)                         | Use OpenRouter's Responses API (beta) with OpenAI-compatible requests across multiple models. |
| [Fallback](/examples/models/openrouter/responses/fallback)                   | Route requests with fallback models using OpenRouter's dynamic model routing.                 |
| [Streaming](/examples/models/openrouter/responses/stream)                    | Stream OpenRouter's Responses API output. Requires `OPENROUTER_API_KEY`.                      |
| [Structured Output](/examples/models/openrouter/responses/structured-output) | Return Pydantic-validated structured output with OpenRouter's Responses API.                  |
| [Tool Use](/examples/models/openrouter/responses/tool-use)                   | Call tools through OpenRouter's Responses API endpoint.                                       |