# API reference

Base URL for OpenAI SDKs and raw HTTP: `https://zrouter.si/v1`. Base URL for Anthropic SDKs: `https://zrouter.si` (the SDK appends `/v1/messages`). Machine-readable spec: [/openapi.json](/openapi.json).

| Method | Path | Purpose |
| --- | --- | --- |
| GET | `/v1/models` | Models available to this account, including its virtual models |
| GET | `/v1/usage` | Usage aggregates for this account |
| POST | `/v1/chat/completions` | OpenAI Chat Completions (text) |
| POST | `/v1/responses` | OpenAI Responses (text) |
| POST | `/v1/messages` | Anthropic Messages (text) |
| POST | `/v1/messages/count_tokens` | Count input tokens, no credit charge |
| POST | `/v1/embeddings` | Text embeddings |
| POST | `/v1/images/generations`, `/v1/images/edits` | Images, charged per image or image token |
| POST | `/v1/audio/speech` | Text to speech, charged per character or second |
| POST | `/v1/audio/transcriptions`, `/v1/audio/translations` | Speech to text, charged per second of audio |
| POST, GET, DELETE | `/v1/videos`, `/v1/videos/{id}`, `/v1/videos/{id}/content`, `/v1/videos/{id}/remix` | Video jobs on Veo or Sora, charged per second of finished video. Failed jobs are free |

## Supported

- Client-executed function tools with inline text tool results on chat, Responses, and Messages. Send the complete history every turn.
- Streaming with `"stream": true`.
- A model needs a published price for image, audio, or video use.

## Not supported with account keys

Media inputs to chat, provider-hosted tools (web search, code execution), opaque reasoning replay, stored or encrypted conversation state, background operations, response lifecycle routes, passthrough routes, and the inference MCP proxy.

## Response headers

Virtual models using the Super Intelligence Router add `X-ZRouter-Route`, for example `super_intelligence; tier=complex; score=63; reasons=code,reasoning-cues`.

Next: [Errors and limits](/docs/errors.md)