---
title: HTTP API
description: OpenAI-compatible endpoints and admin API reference.
---

## OpenAI-Compatible Endpoints

### Chat Completions

```
POST /v1/chat/completions
```

Request and response format follows the OpenAI API specification. Supports streaming via `stream: true`.

### Embeddings

```
POST /v1/embeddings
```

### Models

```
GET /v1/models
```

Returns all models from all registered providers, plus model aliases.

## Admin Endpoints

### Tenants

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/admin/tenants` | List all tenants |
| `POST` | `/admin/tenants` | Create a tenant |
| `GET` | `/admin/tenants/:id` | Get a tenant |
| `PUT` | `/admin/tenants/:id` | Update a tenant |
| `DELETE` | `/admin/tenants/:id` | Delete a tenant |

### API Keys

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/admin/keys` | List keys for a tenant |
| `POST` | `/admin/keys` | Create an API key |
| `DELETE` | `/admin/keys/:id` | Revoke an API key |

### Usage

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/admin/usage` | Query usage records |
| `GET` | `/admin/usage/summary` | Aggregated usage summary |

### Providers

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/admin/providers` | List registered providers |

### Health

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/health` | Gateway health check |

## Response Headers

All responses include:

- `X-Nexus-Request-ID` — Unique request identifier
- `X-Nexus-Provider` — Provider that served the request
- `X-Nexus-Cache` — `HIT` or `MISS`