OnyxWeb2API — Rust Proxy

Convert Onyx Cloud web chat into OpenAI and Anthropic Claude compatible API endpoints.

Use any OpenAI/Claude-compatible client (NextChat, LobeChat, Continue, Cursor, etc.) with your Onyx Cloud account — no official API key required.

Features

• OpenAI-compatible API — POST /v1/chat/completions (streaming + non-streaming)
• Claude-compatible API — POST /v1/messages (streaming + non-streaming)
• Multi-cookie pool — round-robin across multiple Onyx accounts for load balancing
• Cookie management dashboard — add, remove, monitor cookie status via web UI
• Auto cookie capture — login with email/password to automatically capture auth cookies
• SSE streaming — real-time token-by-token streaming for both API formats
• API key protection — optional Bearer token / x-api-key authentication

Supported Models

Model	Provider
gpt-5.2	OpenAI
gpt-5-mini	OpenAI
gpt-4.1	OpenAI
gpt-4o	OpenAI
o3	OpenAI
claude-opus-4.6	Anthropic
claude-opus-4.5	Anthropic
claude-sonnet-4.5	Anthropic

Quick Start

1. Get your Onyx auth cookie

Option A — Email/Password (automatic):

Navigate to http://your-server:8897/auth/login and login with your Onyx Cloud credentials. The cookie is captured automatically.

Option B — Browser DevTools (manual):

1. Login to cloud.onyx.app
2. Open DevTools → Application → Cookies
3. Copy the value of fastapiusersauth

2. Configure

cp .env.example .env
# Edit .env and set ONYX_AUTH_COOKIE to your cookie value

3. Run

From source:

cargo build --release
./target/release/rust-proxy

With environment variables:

ONYX_AUTH_COOKIE=your-cookie PORT=8897 ./rust-proxy

4. Use

OpenAI format:

curl http://localhost:8897/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.2",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": true
  }'

Claude format:

curl http://localhost:8897/v1/messages \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-4.6",
    "messages": [{"role": "user", "content": "Hello!"}],
    "max_tokens": 1024,
    "stream": true
  }'

API Endpoints

Endpoint	Method	Description
/v1/chat/completions	POST	OpenAI-compatible chat (stream + non-stream)
/v1/messages	POST	Claude-compatible messages (stream + non-stream)
/v1/models	GET	List available models
/ui	GET	Dashboard — cookie management, status overview
/auth/login	GET/POST	Login page + email/password cookie capture
/api/cookies	GET/POST	Manage cookie pool (list / add)
/api/cookies/:fingerprint	DELETE	Remove a cookie by fingerprint
/api/status	GET	Proxy status and cookie health
/health	GET	Health check

Client Configuration

NextChat / LobeChat / ChatBox

• API Base URL: http://your-server:8897/v1
• API Key: your configured API_KEY (or leave empty if not set)
• Model: gpt-5.2, claude-opus-4.6, etc.

Continue / Cursor / OpenCode

{
  "apiBase": "http://your-server:8897/v1",
  "apiKey": "your-api-key",
  "model": "gpt-5.2"
}

Claude-compatible clients

• API Base URL: http://your-server:8897
• API Key header: x-api-key: your-api-key
• Endpoint: /v1/messages

Environment Variables

Variable	Default	Description
ONYX_BASE_URL	https://cloud.onyx.app	Onyx Cloud base URL
ONYX_AUTH_COOKIE	(required)	Auth cookie(s), comma-separated
ONYX_PERSONA_ID	0	Persona ID (0 = default)
ONYX_ORIGIN	webapp	Origin field for API payload
ONYX_ORIGIN_URL	$ONYX_BASE_URL	HTTP Origin header value
ONYX_REFERER	https://cloud.onyx.app/app	HTTP Referer header
API_KEY	(none)	Optional API key to protect endpoints
PORT	8897	Server port
LOG_LEVEL	info	Log level (trace/debug/info/warn/error)
REQUEST_TIMEOUT	300	Request timeout in seconds

Building

# Debug build
cargo build

# Release build (optimized, ~5MB stripped)
cargo build --release
strip target/release/rust-proxy

# Run tests
cargo test

Architecture

Client (NextChat, Cursor, etc.)
  │
  ├── POST /v1/chat/completions  (OpenAI format)
  ├── POST /v1/messages          (Claude format)
  │
  ▼
┌─────────────────────┐
│   Rust Proxy (Axum)  │
│                     │
│  ┌── Auth check ──┐ │
│  ┌── Cookie pool ─┐ │  ← Round-robin multi-account
│  ┌── Model map ───┐ │  ← gpt-5.2 → ("OpenAI","gpt-5.2")
│  ┌── SSE bridge ──┐ │  ← Onyx SSE → OpenAI/Claude SSE
└────��────────────────┘
  │
  ▼
cloud.onyx.app (Onyx Cloud backend)

License

MIT