Yupp, Qwen, and LMArena Providers

Relevant source files

• g4f/Provider/Qwen.py
• g4f/Provider/Yupp.py
• g4f/Provider/needs_auth/LMArena.py
• g4f/Provider/qwen/QwenCode.py
• g4f/Provider/qwen/oauthFlow.py
• g4f/Provider/qwen/qwenContentGenerator.py
• g4f/Provider/qwen/qwenOAuth2.py
• g4f/Provider/qwen/sharedTokenManager.py
• g4f/Provider/qwen/stubs.py
• g4f/api/stubs.py
• scripts/start-browser.sh

This page documents three advanced provider implementations: Yupp, Qwen, and LMArena. These providers demonstrate sophisticated authentication patterns including account rotation (Yupp), OAuth2 device flow with shared token management (Qwen/QwenCode), and browser automation (LMArena). For general provider architecture, see Provider Base Classes. For authentication strategies overview, see Authentication Overview.

Overview

These three providers represent distinct approaches to provider implementation:

• Yupp: A complex provider supporting ~100+ models with multi-account rotation, image caching, reward claiming, and variant response handling. g4f/Provider/Yupp.py50-55
• Qwen: A chat provider with cookie-based authentication, OSS file upload, and multiple chat types (text, image generation, web search, artifacts). g4f/Provider/Qwen.py212-227
• QwenCode: An OpenAI-compatible provider using OAuth2 device authorization flow with shared token management across processes. g4f/Provider/qwen/QwenCode.py18-27
• LMArena: A provider requiring reCAPTCHA/Turnstile validation and browser integration for authentication. g4f/Provider/needs_auth/LMArena.py116-125

The key distinction between Qwen and QwenCode is authentication: Qwen uses generated cookies while QwenCode implements full OAuth2 with refresh tokens.

Sources: g4f/Provider/Yupp.py1-55 g4f/Provider/Qwen.py1-40 g4f/Provider/qwen/QwenCode.py1-27 g4f/Provider/needs_auth/LMArena.py1-41

Yupp Provider Architecture

Class Structure and Dependencies

Yupp Implementation Hierarchy:

The Yupp provider extends AsyncGeneratorProvider and ProviderModelMixin, using cloudscraper for Cloudflare bypass and maintaining global state for account rotation and image caching. g4f/Provider/Yupp.py34-45

Sources: g4f/Provider/Yupp.py34-45 g4f/Provider/Yupp.py50-54 g4f/Provider/Yupp.py58-83

Account Rotation System

Account rotation is managed by get_best_yupp_account() which implements:

• Error tracking: Each account has error_count incremented on failures. g4f/Provider/Yupp.py98-100
• Cooldown mechanism: Accounts exceeding MAX_ERROR_COUNT (default: 3) are excluded until ERROR_COOLDOWN (default: 300s) elapses. g4f/Provider/Yupp.py105-118
• Least-recently-used selection: Valid accounts are sorted by (last_used, error_count) to distribute load. g4f/Provider/Yupp.py130-133

Sources: g4f/Provider/Yupp.py104-133 g4f/Provider/Yupp.py86-101

Qwen Provider Architecture

Authentication Strategy Comparison

Aspect	Qwen	QwenCode
Authentication	Cookie generation via generate_cookies()	OAuth2 device authorization flow
Base Class	AsyncGeneratorProvider	OpenaiTemplate
Token Management	Per-request cookies	Shared SharedTokenManager with file locking
API Endpoint	chat.qwen.ai	qwen.ai (OpenAI-compatible)

Sources: g4f/Provider/Qwen.py212-227 g4f/Provider/qwen/QwenCode.py18-27 g4f/Provider/qwen/cookie_generator.py1-18

Qwen Media Upload via OSS

The Qwen provider implements Alibaba Cloud OSS v4 signature for file uploads in get_oss_headers:

1. Canonical Request: Constructs canonical headers including x-oss-content-sha256, x-oss-date, and x-oss-security-token. g4f/Provider/Qwen.py55-87
2. String to Sign: Generates SHA256 hash of canonical request and constructs the signing string. g4f/Provider/Qwen.py90-96
3. Signing Key: Derives key via HMAC chain: date_key → region_key → service_key → signing_key. g4f/Provider/Qwen.py103-106
4. Signature: HMAC-SHA256 of string-to-sign using the derived signing key. g4f/Provider/Qwen.py107-113

Sources: g4f/Provider/Qwen.py55-114

QwenCode OAuth2 Implementation

Shared Token Manager Architecture

Entity mapping for Qwen Token Management:

Singleton Pattern g4f/Provider/qwen/sharedTokenManager.py57-61:

• Uses threading.Lock to ensure single instance across threads.
• Periodically checks file modification time to reload credentials updated by other processes. g4f/Provider/qwen/sharedTokenManager.py115-127

Token Validation g4f/Provider/qwen/qwenOAuth2.py25-26: Uses a 30-second buffer (TOKEN_REFRESH_BUFFER_MS) to prevent race conditions during request execution.

Sources: g4f/Provider/qwen/sharedTokenManager.py43-61 g4f/Provider/qwen/sharedTokenManager.py115-133

OAuth2 Device Authorization Flow

PKCE Parameters g4f/Provider/qwen/qwenOAuth2.py28-42:

• code_verifier: 64-byte random token, base64url-encoded.
• code_challenge: SHA256 hash of code_verifier, base64url-encoded.

Sources: g4f/Provider/qwen/qwenOAuth2.py97-125 g4f/Provider/qwen/oauthFlow.py16-95

LMArena Provider

Authentication and Request Flow

LMArena requires browser automation to handle anti-bot systems:

• Browser Integration: Uses zendriver (nodriver) to extract valid session arguments including cookies and headers via get_args_from_nodriver. g4f/Provider/needs_auth/LMArena.py26-34
• UUIDv7: Generates UUIDv7 identifiers matching browser implementation for session tracking. g4f/Provider/needs_auth/LMArena.py59-73
• Turnstile Bypass: Implements click_trunstile via coordinate-based mouse interaction in the browser tab. g4f/Provider/needs_auth/LMArena.py98-113

Model Loading: Models are loaded from a cache file in the cookies directory (.models/arena.ai.json) or fetched dynamically from the Arena direct mode URL. g4f/Provider/needs_auth/LMArena.py169-184

Sources: g4f/Provider/needs_auth/LMArena.py98-113 g4f/Provider/needs_auth/LMArena.py169-205

Comparison Summary

Feature	Yupp	Qwen	QwenCode	LMArena
Base Class	AsyncGeneratorProvider	AsyncGeneratorProvider	OpenaiTemplate	AsyncGeneratorProvider
Auth Type	Account Rotation	Cookie Generation	OAuth2 Device Flow	Browser Automation
Token Storage	Memory List	Memory Cache	oauth_creds.json	.models Cache
File Upload	Threaded API Calls	OSS HMAC-SHA256	N/A	S3 Signed URL Proxy

Sources: g4f/Provider/Yupp.py34-50 g4f/Provider/Qwen.py212-227 g4f/Provider/qwen/QwenCode.py18-27 g4f/Provider/needs_auth/LMArena.py116-139