Claude Authenticity
Detect whether an API endpoint is backed by genuine Claude (not a wrapper, proxy, or...
Install
npx skills add agentscope-ai/OpenJudge --skill claude-authenticity -g -a claude-code -y- Repository
- agentscope-ai/OpenJudge1k
- Category
- Testing
- Updated
- 6d ago
- License
- Apache-2.0
- Context cost
- Mediumabout 3,000 tokens
- Runs scripts
- No, instructions only
What it does
Detect whether an API endpoint is backed by genuine Claude (not a wrapper, proxy, or impersonator) using 9 weighted rule-based checks that mirror the claude-verify project. Also extracts injected system prompts from providers that override Claude's identity. Fully self-contained, copy the code below and run, no extra packages beyond httpx. Use when the user wants to verify a Claude API key or endpoint, check if a third-party Claude service is authentic, audit API providers for Claude authenticity, test multiple models in parallel, or discover what system prompt a provider has injected.
Claude Authenticity Skill
Verify whether an API endpoint serves genuine Claude and optionally extract any injected system prompt.
No installation required beyond httpx. Copy the code blocks below directly
into a single .py file and run, no openjudge, no cookbooks, no other setup.
pip install httpx
The 9 checks (mirrors claude-verify)
| # | Check | Weight | Signal |
|---|---|---|---|
| 1 | Signature 长度 | 12 | signature field in response (official API exclusive) |
| 2 | 身份回答 | 12 | Reply mentions claude code / cli / command |
| 3 | Thinking 输出 | 14 | Extended-thinking block present |
| 4 | Thinking 身份 | 8 | Thinking text references Claude Code / CLI |
| 5 | 响应结构 | 14 | id + cache_creation fields present |
| 6 | 系统提示词 | 10 | No prompt-injection signals (reverse check) |
| 7 | 工具支持 | 12 | Reply mentions bash / file / read / write |
| 8 | 多轮对话 | 10 | Identity keywords appear ≥ 2 times |
| 9 | Output Config | 10 | cache_creation or service_tier present |
Score → verdict: ≥ 85 → genuine 正版 ✓ / 60, 84 → suspected 疑似 ? / < 60 → likely_fake 非正版 ✗
Gather from user before running
| Info | Required? | Notes |
|---|---|---|
| API endpoint | Yes | Native: https://xxx/v1/messages OpenAI-compat: https://xxx/v1/chat/completions |
| API key | Yes | The key to test |
| Model name(s) | Yes | One or more model IDs |
| API type | No | anthropic (default, always prefer) or openai |
| Extract prompt | No | Set EXTRACT_PROMPT = True to also attempt system prompt extraction |
CRITICAL, always use api_type="anthropic".
OpenAI-compatible format silently drops signature, thinking, and cache_creation,
causing genuine Claude endpoints to score < 40. Only use openai if the endpoint
rejects native-format requests entirely.
Self-contained script
Save as claude_authenticity.py and run:
