claude-authenticity

To verify Claude API authenticity, this Skill runs 9 weighted rule-based checks against the endpoint to score its legitimacy, detecting wrappers and impersonators claiming to use Claude models.

Yes, system prompt detection extracts any injected custom instructions from the endpoint response, revealing hidden prompts that might override Claude's default behavior before you integrate the service.

Claude authenticity verification supports both Anthropic-native and OpenAI-compatible API formats, with a preference for the native format because it provides a richer response structure for analysis.

The best way to check for Claude impersonators is running weighted endpoint testing that scores authenticity across 9 checks, extracting any injected system prompts to identify wrappers misrepresenting their underlying models.

LLM security testing requires endpoint verification because API wrappers and impersonators can misrepresent their underlying models, making authenticity checks necessary to confirm genuine Claude usage and expose hidden system prompts.

Yes, you need the provider's API endpoint URL, the target model name such as claude-opus-4-6, and your API key to authenticate the request and run the weighted authenticity checks.