Your "Claude Opus" API Might Not Be Claude Opus
Researchers at CISPA audited 17 third-party "shadow" LLM APIs and discovered significant performance discrepancies compared to the official models they claimed to represent. These services often provide access to cheaper or entirely different models, leading to degraded accuracy in academic research. The study identified three common substitution patterns: silent downgrades, cross-vendor swaps, and partial routing based on context length, with simple fingerprinting tests capable of detecting many, but not all, of these deceptions. AI
IMPACT Academic research integrity is compromised when studies rely on misrepresented LLM APIs, potentially invalidating findings.