This is a Plain English Papers summary of a research paper called LLM APIs: Are You Getting the Model You Paid For? Audit Finds Swaps. If you like these kinds of analysis, you should join AImodels.fyi or follow us on Twitter.
Overview
- Research reveals API providers sometimes swap out advertised LLMs with cheaper alternatives
- Authors developed a fingerprinting technique to detect model substitution
- Testing on major APIs (OpenAI, Anthropic, Cohere) found evidence of model switching
- The detection method achieved 98%+ accuracy in identifying specific LLMs
- Providers occasionally serve different models than what users paid for
- API changes can happen secretly without user notification
Plain English Explanation
When you pay for access to a specific AI language model through an API service, you expect to get exactly what you paid for. However, this paper reveals that API providers sometimes quietly swap in different models than the ones they advertise or charge for.
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