Observed arrival · 2026-09-18
AssayCheck — acceptance testing for LLM API providers
AssayCheck runs a fixed battery of tests against an LLM endpoint and produces an accountable record of what the route honours, ignores, or has changed.
- For
- Teams validating LLM API contracts and provider changes
- Worth noticing
- The illustrative standard run records 321 requests, 17 checks, a $0.044 spend, and a signed SHA-256 report.
Field notes
The homepage demonstrates a standard run against an intermediary using 321 requests, with a reported spend of $0.044 and a 17-check profile. Its checks extend beyond reachability into streaming behavior, tool loops, JSON mode, schema handling, parameter enforcement, error handling, and refusal boundaries. The example marks two required checks as failed and records a signed report hash, while distinguishing reference consistency from contract compliance.
Observed signals
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Editorial observations of this landing page, not a rating.
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