Black Label Circuit

The brief.

A tool that grades other people's code has no room to be wrong about code. Circuit's first analyzer was — and the honest path was to attack it harder than any user would.

The original build record.

• Problem: the first analyzer pattern-matched raw source text, so docstrings and string templates parsed as code and multiline imports were missed — a whole class of false grades. Fix: every parse now runs through a state machine that blanks comments and strings first. The defect class died at the root, not case by case.
• Problem: we did not trust our own testing. Fix: a 32-agent adversarial review against the grader confirmed 27 real defects. All 27 were fixed, and 16 became permanent regression locks in the test suite.
• Problem: the published download served a stale analyzer missing a line-ending fix — it would mis-grade any repository authored with Windows line endings. Fix: notarized and republished the current build, and confirmed the fix present in the exact file being served. Served-versus-source verification is now standard on every release.
• Decision, July 2026: we removed Circuit from sale rather than keep charging for a tool we were not actively investing in. Existing owners keep their download and their account access. Taking something off the shelf is cheaper than defending it badly.