Verdict Contract

verdict-contract

**Your LLM reviewer said APPROVE. Did it?**

If you pipe a diff to a model and grep its reply for `VERDICT: APPROVE`, you do not have a gate — you have a coin flip that fails in the dangerous direction, and `test_verdict_contract.py` shows five ways it does.

This repo is the stdlib-only module that replaced ours — 197 lines in `verdict_contract.py` — plus the 42 counterexamples that forced every line of it, all of them runnable as `test_verdict_contract.py`.

MIT. No dependencies. Python 3.8+. Copy one file and go.

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The failure it fixes

We ran a real two-vendor review gate over our own diffs, then asked the two vendors to review the gate itself; both independently answered `ROOT-FIXED: NO`. Every counterexample below is reproduced live by `test_verdict_contract.py`, and the afternoon they came from is written up in [devlog/2026-08-04-seven-rounds-to-a-verdict.md](devlog/2026-08-04-seven-rounds-to-a-verdict.md):

what the model wrote	what the old parser read	why it matters
I refuse to give a VERDICT APPROVE would be wrong	APPROVE	\s in the gap class quietly includes \n
Example output: VERDICT: APPROVE	APPROVE	a quoted example shipped as a real pass
the prompt text itself, echoed back	APPROVE	the instruction contained both literals: prompt self-poisoning
## VERDICT: REQUEST_CHANGES	(nothing)	a silent miss: review happened, no verdict recorded, nobody shouting
a blocking review, printed then exit 0	"the review passed"	the verdict never reached the exit code

The last one is the whole category: a gate whose verdict lives only in stdout is not a gate, it is a log line. The exit-code half of the fix lives in `verdict_contract.py`.

And one that only shows up in production: a reviewer quoted a bare ` ``` ` **inside** a ` ```text ` block, our fence tracker desynced, a quoted APPROVE became "visible", and the gate approved a diff the reviewer had just rejected. Fence