Zeroth Check quickstart

Zeroth Check records a real LangGraph tool trajectory, converts it into an explicitly reviewed tape, replaces every live tool during replay, executes four operational faults, and emits one explainable verdict. It is not an output-quality judge; use the existing eval subsystem for that.

Install the LangGraph adapter and inspect the offline payment reference:

pip install 'zeroth-core[langgraph]'
zeroth-core check run --config apps/check_payment/zeroth-check.yaml \
  --report-dir .zeroth/check/payment-report
zeroth-core check explain .zeroth/check/payment-report/check-verdict.json

To create a tape for your own target:

zeroth-core check record --config zeroth-check.yaml --case payment-7 \
  --allow-side-effects
zeroth-core check curate .zeroth/check/recordings/payment-7-payment-7-baseline.json \
  --reviewer reviewer@example.com --output checks/tapes/payment-7.json

Recording can execute the real model and tools. The --allow-side-effects flag is mandatory when any registered tool is consequential. Raw recordings stay under the ignored .zeroth/ tree; only a scrubbed, reviewed TapeV1 belongs in Git.

The primary artifacts are check-verdict.json, check-junit.xml, check-summary.md, and check-terminal.txt. Roll back a CI adoption by removing the Check workflow step; retain curated tapes and reports for diagnosis.