Did your Agent test this code—or an older version?

AET binds test runs, changed files, artifacts, and Agent claims into portable evidence, then tells you when that proof no longer applies.

Run the demo View source

One command. One real transition.

uvx --from agent-engineering-toolkit aet demo stale-proof

Test command executed — PASS

Proof matches tested source — EXACT_MATCH

Source changed without rerunning — RELEVANT_FILES_CHANGED

PyPI currently serves v1.11.1. This command is the v1.18 target and must not be promoted until the exact release is published.

Carry evidence through the workflow

Stale proof

Keep the historical pass, but stop applying it after relevant code changes.

Scope drift

Review change groups against human-approved intent without treating every cross-module edit as drift.

Cross-Agent handoff

Give another Agent or reviewer portable JSON/JSONL evidence that remains readable without AET.

Evidence, not authority theater

AET is not another coding Agent and does not replace tests or CI. Missing evidence stays UNKNOWN. Plans stay PROPOSED. AET never auto-edits, commits, pushes, merges, or releases.

Start here Status and authority