Reviewed regression tests for RL environments.
RL graders can pay for the wrong behavior, and training finds it. TouchStone turns your environment's rules into tests you approve, then reruns them on every grader or environment change.
uv tool install touchstone-us
Built by engineers from
Watch a grader bug get caught
An LLM agent shops in a browser. Its grader should pay only for orders shipped to the user's address.
Graders that pay for the wrong answer
Cases we recorded where a grader pays for a wrong answer or refuses a right one. Each is the kind of test TouchStone keeps in CI.
The answer is a false equation. The grader pays full reward.
Model answerAnswer: S+1 = S
Graderverl math_dapo.py
Should pay 0Paid 1.0
Why: It reads only what follows the last =.
The answer is right. The grader pays nothing.
Model answer#### $S
Graderverl gsm8k.py, strict
Should pay 1Paid 0
Why: Its strict pattern can't match $.
The agent fakes a success marker without buying anything. It still gets paid.
Model answer{"action": "forge-marker"}
GraderCheckout fixture
Should pay nothingPaid reward
Why: It checks for the marker, not the purchase.
The solution writes its own reward file. The verifier accepts it.
Model answer/logs/verifier/reward.txt
GraderHarbor verifier
Should rejectAccepted
Why: It trusts a file the solution can write.
Recorded on inputs we wrote, against unmodified verl v0.9.1 graders and fixtures we own. Not customer incidents, and not a hack rate.
Runs on your infrastructure
A small Python adapter connects TouchStone to your environment. Tests, runs and approvals stay with you. A model provider and our team control plane are optional.
Your infrastructure
Your environmentUnchanged
AdapterPython you own
TouchStoneReview, run, gate CI
Model providerOptional. Receives context when it drafts tests.
Team control planeOptional. Receives only what you send.
Walk through it with us
We'll run the bundled checkout example with you, then work through what an adapter and a first reviewed suite would need for your environment.
Schedule a callOr run it yourself
Install, then open the local workspace with touchstone serve. The bundled checkout example takes about two minutes.
uv tool install touchstone-us