Verify themigration.
Check that your AI-written rewrite preserves the behavior that matters. Compare it with the original, then inspect the first change.
The original system remains the approved reference while an AI-written rewrite is verified under the same behavioral contract. In this example, trimming an account value changes the posting branch. Strust returns MATCH / DIVERGE / INCONCLUSIVE.
Approved behavior
Behavior to verify
Run both. Compare behavior.
- Original
- POST
- Rewrite
- NO WRITE
Catch the change before it ships
See what changed, understand why, then check a correction.
A record goes missing in the rewrite.
The same account should create the same posting record after migration.
The account reaches the posting branch.
An earlier account-handling change alters the branch.
Strust brings you to the first relevant difference, so the coding agent knows what to repair.
One case, within a wider check
18 of 20 cases match. 1 changes behavior. 1 still needs evidence. A corrected case does not approve the migration.
Showing the selected run for the current rewrite.
Technical scope & verdicts
- Rewrite
- c84e21
- Original
- 91b5d2
- Contract
- claims-v12
- Fixture set
- claims-boundaries-04
Selected run: run-042. MATCH: 18 · DIVERGE: 1 · INCONCLUSIVE: 1 · Pending: 0. These results cover this run’s declared fixtures only.
How verification works
A rewrite can compile and still change behavior. Strust compares the original and rewrite under one agreed contract, beginning with COBOL-to-Java migration.
Read the verification methodPin the behavior contract
Agree on inputs, runtime assumptions, observable outputs, and comparison rules. Keep the original fixed while a coding agent changes the rewrite.
Run original and rewrite together
Verification runners execute both systems under the declared conditions. Conformance testing compares their returned values, database writes, emitted records, and error behavior.
Review the first difference
Inspect a match, divergence, or inconclusive result with its evidence. Feed a finding back to the coding agent, then replay the changed revision before owner review.
Common questions
What the verdict means, and where the evidence stops.
What does Strust compare?
The original and rewrite run with the same inputs, runtime assumptions, observations, and comparison policy. Strust looks for the first difference within that declared contract.
Does MATCH mean the rewrite is correct?
MATCH means the declared observations agree for the compared execution. It does not establish correctness for every input or for behavior outside the contract.
When is a result INCONCLUSIVE?
When the evidence does not support a comparison under the declared contract. Missing or unsupported evidence must remain distinct from a match or a behavioral difference.
Is the demo a live verification run?
The interactive demo uses predefined results to show the verification workflow. It does not execute your code or connect to a live migration. Connect a private workspace to verify your own original and rewrite.
Bring your next rewrite.
Tell us what is changing and what behavior must stay the same.
