An engagement is ending. Maybe on schedule, maybe not. Either way, two parties who will not be working together next month need to agree on what was delivered, and every ambiguity in that agreement is a future dispute with a date on it. This page is written for both sides, because the fix is the same artifact.
The failure mode is not malice, it is memory. Six weeks after the contract ends, something breaks, and the question becomes was it delivered like that. The contractor remembers shipping a working system. The company remembers accepting one. Neither has a record either side would accept, because the deliverable was a repository at a moment in time, and repositories keep changing after moments end. With AI-assisted contractors the ambiguity doubles: the delivered code was substantially generated, the company knows it, and what was actually verified before handover exists nowhere at all.
In the final week, the contractor generates a passport at the delivery commit: setup and checks executed in a clean sandbox, claims labelled against evidence, decisions recovered from the agent history, and the open items listed as open. The passport’s digests bind it to the exact commit and file contents delivered, which is what makes it a record rather than a recollection. The company accepts by checking, not by thanking:
Exit 0 on the company’s own hardware is a fair acceptance test. And any later modified like that dispute has a clean answer: re-run receive against the delivery commit. If a file changed after handover, the tool names it. If a check that passed no longer passes, that is named too, with the tampering and the timeline distinguishable from delivery quality. The contract can simply reference it: acceptance equals passport receive exit 0 at the delivery commit.
Where the relationship is already strained, or the amounts justify it, Mantyl Verified takes both parties out of the proof: the delivery bundle is re-executed on neutral infrastructure and the result signed, bound to the commit. One-off £19 to £49, paid by whichever side values the neutrality, occasionally split, and cheap against one hour of the lawyer either side would otherwise eventually call.
Contractors building this into their standard close should read the freelancer delivery and price it as a deliverable. Companies offboarding a contractor who has already gone, with no passport and mixed feelings about what is in the repository, should start from verifying AI-built software and, if things are broken, the pre-rescue diagnosis. The full closing list, credentials rotated, access confirmed, support boundary in writing, is the handover checklist.