“Verifiable,” “trustless,” and “proof” often name different guarantees. Caletta receipts establish reproducibility for declared records. They do not establish hardware identity or a complete execution history.
What a receipt does prove
A receipt is a canonical, content-addressed record. It pins input and output digests, the transformation and its parameters, code identity, and evaluation inputs. Verification recomputes the declared digests and evaluations. Change an output byte, a parameter, or a parent digest, and the check fails. Chained receipts provide a traceable declared history from one model version to the next.
What a receipt does not prove
A receipt is not hardware attestation. It does not prove that a specific model and code ran on hardware no one could silently swap. It does not prove that no undeclared step occurred between two records. Recomputing a declared digest confirms the declared history is consistent; it cannot confirm the history is complete.
Where deterministic replay sits, and where it stops
Deterministic replay is a related, stronger-sounding check that also has a hard limit. By fixing seeds, decoding settings, and caching, a generation run can be made byte-reproducible, and a verifier can re-run one forward pass to confirm that a claimed output sequence is consistent with the model. This detects a worker that fabricated tokens. It does not, on its own, prove to an external party that a particular model ran in a trustworthy environment, because it still trusts whoever ran the verifier. Remote attestation, a trusted execution environment, or a zero-knowledge proof of computation are different guarantees, and we do not conflate them with replay.
Between trust-me and zero-knowledge
Caletta tests a middle option between unchecked trust and a zero-knowledge proof. The claimant commits to its outputs; a verifier re-executes a tunable sample of committed coordinates. Tests against synthetic corruption show that larger samples raise detection at additional verifier cost. The same protocol has not yet been measured against an adversary that recomputes strategically. Verification and credit also remain separate: evidence that work occurred does not decide who receives credit.
Use the narrow guarantee
Deterministic replay, receipt verification, and hardware attestation answer different questions. A deployment should rely only on the property its check establishes. Caletta currently supplies reproducibility and admission checks; stronger primitives remain separate work.