Determinism invariants (spec)

Replayability classification

• If model_metadata.temperature > 0, the trace header MUST set replay_status = NON_REPLAYABLE.
• If model_metadata.temperature == 0, the trace header SHOULD set replay_status = REPLAYABLE.

Deterministic snapshots

• Trace entries MUST be serializable as JSON.
• Trace entries MUST allow a “deterministic snapshot” that excludes observational fields (e.g. timestamps).

Observational fields

• Timestamps are observational and MUST NOT be used as determinism proofs.
• Adding new observational fields is allowed, but they should be explicitly classified.

Hashing and fingerprints

• Run fingerprinting MUST hash a stable representation of:
• pipeline definition
• config snapshot
• contract versions
• Hash computation MUST be order-stable (JSON canonicalization).