Lineage ledger
This document defines the append-only event ledger used to make the AI instrument reproducible.
The ledger is not a log for debugging. It is the provenance substrate for every output.
Properties#
- Append-only
- Ordered
- Exportable
- Hash-addressable (event hashes and run hashes)
Minimal event types#
session_start#
Records initial regime defaults and instrument identity.
user_input#
Raw user text and any declared regime overrides.
retrieval_query#
The query, scope, and constraints used for retrieval.
retrieval_hits#
The returned items, ranked order, and selection rationale (if any).
prompt_assembly#
The compiled prompt package inputs and resulting prompt hash.
model_call#
Model artifact identity and inference parameters.
postproc#
Any transformations, filters, or policy checks applied after generation.
response#
The final emitted response and its binding to prior event hashes.
Minimal fields#
Each event MUST include:
- event_id
- event_type
- timestamp
- parent_event_ids
- regime_snapshot
- payload
- payload_hash
Artifact identity#
Model calls MUST bind to:
- model_hash
- tokenizer_hash (if applicable)
- runtime_version
- quantization / precision descriptor
Reproducibility contract#
A response is reproducible if:
- the ledger is complete
- referenced artifacts are available
- prompt assembly is deterministic given inputs
- inference nondeterminism is declared (seeded vs unseeded)