Chronology, Trajectories, and Receipts
Definition
Chronology is the durable ordered record of an Improvement Session. Event blocks can represent user or assistant messages, activity, Harness output, usage, Goal changes, input requests, external handoffs, and cancellation. Pagination preserves long sessions without implying that the initially loaded page is complete history.
Fields, states, or lifecycle rules
- Chronology event types retain their identity and ordering.
- Trajectory segments link only to observable activity.
- Evaluation ledger rows preserve Case counts, completion, receipts, and hashes.
- Worker packages and sessions have independent lifecycle states.
Safe trajectories
Trajectory segments narrate observable work and link to durable activity references. They may explain that a candidate was prepared, evaluated, retained, or rejected. They exclude hidden reasoning and private worker state. Do not rewrite silence between returned artifacts as a detailed external-worker trajectory.
Benchmark Evaluations does not currently expose Traces / Spans; Improve trajectories are a separate safe session narration surface. They should not be described as raw model reasoning, execution spans, or evaluator authority.
Evaluation ledger and receipts
The evaluation ledger records exact Case counts, evaluable and incomplete populations, scores, constraint results, and receipt or content hashes. A receipt links a candidate claim to the canonical Benchmark Evaluation that supports it. When the cohort is incomplete, preserve that state in frontier and completion decisions.
Usage entries can identify provider use by model. Missing usage evidence is unknown, not zero. Harness output records candidate-visible results without granting access to private runtime reasoning.
External handoffs
An external worker package is prepared only after a Goal Contract is confirmed. Its status can be prepared, submitted, expired, or closed. The return contract accepts an immutable Harness Version or a supported evaluation request. Expiration or closure describes the package lifecycle, not whether private work occurred.
Session lifecycle
Sessions can be draft, active, paused, completing, completed, cancelling, cancelled, or failed. Attention states identify an input or review need. Pausing stops new scheduling while retaining chronology and evidence. Cancelling records a terminal path; it does not erase candidates, receipts, or usage already recorded.
Related task pages
Source confidence
Code-backed: chronology rendering, the session contract, and archive model define event types, safe trajectories, ledger and receipt fields, handoff states, usage, pagination, and lifecycle controls.