UsageFact

One turn's usage, as a durable typed fact (§17.1: committed in the run's own storage before it is published). Ids, counts and a reference - it copies nothing (§17.2a).

Type object

Shape

Field	Type	Description
identityrequired	UsageFactId	Stable across retries and amendments alike.
attemptrequired	RunAttemptId
turnrequired	AgentTurnId
revisionrequired	AmendmentRevision	The monotonic amendment revision of a usage fact. A retry repeats it; a correction raises it.
input	integer (uint64, >= 0) or null	`None` is unavailable. It is never zero for missing.
output	integer (uint64, >= 0) or null
cached_input	integer (uint64, >= 0) or null
modelrequired	ModelRef
completenessrequired	Completeness

Example

{
  "identity": {},
  "attempt": "00000000-0000-4000-8000-000000000000",
  "turn": "00000000-0000-4000-8000-000000000000",
  "revision": 0,
  "input": 0,
  "output": 0,
  "cached_input": 0,
  "model": "00000000-0000-4000-8000-000000000000",
  "completeness": {
    "kind": "complete"
  }
}

The contract has no example values, so example bodies are generated from each schema: every field is shown with a placeholder of its type.

Generated from contract version 1. Last updated November 12, 2026.