Interface: CompactionCostEvent

Defined in: src/batteries/context/compact/contracts.ts:94

One summarization call's estimated token cost — reported via OnCostFn so a caller can total up the real overhead this battery pays (the cost profile a thrift-only pipeline never incurs).

Remarks

inTok/outTok are ESTIMATES, not metered usage: when the injected SummarizeFn's transport doesn't report real token usage back (many don't — a bare Promise<string> return carries no usage envelope), the battery has no other way to know what the call cost. It measures what it CAN measure — the exact text it sent (system + text) and the exact text it got back (the summary) — via the same injected EstimateTokensFn the caller already supplies for its own token accounting, so these numbers are at least self-consistent with whatever budget arithmetic the caller runs elsewhere. A caller whose SummarizeFn DOES have access to real usage counts can ignore this estimate and total its own numbers from inside the function instead.

Properties

Property	Type	Description	Defined in
calls	number	How many summarization calls this event represents — always 1 per OnCostFn firing (one call, one event); a caller totals calls across events to get the run's summarizer call count.	src/batteries/context/compact/contracts.ts:97
inTok	number	Estimated input token cost: estimateTokens(system + text, encoding) for the exact request sent to SummarizeFn this call (system prompt plus the history/prior-summary text).	src/batteries/context/compact/contracts.ts:100
outTok	number	Estimated output token cost: estimateTokens(summary, encoding) for the text SummarizeFn returned.	src/batteries/context/compact/contracts.ts:103