Function: summarizeOldest()

summarizeOldest(options): WindowStrategy

Defined in: src/core/agent/window/strategies/summarizeOldest.ts:57

Fold the oldest contiguous run of foldable turns into one summary message, keeping the recent turns and stepping over anything unresolved.

Triggered by COUNTED tokens: the last call's adapter-reported input tokens against thresholdTokens. A provider that reports no usage gets CompactionUnmeasurableError rather than an invented number.

Parameters

options

CompactionOptions

Returns

WindowStrategy

Example

import { Agent, summarizeOldest } from 'agentfootprint';

const agent = Agent.create({ provider: anthropic(), model: 'claude-sonnet-4-5' })
  .window(summarizeOldest({
    thresholdTokens: 120_000,
    summarizer: anthropic(),
    model: 'claude-haiku-4-5',
  }))
  .build();
// `.compaction({ ... })` is this exact line, spelled shorter.