Function getEffectiveContextWindowSize

src/services/compact/autoCompact.ts:36–57

(model: string)

// Managed models use separate input/output token budgets, so no output reserve
// is subtracted from the prompt budget.
export function getEffectiveContextWindowSize(model: string): number {
  let contextWindow = getContextWindowForModel(model, getSdkBetas())

  const autoCompactWindow = process.env.CLAUDE_CODE_AUTO_COMPACT_WINDOW
  if (autoCompactWindow) {
    const parsed = parseInt(autoCompactWindow, 10)
    if (!isNaN(parsed) && parsed > 0) {
      contextWindow = Math.min(contextWindow, parsed)
    }
  }

  if (resolveNCodeManagedModel(model) !== undefined) {
    return contextWindow
  }

  const reservedTokensForSummary = Math.min(
    getMaxOutputTokensForModel(model),
    MAX_OUTPUT_TOKENS_FOR_SUMMARY,
  )

  return contextWindow - reservedTokensForSummary
}

export type AutoCompactTrackingState = {
  compacted: boolean