Function streamCompactSummary

src/services/compact/compact.ts:1148–1210

({
  messages,
  summaryRequest,
  appState,
  context,
  preCompactTokenCount,
  cacheSafeParams,
}: {
  messages: Message[]
  summaryRequest: UserMessage
  appState: Awaited<ReturnType<ToolUseContext['getAppState']>>
  context: ToolUseContext
  preCompactTokenCount: number
  cacheSafeParams: CacheSafeParams
})

}

async function streamCompactSummary({
  messages,
  summaryRequest,
  appState,
  context,
  preCompactTokenCount,
  cacheSafeParams,
}: {
  messages: Message[]
  summaryRequest: UserMessage
  appState: Awaited<ReturnType<ToolUseContext['getAppState']>>
  context: ToolUseContext
  preCompactTokenCount: number
  cacheSafeParams: CacheSafeParams
}): Promise<AssistantMessage> {
  // Send keep-alive signals during compaction to prevent remote session
  // WebSocket idle timeouts from dropping bridge connections. Compaction
  // API calls can take 5-10+ seconds, during which no other messages
  // flow through the transport — without keep-alives, the server may
  // close the WebSocket for inactivity.
  // Two signals: (1) PUT /worker heartbeat via sessionActivity, and
  // (2) re-emit 'compacting' status so the SDK event stream stays active
  // and the server doesn't consider the session stale.
  const activityInterval = isSessionActivityTrackingActive()
    ? setInterval(
        (statusSetter?: (status: 'compacting' | null) => void) => {
          sendSessionActivitySignal()
          statusSetter?.('compacting')
        },
        30_000,
        context.setSDKStatus,
      )
    : undefined

  try {
    const summary = await withTimeout(
      streamCompactSummaryInner(
        messages,
        summaryRequest,
        appState,
        context,
        preCompactTokenCount,
        cacheSafeParams,
      ),
      COMPACT_SUMMARY_TIMEOUT_MS,
      'compact summary exceeded timeout',
    )
    return summary
  } catch (error) {
    if (
      error instanceof Error &&
      error.message === 'compact summary exceeded timeout'
    ) {
      // Mirror the SDK timeout shape so upstream error handling maps this to
      // API_TIMEOUT_ERROR_MESSAGE and the PTL retry logic treats it as a
      // retriable API failure rather than a successful empty summary.
      throw new APIConnectionTimeoutError({ message: 'Request timed out' })
    }