Method startPreparedStream

src/node/services/agentSession.ts:2829–2874

()

    this.setTurnPhase(TurnPhase.PREPARING);

    const startPreparedStream = async (): Promise<Result<void, SendMessageError>> => {
      try {
        if (preparedTurnAbortController.signal.aborted) {
          return Ok(undefined);
        }
        // If this is a compaction request, terminate background processes first.
        // They won't be included in the summary, so continuing with orphaned processes would be confusing.
        const isCompactionStreamRequest = isCompactionRequest || autoCompactionMessage !== null;
        if (isCompactionStreamRequest && !this.keepBackgroundProcesses) {
          await this.backgroundProcessManager.cleanup(this.workspaceId);

          if (this.disposed) {
            return Ok(undefined);
          }
        }

        // Note: Follow-up content for compaction is now stored on the summary message
        // and dispatched via dispatchPendingFollowUp() after compaction completes.
        // This provides crash safety - the follow-up survives app restarts.

        if (this.disposed || preparedTurnAbortController.signal.aborted) {
          return Ok(undefined);
        }

        // Turn-phase transitions for success are driven by stream events.
        return await this.streamWithHistory(
          modelForStream,
          optionsForStream,
          undefined,
          undefined,
          agentInitiated,
          preparedTurnAbortController.signal,
          goalKind
        );
      } finally {
        // Success should advance via stream events; if startup never emitted any, don't leave the
        // session stuck in PREPARING. Guard by controller identity so an aborted startup cannot
        // mark the replacement edit's new PREPARING turn idle when it unwinds later.
        if (this.activePreparedTurnAbortController === preparedTurnAbortController) {
          this.activePreparedTurnAbortController = null;
          if (this.turnPhase === TurnPhase.PREPARING) {
            this.setTurnPhase(TurnPhase.IDLE);
          }
        }
      }
    };

    if (editMessageId || internal?.startStreamInBackground === true) {
      // The user turn is already persisted + emitted above. Edits and backend