Method runCompaction

src/agent/loop.ts:2487–2521

* Summarize the combined history (base messages + this run's new messages), * collapsing all but the most recent turns into one summary system message. * * Returns the NEW combined message list, or null if compaction didn't run * (below threshold, or summarization failed — caller keeps t

(
    combined: Message[],
    ctxWindow: number,
    signal: AbortSignal | undefined,
  )

      }
    }

    const timeoutSec = this.config.budget.toolTimeoutSeconds ?? 300;
    const timeoutMs = timeoutSec * 1000;
    let timeoutHandle: ReturnType<typeof setTimeout> | undefined;
    const timeoutPromise = new Promise<never>((_, reject) => {
      timeoutHandle = setTimeout(() => {
        // CRITICAL: abort the tool's inner signal so spawn'd processes actually die.
        toolAbort.abort('TOOL_TIMEOUT');
        const err: any = new Error(`Tool '${tc.function.name}' exceeded ${timeoutSec}s timeout`);
        err.code = 'TOOL_TIMEOUT';
        reject(err);
      }, timeoutMs);
    });

    const ctx: ToolContext = {
      cwd: this.effectiveCwd ?? this.cwd,
      sessionId,
      transaction,
      permissions: this.permissions,
      askUser: options.askUser,
      emit: (ev) => {
        uiEvents.push(ev);
        if (options.onToolUI) options.onToolUI(ev);
      },
      signal: toolAbort.signal,
      // The snapshot service (if any) is plumbed in from the agent loop's instance.
      // bash and other destructive tools use it to git-stash before risky commands.
      snapshotService: this.snapshotService,
      // Git sandbox handle (only when runSandboxed is active) — lets a tool or the
      // model request a checkpoint or an autonomous backtrack.
      sandbox: this.activeSandbox ? {
        isActive: () => this.activeSandbox?.isActive() ?? false,
        checkpoint: (label: string) => this.activeSandbox?.checkpoint(label) ?? Promise.resolve(null),
        backtrack: () => this.activeSandbox?.backtrack() ?? Promise.resolve(null),
      } : undefined,
      currentTurn: this.currentTurn,
    };