Function _background_lifecycle

src/tool_system/tools/agent.py:515–626

()

        )

        async def _background_lifecycle() -> None:
            tracker = ProgressTracker()
            messages: list[Any] = []
            transcript: TranscriptWriter | None = None
            if transcript_path:
                try:
                    transcript = TranscriptWriter(transcript_path)
                except OSError:
                    # Transcript open failure must not abort the run —
                    # downstream Chunk D / Chunk F will degrade
                    # gracefully (no outputFile content / no auto-resume
                    # source) rather than crash.
                    logger.exception(
                        "transcript open failed for %s; continuing without disk persistence",
                        agent_id,
                    )
                    transcript = None
            try:
                try:
                    async for message in run_agent(run_params):
                        messages.append(message)
                        # Live progress accounting — feeds the post-hoc
                        # ``finalize_agent_tool`` token total via the
                        # ``progress`` keyword (WI-2.4 fallback also
                        # works if the tracker is somehow empty).
                        try:
                            update_progress_from_message(tracker, message)
                        except Exception:
                            logger.exception(
                                "progress tracker update failed for %s", agent_id
                            )
                        # Persist to disk per WI-2.2. Synchronous IO
                        # outside the registry lock — A6/C5 contract is
                        # preserved (no ``await`` under the registry's
                        # RLock).
                        if transcript is not None:
                            try:
                                transcript.append(message)
                            except OSError:
                                logger.exception(
                                    "transcript append failed for %s; further appends will be skipped",
                                    agent_id,
                                )
                                transcript.close()
                                transcript = None

                    metadata = {
                        "start_time": time.time(),
                        "agent_type": agent_type,
                    }
                    result = finalize_agent_tool(
                        messages, agent_id, metadata, progress=tracker
                    )
                    result_text = "\n".join(
                        block.get("text", "")
                        for block in result.content
                        if isinstance(block, dict) and block.get("type") == "text"
                    ).strip()