Function callback

contributing/samples/mcp/mcp_progress_callback_agent/agent.py:109–129

(
      progress: float,
      total: float | None,
      message: str | None,
  )

    session_id = callback_context.session.id

  async def callback(
      progress: float,
      total: float | None,
      message: str | None,
  ) -> None:
    # Include tool name and session info in the progress output
    prefix = f"[{tool_name}][session:{session_id}]"
    if total is not None:
      percentage = (progress / total) * 100
      bar_length = 20
      filled = int(bar_length * progress / total)
      bar = "=" * filled + "-" * (bar_length - filled)
      print(f"{prefix} [{bar}] {percentage:.0f}% {message or ''}")
      # Example: Store progress in state (callback_context allows modification)
      if callback_context:
        callback_context.state["last_progress"] = progress
        callback_context.state["last_total"] = total
    else:
      print(
          f"{prefix} Progress: {progress} {f'- {message}' if message else ''}"
      )

  return callback