reload_agents reload current_app_name_ref?

[mbao]

🔴 Required Information

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If an item is not applicable to you - please mark it as N/A

Describe the Bug:
A clear and concise description of what the bug is.

Steps to Reproduce:
Please provide a numbered list of steps to reproduce the behavior:

1. update agent py file

Expected Behavior:
A clear and concise description of what you expected to happen.

the agent that I modified reload

Observed Behavior:
What actually happened? Include error messages or crash stack traces here.

current_app_name_ref agent reloaded, but not the one I modified

Environment Details:

• ADK Library Version (pip show google-adk):
  1.27.1

• Desktop OS:** [e.g., macOS, Linux, Windows]
  MacOS

• Python Version (python -V):
  3.12.12
  Model Information:

• Are you using LiteLLM: Yes/No
  Yes

• Which model is being used: (e.g., gemini-2.5-pro)
  qwen-plus

    def setup_observer(observer: Observer, adk_web_server: AdkWebServer):
      agent_change_handler = AgentChangeEventHandler(
          agent_loader=agent_loader,
          runners_to_clean=adk_web_server.runners_to_clean,
          current_app_name_ref=adk_web_server.current_app_name_ref,
      )
      observer.schedule(agent_change_handler, agents_dir, recursive=True)
      observer.start()

[surajksharma07]

@mbao The handler is always reloading current_app_name_ref.value — whichever agent happens to be open in the UI at the time — rather than actually figuring out which agent's files changed on disk.

That's what's causing the wrong agent to reload.

One workaround worth trying: subclass AgentChangeEventHandler, pass agents_dir into the constructor, and in on_modified replace the hardcoded ref with Path(event.src_path).relative_to(agents_dir).parts[0] to pick up the name of the agent that actually changed.

Could you give that a try and let us know if it sorts things out on your end?

[mbao]

@mbao The handler is always reloading current_app_name_ref.value — whichever agent happens to be open in the UI at the time — rather than actually figuring out which agent's files changed on disk.

That's what's causing the wrong agent to reload.

One workaround worth trying: subclass AgentChangeEventHandler, pass agents_dir into the constructor, and in on_modified replace the hardcoded ref with Path(event.src_path).relative_to(agents_dir).parts[0] to pick up the name of the agent that actually changed.

Could you give that a try and let us know if it sorts things out on your end?

For me it works ok. But I just use a simple LlmAgent, I'm not sure for other cases. Thanks.

[surajksharma07]

@mbao Good to hear it works for LlmAgent.

The fix itself is handler-level so it should apply the same way for other agent types too — on_modified just needs to derive the agent name from the changed file path instead of using current_app_name_ref.

We've flagged this as a proper bug in AgentChangeEventHandler to be fixed in the source.

If you do run into anything odd with other agent setups, feel free to drop a note here.

Team is looking more into it.

[surajksharma07]

@wyf7107 Please have a look into it once.