[Bug]: Context Agent crashes with TypeError (tool_status NoneType) due to 400 Bad Request on config init

[Byter3]

Description

Upon freshly deploying the Context Agent, it fails to initialize its default tool configuration. Any attempt to interact with the agent results in a crash because nc.appconfig_ex.get_value('tool_status') returns None.

Under the hood, it appears the enabled_handler is attempting to POST its default preferences to the AppAPI config endpoint, but the Nextcloud server rejects it with a 400 Bad Request. Because the save is rejected, the JSON is never written, causing json.loads() to throw a TypeError on every subsequent task.

Environment

• Nextcloud Version: NC 32.0.8 AIO 12.9.2
• AppAPI Version: Latest
• Context Agent Version: Latest
• LLM Backend: Ollama

Steps to Reproduce

1. Deploy the Context Agent via AppAPI.
2. Send a message to the Nextcloud Assistant assigned to the Context Agent provider.
3. Observe the "Error generating a response" banner in the UI.
4. Attempt to go to Administration Settings -> Context Agent and toggle a permission (e.g., Calendar) to force a save. The UI fails to write the config.

Expected Behavior

The Agent should successfully write its default tool_status JSON via the AppAPI upon deployment, and correctly read those permissions to handle tool-calling tasks.

Actual Behavior & Logs

The container fails to set the configuration during the enabled callback, throwing a 400 error:

2026-04-20 14:54:13,252 - context_agent - INFO - enabled=True
2026-04-20 14:54:13,612 - context_agent - WARNING - App enabled: context_agent
INFO:      - "PUT /enabled?enabled=1 HTTP/1.1" 500 Internal Server Error

# ... [Traceback skipped for brevity] ...

  File "/ex_app/lib/main.py", line 126, in enabled_handler
    await nc.appconfig_ex.set_value('tool_status', json.dumps(pref_settings))
  File "/root/.cache/pypoetry/virtualenvs/context-agent-il7asoJj-py3.11/lib/python3.11/site-packages/nc_py_api/_preferences_ex.py", line 135, in set_value
    await self._session.ocs("POST", f"{self._session.ae_url}/{self._url_suffix}", json=params)
  File "/root/.cache/pypoetry/virtualenvs/context-agent-il7asoJj-py3.11/lib/python3.11/site-packages/nc_py_api/_session.py", line 371, in ocs
    raise NextcloudException(
nc_py_api._exceptions.NextcloudException: [400] Error setting app config value <request: POST /ocs/v1.php/apps/app_api/api/v1/ex-app/config>

When a task is received, it instantly crashes trying to read the blank config:

2026-04-20 14:55:43,874 - context_agent - INFO - {'input': 'Hi there, would you tell me my evening programs from my calendar for today?', 'confirmation': 0, 'conversation_token': '<skipped>', 'memories': None}
2026-04-20 14:55:44,235 - context_agent - ERROR - Error: Traceback (most recent call last):
  File "/ex_app/lib/main.py", line 180, in handle_task
    output = await react(task, nextcloud)
  File "/ex_app/lib/agent.py", line 97, in react
    safe_tools, dangerous_tools = await get_tools(nc)
  File "/ex_app/lib/tools.py", line 21, in get_tools
    is_activated = json.loads(await nc.appconfig_ex.get_value('tool_status'))
  File "/usr/local/lib/python3.11/json/__init__.py", line 339, in loads
    raise TypeError(f'the JSON object must be str, bytes or bytearray, '
TypeError: the JSON object must be str, bytes or bytearray, not NoneType

Troubleshooting Attempted

I attempted to bypass the 400 API error by hardcoding the configuration directly into Nextcloud via OCC:
docker exec --user www-data nextcloud-aio-nextcloud php occ config:app:set context_agent tool_status --value='{"calendar":true}'

This successfully saved to the fast cache, but the nc_py_api bridge still fetched NoneType upon container restart, indicating a disconnect between standard occ configs and appconfig_ex ExApp storage.

[janepie]

Can you please add the software versions to your post? They are needed for an assessment of your issue

[Byter3]

Can you please add the software versions to your post? They are needed for an assessment of your issue

Fixed it! Thank you!

[janepie]

Thank you! I just released version 2.6.0 of Context Agent, I don't think it fixes your issue but could you update and check again just to be sure?

[janepie]

I justed tested re-registering and all works fine here, I cannot reproduce on server master. Please try again with everything up to date and share the server logs where the 500 error should be logged

[Byter3]

@janepie Thank you for the quick response!

I updated my entire stack (Nextcloud AIO is now on version 33.0.3) and deployed Context Agent 2.6.0 to test it.

Unfortunately, you were right to suspect it wouldn't fix it—the issue is still present. It successfully enables, but the moment it receives a task, it crashes trying to read tool_status with the exact same NoneType error.

Here are the Nextcloud logs from the 2.6.0 crash:

{"reqId":"XoDnKpbVoEGlkyYNgiC5","level":3,"time":"2026-05-16T13:55:06+00:00","remoteAddr":"192.168.1.1","user":"--","app":"context_agent","method":"POST","url":"/ocs/v1.php/apps/app_api/api/v1/log?format=json","scriptName":"/ocs/v1.php","message":"Error: Traceback (most recent call last):\n  File \"/ex_app/lib/main.py\", line 179, in handle_task\n    output = await react(task, nextcloud)\n                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/ex_app/lib/agent.py\", line 99, in react\n    safe_tools, dangerous_tools = await get_tools(nc)\n                                  ^^^^^^^^^^^^^^^^^^^\n  File \"/ex_app/lib/all_tools/lib/decorator.py\", line 36, in wrapper\n    result = await func(*args)\n             ^^^^^^^^^^^^^^^^^\n  File \"/ex_app/lib/tools.py\", line 21, in get_tools\n    is_activated = json.loads(await nc.appconfig_ex.get_value('tool_status'))\n                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/usr/local/lib/python3.11/json/__init__.py\", line 339, in loads\n    raise TypeError(f'the JSON object must be str, bytes or bytearray, '\nTypeError: the JSON object must be str, bytes or bytearray, not NoneType\n","userAgent":"ExApp/context_agent/2.6.0 (niquests/3.18.6)","version":"33.0.3.2","data":{"app":"context_agent"},"id":"6a08774b4a2a8"}

This is inside NC AIO. I don't get how in the AIO enviroment this could fail, I mean this is the whole point of the AIO right, so everything is in a controlled environment for every deploy.

[Byter3]

Update after further debugging:

I found one concrete root cause for the startup/config failure.

On my AIO setup, the oc_appconfig_ex.configvalue column was varchar(255), but Context Agent 2.6.0 tries to store a tool_status JSON longer than 255 characters.

That caused the AppAPI config write to fail, and then Context Agent later read tool_status as None, which led to the Python crash:

TypeError: the JSON object must be str, bytes or bytearray, not NoneType

The regular command below did not help because it writes to normal app config, not ExApp config:

occ config:app:set context_agent tool_status ...

The correct AppAPI config path was:

occ app_api:app:config:set context_agent tool_status --value='...'

But this also failed while the DB column was still limited to 255 chars.

Workaround that fixed the config issue for me:

ALTER TABLE oc_appconfig_ex ALTER COLUMN configvalue TYPE TEXT;

After that I was able to save the full tool_status JSON, and Context Agent stopped crashing and could list my calendars.

So I think there are at least two issues here:

AppAPI / migration issue: oc_appconfig_ex.configvalue should not be varchar(255) if ExApps can store JSON config values like this.

Context Agent should handle missing/invalid tool_status more gracefully instead of crashing on json.loads(None).

For reference, my setup:

Nextcloud AIO
Nextcloud 33.0.3
AppAPI 33.0.0
Assistant 3.4.1
Context Agent 2.6.0
Context Chat Backend 5.3.0
OpenAI integration 4.4.0
Ollama / local models

After fixing the DB column manually, the original crash/config failure was resolved.

Separate from the crash: after getting the agent running, I’m also seeing confusing tool behavior. For example, with calendar/mail/files/search enabled, the agent sometimes chooses the mail tool when asked to list calendars. This may be model-related, but it also makes it difficult to understand what is broken: model selection, tool registration, tool descriptions, or Context Agent routing.

[janepie]

Hmm that's interesting, the column should already be of type TEXT:

app_api/lib/Migration/Version1000Date202305221555.php

Line 45 in 2c9093f

$table->addColumn('configvalue', Types::TEXT, [

@oleksandr-nc any idea why this may happen? Gonna move this issue to the app_api repo as it's originating there.

@Byter3 which kind of db in which version are you using?