[Bug]: AgentContext.current_datetime persists in settings.json, causing stale CURRENT_DATETIME in prompts

Is there an existing issue for the same bug?

• I have searched existing issues and this is not a duplicate.

Bug Description

AgentContext.current_datetime defaults to datetime.now().astimezone() (openhands-sdk/openhands/sdk/context/agent_context.py), but the value is also serialized into ~/.openhands/settings.json under agent_settings.agent_context.current_datetime.

Once persisted as a string, FileSettingsStore.load() deserializes it verbatim (the default_factory only fires when the key is absent) and save() full-dumps the object. Result: every settings save re-freezes the timestamp, and every new conversation renders that frozen value in the <CURRENT_DATETIME> prompt block.

Observed 35 days stale in a live install; a no-op PATCH /api/settings re-persisted a fresh "now-at-save-time" value, proving the round-trip.

Expected Behavior

A "now" value is not user configuration and should not round-trip through persisted settings. Each conversation should render a live timestamp, not a value that re-freezes on every settings save.

Actual Behavior

The persisted current_datetime string is re-read verbatim on load and re-written on every settings save, so the injected CURRENT_DATETIME stays stale for all conversations until the key is manually deleted — where it then re-appears on the next save.

Reproduced on a local agent-server install (Agent Canvas 1.16.0, SDK 1.44.0, Python 3.13.12, macOS 26.5.2):

​```bash

1) Simulate what FileSettingsStore.load() does with a persisted value:

python -c "from openhands.sdk.context.agent_context import AgentContext; print(AgentContext(current_datetime='2026-07-25T21:34:21.341574Z').get_formatted_datetime())"

-> 2026-07-25T21:34 (stale value used as-is; the default_factory now() only applies when the key is absent)

2) Compare with a fresh context (no persisted key):

python -c "from openhands.sdk.context.agent_context import AgentContext; print(AgentContext().get_formatted_datetime())"

-> live current time

3) On a live install, after any settings save the key is on disk, re-frozen to save-time:

grep current_datetime ~/.openhands/settings.json

"current_datetime": "2026-08-29T21:04:21.388304+01:00"

a no-op PATCH /api/settings re-persists a new save-time value

​```

Steps to Reproduce

1. Run a local agent-server (e.g. via Agent Canvas).
2. Save any setting once (e.g. PATCH /api/settings, or a no-op change). The agent writes agent_settings.agent_context.current_datetime into ~/.openhands/settings.json as an ISO string.
3. Observe: the prompt's <CURRENT_DATETIME> is frozen at that save time for all subsequent conversations.
4. Repeat any settings save: the timestamp is re-frozen to the new save time (proven by a no-op PATCH re-persisting it).
5. Workaround: delete the key from settings.json; it re-appears on the next settings save.

Acceptance Criteria

• A no-op settings save does not change agent_settings.agent_context.current_datetime in settings.json
• A new conversation renders a CURRENT_DATETIME matching live system time
• current_datetime no longer round-trips through PersistedSettings serialization (or is refreshed to now() on load / at conversation start)

Installation Method

Agent Canvas 1.16.0 (npm @openhands/agent-canvas), which runs the agent-server from a uv-managed Python environment. Not a direct pip install.

If you selected "Other", please specify

No response

SDK Version

1.44.0 (latest bundled with Agent Canvas 1.16.0); confirmed unfixed in 1.44.1 source.

Version Confirmation

• I have confirmed this bug exists on the LATEST version of OpenHands SDK

Python Version

3.13.12

Model Name (if applicable)

N/A — this is a prompt/context-persistence bug, not model-specific.

Operating System

MacOS

Logs and Error Messages

No stack trace (silent misbehavior). Evidence:
$ grep current_datetime ~/.openhands/settings.json
current_datetime": "2026-08-29T21:04:21.388304+01:00" # frozen on first settings save of the new stack

after a no-op PATCH /api/settings, the value was re-persisted to the new save time.

Minimal Code Sample

Illustrates the round-trip: a persisted string wins over the now() default.

from openhands.sdk.context.agent_context import AgentContext

default (no key) -> live now:

print(AgentContext().current_datetime)

but a deserialized value (what FileSettingsStore.load() produces from

settings.json) is used verbatim and re-saved on every save():

ctx = AgentContext(current_datetime="2026-07-25T21:34:21.341574Z")
print(ctx.current_datetime) # stale value, no refresh

Screenshots and Additional Context

Suggested fixes (any one):

1. Exclude current_datetime from PersistedSettings serialization (drop on dump).
2. Refresh to datetime.now() in FileSettingsStore.load() / from_persisted.
3. Replace a persisted string with a fresh timestamp at conversation start.

Start with openhands-sdk/openhands/sdk/context/agent_context.py and trace how FileSettingsStore.load() and save() serialize agent_context.current_datetime. Run the provided Python reproduction and settings-save steps to confirm the persisted value is reused. Done means no-op saves do not round-trip the timestamp and new conversations render live CURRENT_DATETIME values.