AsyncSessionDB methods silently dropped when called without await (e.g. gateway /model switch) → lost writes + RuntimeWarning

[gmoranxyz]

Version

hermes-agent 0.18.0 @ 30e947e · Python gateway running as a systemd user unit

Summary

AsyncSessionDB.__getattr__ (hermes_state.py:5818-5826) returns a coroutine
function for every attribute access on a callable:

def __getattr__(self, name):
    attr = getattr(self._db, name)
    if not callable(attr):
        return attr
    async def _offloaded(*args, **kwargs):
        return await asyncio.to_thread(attr, *args, **kwargs)
    return _offloaded

Any call site that treats an AsyncSessionDB method as synchronous produces a
coroutine that is never awaited: the DB operation never runs and Python emits a
RuntimeWarning. Because it's a generic forwarder, these bugs are invisible to
static analysis — there's no named async def to grep for a missing await.

Observed

On every gateway /model switch:

gateway/slash_commands.py:1773: RuntimeWarning: coroutine
'AsyncSessionDB.__getattr__.<locals>._offloaded' was never awaited

Reproduced on two independent gateways (default + a profile gateway) whenever a
/model command runs. The switch appears to succeed, but a session-DB write
issued during the switch is silently discarded.

Impact

Silent data loss on session state written during the affected paths. Suspected to
be the root cause of the null-system_prompt persistence bug (filed separately),
where the next turn finds no stored system prompt and rebuilds from scratch.

Suggested fixes

• Make the dropped call site await the method (fix the immediate /model path
  around slash_commands.py:1764-1773 / _finish_switch).
• Defensively, have AsyncSessionDB guard against sync misuse — e.g. wrap
  _offloaded so a garbage-collected un-awaited coroutine logs the offending
  method name, not just an anonymous _offloaded.

[gmoranxyz]

Suspected to cause #63713 (null system_prompt persistence) — the dropped write during the /model switch path is plausibly the update_system_prompt persist that #63713 reports as null on the following turn.

[teknium1]

This is an automated hermes-sweeper review. The reported gateway /model dropped-write path is already fixed on current main.

• gateway/slash_commands.py:1872 awaits _sess_db.update_session_model(...) inside _finish_switch; the alternate switch path does the same at line 1627.
• Commit 0a997aabbc90ca65483ca2cb2347f658cfcd9211 (fix(gateway): route aliased SessionDB calls through AsyncSessionDB) introduced this fix and is contained in v2026.7.1.
• tests/gateway/test_async_session_db.py:315 scans the gateway sources and fails if a SessionDB call through either _session_db or a bound alias is not awaited.

The linked #63713 hypothesis was considered, but the specific un-awaited /model write described here is no longer present on main.