The merged webhook session-close fix (#57370, salvaging #57322) wrapped
handle_message in a try/finally — but BasePlatformAdapter.handle_message
is fire-and-forget: it spawns _process_message_background and returns
before the agent run starts. The finally-close therefore ran BEFORE
get_or_create_session created the session row, found no session_id, and
silently no-op'd — the ghost-session leak persisted on the real path.
(The shipped test masked this by stubbing handle_message with a fake
that created the row synchronously.)
Move the close to an on_processing_complete override — the lifecycle
hook the base class fires at the TRUE end of the run, on the success,
failure, and cancellation paths alike. Empirically verified through the
real fire-and-forget pipeline: before, ended_at stayed NULL; after,
ended_at is set with end_reason=webhook_complete and the row is
prunable.
Tests now stub only the runner-side _message_handler (the seam the live
gateway injects) so handle_message / _process_message_background /
on_processing_complete all run for real; adds an AsyncSessionDB-facade
coverage test for the coroutine-await branch.
Replace the webhook delivery-close path's direct reach into private
SessionStore._entries (which also bypassed the store lock) with a public,
lock-held peek_session_id(session_key) accessor. Mirrors the existing
lookup_by_session_id inverse helper. Keeps a getattr fallback for older
stores / test doubles. Adds a unit test for the accessor.
Webhook deliveries created a unique one-shot session (delivery_id baked into
the session key at gateway/platforms/webhook.py:668) but the adapter fired
handle_message via asyncio.create_task WITHOUT ever ending the session
(webhook.py:713, pre-fix). Nothing else closes it: the gateway caches/expires
the agent per session_key but never calls end_session for the webhook path,
and _end_session_on_close teardown doesn't run for these fire-and-forget tasks.
SessionDB.prune_sessions (hermes_state.py:4965) only deletes rows WHERE
ended_at IS NOT NULL. So every webhook session stayed with ended_at NULL ->
unprunable -> unbounded state.db growth. This was the primary driver of the
SQLite lock-contention gateway outage.
Fix: wrap the delivery in _run_delivery_and_close, which awaits
handle_message and then (in finally, so failures still reap) calls
_end_webhook_session -> SessionDB.end_session(session_id, 'webhook_complete').
This mirrors how cron closes its session with 'cron_complete'
(cron/scheduler.py:3065). end_session is first-reason-wins and no-ops on an
already-ended row, so it never clobbers a compression/agent_close reason.
Adds tests/gateway/test_webhook_session_close.py asserting the invariant
(a completed webhook session has ended_at set + is prunable), including the
error-path case, against a real SessionStore + SessionDB.
