hermes-session-reset-policy

Re-arm Hermes Agent's session_reset policy (idle / daily / both) as a plugin.

Why

Upstream Hermes v2026.9.11 (commit 1d5d059410, "stop time-triggered conversation
rotation") removed the background reset timers and made the session_reset
config block inert: only explicit suspension (/stop, /new) replaces a routed
conversation. If you want time-based conversation rotation back — fresh context
after an hour of inactivity, or once per day at 04:00 — this plugin restores it
without patching the core.

How it works

The plugin registers a pre_gateway_dispatch hook. On every inbound gateway
message, before auth and dispatch, it:

Resolves the session key for the message: the hook payload's session_key
when the gateway provides one publicly, else the gateway's own
_session_key_for_source helper — so multiplexed profiles and platform key
layouts match exactly. (No bare build_session_key fallback on purpose:
under multiplexed profiles that key is not profile-namespaced and could
resolve another profile's route for the same chat.)
Reads the profile's config.yaml session_reset block (the profile is
resolved from the message's source.profile through Hermes' own
get_profile_dir, anchored at the Hermes root so both gateway layouts
read the right file: one multiplexed gateway at the root, or a standalone
gateway per profile running with HERMES_HOME set to its own
profiles/<name> dir — see issue #4).
Compares the routing entry's user-activity clock — the plugin's own
srp_last_user_inbound session metadata, advanced only by messages that
reach this hook (slash commands and internal/cron traffic never do) —
against the idle threshold and/or the daily boundary. Entries that predate
the plugin fall back to updated_at/created_at once, then the metadata
clock takes over.
Past the boundary, and with no turn in flight (the entry's durable
active_turn_token marker), resets the conversation through the gateway's
own /new reset funnel (gateway._handle_reset_command, fed a text-free
event) — the exact code path a typed /new takes, so everything a
conversation boundary owes happens: run-generation bump and cached-agent
cleanup/eviction (the compressor's previous summary cannot carry over),
the conversation-scope clear (per-conversation /model and reasoning
overrides), interruption of in-flight async delegations,
SessionStore.reset_session(), the session:end/session:reset gateway
hooks, and the on_session_finalize/on_session_reset plugin hooks. Then
normal dispatch proceeds, so the message lands in the fresh session.

The event handed to the funnel is stripped of its text on purpose: the funnel
treats event.get_command_args() as /new <title> — and on a plain message
that returns the whole utterance, which would title the fresh session with
whatever the user happened to send.

Because the trigger is the first inbound message past the boundary — never a
timer — there are no background writes, no timer threads, and background/cron
activity can neither keep a session alive nor reset it.

Config

The existing session_reset block in your (or your profile's) config.yaml
drives everything; the plugin adds no keys:

session_reset:
  mode: both          # idle | daily | both | none
  idle_minutes: 60
  at_hour: 4          # local hour for the daily boundary

mode: none or an absent block disables the plugin entirely (no reset, no log
noise).

Install

hermes plugins install https://github.com/fastfinge/hermes-session-reset-policy.git

or clone into ~/.hermes/plugins/ and enable:

plugins:
  enabled:
    - hermes-session-reset-policy

Restart the gateway afterwards.

Behaviour notes

The reset is an explicit-style reset (like /new): the fresh session sets
is_fresh_reset, so topic/channel-bound skills re-inject on the first turn —
but it does not carry was_auto_reset bookkeeping, so the agent receives
no "context was reset due to inactivity" sidecar note or channel-continuity
hint. Add your own guidance if you need the agent to know.
A turn in flight is never reset; the clock is left untouched and the reset
re-arms on the next message.
Boundary hooks keep firing downstream (session:end/session:reset,
on_session_finalize/on_session_reset) — the reset goes through the /new
funnel, not around it.
When the funnel is unreachable (older gateways, renamed internals) the
plugin degrades to a bare SessionStore.reset_session() plus the lifecycle
hook pair and the delegation interrupt: a consistent rotation without the
gateway-side cache/scope teardown. A funnel that fails after rotating is
never rotated a second time by the fallback.
Requires Hermes >= v2026.9.11 (needs the pre_gateway_dispatch hook payload
with session_store). The full funnel path uses the gateway's private
_handle_reset_command — deliberately reused until a public reset funnel
exists (see issue #2); the fallback keeps old gateways working if it moves.

License

MIT — see LICENSE.

README from the reviewed commit 0f2ea5a; it updates when the author re-pins.

hermes-session-reset-policy

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