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:

1. Computes the session key for the message (the gateway's own helper, so multiplexed profiles and platform key layouts match exactly).
2. Reads the profile's config.yaml session_reset block (under multiplex_profiles, the profile is resolved from the message's source.profile and read from profiles/<name>/config.yaml).
3. Compares the routing entry's user-activity clock (updated_at, advanced only by real user turns — internal events pass touch_activity=False) against the idle threshold and/or the daily boundary.
4. Past the boundary, and with no turn in flight (the entry's durable active_turn_token marker), calls SessionStore.reset_session() — the same path /new uses — then allows normal dispatch, so the message lands in the fresh session.

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 reset re-arms on the next message.
• Requires Hermes >= v2026.9.11 (needs the pre_gateway_dispatch hook payload with session_store).

License

MIT — see LICENSE.