`connect()` calls `_seed_channel()` unconditionally, and seeding marks every
event currently in the channel as seen so a start never replays history at the
agent. A message that arrives after the process starts but before the seed
completes — or at any point while the gateway is down — sits in exactly that
history, so the seed swallows it permanently even though the Buzz relay still
has it. The `seen` set and `last_ts` lived only in memory, so there was nothing
to distinguish "already handled" from "never seen".
Each watched channel's cursor (`chat_type`, `last_ts`, and the bounded `seen`
id list) is now persisted under `HERMES_HOME/buzz/channel-cursors.json` and
restored at connect. Where a cursor exists the channel resumes from it and the
history fetch is skipped entirely; where none exists the old seed-from-history
behaviour is unchanged, so a first-ever run still never replays a backlog.
Details worth noting:
- The file records the identity and relay it was written for. A cursor from a
different bot or relay is ignored rather than trusted — the channel ids
would collide while the event stream behind them is a different one.
- Any read or parse failure leaves the cursors empty, which degrades to
seeding instead of failing the connect. Writes go through
`utils.atomic_json_write` (temp + fsync + replace), so a crash mid-write
cannot leave a truncated cursor behind.
- The restored `seen` list is trimmed to `_SEEN_CAP` on load, keeping the
newest ids, so a hand-edited or legacy file cannot grow the de-dupe set
without bound.
- Saves are gated on the cursor actually moving, so an idle channel does not
rewrite the file every poll interval. Both inbound transports are covered:
the poll sweep and the WebSocket event path share the same check.
Tests: six new cases in `TestChannelCursorPersistence` — the cursor is written
on seed, a restart resumes without spending a CLI call on history and then
delivers the mention that landed while the gateway was down, a foreign
identity or relay is ignored, a corrupt file falls back to seeding, the
restored `seen` set stays bounded, and an idle poll leaves the file untouched.
All six fail on main.
Tested on: Windows 11, Python 3.12. `python -m pytest
tests/gateway/test_buzz_adapter.py tests/gateway/test_buzz_websocket.py -q` —
33 passed (23 pre-existing + 6 new here, plus 4 WebSocket). Requires
`pytest-asyncio` (pinned at 1.3.0 in pyproject) — without it the async cases
in this file error out as unknown marks.
Alessandro Boni