Every chat sync today is a pull: a screen queues a request row, a pump drains
it, the relay answers, the subscription is closed. Nothing arrives between
pulls, so a message sent one second after EOSE waits for the next time someone
opens a screen.
This note works out what it takes to hold the two chat subscriptions open for
as long as the app is active — kind 1059 p-tagged to us, and kind 445 h-tagged
with every group we belong to — and, more usefully, what in the current
pipeline quietly assumes a subscription is short:
- completeOnSubscriptionEnd finishes the flow at EOSE, which is what releases
the slot and sends the CLOSE,
- SUBSCRIPTION_TIMEOUT hard-kills anything still open at 120s,
- subscriptionSlots is a Semaphore(4) shared with the backfill queue, so a
permanent subscription is a permanently-held permit,
- both saveNostrEvent overloads need a request row to attach provenance to
and to flip to "processed",
- and nothing in the app reconnects a dropped socket at all. That is
invisible today only because every subscription is short and the next
queued request re-opens the socket on its way out.
The design keeps the queue and its three pumps exactly as they are: live
subscriptions replace polling, not reconciliation. Negentropy stays the tool
for first login, the catch-up after a background gap, and "load older".
The group filter is derived from chatRepository.observeChatRoomListByPublicKey
rather than wired at each join site, because a group id can appear four ways
and only one of them (creating a group) is somewhere anyone would think to call
a subscribe function — being added arrives as a Welcome processed deep inside
NostrDao.storeNostrEvent. Observing the room list also closes the loop: a
Welcome lands on the live gift wrap subscription, a ChatRoom row is written,
the Flow re-emits, and the group filter widens without anyone opening a chat.
Two findings fell out of checking the details against our own code:
- `since = now` on kind 1059 would silently drop messages. Gift wraps are
stamped with TimeUtils.randomWithTwoDays(), so a wrap published now can
carry a created_at two days in the past. Kind 445 uses TimeUtils.now() and
can take a watermark — opposite treatment for the two kinds we care about.
- the "sent-messages" filter (kinds=[1059], authors=[me]) cannot match
anything, because gift wraps are signed with a fresh throwaway KeyPair().
It is also unnecessary: createNip17ChatRoom puts the user in their own
participant list, so we wrap a copy to ourselves and the account-wide
#p=[me] subscription already picks it up.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
