Until now a send that failed (offline, homeserver down, a blip) went
straight to "Failed to send": nothing retried it, and a reload dropped it
without trace (chronological pending ordering keeps local echoes in memory
only).
- Outbox (utils/outbox.ts + features/outbox/OutboxFeature): own message
sends (text, stickers, reactions, polls; not call signalling or
redactions) are mirrored to localStorage from their first local echo until
the server confirms them or the user cancels.
- After a reload they come back as local echoes via room.addPendingEvent,
same shape as the SDK's own. Recent ones (< 1 h) are sent again with the
same txnId; older ones come back as "Failed to send" for the user to
retry or cancel. Ones the server already has (transaction id seen in
/sync) are dropped, so no duplicates.
- Retries: network failures (ConnectionError, 408/429/5xx) are re-sent when
the connection returns (sync recovers or the browser goes back online),
and after a blip while online (5 s, backing off, max 10 per message).
Oldest first, in order per room. 4xx / consent / encryption failures are
left to the user.
- UI: a network failure while offline shows a clock, "Queued. Will send
when you're back online" (thread view too), not the red ✕. The ✕ is now
a button: click to retry.
- Logout wipes the outbox with the other plaintext caches (the content is
decrypted, like drafts).
Tested end to end against a local Synapse (Chromium): offline → queued →
sent once on reconnect; homeserver unreachable → queued → sent once; failed
send → reload → sent once and shown once; server accepted but response lost
→ reload → no duplicate; 2 h old entry → failed, not sent, click ✕ → sent;
cancel → gone after reload; encrypted room → restored message goes out as
m.room.encrypted with no plaintext and decrypts; one-off failure retried by
itself in ~5 s; no page errors. Unit tests for the pure parts; Playwright
20 passed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA
Lotus CIandClaude Opus 5.5