v1.4.15 Phase B3, criteria 1 + 2 (atomic — they share migration + retry-
policy types). Until this release the dispatcher fired channels best-
effort and kept retrying every 60s on a 410 Gone — that meant a stale
Web-Push subscription never recovered, a Telegram bot whose chat was
deleted got the same treatment, and the user had no visibility into
WHY their phone had stopped buzzing.
Reliability rules now:
- HARD reject (HTTP 410 web-push / ntfy, Telegram "chat not found" /
"blocked by the user") → channel auto-disabled, `disabled_reason`
captured, audit log `notification.channel.auto_disabled` written.
Sender NEVER retried until the user clicks "Re-enable" in Settings.
- SOFT reject (5xx, 429, network timeout) → exponential backoff:
[30s, 5min, 30min, 2h]. Counter `consecutive_failures` increments
per failure; after the 5th in-a-row the channel is auto-disabled
with reason `give_up_after_5_failures` (criterion 2's "treat as
hard reject after N failures" rule).
- COOLDOWN window (`next_retry_at > now`) → dispatcher skips the
channel without calling the sender — defeats the API-quota-burn
loop a flapping upstream would otherwise create.
Implementation:
- Migration 0028 adds 6 columns to `notification_channels`:
`disabled_reason`, `consecutive_failures`, `last_success_at`,
`last_failure_at`, `last_failure_reason`, `next_retry_at`. All
nullable / zero-default → no-op for existing rows.
- `src/lib/notifications/retry-policy.ts` exports the classifier
(`classifyTelegramError`, `classifyHttpStatus`) plus
`BACKOFF_SCHEDULE_MS` (frozen) and `nextRetryAt(count, now)` /
`shouldAutoDisableAfterTransient(count)` helpers.
- `src/lib/notifications/channel-state.ts` is the only writer of
the new columns: `recordChannelSuccess`, `recordChannelHardReject`,
`recordChannelTransientFailure`, `reEnableChannel`,
`isChannelInCooldown`. Each transient/hard path writes an audit
entry so the user can trace WHY the channel went silent.
- Senders now return a structured `SendOutcome` (`{ ok, hardReject?,
statusCode?, reason?, message? }`) instead of bare booleans. The
Telegram sender additionally exposes `errorDescription` from the
Bot API so "chat not found" / "bot was blocked" can be classified
without parsing free-form text in the dispatcher.
- Dispatcher: cooldown-skip → success → hard-reject branch →
transient/give-up branch. Sender-throws are absorbed as transient
failures (defence-in-depth).
Tests: +20 unit tests (`retry-policy.test.ts`, `channel-state.test.ts`,
`dispatcher.test.ts`). 883/883 pass. Hard-reject scenarios covered:
web-push 410, Telegram chat-not-found, ntfy 410. Soft-reject
scenarios: 429 schedules backoff without disabling; cooldown skip
prevents repeat call; 5th in-a-row triggers give-up + audit.
Pre-existing bug fix: `src/app/api/settings/telegram/test/route.ts`
had `if (!ok)` against a `SendMessageResult` object — always truthy,
so the route never reported test-send failures. Now reads
`result.ok`.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
