YouTube's RSS goes dark per channel for hours (prod 2026-09-18/19: 393 of
396 feeds answered 404 for four hours, sticky per channel, so a retry does
not help), and nothing else read a followed channel's new uploads. A
channel whose feed has not answered for `rss_fallback_hours` (admin knob,
default 2, 0 = off) now gets one page of its uploads playlist through the
Data API (1 unit), at most once per window, yielding to the backfill
reserve. Spend is attributed to its own quota action.
Addresses the code-review findings on the immediate full-history change:
- Extract quota.backfill_reserve_reached(): the remaining/reserve compare was
open-coded at seven sites (recent/deep/immediate backfill, explore, rolling
revalidation, and the new per-page guard). It reads in its OWN short-lived
session (like record_usage/log_action), so a per-page guard no longer holds
the caller's transaction open across the YouTube fetch that follows — the
400-page immediate run no longer pins a pooled connection idle-in-transaction
through each network round-trip. Migrated all call sites; dropped the now-dead
sysconfig imports in channels.py and maintenance.py.
- Simplify the deep-backfill loop: channel.backfill_done = not page_token (done
is False on entry) plus one break, replacing the doubled `if not page_token`.
- Tests patch the backfill_reserve_reached seam directly instead of mocking
remaining_today internals, removing the fragile dead-value budget iterator.
Full backend suite green; ruff clean.
/code-review high on S2 — 4 findings, 2 fixed, 2 no-change:
- test_plex_sync_txn: a faked PlexClient fails on the second library; asserts the
first library's row survives (per-section commit). Mutation-checked — moving the
commit back out of the loop turns it red ([] == ['1']).
- dropped the `[[quota-owns-its-session]]` memory slugs from quota.py docstrings
(a dangling private-note reference in shipped code; the reasoning is already inline).
No change: record_usage's per-call second connection is a transient spike, fine for
this app's concurrency; the two-site `with SessionLocal()` duplication isn't worth a
helper until a third caller appears.
Gate: ruff clean; DB lane 181 green.
Transaction ownership (C-A5):
- quota.record_usage / log_action write in their OWN SessionLocal(), committed
immediately, and no longer take/commit the caller's db. The spend stays DURABLE
regardless of the caller (read-only YouTube paths never commit; a failed job rolls
back) — under-counting the shared daily budget would risk overspending the real
YouTube quota — AND quota stops flushing a job's partial state mid-run behind its
own `except: db.rollback()`. units_used_today switches to a scalar SELECT so
measured()'s before/after diff sees the separate session's commits (READ COMMITTED).
Call sites updated (youtube/client.py ×3, routes/search.py ×1).
- plex sync commits PER SECTION (moved the end-of-loop commit inside), so a PlexError
on a later library keeps the ones already mirrored (idempotent; next run reconciles).
The sync jobs did NOT rely on record_usage's incidental commit for persistence — their
per-item functions (apply_rss_feed, backfill_channel_recent, import_subscriptions,
sync_user_playlists, apply_channel_autotags) all commit internally, so the in-loop
rollback handlers already isolate a failed item. No loop restructuring needed.
DB-lane tests (test_quota_ownership, 4): spend survives a caller rollback while the
caller's uncommitted row does NOT leak; accumulation; measured-style mid-txn read.
Gate: ruff clean; DB lane 180 green.
Adds the backend for a dedicated channel page + ephemeral browsing of un-subscribed
channels:
- migration 0033: channels.{total_view_count,published_at,banner_url,external_links,
from_explore}, videos.via_explore, explored_channels (per-user, grace-clocked).
- enrich channels with part=brandingSettings (banner/links) + statistics.viewCount +
snippet.publishedAt — no extra quota.
- GET /api/channels/{id}: About detail + this user's relationship; lazy-enriches the new
About fields (published_at sentinel).
- POST /api/channels/{id}/explore (require_human, quota-reserve guarded): records the
exploration, flags the channel ephemeral unless followed, ingests one page of uploads
(via_explore) + enriches; returns next_page_token for load-more.
- feed: per-explorer gate — a via_explore video is visible only to users who explored or
subscribe to its channel, so exploration never leaks into everyone's catalog.
- subscribe = keep: clears from_explore + via_explore on the channel's videos.
- scheduler explore_cleanup job + explore_grace_days config: hard-delete explored-but-
unkept channels and their untouched ephemeral videos after a grace period.
Live YouTube search can now use YouTube's internal InnerTube endpoint instead
of search.list, materialising results through the same enrich/provenance path
at zero API quota (search.list costs 100 units/page; scrape costs nothing, only
the cheap shared videos.list enrich is charged).
- youtube/search_scrape.py: InnerTube search returning the same page shape as
YouTubeClient.search_videos (items + continuation cursor); SOCS consent cookie,
videoRenderer walk (channels/playlists/Shorts shelves naturally excluded),
type:video filter, cached InnerTube key/version with constant fallbacks.
- routes/search.py: admin-selectable source (search_source, default scrape).
Scrape path skips the 100-unit budget pre-check and logs a zero-cost search
event so the per-user daily cap still counts it; api path unchanged. Response
carries the active source.
- sysconfig/config: new search_source key (scrape|api).
- quota.log_action: record a zero-cost action event for per-user rate limits.
Add a live YouTube search that materialises results into the shared catalog so
they render with the normal feed cards + in-app player and gain per-user state.
- YouTubeClient.search_videos(): search.list (100 units), embeddable-only, returns
flat stubs + nextPageToken; surfaces liveBroadcastContent for live filtering.
- routes/search.py GET /api/search/youtube: require_human + per-user daily cap
(search_daily_limit_per_user, default 70) + can_spend pre-check (429 on either);
drops live/upcoming, upserts channel stubs (channels.list) + video stubs, enriches
(videos.list), runs the youtube.com/shorts probe, then excludes Shorts/live and
returns feed cards in relevance order with the YouTube pageToken as the cursor.
- Provenance: videos.via_search / channels.from_search (migration 0028) flag
search-discovered rows; the feed hides them from the Library (scope=all) by default
via exclude_search_discovered, leaving the Mine feed untouched.
- quota.actions_today() counts a user's per-action events today for the cap; only the
search.list call is attributed VIDEOS_SEARCH so the counter is exactly 1 per search.
- quota.measured() context manager folds the before/after units diff that the
manual sync routes each re-spelled (also makes quota_remaining_today consistent).
- sync pause/resume now use Depends(admin_user) instead of inline role checks.
- is_messageable_user() unifies the 'real, active, non-suspended human' rule that
was encoded three ways (WS auth, send recipient, and the SQL _messageable()).
Register 8 more keys in the sysconfig registry (quota daily budget + backfill
reserve, recent-backfill window, shorts-probe params, enrich/autotag batch sizes)
and route their reads through the DB-override-or-env resolver at every call site
(quota.py, sync/runner.py, sync/videos.py, sync/autotag.py, sync/maintenance.py,
routes/scheduler.py). All read sites already had a db session in scope. Reads are
read-through (no cache), matching app.state; admin can tune them live, no redeploy.
The quota-attribution action keys were inconsistent (mixed verbs, ad-hoc names,
English-only labels). Introduce a QuotaAction constants holder (one source of
truth), rename every attribution call site to it, and add migration 0020 to
rename historical quota_events.action values. The display label now resolves
from i18n (quotaActions.<key>, EN/HU/DE) instead of a hard-coded English map.
Scheduler job ids and progress phase labels are a separate namespace and are
left untouched.
Track who burned how much YouTube API quota. A QuotaEvent audit log (migration
0009) records every spend with the triggering user (NULL = background/system) and
an action label, set via a request/job-scoped contextvar (quota.attribute) so no
call signatures change. User-initiated work (sync subscriptions, unsubscribe,
opt-in recent backfill, manual enrich) attributes to the user; scheduler work to
System, split by action.
- backend: QuotaEvent model + migration 0009; quota.attribute() contextvar;
record_usage logs events; entry points wrapped (routes/sync, routes/channels,
scheduler); GET /api/quota/my-usage + GET /api/quota/admin
- frontend: admin-only Stats page (header nav, page=stats) with daily bars +
per-user breakdown by action and range picker; 'Your API usage' in Settings ->
Sync for every user
Verified: attribution + endpoints compute correctly; events are per-user vs System.
- Channel/Subscription/Video/ApiQuotaUsage models + migration 0002
- Synchronous YouTube Data API client with OAuth token refresh and per-call
quota accounting (API key preferred for public reads when configured)
- Subscription import: upsert channels + subscription links, prune unsubscribed,
fetch channel details (uploads playlist, topics, stats, handle, country)
- Central quota guard tracking units per US-Pacific day against a daily budget
- POST /api/sync/subscriptions and GET /api/sync/status endpoints
peter