The practice API rejects ~15-20 requests/day with a spurious 401
"Insufficient authorization" while the same token succeeds on adjacent
requests; each one silently cost a full scan cycle on that timeframe.
One retry after RETRY_DELAY_S (2 s) absorbs these plus transient
5xx/network faults. Real credential failures fail both attempts and
raise as before; other 4xx (bad request, 429) are never retried.
Tests: transient-401 recovery, persistent-401 raise, 400 not retried.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tujtmmhxj9mxKjPFSoVjmP
2026-08-04 Fable 5 QA audit. Three batches sharing one test file, all
verified by runnable repros before fixing, all gated below.
Batch C — telegram alert delivery (verified by h4 harness):
- Failed breach rescan shrinks the cooldown to 30 s instead of
silencing the symbol for 5 min; breach during cooldown is PARKED and
fired on the first tick after expiry (was dropped forever).
- Level cache keyed symbol→TF (M5 scans no longer wipe H1/H4 swing
levels within minutes); breach labels TF-qualified.
- Markdown alert sends get a plain-text fallback (mirroring _safe_edit);
fingerprint commits only when a message actually landed.
- Per-key asyncio.Lock closes the dedup TOCTOU between auto-scan and
breach sends (forced-interleave repro produced duplicate alerts).
- _start_scheduler respawns dead per-TF loops (was all-or-nothing).
- Clean WS close now backs off (was a zero-delay reconnect hot loop);
backoff resets only after a connection that received ticks; TD
iter_ticks fires on_connect on the first RECEIVED frame (invalid key
can no longer pin the backoff at minimum).
- Scan-failure logs carry the real traceback (was "NoneType: None").
Batch E — providers (verified by h5 harness):
- fetch_range: 3 consecutive chunk ERRORS raise instead of returning
silently truncated history (verified 731-day silent gap repro; also
covers 429 storms); pagination no-progress guard; head-truncation
ERROR log.
- Single-flight per (symbol,TF): 4 concurrent scans = 1 API call (was
4); cache records requested depth so a longer-lookback call refetches.
- Multi-bar forming/future tail fully dropped (was iloc[:-1] once).
- Oanda: malformed candles skipped, never 0.0-defaulted; cleaning drops
non-positive-price rows BEFORE OHLC repair; inf returns neutralized so
one corrupt bar can no longer disarm the whole 10-sigma filter.
Batch F — backtester internals (verified by h6 harness):
- NaN bar in a trailing window exits at the last valid bar (was NaN R
poisoning every metric); static-path TIMEOUT NaN guard;
compute_metrics excludes non-finite R loudly. Zero real-data exposure
(0 NaN rows in all 10 Oanda parquets) — defensive.
- fetch_history ERROR-logs pre-2026-07-08 cache files (cleaned-bars era)
when loaded for raw-path resolution.
Gates: suite 333/333 green; pinned M15 12mo book reproduced identically
(397 trades, +78.7111R) after E and after F; M5 HEAD-config baseline
reproduced identically (556 trades, +97.5604R) after F.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UnZkzeFcTu9agFg8BDh2tn
One class per provider (TwelveData, Oanda, Tiingo), all subclassing
BaseDataProvider which owns cache, validation/cleaning, freshness +
boundary guarantees, fetch_range pagination, and streaming stubs —
subclasses implement only _fetch_raw. config.json data_providers.active
selects the live feed; data_provider.py / oanda_provider.py stay as
back-compat shims. Module 16 provider-abstraction tests (253 total green).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Mc7XKYyPySVXiUpcN82QEK
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