Round 4 showed tail placement routes the third attempt to junk sources
whenever the credible alternative is gate-skipped (tight-RPM source
admitted as credible, then skipped by the limiter, falling through to
the flapping watchdog source). Demoted sources now sit between credible
and non-credible candidates.
Round 3 showed unconditional yield-after-two-failures pushes the third
attempt onto known-bad sources in heterogeneous pools (83% vs 10%
expected success). OutcomeAwareSelector now exposes health(); a failed
source only yields when some untried candidate scores at least half its
health. Health-blind selectors keep the unconditional rule.
P6 round 2 showed routing convergence turns account-level 429s into
the binding constraint (62% throttle rate at full concurrency). Each
source now carries a local AIMD limit: multiplicative cut on 429,
additive growth on success. Over-limit picks queue via the existing
quota-wait poll instead of burning retry budget or tripping the
circuit-open verdict.
RetryMW keeps a per-call failure map (local, never instance state):
a source failing twice in one call yields to the next candidate.
Attempt outcomes feed OutcomeAwareSelector behind a swallow-and-warn
guard; ResultInvalid and provider-rejected paths record success with
count_attempt=False so the breaker window stays clean. Same accounting
applied in EmbeddingClient.
Classify empty completions as transient per human ruling (fixes flaky
real-gateway smoke and prevents caching empty responses), rename the
factory injection parameter gate to breaker per the frozen design,
rewrite the probe-entry cleanup without except BaseException, declare
python-dotenv explicitly, add a mid-backoff cancellation test, and
record all implementation errata in the design and architecture docs.
Includes config aggregation for multi-source env keys, from_env and
from_settings factories with explicit shared-backend injection,
gather_bounded, top-level exports, tightened import-linter layers with
the gate removed from the Makefile, and the finalized .env.example.
iomgaa