The pool was the only external resource in the library that pre-allocated:
asyncpg's default min_size=10 turned pool creation into an all-or-nothing
action, so on a shared instance running low on connection budget the first
thing to fall over was the one component that must not fail silently
(4 clients x 10 = 40 idle connections just to write telemetry).
min_size=0 means "do not pre-connect" - asyncpg only builds holders - so
pool creation becomes free and never touches the database; connection
failures then land on acquire, the path that already drops one row and lets
the pool recover. max_size and the write budget become the library's
explicit statement about its own footprint, configurable through two new
keys whose defaults live in config alone (the recorder parameters are
required keyword-only, same discipline as auto_migrate).
The whole write - prepare, acquire, execute - now runs inside one
asyncio.timeout: acquire used to have no timeout at all, so a full pool
would hang forever on the caller's path. Release is explicit rather than
`async with`, because asyncpg shields release and reuses the acquire
timeout, which would let a single telemetry write consume twice the budget.
Limiter rejections have always chosen between waiting and failing fast;
breaker rejections had no such choice. The new key is the missing cell
of that matrix, shaped exactly like QUOTA_FULL so there is nothing new
to learn. It defaults to fail_fast: flipping the default would move
every existing deployment's worst-case wall clock from milliseconds to
the stall window, which is the wrong direction to impose on anyone.
Single-source scopes are the ones that want wait, and they now have a
way to say so.
The two keys stay separate despite sharing a domain, because a full
quota is "queue for your share" (your turn always comes) while an open
circuit is "wait for the source to recover" (it might not).
Policy validation collapses into SourceAdmission, the only consumer.
The three client constructors used to each carry their own copy of the
quota_full check; adding a second key there would have made eight
copies of the same two lines. Rejection timing and message are
unchanged -- admission is built inside those constructors.
This commit only wires the key through; the control flow that reads it
lands next.
`PGW_TELEMETRY_TEXT_CAP` now reaches the emitter on every assembly path.
Unset means no truncation, which stays the default: a truncated row is
no longer audit evidence and cannot be replayed, and downstreams rely on
that today. The flip side — contracts and bids sitting in `llm_calls`
indefinitely, multi-tenant — is spelled out in `.env.example` so readers
can weigh both.
All three `from_settings` paths are wired (chat, embedding, OCR): they
write the same table, so capping only chat would leave half of it
uncontrolled. `TelemetryEmitter.__init__` now rejects `text_cap <= 0`;
it is the single point where the three clients converge, so the direct
construction path — a public assembly route the settings guard never
sees — is covered too. `0` would otherwise reduce every body to a bare
elision marker.
_validate_stall still guards stall_window_s >= max ttft_timeout_s, but its
stated reason no longer holds: TTFT waiting is productive time and never
reaches the stall account. The check is harmless and stays, so the
docstring now says why it is kept rather than implying a live hazard.
.env.example dropped the "must be >= max TTFT" advice for what the window
actually measures.
Both Redis backends have lowercased scope in their own constructors since
v1.0.0, so case never split the keyspace. What actually does is whitespace:
the backends lower but do not strip.
The verifier found four more env-only behaviours of the same class the branch
was already fixing. The worst is scope: it goes straight into the Redis keys
(pgw:limit:{scope}, pgw:gate:{scope}), so one process using from_env("LLM")
and another constructing scope="LLM" by hand split the rate limit and breaker
state across two namespaces, each tracking its own quota, with no error.
Blank redis_url and pricing_path now collapse to None as from_env has always
done, so they fall into the required-field checks instead of reaching the redis
client as an unparseable URL. EmbeddingSettings gains the __post_init__ it never
had, moving its batch_size and expected_dim checks off the from_env-only path.
Also adds the cache backend whitelist test that mutation testing showed missing.
The warning added earlier in this branch logged the whole Postgres DSN, password
included, and nothing else in the library has ever printed a connection string.
It now reports only the scheme segment, which is the part that actually changed.
Regression test asserts the password and host/path never reach the log.
Round two of the from_env-only validation problem. Fifteen checks still lived
in the env parsing functions: six enum domains, the redis_url requirement for
redis-backed limiter/breaker/cache, cache namespace and TTL, telemetry path and
DSN, non-negative structured retries and non-blank scope. from_settings and
direct construction bypassed all of them.
The five asserts in client.py that claimed config had already validated
redis_url and the telemetry targets now hold on every path, so they revert to
what CLAUDE.md permits: internal invariant declarations that also narrow the
Optional for type checkers. Their comments now name the method that guarantees
them, since the previous wording is exactly what went stale.
Postgres DSNs built by hand now get the SQLAlchemy +driver suffix stripped the
way from_env has always stripped it, with a warning so the rewrite is not
silent. The env path strips earlier, so it stays quiet.
The lease, stall and probe-TTL guards only ran inside GatewaySettings.from_env,
so from_settings() and direct construction could produce settings that violate
the class's own invariants: the permit lease could expire mid-request (silently
exceeding the concurrency quota), a normal slow first token could be killed as a
stall, and a half-open probe could be taken over while still in flight.
Guards move into __post_init__ as _validate_* methods, matching every frozen
dataclass in types.py, so all six factories plus dataclasses.replace are covered
by one check. Adds a non-empty sources invariant that previously only from_env
enforced. Messages now name fields instead of env keys, since callers who build
settings by hand never set those keys.
AIMD ceiling now respects per-source max_concurrency and the pacer is
assembled explicitly in the client; MIN_CALLS parses as strict int;
acceptance doc corrects source-5 attempt count to 549; design and
migration notes aligned with implemented 429/stall/suppression
semantics and AIMD constants documented.
Round 5 left three residual failure classes; ladder exhaustion (3.2%
of structured calls with a single re-ask) and 429 leakage (5.8%, AIMD
oscillating above the sustainable point) are addressable: re-ask
default goes 1 to 2 (conservative vs instructor's 3) and the AIMD cut
factor drops to 0.5.
Threshold auto-raise now uses per-source concurrency only (the M2
global-concurrency formula neutered the breaker at scale). Four new
optional keys: MIN_CALLS, FAIL_RATE, WINDOW_S, MAX_COOLDOWN_S.
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