Chat rows stored full message and response text with no upper bound, so
downstream contracts and tenders lived in llm_calls indefinitely. Add
_cap_text/_cap_messages in the single telemetry exit (_record), applied
after digest_messages and before json.dumps, plus to response/thinking.
Capping is per text, not over the serialized JSON: cutting the whole
string would emit invalid JSON into an unvalidated TEXT column. The cap
builds new dicts and never mutates in place — digest_messages passes
non-list content straight through as the same object, so an in-place cut
would silently poison the caller's messages and the cache key.
text_cap is required on TelemetryEmitter (internal class, three known
construction sites) and defaults to None on the three public clients, so
the default behaviour stays byte-for-byte identical. Settings wiring
lands separately.
Task 1 of the est_tokens decoupling: capability only, no call site
touched, so library behaviour is unchanged word for word.
SourceConfig.effective_est_tokens() returns the explicit est_tokens when
set, otherwise tpm // 60 floored at 1, otherwise 0 when the TPM gate is
off. The divisor is scale free: any quota size yields the same in-flight
ceiling of roughly sixty calls, which is what makes the default
explainable where a fixed constant was not.
USAGE_SOURCES lands with the two assertions the design asks for, not as
a dead constant. test_usage_source_domain.py drives every production
point -- _resolve_usage, _resolve_embedding_usage, _merge and the three
TelemetryEmitter.emit_* helpers -- and asserts the output stays inside
the domain; it is a separate file because the assertion spans
transports, embedding and telemetry, and the innermost kernel test
should not depend on implementations. The second assertion pins the
opposite ruling: constructing LLMResponse with an out-of-domain value
must not raise, since a bare ValueError at a runtime construction point
falls outside the four error categories and would escape chat().
tpm > 0 with est_tokens = 0 is still rejected until Task 4, so the
derivation tests build the future-legal shape through a helper that
bypasses the constraint; the helper collapses back to _make_source once
the constraint is gone.
iomgaa