[jeffdupont]

Fixes AIC-3572.

Why

When a variation comes back with no _ldMeta, or with _ldMeta but no enabled field, extract_variation treated it as enabled and ran the model. Only an explicit enabled: false was refused. The JS SDK (lifecycle.ts, if (!variation?._ldMeta?.enabled) throw) and the Go SDK (aiserver/lifecycle.go, if !meta.Enabled) both refuse these variations, and Python's own inspect_config already reports them as enabled: false, so one SDK said "disabled" while the other ran the call.

Behaviour change (changelog): a config served without _ldMeta.enabled (for example a plain JSON flag used as an AI config) now raises Variation '<key>' is disabled. instead of running.

Fix

• packages/client/src/launchdarkly_ai_server/lifecycle.py: extract_variation raises the existing "is disabled" error unless _ldMeta is a dict with a truthy enabled. A non-dict or null _ldMeta is guarded. meta["enabled"] is now always True past that check.
• packages/client/tests/test_lifecycle.py: new TestExtractVariationMissingEnabled, parametrized over no _ldMeta and _ldMeta: {}. Each case asserts that extract_variation raises and inspect_config returns enabled: False.

Testing

• make test: 2546 passed, 14 skipped
• make typecheck: no issues in 75 source files
• make lint: all checks passed. make format-check: 161 files already formatted.
• Without the fix, both new cases fail with DID NOT RAISE RuntimeError.
• Every existing fixture sets _ldMeta.enabled explicitly, and the full suite passes unchanged.

Related: https://github.com/launchdarkly/ai-sdks-monorepo/pull/69

🤖 Generated with Claude Code

---

Note

Overview
Aligns Python extract_variation with spec §3.10 and the JS/Go SDKs: a variation is only runnable when _ldMeta is a dict with a truthy enabled. Missing _ldMeta, an empty _ldMeta, or no enabled field now raises Variation '<key>' is disabled. instead of proceeding to parse and invoke the model (previously only enabled: false was rejected).

After that gate, returned meta["enabled"] is always True rather than defaulting from metadata. inspect_config already reported these cases as disabled; invoke paths now match.

Adds parametrized tests (no_ldMeta, empty_ldMeta) asserting extract_variation raises and inspect_config returns enabled: false.

^{Reviewed by Cursor Bugbot for commit 6fc85ea. Bugbot is set up for automated code reviews on this repo. Configure here.}