Files
oO/ml
alvis 4652e4b582 feat(ml): JetStream durable consumers in ml/serving (#98)
Adds a NATS JetStream consumer to ml/serving so the feature pipeline
can react to events without the API triggering every read.

- nats_consumer.py: durable push consumers for signals.> and feedback.>
  streams; acks on success, naks for redeliver, up to NATS_MAX_DELIVER
  attempts; per-consumer health state (last_msg_ts, processed, errors)
- main.py: FastAPI lifespan wires start/stop; /health exposes nats state
- requirements.txt: adds nats-py>=2.9.0
- Dockerfile.ml: copy all *.py from ml/serving (was missing prompts.py)

Handled subjects:
  signals.task.synced   → writes per-user sync metadata to STATE_DIR
  signals.tip.feedback  → logged for observability (reward via HTTP path)

Config: NATS_URL (empty = disabled), NATS_DURABLE_PREFIX, NATS_MAX_DELIVER

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-25 10:19:47 +00:00
..

ml/

Python. Owns models, features, training, online scoring.

Dir Role Phase
serving/ FastAPI online scorer (/score, /generate) + LiteLLM gateway + prompt registry (prompts.py), called by recommender 12
features/ context assembler (context.py): signals → PromptContext; Feast adapter later 2
pipelines/ batch feature + training DAGs (Prefect/Airflow) 4
registry/ MLflow-backed model registry integration 4
experiments/ A/B assignment + multi-armed bandit policies 4
notebooks/ research; never imported by production code

Principles

  • Every model has a model card in registry/ describing inputs, offline metrics, fairness checks, and rollout history.
  • Online inference must be stateless and < 50ms p99.
  • Training reads from the offline feature store; serving reads from the online feature store; definitions are shared (no train/serve skew).
  • Shadow deploys before any policy change that affects real users.

Profile-feature contract

User-level features (completion rate, preferred hour, tip volume…) are computed by the TypeScript recommender and shipped to ml/serving on every /score and /generate call as profile_features: dict | None. The Python mirror in features/profile_schema.py documents the available names + dtypes — keep it in sync with services/api/src/profile/registry.ts (a CI-style test asserts the name sets match). See ADR-0011.

Prompt registry

serving/prompts.py keys tip-generation prompts by stable version string. Adding a new variant means adding an entry — no caller changes. Selection precedence: POST /generate body's prompt_version field → env DEFAULT_PROMPT_VERSION"v1". The TypeScript recommender drives selection via TIP_PROMPT_VERSION (single value or comma-separated rotation); the version actually used flows back in the response and is persisted to tip_scores.prompt_version so the admin reward-analytics dashboard can bucket reactions per variant.