Python backend (FastAPI + Pydantic v2 + Alembic)

Activation cues

Use this skill when the task involves:

1. new or modified FastAPI endpoints, routers, dependencies, middleware
2. request/response validation, schema design, OpenAPI correctness (Pydantic v2)
3. database schema changes (Alembic revisions)
4. backend logging and request tracing
5. ETL / parsers / import pipelines with memory constraints and “bad rows” reporting

Operating principles (agent workflow)

1. Start with a short plan before editing code. Prefer file-path-specific steps and repository-aligned patterns.
2. Ask up to 1–3 clarifying questions only if truly blocking.
3. Prefer verifiable goals: tests, migrations, reproducible API calls, and deterministic outputs.
4. For complex/high-risk changes, run an internal Chain-of-Verification (CoVe): draft → 3–5 verification questions → answer independently → revise; surface only final result + (optional) UNCERTAIN items and how to verify them.

Standard implementation workflow