Architect: Python + uv Batch

Use this skill for non-API Python projects that run as CLI or scheduled jobs, especially data/PDF processing pipelines.

Inputs

Collect these values:

• PROJECT_NAME: kebab-case repo/folder name.
• MODULE_NAME: snake_case import package.
• PYTHON_VERSION: default 3.12.
• USE_RAG: yes or no.
• EMBED_PROVIDER: openai or sentence-transformers (default local sentence-transformers).
• NO_DOCKER: default no. Set to yes only when user explicitly opts out of containerization.

Preflight Checks

Run before scaffolding:

command -v uv >/dev/null && uv --version || echo "uv-missing"
python3 --version
command -v docker >/dev/null && docker --version || echo "docker-missing"

Execution modes:

• production-default: uv + docker available; emit and validate container artifacts.
• local-no-docker: user explicitly sets NO_DOCKER=yes.
• offline-smoke: uv missing and/or no network; scaffold file structure and stdlib smoke path, then record constraints in TEST_NOTES.md.

Production-default contract:

• Must create Dockerfile, .dockerignore, and docker-compose.yml.
• Must include CI image build check.
• Must run at least one containerized smoke command in validation.

Scaffold Workflow

1. Initialize project (production-default or local-no-docker):

uv init --package {{PROJECT_NAME}}
cd {{PROJECT_NAME}}

If offline-smoke mode is required, create equivalent structure manually and keep commands runnable via:

PYTHONPATH=src python3 -m {{MODULE_NAME}}.cli ingest-pdf
python3 -m unittest discover -s tests -v

2. Add core dependencies:

uv add pydantic-settings typer rich pypdf pandas orjson
uv add -d pytest ruff mypy

3. If USE_RAG=yes, add RAG dependencies:

uv add langchain-text-splitters chromadb

• For local embeddings:

uv add sentence-transformers

• For OpenAI embeddings:

uv add openai

4. Create structure:

src/{{MODULE_NAME}}/
  cli.py
  core/config.py
  pipelines/pdf_ingest.py
  pipelines/normalize.py
  rag/chunk.py
  rag/embed.py
  rag/store.py
tests/
  test_ingest.py
data/inbox/
data/processed/

If NO_DOCKER=no, also create:

• Dockerfile
• .dockerignore
• docker-compose.yml

5. Wire command entrypoint in pyproject.toml:

[project.scripts]
{{PROJECT_NAME}} = "{{MODULE_NAME}}.cli:main"

Required Defaults

src/{{MODULE_NAME}}/core/config.py

from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8")
    environment: str = "development"
    inbox_dir: str = "data/inbox"
    processed_dir: str = "data/processed"
    embed_provider: str = "sentence-transformers"
    embed_model: str = "sentence-transformers/all-MiniLM-L6-v2"
    openai_api_key: str | None = None
    chroma_path: str = ".chroma"


settings = Settings()

src/{{MODULE_NAME}}/cli.py

import typer

from {{MODULE_NAME}}.pipelines.pdf_ingest import run_pdf_ingest

app = typer.Typer(no_args_is_help=True)


@app.command("ingest-pdf")
def ingest_pdf() -> None:
    run_pdf_ingest()


def main() -> None:
    app()


if __name__ == "__main__":
    main()

src/{{MODULE_NAME}}/pipelines/pdf_ingest.py

import hashlib
from pathlib import Path

from pypdf import PdfReader

from {{MODULE_NAME}}.core.config import settings


def run_pdf_ingest() -> None:
    inbox = Path(settings.inbox_dir)
    out = Path(settings.processed_dir)
    out.mkdir(parents=True, exist_ok=True)
    for pdf_path in inbox.glob("*.pdf"):
        text = "\n".join(page.extract_text() or "" for page in PdfReader(str(pdf_path)).pages)
        suffix = hashlib.sha1(str(pdf_path).encode("utf-8")).hexdigest()[:8]
        target = out / f"{pdf_path.name}.{suffix}.txt"
        target.write_text(text, encoding="utf-8")

tests/test_ingest.py (import-safe for unittest discover)

from pathlib import Path
import sys

ROOT = Path(__file__).resolve().parents[1]
SRC = ROOT / "src"
if str(SRC) not in sys.path:
    sys.path.insert(0, str(SRC))

from {{MODULE_NAME}}.pipelines.pdf_ingest import run_pdf_ingest

Dockerfile (NO_DOCKER=no)

FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim AS build
WORKDIR /app
COPY pyproject.toml uv.lock* ./
COPY src ./src
RUN uv sync --frozen --no-dev
COPY data ./data

FROM python:3.12-slim AS run
WORKDIR /workspace
ENV PYTHONDONTWRITEBYTECODE=1
ENV PYTHONUNBUFFERED=1
RUN useradd --create-home --shell /bin/bash app
COPY --from=build /app/.venv /app/.venv
COPY --from=build /app /workspace
ENV PATH="/app/.venv/bin:$PATH"
ENV PYTHONPATH="/workspace/src"
USER app
CMD ["python", "-m", "{{MODULE_NAME}}.cli", "ingest-pdf"]

.dockerignore (NO_DOCKER=no)

.git
.venv
__pycache__
.pytest_cache
.mypy_cache
.ruff_cache
data/processed

docker-compose.yml (NO_DOCKER=no)

services:
  app:
    build: .
    environment:
      INBOX_DIR: /workspace/data/inbox
      PROCESSED_DIR: /workspace/data/processed
    volumes:
      - ./data:/workspace/data
    command: ["python", "-m", "{{MODULE_NAME}}.cli", "ingest-pdf"]

CI + Quality

Create .github/workflows/ci.yml:

name: ci
on:
  push:
  pull_request:

jobs:
  quality:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - uses: astral-sh/setup-uv@v5
      - run: uv sync --frozen --dev
      - run: uv run ruff check .
      - run: uv run mypy src
      - run: uv run pytest -q
      - uses: docker/setup-buildx-action@v3
      - uses: docker/build-push-action@v6
        with:
          context: .
          push: false
          tags: {{PROJECT_NAME}}:ci
          cache-from: type=gha
          cache-to: type=gha,mode=max

Guardrails

• Keep batch jobs idempotent; output paths must be safe to re-run.
• Make output names collision-safe across formats and paths (include extension and a stable suffix/hash).
• Never commit secrets; use .env and environment variables.
• Keep processing logic pure where possible, IO at pipeline edges.
• If RAG is optional, keep rag/* modules decoupled from non-RAG pipelines.
• Treat NO_DOCKER=yes as an explicit exception, not a default path.
• Ensure tests can run via plain python3 -m unittest discover -s tests -v without requiring PYTHONPATH for imports.

Validation Checklist

uv run ruff check .
uv run mypy src
uv run pytest -q
uv run {{PROJECT_NAME}} ingest-pdf
docker build -t {{PROJECT_NAME}}:local .
docker compose run --rm app

local-no-docker (NO_DOCKER=yes):

uv run ruff check .
uv run mypy src
uv run pytest -q
uv run {{PROJECT_NAME}} ingest-pdf

Fallback (offline-smoke):

PYTHONPATH=src python3 -m {{MODULE_NAME}}.cli ingest-pdf
python3 -m unittest discover -s tests -v

Decision Justification Rule

• Every non-trivial decision must include a concrete justification.
• Capture the alternatives considered and why they were rejected.
• State tradeoffs and residual risks for the chosen option.
• If justification is missing, treat the task as incomplete and surface it as a blocker.