Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/denyszhak/pystack-skills/python-fastapi-sa-app-setupnpx skills add denyszhak/pystack-skills --skill python-fastapi-sa-app-setupgit clone --depth 1 https://github.com/denyszhak/pystack-skillsWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00173 | $0.04531 |
| Opus 5 | $0.00086 | $0.02266 |
| Sonnet 5 | $0.00035 | $0.00906 |
| Haiku 4.5 | $0.00017 | $0.00453 |
Grade A, and why
python-fastapi-sa-app-setup scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 509 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FastAPI + SQLAlchemy app setup
The skeleton of a typed Python backend service: where every file goes, what initializes when, and how requests flow from HTTP to database. Get this right once; the rest of the skills slot in cleanly.
When to use this skill
- Starting a new FastAPI + SQLAlchemy service
- Refactoring an existing service toward a layered structure
- Adding a new client / middleware / exception handler to an existing service
- Wiring
app/deps/,app/db/, orapp/api/for the first time
The canonical layout
app/
setup.py # provide_app(config) -> FastAPI factory + module-level app instance
config.py # AppConfig + sub-Config classes (DBConfig, OpenAIConfig, ...)
common/
exceptions.py # AppException base + NotFoundException, ConflictException, ...
logging.py # configure_logging(env=...), contextvar correlation_id
db/
__init__.py # init_db_pool, close_db_pool, provide_async_db_pool
deps/
db.py # get_session
clients.py # get_X_client
repos.py # get_X_repo
services.py # get_X_service
models/ # SA ORM (one file per aggregate)
repos/ # repositories (one file per aggregate)
services/ # use cases (one file per use case area: checkout.py, refunds.py)
clients/ # external HTTP clients (BaseHTTPClient + per-system files)
schemas/ # Pydantic in/out (one file per resource)
api/
system.py # /health, /version
exception_handlers.py
middleware/
__init__.py
correlation.py # CorrelationIDMiddleware
logging.py # logging_middleware
v1/
__init__.py # provide_api_v1_router() factory
order.py
lead.py
tests/ is adjacent to app/, not under it (see python-test-pyramid).
Architecture — hexagonal-shaped, not strict
Inbound (api/, consumers/) and outbound (clients/, repos/) are separated at the root rather than nested under adapters/inbound/ + adapters/outbound/. The directory names already communicate the role; nesting adds depth without semantic payoff and makes every import one level longer.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 509 lines · 173 tokens per session scan A 3d98552f8f3a
python-fastapi-sa-app-setup is a skill published in the GitHub repository denyszhak/pystack-skills (4 stars, last pushed 3mo ago), licensed MIT. It adds 173 tokens to every session and 4,531 once invoked, about $0.0009 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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