What is python-fastapi-sa-app-setup?

A setup guide for FastAPI and SQLAlchemy services. FastAPI builds web APIs in Python, while SQLAlchemy connects Python code to databases.

Starting or reorganizing a backend service, creating its app factory, configuring middleware and exceptions, and wiring database sessions and clients.

It provides a consistent structure for application startup, database access, request handling, errors, and shared services.

python-fastapi-sa-app-setup — Skill by denyszhak/pystack-skills

Install

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.

Any agent

npx skills add denyszhak/pystack-skills --skill python-fastapi-sa-app-setup

Clone the repo

git clone --depth 1 https://github.com/denyszhak/pystack-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/denyszhak/pystack-skills/python-fastapi-sa-app-setup/github.svg)](https://agentmods.dev/skills/denyszhak/pystack-skills/python-fastapi-sa-app-setup)

Your own site

<a href="https://agentmods.dev/skills/denyszhak/pystack-skills/python-fastapi-sa-app-setup"><img src="https://agentmods.dev/badge/skills/denyszhak/pystack-skills/python-fastapi-sa-app-setup/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/denyszhak/pystack-skills/python-fastapi-sa-app-setup"><img src="https://agentmods.dev/badge/skills/denyszhak/pystack-skills/python-fastapi-sa-app-setup.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 173 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,531 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What 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 5.1	$0.00173	$0.04531
Opus 5.5	$0.00069	$0.01812
Sonnet 5.5	$0.00035	$0.00906
Haiku 4.5	$0.00017	$0.00453

Measured 1mo ago against content hash 3d98552f8f3a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

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 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (examples/setup.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/python-fastapi-sa-app-setup/SKILL.md · 509 lines

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/, or app/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.

Read the full file on GitHub · 509 lines

Files

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.

examples/setup.py 2.8 KB runs code

Changes

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.

1mo ago First seen · 509 lines · 173 tokens per session scan A 3d98552f8f3a

Subscribe to this mod's changes

python-fastapi-sa-app-setup is a skill published in the GitHub repository denyszhak/pystack-skills (4 stars, last pushed 5mo ago), licensed MIT. It adds 173 tokens to every session and 4,531 once invoked, about $0.0007 per session on Opus 5.5. 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.

Backend and APIs Languages Python

python-fastapi-sa-app-setup

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

FastAPI + SQLAlchemy app setup

When to use this skill

The canonical layout

Architecture — hexagonal-shaped, not strict

What ships with it

What this file has done since we first saw it

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