python-app

A set of rules for structuring a Python application, including its reusable code, web routes, data models, configuration, and internal commands.

In plain words
What is it for?
It guides work on FastAPI routes, SQLModels database models, application setup, helper modules, and internal commands.
Why use it?
It keeps different kinds of Python code in predictable places and standardizes how the application starts and configures itself.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/iloveitaly/llm-ide-rules/python-app
Clone the repo
git clone --depth 1 https://github.com/iloveitaly/llm-ide-rules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,296 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.01296
Opus 5 $0.00000 $0.00648
Sonnet 5 $0.00000 $0.00259
Haiku 4.5 $0.00000 $0.00130

Measured yesterday against content hash aef4b52e23b3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python-app 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 yesterday.

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.

.cursor/rules/python-app.mdc · 120 lines

How it starts

The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python App

  • app/lib/ is for code that is not specified to this application and with some effort could extracted into a external package.
  • app/helpers is for larger reusable modules that if they weren't specific to this application, could be extracted into their own package.
  • app/utils are small helper functions that are specific to a particular page or area of the application.
  • app/__init__.py is the entrypoint for the application which is run when anything is executed (fastapi, celery, etc).
    • It primarily runs configure_* commands for any app.configuration.* modules. These modules primary setup API clients, database connections, python language configuration, etc.
    • Also makes sure anything that mutates global state loads early.
  • FastAPI server and routes are specified in app/routes/
  • SQLModels are specified in app/models/
  • Files within app/commands/ should have:
    • Are not designed for CLI execution, but instead are interactor-style internal commands.
    • Should not be used on the queuing system
    • A perform function that is the main entry point for the command.
    • Look at existing commands for examples of how to structure the command.
    • Use TypeID for any parameters that are IDs of models.
  • Files within app/jobs/ should have:
    • Are designed for use on the queuing system.
    • A perform function that is the main entry point for the job.
    • Look at existing jobs for examples of how to structure the job.
    • Use TypeID | str for any parameters that are IDs of models.
  • When referencing a command, use the full-qualified name, e.g. app.commands.transcript_deletion.perform.
  • When queuing a job or performing it in a test, use the full-qualified name, e.g. app.jobs.transcript_deletion.perform.
  • app/cli/ is for scripts or CLI tools that are specific to the application.

Factories

globs: app/factories/**/.py

  • Each model should get it's own file under app/factories/model_name.py
  • ActiveModelFactory (which is a polyfactory subclass) should be used.
  • Use BaseFactory.__faker__ to generate more specific fake data for important fields (used in routes, etc)
  • Prefer slug = BaseFactory.__faker__.unique.slug to slug = Use(lambda: BaseFactory.__faker__.unique.slug())

Read the full file on GitHub · 120 lines

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.

  1. yesterday First seen · 120 lines · 1,296 tokens per session scan A aef4b52e23b3

Subscribe to this mod's changes

python-app is a cursor rule published in the GitHub repository iloveitaly/llm-ide-rules (13 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,296 tokens. 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 2026-08-30.