python-fastapi-cursorrules-prompt-file

python-fastapi-cursorrules-prompt-file is a cursor rule for coding agents from PatrickJS/awesome-cursorrules. It costs 245 tokens per session, scanned A, original, CC0-1.0.

A set of coding guidelines for Python FastAPI services, covering routes, validation, dependency sharing, asynchronous work, security, and tests.

In plain words
What is it for?
Use it when building FastAPI routes, authentication, background tasks, OpenAPI-based APIs, or unit and integration tests.
Why use it?
It provides a consistent structure for API projects and helps prevent mistakes in validation, error handling, and service organization.

Cursor rule

About the project

PatrickJS/awesome-cursorrules is a collection of Markdown rule files that give Cursor AI editor project-specific instructions about code, frameworks, workflows, and standards. Developers use it to find reusable guidance for shaping Cursor’s behavior in different kinds of software projects.

PatrickJS/awesome-cursorrules · 40,725 stars · on GitHub

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/patrickjs/awesome-cursorrules/python-fastapi-cursorrules-prompt-file
Clone the repo
git clone --depth 1 https://github.com/PatrickJS/awesome-cursorrules

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.

agentmods badge for python-fastapi-cursorrules-prompt-file

README.md
[![agentmods](https://agentmods.dev/badge/rules/patrickjs/awesome-cursorrules/python-fastapi-cursorrules-prompt-file.svg)](https://agentmods.dev/rules/patrickjs/awesome-cursorrules/python-fastapi-cursorrules-prompt-file)
Your own site
<a href="https://agentmods.dev/rules/patrickjs/awesome-cursorrules/python-fastapi-cursorrules-prompt-file"><img src="https://agentmods.dev/badge/rules/patrickjs/awesome-cursorrules/python-fastapi-cursorrules-prompt-file.svg" alt="Measured on agentmods" height="20"></a>
Per session 245 This file is loaded in full into every session.
When invoked 245 The same file — it is already loaded in full.
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 $0.00245 $0.00245
Opus 5 $0.00122 $0.00122
Sonnet 5 $0.00049 $0.00049
Haiku 4.5 $0.00024 $0.00024

Measured yesterday against content hash 1ea60da5030b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python-fastapi-cursorrules-prompt-file 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.

rules/python-fastapi-cursorrules-prompt-file.mdc · 43 lines

What it actually says

Python FastAPI .cursorrules

FastAPI best practices

fastapi_best_practices = [ "Use Pydantic models for request and response schemas", "Implement dependency injection for shared resources", "Utilize async/await for non-blocking operations", "Use path operations decorators (@app.get, @app.post, etc.)", "Implement proper error handling with HTTPException", "Use FastAPI's built-in OpenAPI and JSON Schema support", ]

Folder structure

folder_structure = """ app/ main.py models/ schemas/ routers/ dependencies/ services/ tests/ """

Additional instructions

additional_instructions = """

  1. Use type hints for all function parameters and return values
  2. Implement proper input validation using Pydantic
  3. Use FastAPI's background tasks for long-running operations
  4. Implement proper CORS handling
  5. Use FastAPI's security utilities for authentication
  6. Follow PEP 8 style guide for Python code
  7. Implement comprehensive unit and integration tests """
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 · 43 lines · 245 tokens per session scan A 1ea60da5030b

Subscribe to this mod's changes

python-fastapi-cursorrules-prompt-file is a cursor rule published in the GitHub repository PatrickJS/awesome-cursorrules (40,725 stars, last pushed 3mo ago), licensed CC0-1.0. It adds 245 tokens to every session, about $0.0012 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 2026-09-03.