flake8

flake8 is a cursor rule for Cursor from sanjeed5/awesome-cursor-rules-mdc. It costs 2,447 tokens per session, scanned A, original, CC0-1.0.

Configuration and usage rules for flake8, a Python tool that checks code for style problems, likely bugs, and overly complex functions.

In plain words
What is it for?
Use it to configure repository-wide linting, enforce Python style, check complexity, and integrate with other formatters.
Why use it?
It helps teams catch common mistakes and apply the same code-quality rules across environments.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc).

Good fit Use it to configure repository-wide linting, enforce Python style, check complexity, and integrate with other formatters.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/sanjeed5/awesome-cursor-rules-mdc/flake8
About the project

awesome-cursor-rules-mdc is a generator that creates Cursor MDC rule files from structured library information, using semantic search and language models to gather and organize guidance. Developers use it to produce reusable rules for libraries in Cursor, and the catalogue includes 200 of those rules.

sanjeed5/awesome-cursor-rules-mdc · 3,571 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.

Clone the repo
git clone --depth 1 https://github.com/sanjeed5/awesome-cursor-rules-mdc

Made for: Cursor.

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 flake8

README.md
[![agentmods](https://agentmods.dev/badge/rules/sanjeed5/awesome-cursor-rules-mdc/flake8.svg)](https://agentmods.dev/rules/sanjeed5/awesome-cursor-rules-mdc/flake8)
Your own site
<a href="https://agentmods.dev/rules/sanjeed5/awesome-cursor-rules-mdc/flake8"><img src="https://agentmods.dev/badge/rules/sanjeed5/awesome-cursor-rules-mdc/flake8.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,447 This file is loaded in full into every session.
When invoked 2,447 The same file — it is already loaded in full.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.02447 $0.02447
Opus 5 $0.01223 $0.01223
Sonnet 5 $0.00489 $0.00489
Haiku 4.5 $0.00245 $0.00245

Measured 3d ago against content hash 9cc3254eca00, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

flake8 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 3d 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.

rules-mdc/flake8.mdc · 307 lines

How it starts

The opening of the file, as written. The whole thing — 307 lines — stays where its author put it; the contents beside it link to each section on GitHub.

flake8 Best Practices

flake8 is your essential Python linter, combining pycodestyle, pyflakes, and mccabe complexity checks with a powerful plugin ecosystem. It ensures your codebase adheres to PEP 8, catches common bugs, and maintains high quality. This guide outlines the definitive approach to using flake8 effectively.

1. Configuration: The Single Source of Truth

Always configure flake8 at the repository root using pyproject.toml. This centralizes tooling configuration and ensures consistent behavior across all environments. Avoid .flake8 or setup.cfg for new projects.

✅ GOOD: pyproject.toml

# pyproject.toml
[tool.flake8]
max-line-length = 88 # Black's default, ensures compatibility
extend-ignore = [
    "E203", # Black compatibility: whitespace before ':'
    "W503", # Black compatibility: line break before binary operator
    "E501", # Ignore line length for specific files/legacy (use sparingly)
]
exclude = [
    ".git",
    "__pycache__",
    "build",
    "dist",
    "venv",
    ".venv",
    "*.egg-info",
    "docs", # Exclude documentation build artifacts
    "migrations", # Django migrations often have long lines
]
max-complexity = 10 # Enforce reasonable function complexity
per-file-ignores = [
    "src/legacy_module.py:E501,F401", # Ignore specific errors in legacy files
    "tests/*:S101", # Allow assert for tests (flake8-bandit)
]
# Enable plugins (install them first: pip install flake8-bandit flake8-bugbear flake8-mypy)
enable-extensions = ["B", "B9", "S", "M"] # Bugbear, Bandit, Mypy

❌ BAD: .flake8 (Outdated)

# .flake8 (Avoid this for new projects)
[flake8]
max-line-length = 88
ignore = E203,W503
exclude = .git,__pycache__,build,dist,venv,.venv,*.egg-info,docs,migrations
max-complexity = 10

2. Core Checks: What flake8 Enforces

flake8 combines pycodestyle (PEP 8 style), pyflakes (common bugs), and mccabe (cyclomatic complexity).

a. pycodestyle (E/W codes) - Style Enforcement

Read the full file on GitHub · 307 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. 3d ago First seen · 307 lines · 2,447 tokens per session scan A 9cc3254eca00

Subscribe to this mod's changes

flake8 is a cursor rule published in the GitHub repository sanjeed5/awesome-cursor-rules-mdc (3,571 stars, last pushed 3mo ago), licensed CC0-1.0. It adds 2,447 tokens to every session, about $0.0122 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.