core-files-documentation

A documentation rule for keeping a file called memory-bank/coreFiles.md up to date. The file records what important Python files in src/ contain, including their classes and key methods.

In plain words
What is it for?
Use it in Python projects to document core source files whenever they are created or changed, while leaving entry points and tests out.
Why use it?
It reduces the time needed to understand an unfamiliar codebase. Developers can use one document to find important files and learn their responsibilities.

Cursor rule

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/barisercan/cursorrules/core-files-documentation
Clone the repo
git clone --depth 1 https://github.com/barisercan/cursorrules
Per session 629 This file is loaded in full into every session.
When invoked 629 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 $0.00629 $0.00629
Opus 5 $0.00315 $0.00315
Sonnet 5 $0.00126 $0.00126
Haiku 4.5 $0.00063 $0.00063

Measured 2d ago against content hash e7a6c3b166fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

core-files-documentation 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.

core-files-documentation.mdc · 86 lines

What it actually says


description: Maintain core files documentation in memory-bank for easy codebase navigation globs: "**/*" alwaysApply: true

Core Files Documentation Rule

Automatically maintain documentation of core source files in memory-bank/coreFiles.md.

actions:

  • type: enforce message: | CORE FILES DOCUMENTATION PROTOCOL

    REQUIRED: Update memory-bank/coreFiles.md when core source files change

    TARGET FILES: All .py files under src/ EXCEPT:

    • main.py files
    • init.py files
    • Test files (tests/ directory)

    DOCUMENTATION FORMAT:

    ## path/to/filename.py
    **Description**: Brief explanation of file purpose
    **Classes**:
      - ClassName (line X): What this class does
      - AnotherClass (line Y): Purpose and responsibility
    **Notable Methods**:
      - method_name() (line Z): Key functionality description
      - important_method() (line W): What it accomplishes
    **Important Notes**:
      - Key implementation details
      - Performance characteristics
      - API patterns or special behaviors
      - Known limitations or warnings
    

    UPDATE TRIGGERS:

    • New core file created under src/
    • Existing core file modified (classes/methods added/changed)
    • User requests "update core files" or similar
    • Significant refactoring or architectural changes

    MAINTENANCE RULES:

    • Keep documentation under 20 lines per file
    • Focus on classes, key methods, and important notes
    • Include line numbers for easy navigation
    • Update when file structure changes significantly
    • Remove entries when files are deleted

examples:

  • input: "New file: src/trading/strategy_engine.py" output: "Add documentation entry to memory-bank/coreFiles.md"

  • input: "Modified: src/market_data_collector/binance/rest/symbol_fetcher.py" output: "Update existing entry with new classes/methods"

  • input: "update core files documentation" output: "Review all src/ files and update coreFiles.md"

metadata: priority: high version: 1.0 enforcement: automatic dependencies: ["memory-bank"]

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. 2d ago First seen · 86 lines · 629 tokens per session scan A e7a6c3b166fe

Subscribe to this mod's changes

core-files-documentation is a cursor rule published in the GitHub repository barisercan/cursorrules (35 stars, last pushed 1y ago), licensed MIT. It adds 629 tokens to every session, about $0.0031 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 2026-08-30.