dylan: Instructions file for Claude Code

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Core Principles

KISS (Keep It Simple, Stupid): Simplicity should be a key goal in design. Choose straightforward solutions over complex ones whenever possible. Simple solutions are easier to understand, maintain, and debug.

YAGNI (You Aren't Gonna Need It): Avoid building functionality on speculation. Implement features only when they are needed, not when you anticipate they might be useful in the future.

Dependency Inversion: High-level modules should not depend on low-level modules. Both should depend on abstractions. This principle enables flexibility and testability.

Open/Closed Principle: Software entities should be open for extension but closed for modification. Design your systems so that new functionality can be added with minimal changes to existing code.

KEEP early versions of new concepts in the concept_library/ directory very light and simple. we add complexity step by step and only if needed.

Minimal claude code wrappers with 0 to minimal validation.

• Always remember to use uv run when we run scripts
• We never write commit messages, we have a pre-commit hook for that so always commit with git commit nothing more

Example Claude Code Usage

# Simple prompt
claude -p "make a hello.js script that prints hello" --allowedTools "Write" "Edit"

# Using in a script
#!/usr/bin/env -S uv run --script

import subprocess

prompt = """
GIT checkout a NEW branch.

CREATE src/cc_todo/todo.py: a zero library CLI todo app with basic CRUD.

THEN GIT stage, commit and SWITCH back to main.
"""

command = ["claude", "-p", prompt, "--allowedTools", "Edit", "Bash", "Write"]

process = subprocess.run(command, check=True)

print(f"Claude process exited with output: {process.stdout}")

Claude Code Tools Reference

Claude Code has access to various tools. Here are the most commonly used ones:

Tool	Description	Permission Required
Agent	Runs a sub-agent to handle complex, multi-step tasks	No
Bash	Executes shell commands in your environment	Yes
Glob	Finds files based on pattern matching	No
Grep	Searches for patterns in file contents	No
LS	Lists files and directories	No
Read	Reads the contents of files	No
Edit	Makes targeted edits to specific files	Yes
MultiEdit	Makes targeted edits to multiple files	Yes
Write	Creates or overwrites files	Yes
NotebookEdit	Modifies Jupyter notebook cells	Yes
NotebookRead	Reads and displays Jupyter notebook contents	No
WebFetch	Fetches content from a specified URL	Yes
WebSearch	Searches the web for information	Yes
TodoRead	Reads todo files	No
TodoWrite	Writes to todo files	Yes