The Solo CLAUDE.md
A single CLAUDE.md file under 200 lines with project context, commands, and conventions. The Anthropic-recommended starting point.
Description
The simplest effective setup for Claude Code. Anthropic's own docs recommend keeping CLAUDE.md concise and human-readable — ideally under 200 lines. HumanLayer's production CLAUDE.md is just 60 lines. The key insight from research: frontier LLMs can reliably follow ~150–200 instructions total, and Claude Code's system prompt already uses ~50 of those. Every line you add to CLAUDE.md competes for attention. Start with what Claude gets wrong, not a comprehensive manual. Use /init to generate a starter, then prune aggressively. If Claude keeps ignoring a rule, your file is probably too long.
Who is this for
Solo developers or small teams starting with Claude Code. Best for projects where one person holds the full context.
Why files are split this way
Everything fits in a single file because solo developers can hold full project context. Splitting into multiple files creates maintenance overhead without benefit at this scale. If the file exceeds 200 lines, that is the signal to graduate to a more structured pattern.
What changed from the previous setup
No AI configuration at all — Claude Code was used with its defaults and no project-specific context.
Related patterns
Universal AGENT.md with Symlinks
One AGENT.md file as the single source of truth, with symlinks to CLAUDE.md, .cursorrules, .windsurfrules, and copilot-instructions.md.
Spec-Driven AI Development
Separates what to build (SPEC.md) from how the AI should work (CLAUDE.md). Specs define features and constraints, CLAUDE.md defines workflow and conventions.
Multi-Editor Frontend Setup
Frontend-optimized AI config covering design system tokens, component conventions, and testing patterns across Cursor, Copilot, and Claude Code simultaneously.