A sample instruction file CLAUDE.md is available at https://www.dzombak.com/blog/2025/08/getting-good-results-from-claude-code/

However, there is a discussion about the effectiveness of this file for providing context: some consider it useful for AI's long-term memory, while others argue that the AI often ignores its content. From the HN Discussion, further conclusions can be drawn:

• The best results are achieved when the developer spends significant time creating very clear, step-by-step specifications (documents describing exactly how a project should be implemented). This requires more initial effort but allows Claude Code to follow clear instructions and generate more accurate and organized code.
  • Some users employ other AIs (e.g., ChatGPT, Gemini) for brainstorming, creating specifications, critiquing, and refining them before submitting the final document to Claude Code.
  • Integration with code quality tools (husky, lint-staged, commitlint) helps maintain standards.
• Claude Code, despite marketing, does not "think" in a human sense; at any step, it can make strange mistakes or "hallucinate."
  • Since we have a limited context window, it's better to work with Claude Code in small, sequential steps. Ask it to write one function or make one change, then check the result, fix errors, commit, and only then move to the next step.
  • Some successfully use Claude to write unit tests, and then ask it to write minimal code to pass those tests, similar to TDD (Test-Driven Development).
• Some users have noticed that asking Claude to review its own work can be surprisingly fruitful, as it often points out shortcomings itself.

An analysis of how Claude Code works
https://minusx.ai/blog/decoding-claude-code/
The author believes that the CLAUDE.md file is key for conveying user context and preferences (e.g., which folders to ignore, which libraries to use). Its content is sent with each user request. Phrases like IMPORTANT, VERY IMPORTANT, NEVER, and ALWAYS are still effective for preventing undesirable behavior.

Checkpoints for Claude Code
https://claude-checkpoints.com/
The project adds checkpoints to Claude Code, similar to Cursor. The main goal is to ensure that we do not lose correctly generated code by tracking changes and enabling the restoration of previous project states. It includes a visual diff viewer.

Checkpoints are created automatically after Claude completes tasks. It integrates with Claude Desktop via the MCP (Model Context Protocol) protocol.

#claudecode