尽量不要超过200行

CLAUDE.md files are loaded into the context window at the start of every session, consuming tokens alongside your conversation. The context window visualization shows where CLAUDE.md loads relative to the rest of the startup context. Because they’re context rather than enforced configuration, how you write instructions affects how reliably Claude follows them. Specific, concise, well-structured instructions work best.
Size: target under 200 lines per CLAUDE.md file. Longer files consume more context and reduce adherence. If your instructions are growing large, use path-scoped rules so instructions load only when Claude works with matching files. You can also split content into imports for organization, though imported files still load and enter the context window at launch.
Structure: use markdown headers and bullets to group related instructions. Claude scans structure the same way readers do: organized sections are easier to follow than dense paragraphs.
Specificity: write instructions that are concrete enough to verify. For example:
“Use 2-space indentation” instead of “Format code properly”
“Run npm test before committing” instead of “Test your changes”
“API handlers live in src/api/handlers/” instead of “Keep files organized”
Consistency: if two rules contradict each other, Claude may pick one arbitrarily. Review your CLAUDE.md files, nested CLAUDE.md files in subdirectories, and .claude/rules/ periodically to remove outdated or conflicting instructions. In monorepos, use claudeMdExcludes to skip CLAUDE.md files from other teams that aren’t relevant to your work.
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Import additional files
CLAUDE.md files can import additional files using @path/to/import syntax. Imported files are expanded and loaded into context at launch alongside the CLAUDE.md that references them.
Both relative and absolute paths are allowed. Relative paths resolve relative to the file containing the import, not the working directory. Imported files can recursively import other files, with a maximum depth of four hops.
Import parsing skips Markdown code spans and fenced code blocks. To mention a path in your CLAUDE.md without importing it, wrap it in backticks: writing @README keeps the text literal, while @README outside backticks imports the file.
To pull in a README, package.json, and a workflow guide, reference them with @ syntax anywhere in your CLAUDE.md:
See @README for project overview and @package.json for available npm commands for this project.

Additional Instructions

• git workflow @docs/git-instructions.md For private per-project preferences that shouldn’t be checked into version control, create a CLAUDE.local.md at the project root. It loads alongside CLAUDE.md and is treated the same way. Add CLAUDE.local.md to your .gitignore so it isn’t committed; running /init and choosing the personal option does this for you. If you work across multiple git worktrees of the same repository, a gitignored CLAUDE.local.md only exists in the worktree where you created it. To share personal instructions across worktrees, import a file from your home directory instead:

Individual Preferences

• @~/.claude/my-project-instructions.md The first time Claude Code encounters external imports in a project, it shows an approval dialog listing the files. If you decline, the imports stay disabled and the dialog does not appear again. For a more structured approach to organizing instructions, see .claude/rules/. ​ AGENTS.md Claude Code reads CLAUDE.md, not AGENTS.md. If your repository already uses AGENTS.md for other coding agents, create a CLAUDE.md that imports it so both tools read the same instructions without duplicating them. You can also add Claude-specific instructions below the import. Claude loads the imported file at session start, then appends the rest: CLAUDE.md @AGENTS.md

Claude Code

Use plan mode for changes under src/billing/.
A symlink also works if you don’t need to add Claude-specific content:
ln -s AGENTS.md CLAUDE.md
On Windows, creating a symlink requires Administrator privileges or Developer Mode, so use the @AGENTS.md import instead.
Running /init in a repo that already has an AGENTS.md reads it and incorporates the relevant parts into the generated CLAUDE.md. It also reads other tool configs like .cursorrules, .devin/rules/, and .windsurfrules.