I think it makes sense to include in source control, just as it’s pretty typical to include documentation (such as a readme file) in source control. CLAUDE.md is really just project documentation.
I’ve always struggled with what should be in Claude.md that doesn’t belong in readme.md or a similar supporting file.
I tend to include a well documented justfile, so between the readme and that common commands are covered. If there’s a style guide it should be its own file, or summarized in the readme.
If Claude is making errors I tend to just update my global Claude file, but I haven’t updated it in 6 months — only to disable Claude signatures on generated commit messages.
README.md should be for humans CLAUDE.md for machines.
Most agents use README as a storage for EVERYTHING related to the project by default, which is annoying for humans who just want to figure out a) what the thing does b) how to install it. Then you start reading and there's some intricate documentation on how data flows through the application etc.
If you're only working on your personal projects with no collaborators, just a global claude file is just fine. Per-project files are more for things that are specific to that project.
If you're committed to Anthropic at an organizational level, there's no point to have a 'standard' AGENTS.md with a CLAUDE.md layer on top. Just commit the CLAUDE.md.
I tend to include a well documented justfile, so between the readme and that common commands are covered. If there’s a style guide it should be its own file, or summarized in the readme.
If Claude is making errors I tend to just update my global Claude file, but I haven’t updated it in 6 months — only to disable Claude signatures on generated commit messages.