The file your AI reads before your code

Every AI tool — Claude Code, Cursor, Windsurf, Cline — reads a special file before it reads your code. It's a plain-text standing instruction set: this is the stack, these are the conventions, these are the things that will break the build.

Most repos either skip it entirely or paste a generic template from GitHub that doesn't know anything about the actual codebase.

The minimum viable version is one line:

This is NOT the [framework] you know. Read the relevant guide in [path] before writing any code.

That alone prevents the majority of "AI confidently uses the wrong API" failures. The post covers the seven sections that earn their keep — in order of how much damage skipping them causes — plus a step-by-step workflow for having Claude draft one without getting 400 lines of filler.