rein: Skill for Claude Code

rein-inspect

rein-inspect is a documentation-first reconnaissance skill. Its job is to understand a codebase carefully and maintain a durable map of that understanding under .rein/codebase/.

The skill produces:

• .rein/codebase/MAP.md
• topical companion docs under .rein/codebase/

It observes and records. It does not recommend fixes.

When to Use

Use this skill when:

• you need a high-signal map of an unfamiliar repo or subsystem
• a project has grown beyond what one README can orient cleanly
• you want durable codebase reference docs for future agents or humans
• repeated work keeps re-discovering the same architecture or boundary facts

Do Not Use

Do not use this skill when:

• the user asked for implementation, refactoring, or repair rather than inspection
• the repo already has a maintained codebase map that only needs a tiny manual update
• you only need a quick one-turn explanation instead of persistent docs
• you are not prepared to read enough of the codebase to support the claims you write

Operating Boundaries

• Read before writing.
• Follow actual code evidence, not guessed architecture.
• Keep output rooted at .rein/codebase/.
• Preserve and update existing docs in place.
• Add a new topical doc only when the inspected codebase reveals a real uncovered area.
• Record observations and evidence-backed inferred risks.
• Do not propose fixes, refactors, or migrations.
• Do not edit application code as part of this skill unless the user explicitly asked for code changes outside the inspection pass.

Output Contract

Always maintain this docs tree:

.rein/
  codebase/
    MAP.md
    <topic>.md
    <topic>.md

MAP.md is the entrypoint. It should explain the major sections of the codebase and link to the topical docs.

Topical docs should be created from discovered domains, not a hard-coded list. Examples might include:

• architecture.md
• frontend.md
• backend.md
• data-flow.md
• testing.md
• tooling.md

The exact set depends on the repo.