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Skillpack anatomy

The canonical one-page reference for what a third-party modusbrain skillpack looks like. The reference pack at examples/skillpack-reference/ is the live artifact this page describes; clone its tree and you have a 10/10 starting point.

Tree

modusbrain skillpack init <name> scaffolds this exact tree, pre-filled with stubs that score 10/10 on modusbrain skillpack doctor . --quick immediately. Replace the stubs with real content, run the doctor between edits, and modusbrain skillpack pack produces a deterministic <name>-<version>.tgz ready to publish to the registry.

How the agent uses a scaffolded pack

After modusbrain skillpack scaffold <source> lands the files:
  1. The user’s agent walks skills/*/SKILL.md frontmatter and reads each pack’s triggers: array on startup or per-message.
  2. When a user phrasing matches a trigger, the agent reads that SKILL.md body top-to-bottom as in-context instructions.
  3. modusbrain DISPLAYS runbooks/bootstrap.md once after the scaffold but does NOT auto-execute it. The agent decides whether to walk the steps. This is the codex T1 supply-chain hardening: an auto-walker would let a malicious pack mutate the user’s brain on install, which is how npm postinstall attacks happen.

How the doctor scores a pack

Ten binary dimensions. Each is checked by a pure function in src/core/skillpack/rubric.ts and returns &#123;passed, detail, fix_hint&#125;. The doctor walks them in order and prints the score + per-dimension status + paste-ready fix for every failure. <!— BEGIN auto-generated:rubric —>

Core dimensions (5; must all pass to publish at any tier)

Quality badges (5; earn for tier eligibility)

Generated from src/core/skillpack/rubric.ts by bun run scripts/build-skillpack-anatomy.ts. <!— END auto-generated:rubric —>

Tier eligibility

CLI reference (third-party path)

See also

  • examples/skillpack-reference/ — the live 10/10 reference pack
  • docs/designs/SKILLPACK_REGISTRY_V1_SPEC.md — strategic spec + decisions
  • docs/guides/skillpacks-as-scaffolding.md — v0.36 scaffold/reference model