BuilderIO/adding-a-skill

Adding A Skill

Use this for public skill work in this repo. Keep ordinary skill changes in skills/<skill-name>/; keep repo-only guidance under .agents/skills/.

First Decide The Skill Kind

• Plain public skill: a normal folder under skills/<name>/ with SKILL.md. This is the common case. @agent-native/skills discovers these dynamically from BuilderIO/skills@main, so there is no framework registry to edit just to make npx @agent-native/skills@latest add --skill <name> work.
• Instruction-style skill: a plain skill that should optionally write an always-on managed AGENTS.md / CLAUDE.md line when users pass --update-instructions. These need one extra framework change; see "Managed Instruction Blocks" below.
• App-backed / MCP skill: a skill that registers a hosted/local MCP server or uses framework-owned install behavior. These are not plain public skills; inspect ../agent-native/framework/packages/core/src/cli/skills.ts and ../agent-native/framework/packages/skills/src/built-in-apps.ts.
• Plan skills: visual-plan and visual-recap have generated/synced copies between this repo and ../agent-native/framework. Do not treat them like a standalone prose folder.

Plain Public Skill Checklist

1. Create or update skills/<skill-name>/SKILL.md.

2. Add skills/<skill-name>/README.md when the skill should appear in the public catalog. This repo intentionally uses READMEs for public skill pages.

3. If the collection positioning changes, update root README.md, .codex-plugin/plugin.json, .claude-plugin/plugin.json, and package.json descriptions.

4. Keep the skill concise. Put only essential agent instructions in SKILL.md; avoid extra docs unless they directly support the skill.

5. Validate with:

   python3 /Users/steve/.codex/skills/.system/skill-creator/scripts/quick_validate.py skills/<skill-name>
   

6. Smoke-test install discovery locally before claiming the CLI path works:

   node ../agent-native/framework/packages/skills/dist/cli.js add --copy . --skill <skill-name> --client codex --scope project --dry-run --json
   

7. Run npm run check. If it fails on visual-plan / visual-recap sync while the change is unrelated, report that specifically instead of rewriting those skills casually.

@agent-native/skills Install Path

For a plain public skill, the install path is dynamic:

• ../agent-native/framework/packages/skills/src/index.ts sets DEFAULT_SKILLS_SOURCE = "BuilderIO/skills".

• It materializes that repo, reads plugin manifests via resolveSkillsRoot, and discovers every skills/*/SKILL.md through discoverSkills.

• Therefore a new folder under skills/<name>/ is enough for:

  npx @agent-native/skills@latest add --skill <name>
  

No @agent-native/core built-in registry change is needed unless the skill is app-backed or needs custom install behavior.

Managed Instruction Blocks

If the skill should affect AGENTS.md / CLAUDE.md through --update-instructions, update the framework wrapper:

• Add a concise line in ../agent-native/framework/packages/skills/src/index.ts inside instructionContentForSkill(skillName).

• Add or update tests in ../agent-native/framework/packages/skills/src/index.spec.ts.

• Run:

  pnpm --filter @agent-native/skills test -- src/index.spec.ts --runInBand
  

Use this for durable behavior rules like quick-recap, efficient-fable, stay-within-limits, and likely docs-first behavior such as read-the-damn-docs.

App-Backed Or MCP Skills

If a skill needs hosted tools, auth, MCP registration, local-files mode, or special install flags, inspect the framework before editing:

• ../agent-native/framework/packages/core/src/cli/skills.ts
• ../agent-native/framework/packages/skills/src/built-in-apps.ts
• ../agent-native/framework/packages/skills/src/sync-with-core.spec.ts

Keep the core and standalone @agent-native/skills MCP descriptors in sync.

Plan Skill Sync Gotchas

visual-plan and visual-recap are special:

• Framework contains canonical/generated copies and Plan marketplace bundles.
• This repo's npm run check compares those copies and can fail for drift unrelated to a new plain skill.
• When intentionally changing Plan skills, use the framework sync paths instead of hand-editing generated copies. Search the framework for sync-plan-marketplace, sync-workspace-skills, and skills.sync.spec.ts.

Final Reporting

When finishing a skill change, tell the user:

• Which skill files changed.
• Whether @agent-native/skills dynamic install discovery is enough.
• Whether a framework managed-instruction change was added or intentionally left as a follow-up.
• Which validation commands passed or failed, including unrelated Plan sync failures.