Transforms external repositories (CLIs, libraries, MCP servers) into Claude Code plugins with skills. Use when "build plugin for", "create skills for CLI", "package as plugin", "repo to plugin", or "turn into plugin" are mentioned.
Resources
1Install
npx skillscat add outfitter-dev/agents/plugin-engineer Install via the SkillsCat registry.
Plugin Engineer
Transform external repositories into Claude Code plugins.
External Repo → Research → Recon → Patterns → Codify → Author → Package → Audit → PluginSteps
- Clarify target repo and plugin goals
- Load the
outfitter:researchskill for external discovery (docs, APIs, community patterns) - Load the
outfitter:codebase-reconskill for internal analysis of target repo - Load the
outfitter:patternsskill to extract repeatable patterns worth automating - Load the
outfitter:codifyskill to map patterns to component types - Author components using
outfitter:skills-devoroutfitter:claude-skills - Load the
outfitter:claude-pluginsskill to package into distributable plugin - Delegate by loading the
outfitter:claude-plugin-auditskill for validation
- Turning a CLI tool into a Claude Code plugin
- Creating skills that wrap an external library or API
- Building plugin companions for MCP servers
- Extracting automation opportunities from a third-party repo
- Packaging workflow patterns around external tools
NOT for: plugins from scratch (use claude-plugins), single-skill creation (use skills-dev), existing Claude Code plugins (use claude-plugin-audit)
Artifact Structure
Track progress with artifacts in artifacts/plugin-engineer/:
artifacts/plugin-engineer/
├── discovery.md # Research output (docs, APIs, community patterns)
├── recon.md # Codebase analysis (structure, conventions, key files)
├── patterns.md # Extracted patterns with automation value
├── mapping.md # Pattern → component mapping decisions
├── components/ # Authored skills, agents, hooks, commands
│ ├── skill-1/
│ ├── skill-2/
│ └── ...
└── audit.md # Plugin validation resultsQuick Mode
For simple repos (single-purpose CLI, small API wrapper):
- Skip stages 3-4 — go direct from recon to authoring
- Create 1-2 skills covering primary use cases
- Package immediately
Trigger: User says "quick", repo has < 5 main commands, or clear single purpose.
Stages
Load the maintain-tasks skill for stage tracking. Stages advance only.
| Stage | Skill | activeForm |
|---|---|---|
| 1. Discovery | outfitter:research |
"Researching external docs" |
| 2. Recon | outfitter:codebase-recon |
"Analyzing target repo" |
| 3. Patterns | outfitter:patterns |
"Extracting patterns" |
| 4. Mapping | outfitter:codify |
"Mapping to components" |
| 5. Authoring | outfitter:skills-dev |
"Creating components" |
| 6. Packaging | outfitter:claude-plugins |
"Packaging plugin" |
| 7. Audit | outfitter:claude-plugin-audit |
"Validating plugin" |
Stage 1: Discovery
Load outfitter:research skill. Gather external docs, community patterns, pain points.
See stage-1-discovery.md for details.
Stage 2: Recon
Load outfitter:codebase-recon skill. Analyze structure, API surface, conventions.
See stage-2-recon.md for details.
Stage 3: Patterns
Load outfitter:patterns skill. Extract workflows, command sequences, decision points.
See stage-3-patterns.md for details.
Stage 4: Mapping
Load outfitter:codify skill. Map patterns to component types (skill, command, hook, agent).
See stage-4-mapping.md for details.
Stage 5: Authoring
Load appropriate skill per component type. Create in artifacts/plugin-engineer/components/.
See stage-5-authoring.md for details.
Stage 6: Packaging
Load outfitter:claude-plugins skill. Create plugin structure with manifest and README.
Ask: "Do you have an existing marketplace to add this plugin to?" If yes, prepare the marketplace entry.
See stage-6-packaging.md for details.
Stage 7: Audit
Delegate by loading outfitter:claude-plugin-audit skill. Validate before distribution.
See stage-7-audit.md for details.
Key decisions during engineering process:
Which patterns to automate?
- High frequency + medium complexity = best ROI
- Low frequency + high complexity = consider if audience is technical
- One-off patterns = skip
Skills vs Commands?
- Multi-step, needs guidance → Skill
- Quick action, obvious usage → Command
- User entry point to skill → Both (command loads skill)
Include agents?
- Only for complex repos with orchestration needs
- Most plugins don't need custom agents
- Consider if existing agents (analyst, engineer) suffice
Quick mode vs full pipeline?
- Single-purpose tool → Quick mode
- Complex tool with many features → Full pipeline
- Unclear → Start with recon, decide after
ALWAYS:
- Start with discovery before touching code
- Track artifacts at each stage
- Validate patterns have 3+ use cases before creating components
- Use existing skills for authoring (don't reinvent)
- Run audit before declaring complete
NEVER:
- Skip recon stage (even for familiar repos)
- Create agents without clear orchestration need
- Package without audit validation
- Over-engineer (simpler plugin > feature-complete plugin)
Stage guides:
- overview.md — quick reference
- stage-1-discovery.md — external research
- stage-2-recon.md — codebase analysis
- stage-3-patterns.md — pattern extraction
- stage-4-mapping.md — component selection
- stage-5-authoring.md — creating components
- stage-6-packaging.md — plugin structure
- stage-7-audit.md — validation
- repo-types.md — CLI vs Library vs MCP patterns
Skills loaded:
outfitter:research— external discovery methodologyoutfitter:codebase-recon— repo analysis approachoutfitter:patterns— pattern extractionoutfitter:codify— pattern-to-component mappingoutfitter:claude-plugins— plugin packaging