Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add MadAppGang/claude-code/plugin install devWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/madappgang/claude-code/plugin-sdk-patterns)<a href="https://agentmods.dev/skills/madappgang/claude-code/plugin-sdk-patterns"><img src="https://agentmods.dev/badge/skills/madappgang/claude-code/plugin-sdk-patterns/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/madappgang/claude-code/plugin-sdk-patterns"><img src="https://agentmods.dev/badge/skills/madappgang/claude-code/plugin-sdk-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00067 | $0.06474 |
| Opus 5.5 | $0.00027 | $0.02590 |
| Sonnet 5.5 | $0.00013 | $0.01295 |
| Haiku 4.5 | $0.00007 | $0.00647 |
Grade A, and why
plugin-sdk-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- plugin-sdk-patterns — 91% identical, 1,172 lines differ
How it starts
The opening of the file, as written. The whole thing — 1,032 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Plugin SDK Patterns
Overview
This skill documents unified patterns and templates for creating consistent, professional Claude Code plugins. Following these patterns ensures your plugins integrate seamlessly with Claude Code's ecosystem and provide a predictable developer experience.
Why Standardized Plugin Patterns Matter
Consistency: Users expect the same structure across all plugins, making them easier to learn and use.
Maintainability: Standard patterns make it easier to update and extend plugins over time.
Discoverability: Consistent naming and structure helps users find what they need quickly.
Quality: Templates enforce best practices and reduce common errors.
Collaboration: Teams can work together more effectively with shared conventions.
The Builder Pattern Approach
Claude Code plugins follow a builder pattern where components (skills, commands, agents, hooks) are modular and composable:
- Each component is self-contained in its own directory
- Components declare their metadata via frontmatter
- The plugin.json manifest ties everything together
- Hooks provide lifecycle integration points
Plugin Anatomy
my-plugin/
├── plugin.json # Plugin manifest (required)
├── README.md # User-facing documentation
├── DEPENDENCIES.md # External dependencies (if any)
├── skills/ # Reusable knowledge modules
│ ├── skill-one/
│ │ └── SKILL.md
│ └── skill-two/
│ └── SKILL.md
├── commands/ # Interactive commands
│ ├── command-one.md
│ └── command-two.md
├── agents/ # Autonomous agents
│ ├── agent-one.md
│ └── agent-two.md
├── hooks/ # Lifecycle hooks (optional)
│ └── hooks.json
├── mcp-servers/ # MCP server configurations (optional)
│ └── servers.json
└── examples/ # Example workflows (optional)
└── example-workflow.md
Plugin Manifest (plugin.json) Template
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 1,032 lines · 67 tokens per session scan A f40902424f36
plugin-sdk-patterns is a skill published in the GitHub repository MadAppGang/claude-code (286 stars, last pushed 7mo ago), licensed MIT. It adds 67 tokens to every session and 6,474 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
plugin-system
Generic plugin system for Python applications. Auto-discovery, validation, fault tolerance. Zero dependencies (Python stdlib only).
architecture-paradigms
Selects and routes to the right architecture paradigm. Use when choosing patterns for a new system or comparing trade-offs before making architecture decisions.
shared-patterns
Provide reusable patterns for validation, error handling, scaffolding. Use for skill consistency.
architecture-paradigm-microkernel
Applies microkernel architecture with minimal core and plugin extensibility. Use when building platforms where third parties extend core functionality.
commands-create-slash-command
Create or edit reusable Agent Zero /commands with YAML and text/Python templates.
lightcad
Use when building or extending a desktop CAD/BIM application with the open-source FeiYang LightCAD platform — plugin development, custom elements, DWG/DXF I/O, 2D drafting and 3D/BIM modeling on C#/.NET. LightCAD (FeiYang Integrated Design Platform) is a C# CAD system integrating 2D design, 3D design, and BIM.