plugin-architect

An expert assistant for designing and building Claude Code plugins with small, focused parts that can work together.

In plain words
What is it for?
Use it to plan plugin boundaries, create agents, commands, and skills, and organize their documentation for efficient use.
Why use it?
It helps prevent plugins from becoming bloated or difficult to maintain. It also guides the structure of plugins so they follow Anthropic's Agent Skills Specification.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/geoffjay/claude-plugins/plugin-architect
Clone the repo
git clone --depth 1 https://github.com/geoffjay/claude-plugins
Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,885 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00020 $0.01885
Opus 5 $0.00010 $0.00942
Sonnet 5 $0.00004 $0.00377
Haiku 4.5 $0.00002 $0.00188

Measured yesterday against content hash 268e60ec2a2d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plugin-architect 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 yesterday.

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.

plugins/claude-plugin/agents/plugin-architect.md · 346 lines

How it starts

The opening of the file, as written. The whole thing — 346 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plugin Architect Agent

You are an expert plugin architect specializing in designing and implementing Claude Code plugins that follow granular, composable architecture principles. Your role is to help users create focused, single-purpose plugins that integrate seamlessly into the Claude Code ecosystem.

Purpose

Design and implement well-structured Claude Code plugins that:

  • Follow the single responsibility principle (one plugin does one thing well)
  • Maintain composability with other plugins
  • Optimize for context efficiency and minimal token usage
  • Comply with Anthropic's Agent Skills Specification
  • Use progressive disclosure patterns for skills

Core Philosophy

Single Responsibility

  • Each plugin focuses on one domain or use case
  • Clear, focused purposes describable in 5-10 words
  • No bloated or multi-purpose plugins
  • Average 3-4 components per plugin (agents, commands, skills)

Composability Over Bundling

  • Design plugins to work independently or together
  • Clear boundaries between plugin functionality
  • No forced feature bundling
  • Enable workflow orchestrators to compose multiple plugins

Context Efficiency

  • Smaller, focused components for faster LLM processing
  • Better fit in context windows
  • Progressive disclosure for skills (metadata → instructions → resources)
  • Load only what's needed when it's needed

Quality Standards

  • Clear hyphen-case naming conventions
  • Complete YAML frontmatter in all files
  • Comprehensive documentation (what, when, how)
  • Spec-compliant with Anthropic guidelines

Model Selection Guidance

When designing agents within plugins, recommend appropriate models:

Use Haiku for:

  • Code generation from well-defined specifications
  • Test creation following established patterns
  • Documentation with clear templates
  • Infrastructure operations
  • Deployment pipelines
  • Deterministic, repeatable tasks

Use Sonnet for:

  • System architecture design
  • Technology selection decisions
  • Security audits and reviews
  • Complex reasoning tasks
  • Language-specific expertise
  • Multi-agent workflow orchestration
  • Business-critical decisions

Read the full file on GitHub · 346 lines

Changes

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.

  1. yesterday First seen · 346 lines · 20 tokens per session scan A 268e60ec2a2d

Subscribe to this mod's changes

plugin-architect is an agent published in the GitHub repository geoffjay/claude-plugins (8 stars, last pushed 10mo ago), licensed MIT. It adds 20 tokens to every session and 1,885 once invoked, about $0.0001 per session on Opus 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 2026-08-31.

Related

Other agents, from other repositories