feat(plugin): mcp-server-dev — close remote-path dead-end with deploy/test/connect guidance

The remote HTTP path (starred default) previously ended at localhost:3000
with no next steps. Adds CF Workers deploy reference, Inspector test
commands, user-connection guide, and a versions ledger. Swaps the
build-mcp-app scaffold from stdio to streamable-HTTP to match the
remote-first stance.

.claude-plugin/marketplace.json

@@ -769,7 +769,7 @@
       "homepage": "https://planetscale.com/"
     },
     {
-      "name": "rc",
+      "name": "revenuecat",
       "description": "Configure RevenueCat projects, apps, products, entitlements, and offerings directly from Claude Code. Manage your in-app purchase backend without leaving your development workflow.",
       "category": "development",
       "source": {
@@ -829,7 +829,7 @@
       "homepage": "https://www.sanity.io"
     },
     {
-      "name": "data",
+      "name": "astronomer-data-agents",
       "description": "Data engineering for Apache Airflow and Astronomer. Author DAGs with best practices, debug pipeline failures, trace data lineage, profile tables, migrate Airflow 2 to 3, and manage local and cloud deployments.",
       "category": "development",
       "source": {
@@ -1039,6 +1039,147 @@
       },
       "homepage": "https://github.com/intercom/claude-plugin-external"
     },
+    {
+      "name": "zoominfo",
+      "description": "Search companies and contacts, enrich leads, find lookalikes, and get AI-ranked contact recommendations. Pre-built skills chain multiple ZoomInfo tools into complete B2B sales workflows.",
+      "category": "productivity",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/Zoominfo/zoominfo-mcp-plugin.git",
+        "sha": "0705316ef8a2d0c64f81e50d4612ccc6a74edf03"
+      },
+      "homepage": "https://zoominfo.com"
+    },
+    {
+      "name": "cockroachdb",
+      "description": "CockroachDB plugin for Claude Code — explore schemas, write optimized SQL, debug queries, and manage distributed database clusters directly from your AI coding agent.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/cockroachdb/claude-plugin.git",
+        "sha": "a54566e03c852567589ef85bb449d1e4de229667"
+      },
+      "homepage": "https://github.com/cockroachdb/claude-plugin"
+    },
+    {
+      "name": "prisma",
+      "description": "Prisma MCP integration for Postgres database management, schema migrations, SQL queries, and connection string management. Provision Prisma Postgres databases, run migrations, and interact with your data directly.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/prisma/claude-plugin.git",
+        "sha": "815dbc4a045a29e3b81510ba0e3ab806f1baaf0e"
+      },
+      "homepage": "https://prisma.io"
+    },
+    {
+      "name": "fastly-agent-toolkit",
+      "description": "Fastly development tools and platform skills",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/fastly/fastly-agent-toolkit.git",
+        "sha": "d9ba949011e725be55cae11acc741aa1f1f393d3"
+      },
+      "homepage": "https://github.com/fastly/fastly-agent-toolkit/blob/main/README.md"
+    },
+    {
+      "name": "cloudinary",
+      "description": "Use Cloudinary directly in Claude. Manage assets, apply transformations, optimize media, and more through natural conversation.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/cloudinary-devs/cloudinary-plugin.git",
+        "sha": "137c5d7acd9c3f10e80cd2a400486971e1664f31"
+      },
+      "homepage": "https://cloudinary.com/documentation"
+    },
+    {
+      "name": "wordpress.com",
+      "description": "Uses Claude Code to create and edit WordPress sites with WordPress Studio before deploying changes to your WordPress.com site.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/Automattic/claude-code-wordpress.com.git",
+        "sha": "e4d23c3bffdcdb7f70134ab6a1a110258ff75cfd"
+      },
+      "homepage": "https://developer.wordpress.com/wordpress-com-claude-code-plugin/"
+    },
+    {
+      "name": "nimble",
+      "description": "Nimble web data toolkit — search, extract, map, crawl the web and work with structured data agents",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/Nimbleway/agent-skills.git",
+        "sha": "cf391e95bd8ac009e3641f172434a1d130dde7fe"
+      },
+      "homepage": "https://docs.nimbleway.com/integrations/agent-skills/plugin-installation"
+    },
+    {
+      "name": "followrabbit",
+      "description": "Cloud cost optimization for GCP infrastructure. Review changes for cost impact and auto-apply savings recommendations using the followrabbit CLI.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/followrabbit-ai/awesome-rabbit.git",
+        "sha": "f59ec3d1f6337a6ed825ef06836a221ed3d2ffb0"
+      },
+      "homepage": "https://subscriptions.agentic.followrabbit.ai/"
+    },
+    {
+      "name": "brightdata-plugin",
+      "description": "Web scraping, Google search, structured data extraction, and MCP server integration powered by Bright Data. Includes 7 skills: scrape any webpage as markdown (with bot detection/CAPTCHA bypass), search Google with structured JSON results, extract data from 40+ websites (Amazon, LinkedIn, Instagram, TikTok, YouTube, and more), orchestrate Bright Data's 60+ MCP tools, built-in best practices for Web Unlocker, SERP API, Web Scraper API, and Browser API, Python SDK best practices for the brightda...",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/brightdata/skills.git",
+        "sha": "e671da495f7ec0ed6be5e9fa71e260f886a1dc36"
+      },
+      "homepage": "https://docs.brightdata.com"
+    },
+    {
+      "name": "fiftyone",
+      "description": "Build high-quality datasets and computer vision models. Visualize datasets, analyze models, find duplicates, run inference, evaluate predictions, and develop custom plugins.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/voxel51/fiftyone-skills.git",
+        "sha": "593e0553fc9fd94db52386ada2c9e2074a6ecf89"
+      },
+      "homepage": "https://docs.voxel51.com/"
+    },
+    {
+      "name": "data-engineering",
+      "description": "Data engineering plugin - warehouse exploration, pipeline authoring, Airflow integration",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/astronomer/agents.git",
+        "sha": "85d6053b1e21724f9cefb1e3f5219bd54fc77224"
+      },
+      "homepage": "https://github.com/astronomer/agents"
+    },
+    {
+      "name": "goodmem",
+      "description": "GoodMem memory infrastructure for AI agents. Use Python SDK skills to write code that manages embedders, spaces, and memories, or use MCP tools to perform GoodMem operations directly via natural language.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/PAIR-Systems-Inc/goodmem-claude-code-plugin.git",
+        "sha": "215568baf203887b5d7f8245e0503dd4a81336c2"
+      },
+      "homepage": "https://github.com/PAIR-Systems-Inc/goodmem-claude-code-plugin"
+    },
+    {
+      "name": "elixir-ls-lsp",
+      "description": "Elixir language server (ElixirLS) for Claude Code — provides code intelligence and diagnostics for .ex, .exs, and .heex files.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/MikaelFangel/claude-elixir-ls-lsp.git",
+        "sha": "806a6eeeb88b9a306a59b3212a1d5d88aa5c70af"
+      },
+      "homepage": "https://elixir-lsp.github.io/elixir-ls/"
+    },
+    {
+      "name": "optibot",
+      "description": "AI code review that catches production-breaking bugs, business logic issues, and security vulnerabilities — directly in Claude Code.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/Optimal-AI/optibot-skill.git",
+        "sha": "981db1f630c3116d7df0a71e5967af55b08e813c"
+      },
+      "homepage": "https://getoptimal.ai"
+    },
     {
       "name": "firetiger",
       "description": "Claude Code plugin for Firetiger observability workflows and MCP-powered investigations.",
@@ -1048,6 +1189,141 @@
         "sha": "51421ce20adc7c30eb014e6847c7087ed34cb879"
       },
       "homepage": "https://www.firetiger.com/"
+    },
+    {
+      "name": "opsera-devsecops",
+      "description": "Opsera DevSecOps Agent — AI-powered architecture analysis, security scanning, compliance auditing, and SQL security for your codebase. Free trial included.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/opsera-agents/opsera-devsecops.git",
+        "sha": "e797228134ee7d3199594eb0ee5a659df40c91da"
+      },
+      "homepage": "https://opsera.ai/agents"
+    },
+    {
+      "name": "searchfit-seo",
+      "description": "Free AI-powered SEO toolkit — audit websites, plan content strategy, optimize pages, generate schema markup, cluster keywords, and track AI visibility. Works with any website or codebase.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/searchfit/searchfit-seo.git",
+        "sha": "ced1a99a9fadfc10aa573a05829fc1bd357d4e4c"
+      },
+      "homepage": "https://searchfit.ai"
+    },
+    {
+      "name": "aikido",
+      "description": "Aikido Security scanning for Claude Code — SAST, secrets, and IaC vulnerability detection powered by the Aikido MCP server.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/AikidoSec/aikido-claude-plugin.git",
+        "sha": "d7fa8b8e192680d9a26c1a5dcaead7cf5cdb7139"
+      },
+      "homepage": "https://github.com/AikidoSec/aikido-claude-plugin"
+    },
+    {
+      "name": "helius",
+      "description": "Build on Solana with Helius — live blockchain tools, expert coding patterns, and autonomous account signup",
+      "source": {
+        "source": "git-subdir",
+        "url": "helius-labs/core-ai",
+        "path": "helius-plugin",
+        "ref": "main",
+        "sha": "05ea4d1128d46618266bbcc23a5e7019c57be0d6"
+      },
+      "homepage": "https://www.helius.dev/docs"
+    },
+    {
+      "name": "atlan",
+      "description": "Atlan data catalog plugin for Claude Code. Search, explore, govern, and manage your data assets through natural language. Powered by the Atlan MCP server with semantic search, lineage traversal, glossary management, data quality rules, and more.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/atlanhq/agent-toolkit.git",
+        "sha": "acdf284da6aa98b14f8dad90a9827006d8df425c"
+      },
+      "homepage": "https://docs.atlan.com/"
+    },
+    {
+      "name": "ai-firstify",
+      "description": "AI-first project auditor and re-engineer based on the 9 design principles and 7 design patterns from the TechWolf AI-First Bootcamp",
+      "source": {
+        "source": "git-subdir",
+        "url": "techwolf-ai/ai-first-toolkit",
+        "path": "plugins/ai-firstify",
+        "ref": "main",
+        "sha": "7f18e11d694b9ae62ea3009fbbc175f08ae913df"
+      },
+      "homepage": "https://ai-first.techwolf.ai"
+    },
+    {
+      "name": "product-tracking-skills",
+      "description": "AI agent skills that make SaaS products data-ready for product analytics — from codebase scan to tracking plan to working instrumentation code.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/Accoil/product-tracking-skills.git",
+        "sha": "341f8cf47d8b5dda550222152377c50aee34c723"
+      },
+      "homepage": "https://www.accoil.com/product-tracking"
+    },
+    {
+      "name": "nightvision",
+      "description": "Skills for working with NightVision, a DAST and API Discovery platform that finds exploitable vulnerabilities in web applications and REST APIs",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/nvsecurity/nightvision-skills.git",
+        "sha": "7d7a3f342bbf4d02b6e012279800cf91ff0c1c97"
+      },
+      "homepage": "https://github.com/nvsecurity/nightvision-skills"
+    },
+    {
+      "name": "postiz",
+      "description": "Social media automation CLI for scheduling posts, managing integrations, uploading media, and tracking analytics across 28+ platforms including X, LinkedIn, Reddit, YouTube, TikTok, Instagram, and more",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/gitroomhq/postiz-agent.git",
+        "sha": "c5d1bf5f7e95a71e230fc19ae2150ddd9c549854"
+      },
+      "homepage": "https://postiz.com/agent"
+    },
+    {
+      "name": "voila-api",
+      "description": "Definitive guide for the Voila API. Covers shipment creation (Manual/Smart Shipping), real-time tracking, detailed history, manifesting, collections, webhooks, and third-party integrations (Sorted, Peoplevox, Mintsoft, Veeqo, JD).",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/TSedmanDC/Voila-API-Skill.git",
+        "sha": "b9cfcb860cb5ae4ece57d67422a6cdd92ef96739"
+      },
+      "homepage": "https://github.com/TSedmanDC/Voila-API-Skill"
+    },
+    {
+      "name": "remember",
+      "description": "Continuous memory for Claude Code. Extracts, summarizes, and compresses conversations into tiered daily logs. Claude remembers what you did yesterday.",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/Digital-Process-Tools/claude-remember.git",
+        "sha": "779ab61d8d412230eeec1840b8ca104bebea4358"
+      },
+      "homepage": "https://github.com/Digital-Process-Tools/claude-remember"
+    },
+    {
+      "name": "ai-plugins",
+      "description": "Set up endorctl and use Endor Labs to scan, prioritize, and fix security risks across your software supply chain",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/endorlabs/ai-plugins.git",
+        "sha": "a0f1d5632b6f9e6c26eaa9806f5d8d454ca5b06f"
+      },
+      "homepage": "https://www.endorlabs.com"
+    },
+    {
+      "name": "mcp-server-dev",
+      "description": "Skills for designing and building MCP servers that work seamlessly with Claude. Guides you through deployment models (remote HTTP, MCPB, local), tool design patterns, auth, and interactive MCP apps.",
+      "author": {
+        "name": "Anthropic",
+        "email": "support@anthropic.com"
+      },
+      "source": "./plugins/mcp-server-dev",
+      "category": "development",
+      "homepage": "https://github.com/anthropics/claude-plugins-official/tree/main/plugins/mcp-server-dev"
     }
   ]
 }

plugins/example-plugin/README.md

@@ -7,32 +7,24 @@ A comprehensive example plugin demonstrating Claude Code extension options.
 ```
 example-plugin/
 ├── .claude-plugin/
-│   └── plugin.json        # Plugin metadata
-├── .mcp.json              # MCP server configuration
-├── commands/
-│   └── example-command.md # Slash command definition
-└── skills/
-    └── example-skill/
-        └── SKILL.md       # Skill definition
+│   └── plugin.json            # Plugin metadata
+├── .mcp.json                  # MCP server configuration
+├── skills/
+│   ├── example-skill/
+│   │   └── SKILL.md           # Model-invoked skill (contextual guidance)
+│   └── example-command/
+│       └── SKILL.md           # User-invoked skill (slash command)
+└── commands/
+    └── example-command.md     # Legacy slash command format (see note below)
 ```
 
 ## Extension Options
 
-### Commands (`commands/`)
-
-Slash commands are user-invoked via `/command-name`. Define them as markdown files with frontmatter:
-
-```yaml
----
-description: Short description for /help
-argument-hint: <arg1> [optional-arg]
-allowed-tools: [Read, Glob, Grep]
----
-```
-
 ### Skills (`skills/`)
 
-Skills are model-invoked capabilities. Create a `SKILL.md` in a subdirectory:
+Skills are the preferred format for both model-invoked capabilities and user-invoked slash commands. Create a `SKILL.md` in a subdirectory:
+
+**Model-invoked skill** (activated by task context):
 
 ```yaml
 ---
@@ -42,6 +34,21 @@ version: 1.0.0
 ---
 ```
 
+**User-invoked skill** (slash command — `/skill-name`):
+
+```yaml
+---
+name: skill-name
+description: Short description for /help
+argument-hint: <arg1> [optional-arg]
+allowed-tools: [Read, Glob, Grep]
+---
+```
+
+### Commands (`commands/`) — legacy
+
+> **Note:** The `commands/*.md` layout is a legacy format. It is loaded identically to `skills/<name>/SKILL.md` — the only difference is file layout. For new plugins, prefer the `skills/` directory format. This plugin keeps `commands/example-command.md` as a reference for the legacy layout.
+
 ### MCP Servers (`.mcp.json`)
 
 Configure external tool integration via Model Context Protocol:

plugins/example-plugin/commands/example-command.md

@@ -1,10 +1,12 @@
 ---
-description: An example slash command that demonstrates command frontmatter options
+description: An example slash command that demonstrates command frontmatter options (legacy format)
 argument-hint: <required-arg> [optional-arg]
 allowed-tools: [Read, Glob, Grep, Bash]
 ---
 
-# Example Command
+# Example Command (Legacy `commands/` Format)
+
+> **Note:** This demonstrates the legacy `commands/*.md` layout. For new plugins, prefer the `skills/<name>/SKILL.md` directory format (see `skills/example-command/SKILL.md` in this plugin). Both are loaded identically — the only difference is file layout.
 
 This command demonstrates slash command structure and frontmatter options.
 

plugins/example-plugin/skills/example-command/SKILL.md

@@ -0,0 +1,39 @@
+---
+name: example-command
+description: An example user-invoked skill that demonstrates frontmatter options and the skills/<name>/SKILL.md layout
+argument-hint: <required-arg> [optional-arg]
+allowed-tools: [Read, Glob, Grep, Bash]
+---
+
+# Example Command (Skill Format)
+
+This demonstrates the `skills/<name>/SKILL.md` layout for user-invoked slash commands. It is functionally identical to the legacy `commands/example-command.md` format — both are loaded the same way; only the file layout differs.
+
+## Arguments
+
+The user invoked this with: $ARGUMENTS
+
+## Instructions
+
+When this skill is invoked:
+
+1. Parse the arguments provided by the user
+2. Perform the requested action using allowed tools
+3. Report results back to the user
+
+## Frontmatter Options Reference
+
+Skills in this layout support these frontmatter fields:
+
+- **name**: Skill identifier (matches directory name)
+- **description**: Short description shown in /help
+- **argument-hint**: Hints for command arguments shown to user
+- **allowed-tools**: Pre-approved tools for this skill (reduces permission prompts)
+- **model**: Override the model (e.g., "haiku", "sonnet", "opus")
+
+## Example Usage
+
+```
+/example-command my-argument
+/example-command arg1 arg2
+```

plugins/mcp-server-dev/.claude-plugin/plugin.json

@@ -0,0 +1,8 @@
+{
+  "name": "mcp-server-dev",
+  "description": "Skills for designing and building MCP servers that work seamlessly with Claude — guides you through deployment models (remote HTTP, MCPB, local), tool design patterns, auth, and interactive MCP apps.",
+  "author": {
+    "name": "Anthropic",
+    "email": "support@anthropic.com"
+  }
+}

plugins/mcp-server-dev/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
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+
+      "Legal Entity" shall mean the union of the acting entity and all
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+
+      "You" (or "Your") shall mean an individual or Legal Entity
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plugins/mcp-server-dev/README.md

@@ -0,0 +1,32 @@
+# mcp-server-dev
+
+Skills for designing and building MCP servers that work seamlessly with Claude.
+
+## What's inside
+
+Three skills that compose into a full build path:
+
+| Skill | Purpose |
+|---|---|
+| **`build-mcp-server`** | Entry point. Interrogates the use case, picks deployment model (remote HTTP / MCPB / local stdio), picks tool-design pattern, routes to a specialized skill. |
+| **`build-mcp-app`** | Adds interactive UI widgets (forms, pickers, confirm dialogs) rendered inline in chat. Works on remote servers and MCPB bundles. |
+| **`build-mcpb`** | Packages a local stdio server with its runtime so users can install it without Node/Python. For servers that must touch the local machine. |
+
+## How it works
+
+`build-mcp-server` is the front door. It asks what you're connecting to, who'll use it, how big the action surface is, and whether you need in-chat UI. From those answers it recommends one of four paths:
+
+- **Remote streamable-HTTP** (the default recommendation for anything wrapping a cloud API) — scaffolded inline
+- **MCP app** — hands off to `build-mcp-app`
+- **MCPB** — hands off to `build-mcpb`
+- **Local stdio prototype** — scaffolded inline with an MCPB upgrade note
+
+Each skill ships reference files for the parts that don't fit in the main instructions: auth flows (DCR/CIMD), tool-description writing, widget templates, manifest schemas, security hardening.
+
+## Usage
+
+Ask Claude to "help me build an MCP server" and the entry skill will trigger. Or invoke directly:
+
+```
+/mcp-server-dev:build-mcp-server
+```

plugins/mcp-server-dev/skills/build-mcp-app/SKILL.md

@@ -0,0 +1,289 @@
+---
+name: build-mcp-app
+description: This skill should be used when the user wants to build an "MCP app", add "interactive UI" or "widgets" to an MCP server, "render components in chat", build "MCP UI resources", make a tool that shows a "form", "picker", "dashboard" or "confirmation dialog" inline in the conversation, or mentions "apps SDK" in the context of MCP. Use AFTER the build-mcp-server skill has settled the deployment model, or when the user already knows they want UI widgets.
+version: 0.1.0
+---
+
+# Build an MCP App (Interactive UI Widgets)
+
+An MCP app is a standard MCP server that **also serves UI resources** — interactive components rendered inline in the chat surface. Build once, runs in Claude *and* ChatGPT and any other host that implements the apps surface.
+
+The UI layer is **additive**. Under the hood it's still tools, resources, and the same wire protocol. If you haven't built a plain MCP server before, the `build-mcp-server` skill covers the base layer. This skill adds widgets on top.
+
+---
+
+## When a widget beats plain text
+
+Don't add UI for its own sake — most tools are fine returning text or JSON. Add a widget when one of these is true:
+
+| Signal | Widget type |
+|---|---|
+| Tool needs structured input Claude can't reliably infer | Form |
+| User must pick from a list Claude can't rank (files, contacts, records) | Picker / table |
+| Destructive or billable action needs explicit confirmation | Confirm dialog |
+| Output is spatial or visual (charts, maps, diffs, previews) | Display widget |
+| Long-running job the user wants to watch | Progress / live status |
+
+If none apply, skip the widget. Text is faster to build and faster for the user.
+
+---
+
+## Widgets vs Elicitation — route correctly
+
+Before building a widget, check if **elicitation** covers it. Elicitation is spec-native, zero UI code, works in any compliant host.
+
+| Need | Elicitation | Widget |
+|---|---|---|
+| Confirm yes/no | ✅ | overkill |
+| Pick from short enum | ✅ | overkill |
+| Fill a flat form (name, email, date) | ✅ | overkill |
+| Pick from a large/searchable list | ❌ (no scroll/search) | ✅ |
+| Visual preview before choosing | ❌ | ✅ |
+| Chart / map / diff view | ❌ | ✅ |
+| Live-updating progress | ❌ | ✅ |
+
+If elicitation covers it, use it. See `../build-mcp-server/references/elicitation.md`.
+
+---
+
+## Architecture: two deployment shapes
+
+### Remote MCP app (most common)
+
+Hosted streamable-HTTP server. Widget templates are served as **resources**; tool results reference them. The host fetches the resource, renders it in an iframe sandbox, and brokers messages between the widget and Claude.
+
+```
+┌──────────┐  tools/call   ┌────────────┐
+│  Claude  │─────────────> │ MCP server │
+│   host   │<── result ────│  (remote)  │
+│          │  + widget ref │            │
+│          │               │            │
+│          │ resources/read│            │
+│          │─────────────> │  widget    │
+│ ┌──────┐ │<── template ──│  HTML/JS   │
+│ │iframe│ │               └────────────┘
+│ │widget│ │
+│ └──────┘ │
+└──────────┘
+```
+
+### MCPB-packaged MCP app (local + UI)
+
+Same widget mechanism, but the server runs locally inside an MCPB bundle. Use this when the widget needs to drive a **local** application — e.g., a file picker that browses the actual local disk, a dialog that controls a desktop app.
+
+For MCPB packaging mechanics, defer to the **`build-mcpb`** skill. Everything below applies to both shapes.
+
+---
+
+## How widgets attach to tools
+
+A widget-enabled tool has **two separate registrations**:
+
+1. **The tool** declares a UI resource via `_meta.ui.resourceUri`. Its handler returns plain text/JSON — NOT the HTML.
+2. **The resource** is registered separately and serves the HTML.
+
+When Claude calls the tool, the host sees `_meta.ui.resourceUri`, fetches that resource, renders it in an iframe, and pipes the tool's return value into the iframe via the `ontoolresult` event.
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { registerAppTool, registerAppResource, RESOURCE_MIME_TYPE }
+  from "@modelcontextprotocol/ext-apps/server";
+import { z } from "zod";
+
+const server = new McpServer({ name: "contacts", version: "1.0.0" });
+
+// 1. The tool — returns DATA, declares which UI to show
+registerAppTool(server, "pick_contact", {
+  description: "Open an interactive contact picker",
+  inputSchema: { filter: z.string().optional() },
+  _meta: { ui: { resourceUri: "ui://widgets/contact-picker.html" } },
+}, async ({ filter }) => {
+  const contacts = await db.contacts.search(filter);
+  // Plain JSON — the widget receives this via ontoolresult
+  return { content: [{ type: "text", text: JSON.stringify(contacts) }] };
+});
+
+// 2. The resource — serves the HTML
+registerAppResource(
+  server,
+  "Contact Picker",
+  "ui://widgets/contact-picker.html",
+  {},
+  async () => ({
+    contents: [{
+      uri: "ui://widgets/contact-picker.html",
+      mimeType: RESOURCE_MIME_TYPE,
+      text: pickerHtml,  // your HTML string
+    }],
+  }),
+);
+```
+
+The URI scheme `ui://` is convention. The mime type MUST be `RESOURCE_MIME_TYPE` (`"text/html;profile=mcp-app"`) — this is how the host knows to render it as an interactive iframe, not just display the source.
+
+---
+
+## Widget runtime — the `App` class
+
+Inside the iframe, your script talks to the host via the `App` class from `@modelcontextprotocol/ext-apps`. This is a **persistent bidirectional connection** — the widget stays alive as long as the conversation is active, receiving new tool results and sending user actions.
+
+```html
+<script type="module">
+  import { App } from "https://esm.sh/@modelcontextprotocol/ext-apps@1.2.2";
+
+  const app = new App({ name: "ContactPicker", version: "1.0.0" }, {});
+
+  // Set handlers BEFORE connecting
+  app.ontoolresult = ({ content }) => {
+    const contacts = JSON.parse(content[0].text);
+    render(contacts);
+  };
+
+  await app.connect();
+
+  // Later, when the user clicks something:
+  function onPick(contact) {
+    app.sendMessage({
+      role: "user",
+      content: [{ type: "text", text: `Selected contact: ${contact.id}` }],
+    });
+  }
+</script>
+```
+
+| Method | Direction | Use for |
+|---|---|---|
+| `app.ontoolresult = fn` | Host → widget | Receive the tool's return value |
+| `app.ontoolinput = fn` | Host → widget | Receive the tool's input args (what Claude passed) |
+| `app.sendMessage({...})` | Widget → host | Inject a message into the conversation |
+| `app.updateModelContext({...})` | Widget → host | Update context silently (no visible message) |
+| `app.callServerTool({name, arguments})` | Widget → server | Call another tool on your server |
+
+`sendMessage` is the typical "user picked something, tell Claude" path. `updateModelContext` is for state that Claude should know about but shouldn't clutter the chat.
+
+**What widgets cannot do:**
+- Access the host page's DOM, cookies, or storage
+- Make network calls to arbitrary origins (CSP-restricted — route through `callServerTool`)
+
+Keep widgets **small and single-purpose**. A picker picks. A chart displays. Don't build a whole sub-app inside the iframe — split it into multiple tools with focused widgets.
+
+---
+
+## Scaffold: minimal picker widget
+
+**Install:**
+
+```bash
+npm install @modelcontextprotocol/sdk @modelcontextprotocol/ext-apps zod express
+```
+
+**Server (`src/server.ts`):**
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { registerAppTool, registerAppResource, RESOURCE_MIME_TYPE }
+  from "@modelcontextprotocol/ext-apps/server";
+import express from "express";
+import { readFileSync } from "node:fs";
+import { z } from "zod";
+
+const server = new McpServer({ name: "contact-picker", version: "1.0.0" });
+
+const pickerHtml = readFileSync("./widgets/picker.html", "utf8");
+
+registerAppTool(server, "pick_contact", {
+  description: "Open an interactive contact picker. User selects one contact.",
+  inputSchema: { filter: z.string().optional().describe("Name/email prefix filter") },
+  _meta: { ui: { resourceUri: "ui://widgets/picker.html" } },
+}, async ({ filter }) => {
+  const contacts = await db.contacts.search(filter ?? "");
+  return { content: [{ type: "text", text: JSON.stringify(contacts) }] };
+});
+
+registerAppResource(server, "Contact Picker", "ui://widgets/picker.html", {},
+  async () => ({
+    contents: [{ uri: "ui://widgets/picker.html", mimeType: RESOURCE_MIME_TYPE, text: pickerHtml }],
+  }),
+);
+
+const app = express();
+app.use(express.json());
+app.post("/mcp", async (req, res) => {
+  const transport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined });
+  res.on("close", () => transport.close());
+  await server.connect(transport);
+  await transport.handleRequest(req, res, req.body);
+});
+app.listen(process.env.PORT ?? 3000);
+```
+
+For local-only widget apps (driving a desktop app, reading local files), swap the transport to `StdioServerTransport` and package via the `build-mcpb` skill.
+
+**Widget (`widgets/picker.html`):**
+
+```html
+<!doctype html>
+<meta charset="utf-8" />
+<style>
+  body { font: 14px system-ui; margin: 0; }
+  ul { list-style: none; padding: 0; margin: 0; max-height: 300px; overflow-y: auto; }
+  li { padding: 10px 14px; cursor: pointer; border-bottom: 1px solid #eee; }
+  li:hover { background: #f5f5f5; }
+  .sub { color: #666; font-size: 12px; }
+</style>
+<ul id="list"></ul>
+<script type="module">
+  import { App } from "https://esm.sh/@modelcontextprotocol/ext-apps@1.2.2";
+
+  const app = new App({ name: "ContactPicker", version: "1.0.0" }, {});
+  const ul = document.getElementById("list");
+
+  app.ontoolresult = ({ content }) => {
+    const contacts = JSON.parse(content[0].text);
+    ul.innerHTML = "";
+    for (const c of contacts) {
+      const li = document.createElement("li");
+      li.innerHTML = `<div>${c.name}</div><div class="sub">${c.email}</div>`;
+      li.addEventListener("click", () => {
+        app.sendMessage({
+          role: "user",
+          content: [{ type: "text", text: `Selected contact: ${c.id} (${c.name})` }],
+        });
+      });
+      ul.append(li);
+    }
+  };
+
+  await app.connect();
+</script>
+```
+
+See `references/widget-templates.md` for more widget shapes.
+
+---
+
+## Design notes that save you a rewrite
+
+**One widget per tool.** Resist the urge to build one mega-widget that does everything. One tool → one focused widget → one clear result shape. Claude reasons about these far better.
+
+**Tool description must mention the widget.** Claude only sees the tool description when deciding what to call. "Opens an interactive picker" in the description is what makes Claude reach for it instead of guessing an ID.
+
+**Widgets are optional at runtime.** Hosts that don't support the apps surface simply ignore `_meta.ui` and render the tool's text content normally. Since your tool handler already returns meaningful text/JSON (the widget's data), degradation is automatic — Claude sees the data directly instead of via the widget.
+
+**Don't block on widget results for read-only tools.** A widget that just *displays* data (chart, preview) shouldn't require a user action to complete. Return the display widget *and* a text summary in the same result so Claude can continue reasoning without waiting.
+
+---
+
+## Testing
+
+- **Local:** point Claude desktop's MCP config at your server, trigger the tool, check the widget renders and `sendMessage` flows back into the chat.
+- **Host fallback:** disable the apps surface (or use a host without it) and confirm the tool degrades gracefully.
+- **CSP:** open browser devtools on the iframe — CSP violations are the #1 reason widgets silently fail.
+
+---
+
+## Reference files
+
+- `references/widget-templates.md` — reusable HTML scaffolds for picker / confirm / progress / display
+- `references/apps-sdk-messages.md` — the `App` class API: widget ↔ host ↔ server messaging

plugins/mcp-server-dev/skills/build-mcp-app/references/apps-sdk-messages.md

@@ -0,0 +1,120 @@
+# ext-apps messaging — widget ↔ host ↔ server
+
+The `@modelcontextprotocol/ext-apps` package provides the `App` class (browser side) and `registerAppTool`/`registerAppResource` helpers (server side). Messaging is bidirectional and persistent.
+
+---
+
+## Widget → Host
+
+### `app.sendMessage({ role, content })`
+
+Inject a visible message into the conversation. This is how user actions become conversation turns.
+
+```js
+app.sendMessage({
+  role: "user",
+  content: [{ type: "text", text: "User selected order #1234" }],
+});
+```
+
+The message appears in chat and Claude responds to it. Use `role: "user"` — the widget speaks on the user's behalf.
+
+### `app.updateModelContext({ content })`
+
+Update Claude's context **silently** — no visible message. Use for state that informs but doesn't warrant a chat bubble.
+
+```js
+app.updateModelContext({
+  content: [{ type: "text", text: "Currently viewing: orders from last 30 days" }],
+});
+```
+
+### `app.callServerTool({ name, arguments })`
+
+Call a tool on your MCP server directly, bypassing Claude. Returns the tool result.
+
+```js
+const result = await app.callServerTool({
+  name: "fetch_order_details",
+  arguments: { orderId: "1234" },
+});
+```
+
+Use for data fetches that don't need Claude's reasoning — pagination, detail lookups, refreshes.
+
+---
+
+## Host → Widget
+
+### `app.ontoolresult = ({ content }) => {...}`
+
+Fires when the tool handler's return value is piped to the widget. This is the primary data-in path.
+
+```js
+app.ontoolresult = ({ content }) => {
+  const data = JSON.parse(content[0].text);
+  renderUI(data);
+};
+```
+
+**Set this BEFORE `await app.connect()`** — the result may arrive immediately after connection.
+
+### `app.ontoolinput = ({ arguments }) => {...}`
+
+Fires with the arguments Claude passed to the tool. Useful if the widget needs to know what was asked for (e.g., highlight the search term).
+
+---
+
+## Server → Widget (progress)
+
+For long-running operations, emit progress notifications. The client sends a `progressToken` in the request's `_meta`; the server emits against it.
+
+```typescript
+// In the tool handler
+async ({ query }, extra) => {
+  const token = extra._meta?.progressToken;
+  for (let i = 0; i < steps.length; i++) {
+    if (token !== undefined) {
+      await extra.sendNotification({
+        method: "notifications/progress",
+        params: { progressToken: token, progress: i, total: steps.length, message: steps[i].name },
+      });
+    }
+    await steps[i].run();
+  }
+  return { content: [{ type: "text", text: "Complete" }] };
+}
+```
+
+No `{ notify }` destructure — `extra` is `RequestHandlerExtra`; progress goes through `sendNotification`.
+
+---
+
+## Lifecycle
+
+1. Claude calls a tool with `_meta.ui.resourceUri` declared
+2. Host fetches the resource (your HTML) and renders it in an iframe
+3. Widget script runs, sets handlers, calls `await app.connect()`
+4. Host pipes the tool's return value → `ontoolresult` fires
+5. Widget renders, user interacts
+6. Widget calls `sendMessage` / `updateModelContext` / `callServerTool` as needed
+7. Widget persists until conversation context moves on — subsequent calls to the same tool reuse the iframe and fire `ontoolresult` again
+
+There's no explicit "submit and close" — the widget is a long-lived surface.
+
+---
+
+## CSP gotchas
+
+The iframe runs under a restrictive Content-Security-Policy:
+
+| Symptom | Cause | Fix |
+|---|---|---|
+| Widget renders but JS doesn't run | Inline event handlers blocked | Use `addEventListener` — never `onclick="..."` in HTML |
+| `eval` / `new Function` errors | Script-src restriction | Don't use them; use JSON.parse for data |
+| External scripts fail | CDN not allowlisted | `esm.sh` is safe; avoid others |
+| `fetch()` to your API fails | Cross-origin blocked | Route through `app.callServerTool()` instead |
+| External CSS doesn't load | `style-src` restriction | Inline styles in a `<style>` tag |
+| Fonts don't load | `font-src` restriction | Use system fonts (`font: 14px system-ui`) |
+
+When in doubt, open the iframe's devtools console — CSP violations log there.

plugins/mcp-server-dev/skills/build-mcp-app/references/widget-templates.md

@@ -0,0 +1,199 @@
+# Widget Templates
+
+Minimal HTML scaffolds for the common widget shapes. Copy, fill in, ship.
+
+All templates use the `App` class from `@modelcontextprotocol/ext-apps` via ESM CDN. They're intentionally framework-free — widgets are small enough that React/Vue hydration cost usually isn't worth it.
+
+---
+
+## Serving widget HTML
+
+Widgets are static HTML — data arrives at runtime via `ontoolresult`, not baked in. Store each widget as a string constant or read from disk:
+
+```typescript
+import { readFileSync } from "node:fs";
+import { registerAppResource, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
+
+const pickerHtml = readFileSync("./widgets/picker.html", "utf8");
+
+registerAppResource(server, "Picker", "ui://widgets/picker.html", {},
+  async () => ({
+    contents: [{ uri: "ui://widgets/picker.html", mimeType: RESOURCE_MIME_TYPE, text: pickerHtml }],
+  }),
+);
+```
+
+---
+
+## Picker (single-select list)
+
+```html
+<!doctype html>
+<meta charset="utf-8" />
+<style>
+  body { font: 14px system-ui; margin: 0; }
+  ul { list-style: none; padding: 0; margin: 0; max-height: 280px; overflow-y: auto; }
+  li { padding: 10px 14px; cursor: pointer; border-bottom: 1px solid #eee; }
+  li:hover { background: #f5f5f5; }
+  .sub { color: #666; font-size: 12px; }
+</style>
+<ul id="list"></ul>
+<script type="module">
+  import { App } from "https://esm.sh/@modelcontextprotocol/ext-apps@1.2.2";
+
+  const app = new App({ name: "Picker", version: "1.0.0" }, {});
+  const ul = document.getElementById("list");
+
+  app.ontoolresult = ({ content }) => {
+    const { items } = JSON.parse(content[0].text);
+    ul.innerHTML = "";
+    for (const it of items) {
+      const li = document.createElement("li");
+      li.innerHTML = `<div>${it.label}</div><div class="sub">${it.sub ?? ""}</div>`;
+      li.addEventListener("click", () => {
+        app.sendMessage({
+          role: "user",
+          content: [{ type: "text", text: `Selected: ${it.id}` }],
+        });
+      });
+      ul.append(li);
+    }
+  };
+
+  await app.connect();
+</script>
+```
+
+**Tool returns:** `{ content: [{ type: "text", text: JSON.stringify({ items: [{ id, label, sub? }] }) }] }`
+
+---
+
+## Confirm dialog
+
+```html
+<!doctype html>
+<meta charset="utf-8" />
+<style>
+  body { font: 14px system-ui; margin: 16px; }
+  .actions { display: flex; gap: 8px; margin-top: 16px; }
+  button { padding: 8px 16px; cursor: pointer; }
+  .danger { background: #d33; color: white; border: none; }
+</style>
+<p id="msg"></p>
+<div class="actions">
+  <button id="cancel">Cancel</button>
+  <button id="confirm" class="danger">Confirm</button>
+</div>
+<script type="module">
+  import { App } from "https://esm.sh/@modelcontextprotocol/ext-apps@1.2.2";
+
+  const app = new App({ name: "Confirm", version: "1.0.0" }, {});
+
+  app.ontoolresult = ({ content }) => {
+    const { message, confirmLabel } = JSON.parse(content[0].text);
+    document.getElementById("msg").textContent = message;
+    if (confirmLabel) document.getElementById("confirm").textContent = confirmLabel;
+  };
+
+  await app.connect();
+
+  document.getElementById("confirm").addEventListener("click", () => {
+    app.sendMessage({ role: "user", content: [{ type: "text", text: "Confirmed." }] });
+  });
+  document.getElementById("cancel").addEventListener("click", () => {
+    app.sendMessage({ role: "user", content: [{ type: "text", text: "Cancelled." }] });
+  });
+</script>
+```
+
+**Tool returns:** `{ content: [{ type: "text", text: JSON.stringify({ message, confirmLabel? }) }] }`
+
+**Note:** For simple confirmation, prefer **elicitation** over a widget — see `../build-mcp-server/references/elicitation.md`. Use this widget when you need custom styling or context beyond what a native form offers.
+
+---
+
+## Progress (long-running)
+
+```html
+<!doctype html>
+<meta charset="utf-8" />
+<style>
+  body { font: 14px system-ui; margin: 16px; }
+  .bar { height: 8px; background: #eee; border-radius: 4px; overflow: hidden; }
+  .fill { height: 100%; background: #2a7; transition: width 200ms; }
+</style>
+<p id="label">Starting…</p>
+<div class="bar"><div id="fill" class="fill" style="width:0%"></div></div>
+<script type="module">
+  import { App } from "https://esm.sh/@modelcontextprotocol/ext-apps@1.2.2";
+
+  const app = new App({ name: "Progress", version: "1.0.0" }, {});
+  const label = document.getElementById("label");
+  const fill = document.getElementById("fill");
+
+  // The tool result fires when the job completes — intermediate updates
+  // arrive via the same handler if the server streams them
+  app.ontoolresult = ({ content }) => {
+    const state = JSON.parse(content[0].text);
+    if (state.progress !== undefined) {
+      label.textContent = state.message ?? `${state.progress}/${state.total}`;
+      fill.style.width = `${(state.progress / state.total) * 100}%`;
+    }
+    if (state.done) {
+      label.textContent = "Complete";
+      fill.style.width = "100%";
+    }
+  };
+
+  await app.connect();
+</script>
+```
+
+Server side, emit progress via `extra.sendNotification({ method: "notifications/progress", ... })` — see `apps-sdk-messages.md`.
+
+---
+
+## Display-only (chart / preview)
+
+Display widgets don't call `sendMessage` — they render and sit there. The tool should return a text summary **alongside** the widget so Claude can keep reasoning while the user sees the visual:
+
+```typescript
+registerAppTool(server, "show_chart", {
+  description: "Render a revenue chart",
+  inputSchema: { range: z.enum(["week", "month", "year"]) },
+  _meta: { ui: { resourceUri: "ui://widgets/chart.html" } },
+}, async ({ range }) => {
+  const data = await fetchRevenue(range);
+  return {
+    content: [{
+      type: "text",
+      text: `Revenue is up ${data.change}% over the ${range}. Chart rendered.\n\n` +
+            JSON.stringify(data.points),
+    }],
+  };
+});
+```
+
+```html
+<!doctype html>
+<meta charset="utf-8" />
+<style>body { font: 14px system-ui; margin: 12px; }</style>
+<canvas id="chart" width="400" height="200"></canvas>
+<script type="module">
+  import { App } from "https://esm.sh/@modelcontextprotocol/ext-apps@1.2.2";
+
+  const app = new App({ name: "Chart", version: "1.0.0" }, {});
+
+  app.ontoolresult = ({ content }) => {
+    // Parse the JSON points from the text content (after the summary line)
+    const text = content[0].text;
+    const jsonStart = text.indexOf("\n\n") + 2;
+    const points = JSON.parse(text.slice(jsonStart));
+    drawChart(document.getElementById("chart"), points);
+  };
+
+  await app.connect();
+
+  function drawChart(canvas, points) { /* ... */ }
+</script>
+```

plugins/mcp-server-dev/skills/build-mcp-server/SKILL.md

@@ -0,0 +1,208 @@
+---
+name: build-mcp-server
+description: This skill should be used when the user asks to "build an MCP server", "create an MCP", "make an MCP integration", "wrap an API for Claude", "expose tools to Claude", "make an MCP app", or discusses building something with the Model Context Protocol. It is the entry point for MCP server development — it interrogates the user about their use case, determines the right deployment model (remote HTTP, MCPB, local stdio), picks a tool-design pattern, and hands off to specialized skills.
+version: 0.1.0
+---
+
+# Build an MCP Server
+
+You are guiding a developer through designing and building an MCP server that works seamlessly with Claude. MCP servers come in many forms — picking the wrong shape early causes painful rewrites later. Your first job is **discovery, not code**.
+
+Do not start scaffolding until you have answers to the questions in Phase 1. If the user's opening message already answers them, acknowledge that and skip straight to the recommendation.
+
+---
+
+## Phase 1 — Interrogate the use case
+
+Ask these questions conversationally (batch them into one message, don't interrogate one-at-a-time). Adapt wording to what the user has already told you.
+
+### 1. What does it connect to?
+
+| If it connects to… | Likely direction |
+|---|---|
+| A cloud API (SaaS, REST, GraphQL) | Remote HTTP server |
+| A local process, filesystem, or desktop app | MCPB or local stdio |
+| Hardware, OS-level APIs, or user-specific state | MCPB |
+| Nothing external — pure logic / computation | Either — default to remote |
+
+### 2. Who will use it?
+
+- **Just me / my team, on our machines** → Local stdio is acceptable (easiest to prototype)
+- **Anyone who installs it** → Remote HTTP (strongly preferred) or MCPB (if it *must* be local)
+- **Users of Claude desktop who want UI widgets** → MCP app (remote or MCPB)
+
+### 3. How many distinct actions does it expose?
+
+This determines the tool-design pattern — see Phase 3.
+
+- **Under ~15 actions** → one tool per action
+- **Dozens to hundreds of actions** (e.g. wrapping a large API surface) → search + execute pattern
+
+### 4. Does a tool need mid-call user input or rich display?
+
+- **Simple structured input** (pick from list, enter a value, confirm) → **Elicitation** — spec-native, zero UI code. *Host support is rolling out* (Claude Code ≥2.1.76) — always pair with a capability check and fallback. See `references/elicitation.md`.
+- **Rich/visual UI** (charts, custom pickers with search, live dashboards) → **MCP app widgets** — iframe-based, needs `@modelcontextprotocol/ext-apps`. See `build-mcp-app` skill.
+- **Neither** → plain tool returning text/JSON.
+
+### 5. What auth does the upstream service use?
+
+- None / API key → straightforward
+- OAuth 2.0 → you'll need a remote server with CIMD (preferred) or DCR support; see `references/auth.md`
+
+---
+
+## Phase 2 — Recommend a deployment model
+
+Based on the answers, recommend **one** path. Be opinionated. The ranked options:
+
+### ⭐ Remote streamable-HTTP MCP server (default recommendation)
+
+A hosted service speaking MCP over streamable HTTP. This is the **recommended path** for anything wrapping a cloud API.
+
+**Why it wins:**
+- Zero install friction — users add a URL, done
+- One deployment serves all users; you control upgrades
+- OAuth flows work properly (the server can handle redirects, DCR, token storage)
+- Works across Claude desktop, Claude Code, Claude.ai, and third-party MCP hosts
+
+**Choose this unless** the server *must* touch the user's local machine.
+
+→ **Fastest deploy:** Cloudflare Workers — `references/deploy-cloudflare-workers.md` (zero to live URL in two commands)
+→ **Portable Node/Python:** `references/remote-http-scaffold.md` (Express or FastMCP, runs on any host)
+
+### Elicitation (structured input, no UI build)
+
+If a tool just needs the user to confirm, pick an option, or fill a short form, **elicitation** does it with zero UI code. The server sends a flat JSON schema; the host renders a native form. Spec-native, no extra packages.
+
+**Caveat:** Host support is new (Claude Code shipped it in v2.1.76; Desktop unconfirmed). The SDK throws if the client doesn't advertise the capability. Always check `clientCapabilities.elicitation` first and have a fallback — see `references/elicitation.md` for the canonical pattern. This is the right spec-correct approach; host coverage will catch up.
+
+Escalate to `build-mcp-app` widgets when you need: nested/complex data, scrollable/searchable lists, visual previews, live updates.
+
+### MCP app (remote HTTP + interactive UI)
+
+Same as above, plus **UI resources** — interactive widgets rendered in chat. Rich pickers with search, charts, live dashboards, visual previews. Built once, renders in Claude *and* ChatGPT.
+
+**Choose this when** elicitation's flat-form constraints don't fit — you need custom layout, large searchable lists, visual content, or live updates.
+
+Usually remote, but can be shipped as MCPB if the UI needs to drive a local app.
+
+→ Hand off to the **`build-mcp-app`** skill.
+
+### MCPB (bundled local server)
+
+A local MCP server **packaged with its runtime** so users don't need Node/Python installed. The sanctioned way to ship local servers.
+
+**Choose this when** the server *must* run on the user's machine — it reads local files, drives a desktop app, talks to localhost services, or needs OS-level access.
+
+→ Hand off to the **`build-mcpb`** skill.
+
+### Local stdio (npx / uvx) — *not recommended for distribution*
+
+A script launched via `npx` / `uvx` on the user's machine. Fine for **personal tools and prototypes**. Painful to distribute: users need the right runtime, you can't push updates, and the only distribution channel is Claude Code plugins.
+
+Recommend this only as a stepping stone. If the user insists, scaffold it but note the MCPB upgrade path.
+
+---
+
+## Phase 3 — Pick a tool-design pattern
+
+Every MCP server exposes tools. How you carve them matters more than most people expect — tool schemas land directly in Claude's context window.
+
+### Pattern A: One tool per action (small surface)
+
+When the action space is small (< ~15 operations), give each a dedicated tool with a tight description and schema.
+
+```
+create_issue    — Create a new issue. Params: title, body, labels[]
+update_issue    — Update an existing issue. Params: id, title?, body?, state?
+search_issues   — Search issues by query string. Params: query, limit?
+add_comment     — Add a comment to an issue. Params: issue_id, body
+```
+
+**Why it works:** Claude reads the tool list once and knows exactly what's possible. No discovery round-trips. Each tool's schema validates inputs precisely.
+
+**Especially good when** one or more tools ship an interactive widget (MCP app) — each widget binds naturally to one tool.
+
+### Pattern B: Search + execute (large surface)
+
+When wrapping a large API (dozens to hundreds of endpoints), listing every operation as a tool floods the context window and degrades model performance. Instead, expose **two** tools:
+
+```
+search_actions  — Given a natural-language intent, return matching actions
+                  with their IDs, descriptions, and parameter schemas.
+execute_action  — Run an action by ID with a params object.
+```
+
+The server holds the full catalog internally. Claude searches, picks, executes. Context stays lean.
+
+**Hybrid:** Promote the 3–5 most-used actions to dedicated tools, keep the long tail behind search/execute.
+
+→ See `references/tool-design.md` for schema examples and description-writing guidance.
+
+---
+
+## Phase 4 — Pick a framework
+
+Recommend one of these two. Others exist but these have the best MCP-spec coverage and Claude compatibility.
+
+| Framework | Language | Use when |
+|---|---|---|
+| **Official TypeScript SDK** (`@modelcontextprotocol/sdk`) | TS/JS | Default choice. Best spec coverage, first to get new features. |
+| **FastMCP 3.x** (`fastmcp` on PyPI) | Python | User prefers Python, or wrapping a Python library. Decorator-based, very low boilerplate. This is jlowin's package — not the frozen FastMCP 1.0 bundled in the official `mcp` SDK. |
+
+If the user already has a language/stack in mind, go with it — both produce identical wire protocol.
+
+---
+
+## Phase 5 — Scaffold and hand off
+
+Once you've settled the four decisions (deployment model, tool pattern, framework, auth), do **one** of:
+
+1. **Remote HTTP, no UI** → Scaffold inline using `references/remote-http-scaffold.md` (portable) or `references/deploy-cloudflare-workers.md` (fastest deploy). This skill can finish the job.
+2. **MCP app (UI widgets)** → Summarize the decisions so far, then load the **`build-mcp-app`** skill.
+3. **MCPB (bundled local)** → Summarize the decisions so far, then load the **`build-mcpb`** skill.
+4. **Local stdio prototype** → Scaffold inline (simplest case), flag the MCPB upgrade path.
+
+When handing off, restate the design brief in one paragraph so the next skill doesn't re-ask.
+
+---
+
+## Beyond tools — the other primitives
+
+Tools are one of three server primitives. Most servers start with tools and never need the others, but knowing they exist prevents reinventing wheels:
+
+| Primitive | Who triggers it | Use when |
+|---|---|---|
+| **Resources** | Host app (not Claude) | Exposing docs/files/data as browsable context |
+| **Prompts** | User (slash command) | Canned workflows ("/summarize-thread") |
+| **Elicitation** | Server, mid-tool | Asking user for input without building UI |
+| **Sampling** | Server, mid-tool | Need LLM inference in your tool logic |
+
+→ `references/resources-and-prompts.md`, `references/elicitation.md`, `references/server-capabilities.md`
+
+---
+
+## Quick reference: decision matrix
+
+| Scenario | Deployment | Tool pattern |
+|---|---|---|
+| Wrap a small SaaS API | Remote HTTP | One-per-action |
+| Wrap a large SaaS API (50+ endpoints) | Remote HTTP | Search + execute |
+| SaaS API with rich forms / pickers | MCP app (remote) | One-per-action |
+| Drive a local desktop app | MCPB | One-per-action |
+| Local desktop app with in-chat UI | MCP app (MCPB) | One-per-action |
+| Read/write local filesystem | MCPB | Depends on surface |
+| Personal prototype | Local stdio | Whatever's fastest |
+
+---
+
+## Reference files
+
+- `references/remote-http-scaffold.md` — minimal remote server in TS SDK and FastMCP
+- `references/deploy-cloudflare-workers.md` — fastest deploy path (Workers-native scaffold)
+- `references/tool-design.md` — writing tool descriptions and schemas Claude understands well
+- `references/auth.md` — OAuth, CIMD, DCR, token storage patterns
+- `references/resources-and-prompts.md` — the two non-tool primitives
+- `references/elicitation.md` — spec-native user input mid-tool (capability check + fallback)
+- `references/server-capabilities.md` — instructions, sampling, roots, logging, progress, cancellation
+- `references/versions.md` — version-sensitive claims ledger (check when updating)

plugins/mcp-server-dev/skills/build-mcp-server/references/auth.md

@@ -0,0 +1,92 @@
+# Auth for MCP Servers
+
+Auth is the reason most people end up needing a **remote** server even when a local one would be simpler. OAuth redirects, token storage, and refresh all work cleanly when there's a real hosted endpoint to redirect back to.
+
+---
+
+## The three tiers
+
+### Tier 1: No auth / static API key
+
+Server reads a key from env. User provides it once at setup. Done.
+
+```typescript
+const apiKey = process.env.UPSTREAM_API_KEY;
+if (!apiKey) throw new Error("UPSTREAM_API_KEY not set");
+```
+
+Works for local stdio, MCPB, and remote servers alike. If this is all you need, stop here.
+
+### Tier 2: OAuth 2.0 via CIMD (preferred per spec 2025-11-25)
+
+**Client ID Metadata Document.** The MCP host publishes its client metadata at an HTTPS URL and uses that URL *as* its `client_id`. Your authorization server fetches the document, validates it, and proceeds with the auth-code flow. No registration endpoint, no stored client records.
+
+Spec 2025-11-25 promoted CIMD to SHOULD (preferred). Advertise support via `client_id_metadata_document_supported: true` in your OAuth AS metadata.
+
+**Server responsibilities:**
+
+1. Serve OAuth Authorization Server Metadata (RFC 8414) at `/.well-known/oauth-authorization-server` with `client_id_metadata_document_supported: true`
+2. Serve an MCP-protected-resource metadata document pointing at (1)
+3. At authorize time: fetch `client_id` as an HTTPS URL, validate the returned client metadata, proceed
+4. Validate bearer tokens on incoming `/mcp` requests
+
+```
+┌─────────┐  client_id=https://...  ┌──────────────┐   upstream OAuth   ┌──────────┐
+│ MCP host│ ──────────────────────> │ Your MCP srv │ ─────────────────> │ Upstream │
+└─────────┘ <─── bearer token ───── └──────────────┘ <── access token ──└──────────┘
+```
+
+### Tier 3: OAuth 2.0 via Dynamic Client Registration (DCR)
+
+**Backward-compat fallback** — spec 2025-11-25 demoted DCR to MAY. The host discovers your `registration_endpoint`, POSTs its metadata to register itself as a client, gets back a `client_id`, then runs the auth-code flow.
+
+Implement DCR if you need to support hosts that haven't moved to CIMD yet. Same server responsibilities as CIMD, but instead of fetching the `client_id` URL you run a registration endpoint that stores client records.
+
+**Client priority order:** pre-registered → CIMD (if AS advertises `client_id_metadata_document_supported`) → DCR (if AS has `registration_endpoint`) → prompt user.
+
+---
+
+## Hosting providers with built-in DCR/CIMD support
+
+Several MCP-focused hosting providers handle the OAuth plumbing for you — you implement tool logic, they run the authorization server. Check their docs for current capabilities. If the user doesn't have strong hosting preferences, this is usually the fastest path to a working OAuth-protected server.
+
+---
+
+## Local servers and OAuth
+
+Local stdio servers **can** do OAuth (open a browser, catch the redirect on a localhost port, stash the token in the OS keychain). It's fragile:
+
+- Breaks in headless/remote environments
+- Every user re-does the dance
+- No central token refresh or revocation
+
+If OAuth is required, lean hard toward remote HTTP. If you *must* ship local + OAuth, the `@modelcontextprotocol/sdk` includes a localhost-redirect helper, and MCPB is the right packaging so at least the runtime is predictable.
+
+---
+
+## Token storage
+
+| Deployment | Store tokens in |
+|---|---|
+| Remote, stateless | Nowhere — host sends bearer each request |
+| Remote, stateful | Session store keyed by MCP session ID (Redis, etc.) |
+| MCPB / local | OS keychain (`keytar` on Node, `keyring` on Python). **Never plaintext on disk.** |
+
+---
+
+## Token audience validation (spec MUST)
+
+Validating "is this a valid bearer token" isn't enough. The spec requires validating "was this token minted *for this server*" — RFC 8707 audience. A token issued for `api.other-service.com` must be rejected even if the signature checks out.
+
+**Token passthrough is explicitly forbidden.** Don't accept a token, then forward it upstream. If your server needs to call another service, exchange the token or use its own credentials.
+
+---
+
+## SDK helpers — don't hand-roll
+
+`@modelcontextprotocol/sdk/server/auth` ships:
+- `mcpAuthRouter()` — Express router for the full OAuth AS surface (metadata, authorize, token)
+- `bearerAuth` — middleware that validates bearer tokens against your verifier
+- `proxyProvider` — forward auth to an upstream IdP
+
+If you're wiring auth from scratch, check these first.

plugins/mcp-server-dev/skills/build-mcp-server/references/deploy-cloudflare-workers.md

@@ -0,0 +1,106 @@
+# Deploy to Cloudflare Workers
+
+Fastest path from zero to a live `https://` MCP URL. Free tier, no credit card to start, two commands to deploy.
+
+**Trade-off:** This is a Workers-native scaffold, not a deploy target for the Express scaffold in `remote-http-scaffold.md`. Different runtime. If you need portability across hosts, stick with Express. If you just want it live, start here.
+
+---
+
+## Bootstrap
+
+```bash
+npm create cloudflare@latest -- my-mcp-server \
+  --template=cloudflare/ai/demos/remote-mcp-authless
+cd my-mcp-server
+```
+
+This pulls a minimal template with the right deps (`agents`, `zod`) and a working `wrangler.jsonc`.
+
+---
+
+## `src/index.ts`
+
+Replace the template's calculator example with your tools. Use `registerTool()` (same API as the Express scaffold — the `McpServer` instance is identical):
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpAgent } from "agents/mcp";
+import { z } from "zod";
+
+export class MyMCP extends McpAgent {
+  server = new McpServer(
+    { name: "my-service", version: "0.1.0" },
+    { instructions: "Prefer search_items before get_item — IDs aren't guessable." },
+  );
+
+  async init() {
+    this.server.registerTool(
+      "search_items",
+      {
+        description: "Search items by keyword. Returns up to `limit` matches.",
+        inputSchema: {
+          query: z.string().describe("Search keywords"),
+          limit: z.number().int().min(1).max(50).default(10),
+        },
+        annotations: { readOnlyHint: true },
+      },
+      async ({ query, limit }) => {
+        const results = await upstreamApi.search(query, limit);
+        return { content: [{ type: "text", text: JSON.stringify(results, null, 2) }] };
+      },
+    );
+  }
+}
+
+export default {
+  fetch(request: Request, env: Env, ctx: ExecutionContext) {
+    const url = new URL(request.url);
+    if (url.pathname === "/mcp") {
+      return MyMCP.serve("/mcp").fetch(request, env, ctx);
+    }
+    return new Response("Not found", { status: 404 });
+  },
+};
+```
+
+`McpAgent` is Cloudflare's wrapper — it handles the streamable-HTTP transport, session routing, and Durable Object plumbing. Your code only touches `this.server`, which is the same `McpServer` class from the SDK. Everything in `tool-design.md` and `server-capabilities.md` applies unchanged.
+
+---
+
+## `wrangler.jsonc`
+
+The template ships this. The Durable Objects block is **boilerplate** — `McpAgent` uses DO for session state. You don't interact with it directly.
+
+```jsonc
+{
+  "name": "my-mcp-server",
+  "main": "src/index.ts",
+  "compatibility_date": "2025-03-10",
+  "compatibility_flags": ["nodejs_compat"],
+  "migrations": [{ "new_sqlite_classes": ["MyMCP"], "tag": "v1" }],
+  "durable_objects": {
+    "bindings": [{ "class_name": "MyMCP", "name": "MCP_OBJECT" }]
+  }
+}
+```
+
+If you rename the `MyMCP` class, update both `new_sqlite_classes` and `class_name` to match.
+
+---
+
+## Run and deploy
+
+```bash
+npx wrangler dev     # → http://localhost:8787/mcp
+npx wrangler deploy  # → https://my-mcp-server.<account>.workers.dev/mcp
+```
+
+`wrangler deploy` prints the live URL. That's the URL users paste into Claude.
+
+Secrets (upstream API keys): `npx wrangler secret put UPSTREAM_API_KEY`, then read `env.UPSTREAM_API_KEY` inside `init()`.
+
+---
+
+## OAuth
+
+Cloudflare ships `@cloudflare/workers-oauth-provider` — a drop-in that handles the authorization server side (CIMD/DCR endpoints, token issuance, consent UI). It wraps your `McpAgent` and gates `/mcp` behind a token check. See `auth.md` for the protocol details; the CF template `cloudflare/ai/demos/remote-mcp-github-oauth` shows the wiring.

plugins/mcp-server-dev/skills/build-mcp-server/references/elicitation.md

@@ -0,0 +1,129 @@
+# Elicitation — spec-native user input
+
+Elicitation lets a server pause mid-tool-call and ask the user for structured input. The client renders a native form (no iframe, no HTML). User fills it, server continues.
+
+**This is the right answer for simple input.** Widgets (`build-mcp-app`) are for when you need rich UI — charts, searchable lists, visual previews. If you just need a confirmation, a picked option, or a few form fields, elicitation is simpler, spec-native, and works in any compliant host.
+
+---
+
+## ⚠️ Check capability first — support is new
+
+Host support is very recent:
+
+| Host | Status |
+|---|---|
+| Claude Code | ✅ since v2.1.76 (both `form` and `url` modes) |
+| Claude Desktop | Unconfirmed — likely not yet or very recent |
+| claude.ai | Unknown |
+
+**The SDK throws `CapabilityNotSupported` if the client doesn't advertise elicitation.** There is no graceful degradation built in. You MUST check and have a fallback.
+
+### The canonical pattern
+
+```typescript
+server.registerTool("delete_all", {
+  description: "Delete all items after confirmation",
+  inputSchema: {},
+}, async ({}, extra) => {
+  const caps = server.getClientCapabilities();
+  if (caps?.elicitation) {
+    const r = await server.elicitInput({
+      mode: "form",
+      message: "Delete all items? This cannot be undone.",
+      requestedSchema: {
+        type: "object",
+        properties: { confirm: { type: "boolean", title: "Confirm deletion" } },
+        required: ["confirm"],
+      },
+    });
+    if (r.action === "accept" && r.content?.confirm) {
+      await deleteAll();
+      return { content: [{ type: "text", text: "Deleted." }] };
+    }
+    return { content: [{ type: "text", text: "Cancelled." }] };
+  }
+  // Fallback: return text asking Claude to relay the question
+  return { content: [{ type: "text", text: "Confirmation required. Please ask the user: 'Delete all items? This cannot be undone.' Then call this tool again with their answer." }] };
+});
+```
+
+```python
+# fastmcp
+from fastmcp import Context
+from fastmcp.exceptions import CapabilityNotSupported
+
+@mcp.tool
+async def delete_all(ctx: Context) -> str:
+    try:
+        result = await ctx.elicit("Delete all items? This cannot be undone.", response_type=bool)
+        if result.action == "accept" and result.data:
+            await do_delete()
+            return "Deleted."
+        return "Cancelled."
+    except CapabilityNotSupported:
+        return "Confirmation required. Ask the user to confirm deletion, then retry."
+```
+
+---
+
+## Schema constraints
+
+Elicitation schemas are deliberately limited — keep forms simple:
+
+- **Flat objects only** — no nesting, no arrays of objects
+- **Primitives only** — `string`, `number`, `integer`, `boolean`, `enum`
+- String formats limited to: `email`, `uri`, `date`, `date-time`
+- Use `title` and `description` on each property — they become form labels
+
+If your data doesn't fit these constraints, that's the signal to escalate to a widget.
+
+---
+
+## Three-state response
+
+| Action | Meaning | `content` present? |
+|---|---|---|
+| `accept` | User submitted the form | ✅ validated against your schema |
+| `decline` | User explicitly said no | ❌ |
+| `cancel` | User dismissed (escape, clicked away) | ❌ |
+
+Treat `decline` and `cancel` differently if it matters — `decline` is intentional, `cancel` might be accidental.
+
+The TS SDK's `server.elicitInput()` auto-validates `accept` responses against your schema via Ajv. fastmcp's `ctx.elicit()` returns a typed discriminated union (`AcceptedElicitation[T] | DeclinedElicitation | CancelledElicitation`).
+
+---
+
+## fastmcp response_type shorthand
+
+```python
+await ctx.elicit("Pick a color", response_type=["red", "green", "blue"])  # enum
+await ctx.elicit("Enter email", response_type=str)                         # string
+await ctx.elicit("Confirm?", response_type=bool)                           # boolean
+
+@dataclass
+class ContactInfo:
+    name: str
+    email: str
+await ctx.elicit("Contact details", response_type=ContactInfo)             # flat dataclass
+```
+
+Accepts: primitives, `list[str]` (becomes enum), dataclass, TypedDict, Pydantic BaseModel. All must be flat.
+
+---
+
+## Security
+
+**MUST NOT request passwords, API keys, or tokens via elicitation** — spec requirement. Those go through OAuth or `user_config` with `sensitive: true` (MCPB), not runtime forms.
+
+---
+
+## When to escalate to widgets
+
+Elicitation handles: confirm dialogs, enum pickers, short flat forms.
+
+Reach for `build-mcp-app` widgets when you need:
+- Nested or complex data structures
+- Scrollable/searchable lists (100+ items)
+- Visual preview before choosing (image thumbnails, file tree)
+- Live-updating progress or streaming content
+- Custom layouts, charts, maps

plugins/mcp-server-dev/skills/build-mcp-server/references/remote-http-scaffold.md

@@ -0,0 +1,211 @@
+# Remote Streamable-HTTP MCP Server — Scaffold
+
+Minimal working servers in both recommended frameworks. Start here, then add tools.
+
+---
+
+## TypeScript SDK (`@modelcontextprotocol/sdk`)
+
+```bash
+npm init -y
+npm install @modelcontextprotocol/sdk zod express
+npm install -D typescript @types/express @types/node tsx
+```
+
+**`src/server.ts`**
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import express from "express";
+import { z } from "zod";
+
+const server = new McpServer(
+  { name: "my-service", version: "0.1.0" },
+  { instructions: "Prefer search_items before calling get_item directly — IDs aren't guessable." },
+);
+
+// Pattern A: one tool per action
+server.registerTool(
+  "search_items",
+  {
+    description: "Search items by keyword. Returns up to `limit` matches ranked by relevance.",
+    inputSchema: {
+      query: z.string().describe("Search keywords"),
+      limit: z.number().int().min(1).max(50).default(10),
+    },
+    annotations: { readOnlyHint: true },
+  },
+  async ({ query, limit }, extra) => {
+    // extra.signal is an AbortSignal — check it in long loops for cancellation
+    const results = await upstreamApi.search(query, limit);
+    return {
+      content: [{ type: "text", text: JSON.stringify(results, null, 2) }],
+    };
+  },
+);
+
+server.registerTool(
+  "get_item",
+  {
+    description: "Fetch a single item by its ID.",
+    inputSchema: { id: z.string() },
+    annotations: { readOnlyHint: true },
+  },
+  async ({ id }) => {
+    const item = await upstreamApi.get(id);
+    return { content: [{ type: "text", text: JSON.stringify(item) }] };
+  },
+);
+
+// Streamable HTTP transport (stateless mode — simplest)
+const app = express();
+app.use(express.json());
+
+app.post("/mcp", async (req, res) => {
+  const transport = new StreamableHTTPServerTransport({
+    sessionIdGenerator: undefined, // stateless
+  });
+  res.on("close", () => transport.close());
+  await server.connect(transport);
+  await transport.handleRequest(req, res, req.body);
+});
+
+app.listen(process.env.PORT ?? 3000);
+```
+
+**Stateless vs stateful:** The snippet above creates a fresh transport per request (stateless). Fine for most API-wrapping servers. If tools need to share state across calls in a session (rare), use a session-keyed transport map — see the SDK's `examples/server/simpleStreamableHttp.ts`.
+
+---
+
+## FastMCP 3.x (Python)
+
+```bash
+pip install fastmcp
+```
+
+**`server.py`**
+
+```python
+from fastmcp import FastMCP
+
+mcp = FastMCP(
+    name="my-service",
+    instructions="Prefer search_items before calling get_item directly — IDs aren't guessable.",
+)
+
+@mcp.tool(annotations={"readOnlyHint": True})
+def search_items(query: str, limit: int = 10) -> list[dict]:
+    """Search items by keyword. Returns up to `limit` matches ranked by relevance."""
+    return upstream_api.search(query, limit)
+
+@mcp.tool(annotations={"readOnlyHint": True})
+def get_item(id: str) -> dict:
+    """Fetch a single item by its ID."""
+    return upstream_api.get(id)
+
+if __name__ == "__main__":
+    mcp.run(transport="http", host="0.0.0.0", port=3000)
+```
+
+FastMCP derives the JSON schema from type hints and the docstring becomes the tool description. Keep docstrings terse and action-oriented — they land in Claude's context window verbatim.
+
+---
+
+## Search + execute pattern (large API surface)
+
+When wrapping 50+ endpoints, don't register them all. Two tools:
+
+```typescript
+const CATALOG = loadActionCatalog(); // { id, description, paramSchema }[]
+
+server.registerTool(
+  "search_actions",
+  {
+    description: "Find available actions matching an intent. Call this first to discover what's possible. Returns action IDs, descriptions, and parameter schemas.",
+    inputSchema: { intent: z.string().describe("What you want to do, in plain English") },
+    annotations: { readOnlyHint: true },
+  },
+  async ({ intent }) => {
+    const matches = rankActions(CATALOG, intent).slice(0, 10);
+    return { content: [{ type: "text", text: JSON.stringify(matches, null, 2) }] };
+  },
+);
+
+server.registerTool(
+  "execute_action",
+  {
+    description: "Execute an action by ID. Get the ID and params schema from search_actions first.",
+    inputSchema: {
+      action_id: z.string(),
+      params: z.record(z.unknown()),
+    },
+  },
+  async ({ action_id, params }) => {
+    const action = CATALOG.find(a => a.id === action_id);
+    if (!action) throw new Error(`Unknown action: ${action_id}`);
+    validate(params, action.paramSchema);
+    const result = await dispatch(action, params);
+    return { content: [{ type: "text", text: JSON.stringify(result) }] };
+  },
+);
+```
+
+`rankActions` can be simple keyword matching to start. Upgrade to embeddings if precision matters.
+
+---
+
+## Test it
+
+The MCP Inspector connects to any transport and lets you poke tools interactively.
+
+```bash
+# Interactive — opens a UI on localhost:6274
+npx @modelcontextprotocol/inspector
+# → select "Streamable HTTP", paste http://localhost:3000/mcp, Connect
+```
+
+For scripted checks (CI, smoke tests):
+
+```bash
+npx @modelcontextprotocol/inspector --cli http://localhost:3000/mcp \
+  --transport http --method tools/list
+
+npx @modelcontextprotocol/inspector --cli http://localhost:3000/mcp \
+  --transport http --method tools/call --tool-name search_items --tool-arg query=test
+```
+
+---
+
+## Connect users
+
+Once deployed, users add the URL directly — no install step.
+
+| Surface | How |
+|---|---|
+| **Claude Code** | `claude mcp add --transport http <name> <url>` (add `--scope user` for global, `--header "Authorization: Bearer ..."` for auth) |
+| **Claude Desktop / Claude.ai** | Settings → Connectors → Add custom connector. **Not** `claude_desktop_config.json` — remote servers configured there are ignored. |
+| **Connector directory** | Anthropic maintains a submission guide for listing in the public connector directory. |
+
+---
+
+## Deploy
+
+**Fastest path:** Cloudflare Workers — two commands from zero to a live `https://` URL on the free tier. Uses a Workers-native scaffold (not Express). → `deploy-cloudflare-workers.md`
+
+**This Express scaffold** runs on any Node host — Render, Railway, Fly.io, a VPS. Containerize it (`node:20-slim`, copy, `npm ci`, `node dist/server.js`) and ship. FastMCP is the same story with a Python base image.
+
+---
+
+## Deployment checklist
+
+- [ ] `POST /mcp` responds to `initialize` with server capabilities
+- [ ] `tools/list` returns your tools with complete schemas
+- [ ] Errors return structured MCP errors, not HTTP 500s with HTML bodies
+- [ ] CORS headers set if browser clients will connect
+- [ ] `Origin` header validated on `/mcp` (spec MUST — DNS rebinding prevention)
+- [ ] `MCP-Protocol-Version` header honored (return 400 for unsupported versions)
+- [ ] `instructions` field set if tool-use needs hints
+- [ ] Health check endpoint separate from `/mcp` (hosts poll it)
+- [ ] Secrets from env vars, never hardcoded
+- [ ] If OAuth: CIMD or DCR endpoint implemented — see `auth.md`

plugins/mcp-server-dev/skills/build-mcp-server/references/resources-and-prompts.md

@@ -0,0 +1,122 @@
+# Resources & Prompts — the other two primitives
+
+MCP defines three server-side primitives. Tools are model-controlled (Claude decides when to call them). The other two are different:
+
+- **Resources** are application-controlled — the host decides what to pull into context
+- **Prompts** are user-controlled — surfaced as slash commands or menu items
+
+Most servers only need tools. Reach for these when the shape of your integration doesn't fit "Claude calls a function."
+
+---
+
+## Resources
+
+A resource is data identified by a URI. Unlike a tool, it's not *called* — it's *read*. The host browses available resources and decides which to load into context.
+
+**When a resource beats a tool:**
+- Large reference data (docs, schemas, configs) that Claude should be able to browse
+- Content that changes independently of conversation (log files, live data)
+- Anything where "Claude decides to fetch" is the wrong mental model
+
+**When a tool is better:**
+- The operation has side effects
+- The result depends on parameters Claude chooses
+- You want Claude (not the host UI) to decide when to pull it in
+
+### Static resources
+
+```typescript
+// TypeScript SDK
+server.registerResource(
+  "config",
+  "config://app/settings",
+  { name: "App Settings", description: "Current configuration", mimeType: "application/json" },
+  async (uri) => ({
+    contents: [{ uri: uri.href, mimeType: "application/json", text: JSON.stringify(config) }],
+  }),
+);
+```
+
+```python
+# fastmcp
+@mcp.resource("config://app/settings")
+def get_settings() -> str:
+    """Current application configuration."""
+    return json.dumps(config)
+```
+
+### Dynamic resources (URI templates)
+
+RFC 6570 templates let one registration serve many URIs:
+
+```typescript
+import { ResourceTemplate } from "@modelcontextprotocol/sdk/server/mcp.js";
+
+server.registerResource(
+  "file",
+  new ResourceTemplate("file:///{path}", { list: undefined }),
+  { name: "File", description: "Read a file from the workspace" },
+  async (uri, { path }) => ({
+    contents: [{ uri: uri.href, text: await fs.readFile(path, "utf8") }],
+  }),
+);
+```
+
+```python
+@mcp.resource("file:///{path}")
+def read_file(path: str) -> str:
+    return Path(path).read_text()
+```
+
+### Subscriptions
+
+Resources can notify the client when they change. Declare `subscribe: true` in capabilities, then emit `notifications/resources/updated`. The host re-reads. Useful for log tails, live dashboards, watched files.
+
+---
+
+## Prompts
+
+A prompt is a parameterized message template. The host surfaces it as a slash command or menu item. The user picks it, fills in arguments, and the resulting messages land in the conversation.
+
+**When to use:** canned workflows users run repeatedly — `/summarize-thread`, `/draft-reply`, `/explain-error`. Near-zero code, high UX leverage.
+
+```typescript
+server.registerPrompt(
+  "summarize",
+  {
+    title: "Summarize document",
+    description: "Generate a concise summary of the given text",
+    argsSchema: { text: z.string(), max_words: z.string().optional() },
+  },
+  ({ text, max_words }) => ({
+    messages: [{
+      role: "user",
+      content: { type: "text", text: `Summarize in ${max_words ?? "100"} words:\n\n${text}` },
+    }],
+  }),
+);
+```
+
+```python
+@mcp.prompt
+def summarize(text: str, max_words: str = "100") -> str:
+    """Generate a concise summary of the given text."""
+    return f"Summarize in {max_words} words:\n\n{text}"
+```
+
+**Constraints:**
+- Arguments are **string-only** (no numbers, booleans, objects) — convert inside the handler
+- Returns a `messages[]` array — can include embedded resources/images, not just text
+- No side effects — the handler just builds a message, it doesn't *do* anything
+
+---
+
+## Quick decision table
+
+| You want to... | Use |
+|---|---|
+| Let Claude fetch something on demand, with parameters | **Tool** |
+| Expose browsable context (files, docs, schemas) | **Resource** |
+| Expose a dynamic family of things (`db://{table}`) | **Resource template** |
+| Give users a one-click workflow | **Prompt** |
+| Ask the user something mid-tool | **Elicitation** (see `elicitation.md`) |

plugins/mcp-server-dev/skills/build-mcp-server/references/server-capabilities.md

@@ -0,0 +1,164 @@
+# Server capabilities — the rest of the spec
+
+Features beyond the three core primitives. Most are optional, a few are near-free wins.
+
+---
+
+## `instructions` — system prompt injection
+
+One line of config, lands directly in Claude's system prompt. Use it for tool-use hints that don't fit in individual tool descriptions.
+
+```typescript
+const server = new McpServer(
+  { name: "my-server", version: "1.0.0" },
+  { instructions: "Always call search_items before get_item — IDs aren't guessable." },
+);
+```
+
+```python
+mcp = FastMCP("my-server", instructions="Always call search_items before get_item — IDs aren't guessable.")
+```
+
+This is the highest-leverage one-liner in the spec. If Claude keeps misusing your tools, put the fix here.
+
+---
+
+## Sampling — delegate LLM calls to the host
+
+If your tool logic needs LLM inference (summarize, classify, generate), don't ship your own model client. Ask the host to do it.
+
+```typescript
+// Inside a tool handler
+const result = await extra.sendRequest({
+  method: "sampling/createMessage",
+  params: {
+    messages: [{ role: "user", content: { type: "text", text: `Summarize: ${doc}` } }],
+    maxTokens: 500,
+  },
+}, CreateMessageResultSchema);
+```
+
+```python
+# fastmcp
+response = await ctx.sample("Summarize this document", context=doc)
+```
+
+**Requires client support** — check `clientCapabilities.sampling` first. Model preference hints are substring-matched (`"claude-3-5"` matches any Claude 3.5 variant).
+
+---
+
+## Roots — query workspace boundaries
+
+Instead of hardcoding a root directory, ask the host which directories the user approved.
+
+```typescript
+const caps = server.getClientCapabilities();
+if (caps?.roots) {
+  const { roots } = await server.server.listRoots();
+  // roots: [{ uri: "file:///home/user/project", name: "My Project" }]
+}
+```
+
+```python
+roots = await ctx.list_roots()
+```
+
+Particularly relevant for MCPB local servers — see `build-mcpb/references/local-security.md`.
+
+---
+
+## Logging — structured, level-aware
+
+Better than stderr for remote servers. Client can filter by level.
+
+```typescript
+// In a tool handler
+await extra.sendNotification({
+  method: "notifications/message",
+  params: { level: "info", logger: "my-tool", data: { msg: "Processing", count: 42 } },
+});
+```
+
+```python
+await ctx.info("Processing", count=42)   # also: ctx.debug, ctx.warning, ctx.error
+```
+
+Levels follow syslog: `debug`, `info`, `notice`, `warning`, `error`, `critical`, `alert`, `emergency`. Client sets minimum via `logging/setLevel`.
+
+---
+
+## Progress — for long-running tools
+
+Client sends a `progressToken` in request `_meta`. Server emits progress notifications against it.
+
+```typescript
+async (args, extra) => {
+  const token = extra._meta?.progressToken;
+  for (let i = 0; i < 100; i++) {
+    if (token !== undefined) {
+      await extra.sendNotification({
+        method: "notifications/progress",
+        params: { progressToken: token, progress: i, total: 100, message: `Step ${i}` },
+      });
+    }
+    await doStep(i);
+  }
+  return { content: [{ type: "text", text: "Done" }] };
+}
+```
+
+```python
+async def long_task(ctx: Context) -> str:
+    for i in range(100):
+        await ctx.report_progress(progress=i, total=100, message=f"Step {i}")
+        await do_step(i)
+    return "Done"
+```
+
+---
+
+## Cancellation — honor the abort signal
+
+Long tools should check the SDK-provided `AbortSignal`:
+
+```typescript
+async (args, extra) => {
+  for (const item of items) {
+    if (extra.signal.aborted) throw new Error("Cancelled");
+    await process(item);
+  }
+}
+```
+
+fastmcp handles this via asyncio cancellation — no explicit check needed if your handler is properly async.
+
+---
+
+## Completion — autocomplete for prompt args
+
+If you've registered prompts or resource templates with arguments, you can offer autocomplete:
+
+```typescript
+server.registerPrompt("query", {
+  argsSchema: {
+    table: completable(z.string(), async (partial) => tables.filter(t => t.startsWith(partial))),
+  },
+}, ...);
+```
+
+Low priority unless your prompts have many valid values.
+
+---
+
+## Which capabilities need client support?
+
+| Feature | Server declares | Client must support | Fallback if not |
+|---|---|---|---|
+| `instructions` | implicit | — | — (always works) |
+| Logging | `logging: {}` | — | stderr |
+| Progress | — | sends `progressToken` | silently skip |
+| Sampling | — | `sampling: {}` | bring your own LLM |
+| Elicitation | — | `elicitation: {}` | return text, ask Claude to relay |
+| Roots | — | `roots: {}` | config env var |
+
+Check client caps via `server.getClientCapabilities()` (TS) or `ctx.session.client_params.capabilities` (fastmcp) before using the bottom three.

plugins/mcp-server-dev/skills/build-mcp-server/references/tool-design.md

@@ -0,0 +1,179 @@
+# Tool Design — Writing Tools Claude Uses Correctly
+
+Tool schemas and descriptions are prompt engineering. They land directly in Claude's context and determine whether Claude picks the right tool with the right arguments. Most MCP integration bugs trace back to vague descriptions or loose schemas.
+
+---
+
+## Descriptions
+
+**The description is the contract.** It's the only thing Claude reads before deciding whether to call the tool. Write it like a one-line manpage entry plus disambiguating hints.
+
+### Good
+
+```
+search_issues — Search issues by keyword across title and body. Returns up
+to `limit` results ranked by recency. Does NOT search comments or PRs —
+use search_comments / search_prs for those.
+```
+
+- Says what it does
+- Says what it returns
+- Says what it *doesn't* do (prevents wrong-tool calls)
+
+### Bad
+
+```
+search_issues — Searches for issues.
+```
+
+Claude will call this for anything vaguely search-shaped, including things it can't do.
+
+### Disambiguate siblings
+
+When two tools are similar, each description should say when to use the *other* one:
+
+```
+get_user      — Fetch a user by ID. If you only have an email, use find_user_by_email.
+find_user_by_email — Look up a user by email address. Returns null if not found.
+```
+
+---
+
+## Parameter schemas
+
+**Tight schemas prevent bad calls.** Every constraint you express in the schema is one fewer thing that can go wrong at runtime.
+
+| Instead of | Use |
+|---|---|
+| `z.string()` for an ID | `z.string().regex(/^usr_[a-z0-9]{12}$/)` |
+| `z.number()` for a limit | `z.number().int().min(1).max(100).default(20)` |
+| `z.string()` for a choice | `z.enum(["open", "closed", "all"])` |
+| optional with no hint | `.optional().describe("Defaults to the caller's workspace")` |
+
+**Describe every parameter.** The `.describe()` text shows up in the schema Claude sees. Omitting it is leaving money on the table.
+
+```typescript
+{
+  query: z.string().describe("Keywords to search for. Supports quoted phrases."),
+  status: z.enum(["open", "closed", "all"]).default("open")
+    .describe("Filter by status. Use 'all' to include closed items."),
+  limit: z.number().int().min(1).max(50).default(10)
+    .describe("Max results. Hard cap at 50."),
+}
+```
+
+---
+
+## Return shapes
+
+Claude reads whatever you put in `content[].text`. Make it parseable.
+
+**Do:**
+- Return JSON for structured data (`JSON.stringify(result, null, 2)`)
+- Return short confirmations for mutations (`"Created issue #123"`)
+- Include IDs Claude will need for follow-up calls
+- Truncate huge payloads and say so (`"Showing 10 of 847 results. Refine the query to narrow down."`)
+
+**Don't:**
+- Return raw HTML
+- Return megabytes of unfiltered API response
+- Return bare success with no identifier (`"ok"` after a create — Claude can't reference what it made)
+
+---
+
+## How many tools?
+
+| Tool count | Guidance |
+|---|---|
+| 1–15 | One tool per action. Sweet spot. |
+| 15–30 | Still workable. Audit for near-duplicates that could merge. |
+| 30+ | Switch to search + execute. Optionally promote the top 3–5 to dedicated tools. |
+
+The ceiling isn't a hard protocol limit — it's context-window economics. Every tool schema is tokens Claude spends *every turn*. Thirty tools with rich schemas can eat 3–5k tokens before the conversation even starts.
+
+---
+
+## Errors
+
+Return MCP tool errors, not exceptions that crash the transport. Include enough detail for Claude to recover or retry differently.
+
+```typescript
+if (!item) {
+  return {
+    isError: true,
+    content: [{
+      type: "text",
+      text: `Item ${id} not found. Use search_items to find valid IDs.`,
+    }],
+  };
+}
+```
+
+The hint ("use search_items…") turns a dead end into a next step.
+
+---
+
+## Tool annotations
+
+Hints the host uses for UX — red confirm button for destructive, auto-approve for readonly. All default to unset (host assumes worst case).
+
+| Annotation | Meaning | Host behavior |
+|---|---|---|
+| `readOnlyHint: true` | No side effects | May auto-approve |
+| `destructiveHint: true` | Deletes/overwrites | Confirmation dialog |
+| `idempotentHint: true` | Safe to retry | May retry on transient error |
+| `openWorldHint: true` | Talks to external world (web, APIs) | May show network indicator |
+
+```typescript
+server.registerTool("delete_file", {
+  description: "Delete a file",
+  inputSchema: { path: z.string() },
+  annotations: { destructiveHint: true, idempotentHint: false },
+}, handler);
+```
+
+```python
+@mcp.tool(annotations={"destructiveHint": True, "idempotentHint": False})
+def delete_file(path: str) -> str:
+    ...
+```
+
+Pair with the read/write split advice in `build-mcpb/references/local-security.md` — mark every read tool `readOnlyHint: true`.
+
+---
+
+## Structured output
+
+`JSON.stringify(result)` in a text block works, but the spec has first-class typed output: `outputSchema` + `structuredContent`. Clients can validate.
+
+```typescript
+server.registerTool("get_weather", {
+  description: "Get current weather",
+  inputSchema: { city: z.string() },
+  outputSchema: { temp: z.number(), conditions: z.string() },
+}, async ({ city }) => {
+  const data = await fetchWeather(city);
+  return {
+    content: [{ type: "text", text: JSON.stringify(data) }],  // backward compat
+    structuredContent: data,                                    // typed output
+  };
+});
+```
+
+Always include the text fallback — not all hosts read `structuredContent` yet.
+
+---
+
+## Content types beyond text
+
+Tools can return more than strings:
+
+| Type | Shape | Use for |
+|---|---|---|
+| `text` | `{ type: "text", text: string }` | Default |
+| `image` | `{ type: "image", data: base64, mimeType }` | Screenshots, charts, diagrams |
+| `audio` | `{ type: "audio", data: base64, mimeType }` | TTS output, recordings |
+| `resource_link` | `{ type: "resource_link", uri, name?, description? }` | Pointer — client fetches later |
+| `resource` (embedded) | `{ type: "resource", resource: { uri, text\|blob, mimeType } }` | Inline the full content |
+
+**`resource_link` vs embedded:** link for large payloads or when the client might not need it (let them decide). Embed when it's small and always needed.

plugins/mcp-server-dev/skills/build-mcp-server/references/versions.md

@@ -0,0 +1,25 @@
+# Version pins
+
+Every version-sensitive claim in this skill, in one place. When updating the skill, check these first.
+
+| Claim | Where stated | Last verified |
+|---|---|---|
+| `@modelcontextprotocol/ext-apps@1.2.2` CDN pin | `build-mcp-app/SKILL.md`, `build-mcp-app/references/widget-templates.md` (4×) | 2026-03 |
+| Claude Code ≥2.1.76 for elicitation | `elicitation.md:15`, `build-mcp-server/SKILL.md:43,76` | 2026-03 |
+| MCP spec 2025-11-25 CIMD/DCR status | `auth.md:20,24,41` | 2026-03 |
+| MCPB manifest schema v0.4 | `build-mcpb/references/manifest-schema.md` | 2026-03 |
+| CF `agents` SDK / `McpAgent` API | `deploy-cloudflare-workers.md` | 2026-03 |
+| CF template path `cloudflare/ai/demos/remote-mcp-authless` | `deploy-cloudflare-workers.md` | 2026-03 |
+
+## How to verify
+
+```bash
+# ext-apps latest
+npm view @modelcontextprotocol/ext-apps version
+
+# CF template still exists
+gh api repos/cloudflare/ai/contents/demos/remote-mcp-authless/src/index.ts --jq '.sha'
+
+# MCPB schema
+curl -sI https://raw.githubusercontent.com/anthropics/mcpb/main/schemas/mcpb-manifest-v0.4.schema.json | head -1
+```

plugins/mcp-server-dev/skills/build-mcpb/SKILL.md

@@ -0,0 +1,197 @@
+---
+name: build-mcpb
+description: This skill should be used when the user wants to "package an MCP server", "bundle an MCP", "make an MCPB", "ship a local MCP server", "distribute a local MCP", discusses ".mcpb files", mentions bundling a Node or Python runtime with their MCP server, or needs an MCP server that interacts with the local filesystem, desktop apps, or OS and must be installable without the user having Node/Python set up.
+version: 0.1.0
+---
+
+# Build an MCPB (Bundled Local MCP Server)
+
+MCPB is a local MCP server **packaged with its runtime**. The user installs one file; it runs without needing Node, Python, or any toolchain on their machine. It's the sanctioned way to distribute local MCP servers.
+
+**Use MCPB when the server must run on the user's machine** — reading local files, driving a desktop app, talking to localhost services, OS-level APIs. If your server only hits cloud APIs, you almost certainly want a remote HTTP server instead (see `build-mcp-server`). Don't pay the MCPB packaging tax for something that could be a URL.
+
+---
+
+## What an MCPB bundle contains
+
+```
+my-server.mcpb              (zip archive)
+├── manifest.json           ← identity, entry point, config schema, compatibility
+├── server/                 ← your MCP server code
+│   ├── index.js
+│   └── node_modules/       ← bundled dependencies (or vendored)
+└── icon.png
+```
+
+The host reads `manifest.json`, launches `server.mcp_config.command` as a **stdio** MCP server, and pipes messages. From your code's perspective it's identical to a local stdio server — the only difference is packaging.
+
+---
+
+## Manifest
+
+```json
+{
+  "$schema": "https://raw.githubusercontent.com/anthropics/mcpb/main/schemas/mcpb-manifest-v0.4.schema.json",
+  "manifest_version": "0.4",
+  "name": "local-files",
+  "version": "0.1.0",
+  "description": "Read, search, and watch files on the local filesystem.",
+  "author": { "name": "Your Name" },
+  "server": {
+    "type": "node",
+    "entry_point": "server/index.js",
+    "mcp_config": {
+      "command": "node",
+      "args": ["${__dirname}/server/index.js"],
+      "env": {
+        "ROOT_DIR": "${user_config.rootDir}"
+      }
+    }
+  },
+  "user_config": {
+    "rootDir": {
+      "type": "directory",
+      "title": "Root directory",
+      "description": "Directory to expose. Defaults to ~/Documents.",
+      "default": "${HOME}/Documents",
+      "required": true
+    }
+  },
+  "compatibility": {
+    "claude_desktop": ">=1.0.0",
+    "platforms": ["darwin", "win32", "linux"]
+  }
+}
+```
+
+**`server.type`** — `node`, `python`, or `binary`. Informational; the actual launch comes from `mcp_config`.
+
+**`server.mcp_config`** — the literal command/args/env to spawn. Use `${__dirname}` for bundle-relative paths and `${user_config.<key>}` to substitute install-time config. **There's no auto-prefix** — the env var names your server reads are exactly what you put in `env`.
+
+**`user_config`** — install-time settings surfaced in the host's UI. `type: "directory"` renders a native folder picker. `sensitive: true` stores in OS keychain. See `references/manifest-schema.md` for all fields.
+
+---
+
+## Server code: same as local stdio
+
+The server itself is a standard stdio MCP server. Nothing MCPB-specific in the tool logic.
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
+import { z } from "zod";
+import { readFile, readdir } from "node:fs/promises";
+import { join } from "node:path";
+import { homedir } from "node:os";
+
+// ROOT_DIR comes from what you put in manifest's server.mcp_config.env — no auto-prefix
+const ROOT = (process.env.ROOT_DIR ?? join(homedir(), "Documents"));
+
+const server = new McpServer({ name: "local-files", version: "0.1.0" });
+
+server.registerTool(
+  "list_files",
+  {
+    description: "List files in a directory under the configured root.",
+    inputSchema: { path: z.string().default(".") },
+    annotations: { readOnlyHint: true },
+  },
+  async ({ path }) => {
+    const entries = await readdir(join(ROOT, path), { withFileTypes: true });
+    const list = entries.map(e => ({ name: e.name, dir: e.isDirectory() }));
+    return { content: [{ type: "text", text: JSON.stringify(list, null, 2) }] };
+  },
+);
+
+server.registerTool(
+  "read_file",
+  {
+    description: "Read a file's contents. Path is relative to the configured root.",
+    inputSchema: { path: z.string() },
+    annotations: { readOnlyHint: true },
+  },
+  async ({ path }) => {
+    const text = await readFile(join(ROOT, path), "utf8");
+    return { content: [{ type: "text", text }] };
+  },
+);
+
+const transport = new StdioServerTransport();
+await server.connect(transport);
+```
+
+**Sandboxing is entirely your job.** There is no manifest-level sandbox — the process runs with full user privileges. Validate paths, refuse to escape `ROOT`, allowlist spawns. See `references/local-security.md`.
+
+Before hardcoding `ROOT` from a config env var, check if the host supports `roots/list` — the spec-native way to get user-approved directories. See `references/local-security.md` for the pattern.
+
+---
+
+## Build pipeline
+
+### Node
+
+```bash
+npm install
+npx esbuild src/index.ts --bundle --platform=node --outfile=server/index.js
+# or: copy node_modules wholesale if native deps resist bundling
+npx @anthropic-ai/mcpb pack
+```
+
+`mcpb pack` zips the directory and validates `manifest.json` against the schema.
+
+### Python
+
+```bash
+pip install -t server/vendor -r requirements.txt
+npx @anthropic-ai/mcpb pack
+```
+
+Vendor dependencies into a subdirectory and prepend it to `sys.path` in your entry script. Native extensions (numpy, etc.) must be built for each target platform — avoid native deps if you can.
+
+---
+
+## MCPB has no sandbox — security is on you
+
+Unlike mobile app stores, MCPB does NOT enforce permissions. The manifest has no `permissions` block — the server runs with full user privileges. `references/local-security.md` is mandatory reading, not optional. Every path must be validated, every spawn must be allowlisted, because nothing stops you at the platform level.
+
+If you came here expecting filesystem/network scoping from the manifest: it doesn't exist. Build it yourself in tool handlers.
+
+If your server's only job is hitting a cloud API, stop — that's a remote server wearing an MCPB costume. The user gains nothing from running it locally, and you're taking on local-security burden for no reason.
+
+---
+
+## MCPB + UI widgets
+
+MCPB servers can serve UI resources exactly like remote MCP apps — the widget mechanism is transport-agnostic. A local file picker that browses the actual disk, a dialog that controls a native app, etc.
+
+Widget authoring is covered in the **`build-mcp-app`** skill; it works the same here. The only difference is where the server runs.
+
+---
+
+## Testing
+
+```bash
+# Interactive manifest creation (first time)
+npx @anthropic-ai/mcpb init
+
+# Run the server directly over stdio, poke it with the inspector
+npx @modelcontextprotocol/inspector node server/index.js
+
+# Validate manifest against schema, then pack
+npx @anthropic-ai/mcpb validate
+npx @anthropic-ai/mcpb pack
+
+# Sign for distribution
+npx @anthropic-ai/mcpb sign dist/local-files.mcpb
+
+# Install: drag the .mcpb file onto Claude Desktop
+```
+
+Test on a machine **without** your dev toolchain before shipping. "Works on my machine" failures in MCPB almost always trace to a dependency that wasn't actually bundled.
+
+---
+
+## Reference files
+
+- `references/manifest-schema.md` — full `manifest.json` field reference
+- `references/local-security.md` — path traversal, sandboxing, least privilege

plugins/mcp-server-dev/skills/build-mcpb/references/local-security.md

@@ -0,0 +1,149 @@
+# Local MCP Security
+
+**MCPB provides no sandbox.** There's no `permissions` block in the manifest, no filesystem scoping, no network allowlist enforced by the platform. The server process runs with the user's full privileges — it can read any file the user can, spawn any process, hit any network endpoint.
+
+Claude drives it. That combination means: **tool inputs are untrusted**, even though they come from an AI the user trusts. A prompt-injected web page can make Claude call your `delete_file` tool with a path you didn't intend.
+
+Your tool handlers are the only defense. Everything below is about building that defense yourself.
+
+---
+
+## Path traversal
+
+The #1 bug in local MCP servers. If you take a path parameter and join it to a root, **resolve and check containment**.
+
+```typescript
+import { resolve, relative, isAbsolute } from "node:path";
+
+function safeJoin(root: string, userPath: string): string {
+  const full = resolve(root, userPath);
+  const rel = relative(root, full);
+  if (rel.startsWith("..") || isAbsolute(rel)) {
+    throw new Error(`Path escapes root: ${userPath}`);
+  }
+  return full;
+}
+```
+
+`resolve` normalizes `..`, symlink segments, etc. `relative` tells you if the result left the root. Don't just `String.includes("..")` — that misses encoded and symlink-based escapes.
+
+**Python equivalent:**
+
+```python
+from pathlib import Path
+
+def safe_join(root: Path, user_path: str) -> Path:
+    full = (root / user_path).resolve()
+    if not full.is_relative_to(root.resolve()):
+        raise ValueError(f"Path escapes root: {user_path}")
+    return full
+```
+
+---
+
+## Roots — ask the host, don't hardcode
+
+Before hardcoding `ROOT` from a config env var, check if the host supports `roots/list`. This is the spec-native way to get user-approved workspace boundaries.
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+
+const server = new McpServer({ name: "...", version: "..." });
+
+let allowedRoots: string[] = [];
+server.server.oninitialized = async () => {
+  const caps = server.getClientCapabilities();
+  if (caps?.roots) {
+    const { roots } = await server.server.listRoots();
+    allowedRoots = roots.map(r => new URL(r.uri).pathname);
+  } else {
+    allowedRoots = [process.env.ROOT_DIR ?? process.cwd()];
+  }
+};
+```
+
+```python
+# fastmcp — inside a tool handler
+async def my_tool(ctx: Context) -> str:
+    try:
+        roots = await ctx.list_roots()
+        allowed = [urlparse(r.uri).path for r in roots]
+    except Exception:
+        allowed = [os.environ.get("ROOT_DIR", os.getcwd())]
+```
+
+If roots are available, use them. If not, fall back to config. Either way, validate every path against the allowed set.
+
+---
+
+## Command injection
+
+If you spawn processes, **never pass user input through a shell**.
+
+```typescript
+// ❌ catastrophic
+exec(`git log ${branch}`);
+
+// ✅ array-args, no shell
+execFile("git", ["log", branch]);
+```
+
+If you're wrapping a CLI, build the full argv as an array. Validate each flag against an allowlist if the tool accepts flags at all.
+
+---
+
+## Read-only by default
+
+Split read and write into separate tools. Most workflows only need read. A tool that's read-only can't be weaponized into data loss no matter what Claude is tricked into calling it with.
+
+```
+list_files   ← safe to call freely
+read_file    ← safe to call freely
+write_file   ← separate tool, separate scrutiny
+delete_file  ← consider not shipping this at all
+```
+
+Pair this with tool annotations — `readOnlyHint: true` on every read tool, `destructiveHint: true` on delete/overwrite tools. Hosts surface these in permission UI (auto-approve reads, confirm-dialog destructive). See `../build-mcp-server/references/tool-design.md`.
+
+If you ship write/delete, consider requiring explicit confirmation via elicitation (see `../build-mcp-server/references/elicitation.md`) or a confirmation widget (see `build-mcp-app`) so the user approves each destructive call.
+
+---
+
+## Resource limits
+
+Claude will happily ask to read a 4GB log file. Cap everything:
+
+```typescript
+const MAX_BYTES = 1_000_000;
+const buf = await readFile(path);
+if (buf.length > MAX_BYTES) {
+  return {
+    content: [{
+      type: "text",
+      text: `File is ${buf.length} bytes — too large. Showing first ${MAX_BYTES}:\n\n`
+            + buf.subarray(0, MAX_BYTES).toString("utf8"),
+    }],
+  };
+}
+```
+
+Same for directory listings (cap entry count), search results (cap matches), and anything else unbounded.
+
+---
+
+## Secrets
+
+- **Config secrets** (`sensitive: true` in manifest `user_config`): host stores in OS keychain, delivers via env var. Don't log them. Don't include them in tool results.
+- **Never store secrets in plaintext files.** If the host's keychain integration isn't enough, use `keytar` (Node) / `keyring` (Python) yourself.
+- **Tool results flow into the chat transcript.** Anything you return, the user (and any log export) can see. Redact before returning.
+
+---
+
+## Checklist before shipping
+
+- [ ] Every path parameter goes through containment check
+- [ ] No `exec()` / `shell=True` — `execFile` / array-argv only
+- [ ] Write/delete split from read tools; `readOnlyHint`/`destructiveHint` annotations set
+- [ ] Size caps on file reads, listing lengths, search results
+- [ ] Secrets never logged or returned in tool results
+- [ ] Tested with adversarial inputs: `../../etc/passwd`, `; rm -rf ~`, 10GB file

plugins/mcp-server-dev/skills/build-mcpb/references/manifest-schema.md

@@ -0,0 +1,156 @@
+# MCPB Manifest Schema (v0.4)
+
+Validated against `github.com/anthropics/mcpb/schemas/mcpb-manifest-v0.4.schema.json`. The schema uses `additionalProperties: false` — unknown keys are rejected. Add `"$schema"` to your manifest for editor validation.
+
+---
+
+## Top-level fields
+
+| Field | Required | Description |
+|---|---|---|
+| `manifest_version` | ✅ | Schema version. Use `"0.4"`. |
+| `name` | ✅ | Package identifier (lowercase, hyphens). Must be unique. |
+| `version` | ✅ | Semver version of YOUR package. |
+| `description` | ✅ | One-line summary. Shown in marketplace. |
+| `author` | ✅ | `{name, email?, url?}` |
+| `server` | ✅ | Entry point and launch config. See below. |
+| `display_name` | | Human-friendly name. Falls back to `name`. |
+| `long_description` | | Markdown. Shown on detail page. |
+| `icon` / `icons` | | Path(s) to icon file(s) in the bundle. |
+| `homepage` / `repository` / `documentation` / `support` | | URLs. |
+| `license` | | SPDX identifier. |
+| `keywords` | | String array for search. |
+| `user_config` | | Install-time config fields. See below. |
+| `compatibility` | | Host/platform/runtime requirements. See below. |
+| `tools` / `prompts` | | Optional declarative list for marketplace display. Not enforced at runtime. |
+| `tools_generated` / `prompts_generated` | | `true` if tools/prompts are dynamic (can't list statically). |
+| `screenshots` | | Array of image paths. |
+| `localization` | | i18n bundles. |
+| `privacy_policies` | | URLs. |
+
+---
+
+## `server` — launch configuration
+
+```json
+"server": {
+  "type": "node",
+  "entry_point": "server/index.js",
+  "mcp_config": {
+    "command": "node",
+    "args": ["${__dirname}/server/index.js"],
+    "env": {
+      "API_KEY": "${user_config.apiKey}",
+      "ROOT_DIR": "${user_config.rootDir}"
+    }
+  }
+}
+```
+
+| Field | Description |
+|---|---|
+| `type` | `"node"`, `"python"`, or `"binary"` |
+| `entry_point` | Relative path to main file. Informational. |
+| `mcp_config.command` | Executable to launch. |
+| `mcp_config.args` | Argv array. Use `${__dirname}` for bundle-relative paths. |
+| `mcp_config.env` | Environment variables. Use `${user_config.KEY}` to substitute user config. |
+
+**Substitution variables** (in `args` and `env` only):
+- `${__dirname}` — absolute path to the unpacked bundle directory
+- `${user_config.<key>}` — value the user entered at install time
+- `${HOME}` — user's home directory
+
+**There are no auto-prefixed env vars.** The env var names your server reads are exactly what you declare in `mcp_config.env`. If you write `"ROOT_DIR": "${user_config.rootDir}"`, your server reads `process.env.ROOT_DIR`.
+
+---
+
+## `user_config` — install-time settings
+
+```json
+"user_config": {
+  "apiKey": {
+    "type": "string",
+    "title": "API Key",
+    "description": "Your service API key. Stored encrypted.",
+    "sensitive": true,
+    "required": true
+  },
+  "rootDir": {
+    "type": "directory",
+    "title": "Root directory",
+    "description": "Directory to expose to the server.",
+    "default": "${HOME}/Documents"
+  },
+  "maxResults": {
+    "type": "number",
+    "title": "Max results",
+    "description": "Maximum items returned per query.",
+    "default": 50,
+    "min": 1,
+    "max": 500
+  }
+}
+```
+
+| Field | Required | Description |
+|---|---|---|
+| `type` | ✅ | `"string"`, `"number"`, `"boolean"`, `"directory"`, `"file"` |
+| `title` | ✅ | Form label. |
+| `description` | ✅ | Help text under the input. |
+| `default` | | Pre-filled value. Supports `${HOME}`. |
+| `required` | | If `true`, install blocks until filled. |
+| `sensitive` | | If `true`, stored in OS keychain + masked in UI. **NOT `secret`** — that field doesn't exist. |
+| `multiple` | | If `true`, user can enter multiple values (array). |
+| `min` / `max` | | Numeric bounds (for `type: "number"`). |
+
+`directory` and `file` types render native OS pickers — prefer these over free-text paths for UX and validation.
+
+---
+
+## `compatibility` — gate installs
+
+```json
+"compatibility": {
+  "claude_desktop": ">=1.0.0",
+  "platforms": ["darwin", "win32", "linux"],
+  "runtimes": { "node": ">=20" }
+}
+```
+
+| Field | Description |
+|---|---|
+| `claude_desktop` | Semver range. Install blocked if host is older. |
+| `platforms` | OS allowlist. Subset of `["darwin", "win32", "linux"]`. |
+| `runtimes` | Required runtime versions, e.g. `{"node": ">=20"}` or `{"python": ">=3.11"}`. |
+
+---
+
+## Minimal valid manifest
+
+```json
+{
+  "$schema": "https://raw.githubusercontent.com/anthropics/mcpb/main/schemas/mcpb-manifest-v0.4.schema.json",
+  "manifest_version": "0.4",
+  "name": "hello",
+  "version": "0.1.0",
+  "description": "Minimal MCPB server.",
+  "author": { "name": "Your Name" },
+  "server": {
+    "type": "node",
+    "entry_point": "server/index.js",
+    "mcp_config": {
+      "command": "node",
+      "args": ["${__dirname}/server/index.js"]
+    }
+  }
+}
+```
+
+---
+
+## What MCPB does NOT have
+
+- **No `permissions` block.** There is no manifest-level filesystem/network/process scoping. The server runs with full user privileges. Enforce boundaries in your tool handlers — see `local-security.md`.
+- **No auto env var prefix.** No `MCPB_CONFIG_*` convention. You wire config → env explicitly in `server.mcp_config.env`.
+- **No `entry` field.** It's `server` with `entry_point` inside.
+- **No `minHostVersion`.** It's `compatibility.claude_desktop`.

plugins/plugin-dev/commands/create-plugin.md

@@ -1,7 +1,18 @@
 ---
 description: Guided end-to-end plugin creation workflow with component design, implementation, and validation
 argument-hint: Optional plugin description
-allowed-tools: ["Read", "Write", "Grep", "Glob", "Bash", "TodoWrite", "AskUserQuestion", "Skill", "Task"]
+allowed-tools:
+  [
+    "Read",
+    "Write",
+    "Grep",
+    "Glob",
+    "Bash",
+    "TodoWrite",
+    "AskUserQuestion",
+    "Skill",
+    "Task",
+  ]
 ---
 
 # Plugin Creation Workflow
@@ -26,6 +37,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Goal**: Understand what plugin needs to be built and what problem it solves
 
 **Actions**:
+
 1. Create todo list with all 7 phases
 2. If plugin purpose is clear from arguments:
    - Summarize understanding
@@ -48,14 +60,17 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **MUST load plugin-structure skill** using Skill tool before this phase.
 
 **Actions**:
+
 1. Load plugin-structure skill to understand component types
 2. Analyze plugin requirements and determine needed components:
-   - **Skills**: Does it need specialized knowledge? (hooks API, MCP patterns, etc.)
-   - **Commands**: User-initiated actions? (deploy, configure, analyze)
+   - **Skills**: Specialized knowledge OR user-initiated actions (deploy, configure, analyze). Skills are the preferred format for both — see note below.
    - **Agents**: Autonomous tasks? (validation, generation, analysis)
    - **Hooks**: Event-driven automation? (validation, notifications)
    - **MCP**: External service integration? (databases, APIs)
    - **Settings**: User configuration? (.local.md files)
+
+   > **Note:** The `commands/` directory is a legacy format. For new plugins, user-invoked slash commands should be created as skills in `skills/<name>/SKILL.md`. Both are loaded identically — the only difference is file layout. `commands/` remains an acceptable legacy alternative.
+
 3. For each component type needed, identify:
    - How many of each type
    - What each one does
@@ -64,8 +79,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
    ```
    | Component Type | Count | Purpose |
    |----------------|-------|---------|
-   | Skills         | 2     | Hook patterns, MCP usage |
-   | Commands       | 3     | Deploy, configure, validate |
+   | Skills         | 5     | Hook patterns, MCP usage, deploy, configure, validate |
    | Agents         | 1     | Autonomous validation |
    | Hooks          | 0     | Not needed |
    | MCP            | 1     | Database integration |
@@ -83,9 +97,9 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **CRITICAL**: This is one of the most important phases. DO NOT SKIP.
 
 **Actions**:
+
 1. For each component in the plan, identify underspecified aspects:
-   - **Skills**: What triggers them? What knowledge do they provide? How detailed?
-   - **Commands**: What arguments? What tools? Interactive or automated?
+   - **Skills**: What triggers them? What knowledge do they provide? How detailed? For user-invoked skills: what arguments, what tools, interactive or automated?
    - **Agents**: When to trigger (proactive/reactive)? What tools? Output format?
    - **Hooks**: Which events? Prompt or command based? Validation criteria?
    - **MCP**: What server type? Authentication? Which tools?
@@ -98,12 +112,14 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 4. If user says "whatever you think is best", provide specific recommendations and get explicit confirmation
 
 **Example questions for a skill**:
+
 - What specific user queries should trigger this skill?
 - Should it include utility scripts? What functionality?
 - How detailed should the core SKILL.md be vs references/?
 - Any real-world examples to include?
 
 **Example questions for an agent**:
+
 - Should this agent trigger proactively after certain actions, or only when explicitly requested?
 - What tools does it need (Read, Write, Bash, etc.)?
 - What should the output format be?
@@ -118,6 +134,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Goal**: Create plugin directory structure and manifest
 
 **Actions**:
+
 1. Determine plugin name (kebab-case, descriptive)
 2. Choose plugin location:
    - Ask user: "Where should I create the plugin?"
@@ -125,10 +142,10 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 3. Create directory structure using bash:
    ```bash
    mkdir -p plugin-name/.claude-plugin
-   mkdir -p plugin-name/skills     # if needed
-   mkdir -p plugin-name/commands   # if needed
-   mkdir -p plugin-name/agents     # if needed
-   mkdir -p plugin-name/hooks      # if needed
+   mkdir -p plugin-name/skills/<skill-name>   # one dir per skill, each with a SKILL.md
+   mkdir -p plugin-name/agents                # if needed
+   mkdir -p plugin-name/hooks                 # if needed
+   # Note: plugin-name/commands/ is a legacy alternative to skills/ — prefer skills/
    ```
 4. Create plugin.json manifest using Write tool:
    ```json
@@ -143,7 +160,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
    }
    ```
 5. Create README.md template
-6. Create .gitignore if needed (for .claude/*.local.md, etc.)
+6. Create .gitignore if needed (for .claude/\*.local.md, etc.)
 7. Initialize git repo if creating new directory
 
 **Output**: Plugin directory structure created and ready for components
@@ -155,8 +172,9 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Goal**: Create each component following best practices
 
 **LOAD RELEVANT SKILLS** before implementing each component type:
+
 - Skills: Load skill-development skill
-- Commands: Load command-development skill
+- Legacy `commands/` format (only if user explicitly requests): Load command-development skill
 - Agents: Load agent-development skill
 - Hooks: Load hook-development skill
 - MCP: Load mcp-integration skill
@@ -165,21 +183,26 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Actions for each component**:
 
 ### For Skills:
+
 1. Load skill-development skill using Skill tool
 2. For each skill:
    - Ask user for concrete usage examples (or use from Phase 3)
    - Plan resources (scripts/, references/, examples/)
-   - Create skill directory structure
-   - Write SKILL.md with:
+   - Create skill directory: `skills/<skill-name>/`
+   - Write `SKILL.md` with:
      - Third-person description with specific trigger phrases
      - Lean body (1,500-2,000 words) in imperative form
      - References to supporting files
+   - For user-invoked skills (slash commands): include `description`, `argument-hint`, and `allowed-tools` frontmatter; write instructions FOR Claude (not TO user)
    - Create reference files for detailed content
    - Create example files for working code
    - Create utility scripts if needed
 3. Use skill-reviewer agent to validate each skill
 
-### For Commands:
+### For legacy `commands/` format (only if user explicitly requests):
+
+> Prefer `skills/<name>/SKILL.md` for new plugins. Use `commands/` only when maintaining an existing plugin that already uses this layout.
+
 1. Load command-development skill using Skill tool
 2. For each command:
    - Write command markdown with frontmatter
@@ -190,6 +213,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
    - Reference relevant skills if applicable
 
 ### For Agents:
+
 1. Load agent-development skill using Skill tool
 2. For each agent, use agent-creator agent:
    - Provide description of what agent should do
@@ -199,6 +223,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
    - Validate with validate-agent.sh script
 
 ### For Hooks:
+
 1. Load hook-development skill using Skill tool
 2. For each hook:
    - Create hooks/hooks.json with hook configuration
@@ -208,6 +233,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
    - Test with validate-hook-schema.sh and test-hook.sh utilities
 
 ### For MCP:
+
 1. Load mcp-integration skill using Skill tool
 2. Create .mcp.json configuration with:
    - Server type (stdio for local, SSE for hosted)
@@ -218,6 +244,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 4. Provide setup instructions
 
 ### For Settings:
+
 1. Load plugin-settings skill using Skill tool
 2. Create settings template in README
 3. Create example .claude/plugin-name.local.md file (as documentation)
@@ -235,6 +262,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Goal**: Ensure plugin meets quality standards and works correctly
 
 **Actions**:
+
 1. **Run plugin-validator agent**:
    - Use plugin-validator agent to comprehensively validate plugin
    - Check: manifest, structure, naming, components, security
@@ -275,6 +303,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Goal**: Test that plugin works correctly in Claude Code
 
 **Actions**:
+
 1. **Installation instructions**:
    - Show user how to test locally:
      ```bash
@@ -284,7 +313,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 
 2. **Verification checklist** for user to perform:
    - [ ] Skills load when triggered (ask questions with trigger phrases)
-   - [ ] Commands appear in `/help` and execute correctly
+   - [ ] User-invoked skills appear in `/help` and execute correctly
    - [ ] Agents trigger on appropriate scenarios
    - [ ] Hooks activate on events (if applicable)
    - [ ] MCP servers connect (if applicable)
@@ -292,7 +321,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 
 3. **Testing recommendations**:
    - For skills: Ask questions using trigger phrases from descriptions
-   - For commands: Run `/plugin-name:command-name` with various arguments
+   - For user-invoked skills: Run `/plugin-name:skill-name` with various arguments
    - For agents: Create scenarios matching agent examples
    - For hooks: Use `claude --debug` to see hook execution
    - For MCP: Use `/mcp` to verify servers and tools
@@ -310,6 +339,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 **Goal**: Ensure plugin is well-documented and ready for distribution
 
 **Actions**:
+
 1. **Verify README completeness**:
    - Check README has: overview, features, installation, prerequisites, usage
    - For MCP plugins: Document required environment variables
@@ -325,7 +355,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
    - Mark all todos complete
    - List what was created:
      - Plugin name and purpose
-     - Components created (X skills, Y commands, Z agents, etc.)
+     - Components created (X skills, Y agents, etc.)
      - Key files and their purposes
      - Total file count and structure
    - Next steps:
@@ -354,7 +384,7 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 - **Apply best practices**:
   - Third-person descriptions for skills
   - Imperative form in skill bodies
-  - Commands written FOR Claude
+  - Skill instructions written FOR Claude (not TO user)
   - Strong trigger phrases
   - ${CLAUDE_PLUGIN_ROOT} for portability
   - Progressive disclosure
@@ -371,12 +401,13 @@ Guide the user through creating a complete, high-quality Claude Code plugin from
 ### Skills to Load by Phase
 
 - **Phase 2**: plugin-structure
-- **Phase 5**: skill-development, command-development, agent-development, hook-development, mcp-integration, plugin-settings (as needed)
+- **Phase 5**: skill-development, agent-development, hook-development, mcp-integration, plugin-settings (as needed); command-development only for legacy `commands/` layout
 - **Phase 6**: (agents will use skills automatically)
 
 ### Quality Standards
 
 Every component must meet these standards:
+
 - ✅ Follows plugin-dev's proven patterns
 - ✅ Uses correct naming conventions
 - ✅ Has strong trigger conditions (skills/agents)
@@ -390,19 +421,22 @@ Every component must meet these standards:
 ## Example Workflow
 
 ### User Request
+
 "Create a plugin for managing database migrations"
 
 ### Phase 1: Discovery
+
 - Understand: Migration management, database schema versioning
 - Confirm: User wants to create, run, rollback migrations
 
 ### Phase 2: Component Planning
-- Skills: 1 (migration best practices)
-- Commands: 3 (create-migration, run-migrations, rollback)
+
+- Skills: 4 (migration best practices, create-migration, run-migrations, rollback)
 - Agents: 1 (migration-validator)
 - MCP: 1 (database connection)
 
 ### Phase 3: Clarifying Questions
+
 - Which databases? (PostgreSQL, MySQL, etc.)
 - Migration file format? (SQL, code-based?)
 - Should agent validate before applying?

plugins/plugin-dev/skills/command-development/SKILL.md

@@ -6,11 +6,14 @@ version: 0.2.0
 
 # Command Development for Claude Code
 
+> **Note:** The `.claude/commands/` directory is a legacy format. For new skills, use the `.claude/skills/<name>/SKILL.md` directory format. Both are loaded identically — the only difference is file layout. See the `skill-development` skill for the preferred format.
+
 ## Overview
 
 Slash commands are frequently-used prompts defined as Markdown files that Claude executes during interactive sessions. Understanding command structure, frontmatter options, and dynamic features enables creating powerful, reusable workflows.
 
 **Key concepts:**
+
 - Markdown file format for commands
 - YAML frontmatter for configuration
 - Dynamic arguments and file references
@@ -22,6 +25,7 @@ Slash commands are frequently-used prompts defined as Markdown files that Claude
 ### What is a Slash Command?
 
 A slash command is a Markdown file containing a prompt that Claude executes when invoked. Commands provide:
+
 - **Reusability**: Define once, use repeatedly
 - **Consistency**: Standardize common workflows
 - **Sharing**: Distribute across team or projects
@@ -34,8 +38,10 @@ A slash command is a Markdown file containing a prompt that Claude executes when
 When a user invokes `/command-name`, the command content becomes Claude's instructions. Write commands as directives TO Claude about what to do, not as messages TO the user.
 
 **Correct approach (instructions for Claude):**
+
 ```markdown
 Review this code for security vulnerabilities including:
+
 - SQL injection
 - XSS attacks
 - Authentication issues
@@ -44,6 +50,7 @@ Provide specific line numbers and severity ratings.
 ```
 
 **Incorrect approach (messages to user):**
+
 ```markdown
 This command will review your code for security issues.
 You'll receive a report with vulnerability details.
@@ -54,18 +61,21 @@ The first example tells Claude what to do. The second tells the user what will h
 ### Command Locations
 
 **Project commands** (shared with team):
+
 - Location: `.claude/commands/`
 - Scope: Available in specific project
 - Label: Shown as "(project)" in `/help`
 - Use for: Team workflows, project-specific tasks
 
 **Personal commands** (available everywhere):
+
 - Location: `~/.claude/commands/`
 - Scope: Available in all projects
 - Label: Shown as "(user)" in `/help`
 - Use for: Personal workflows, cross-project utilities
 
 **Plugin commands** (bundled with plugins):
+
 - Location: `plugin-name/commands/`
 - Scope: Available when plugin installed
 - Label: Shown as "(plugin-name)" in `/help`
@@ -85,8 +95,10 @@ Commands are Markdown files with `.md` extension:
 ```
 
 **Simple command:**
+
 ```markdown
 Review this code for security vulnerabilities including:
+
 - SQL injection
 - XSS attacks
 - Authentication bypass
@@ -138,6 +150,7 @@ allowed-tools: Read, Write, Edit, Bash(git:*)
 ```
 
 **Patterns:**
+
 - `Read, Write, Edit` - Specific tools
 - `Bash(git:*)` - Bash with git commands only
 - `*` - All tools (rarely needed)
@@ -157,6 +170,7 @@ model: haiku
 ```
 
 **Use cases:**
+
 - `haiku` - Fast, simple commands
 - `sonnet` - Standard workflows
 - `opus` - Complex analysis
@@ -174,6 +188,7 @@ argument-hint: [pr-number] [priority] [assignee]
 ```
 
 **Benefits:**
+
 - Helps users understand command arguments
 - Improves command discovery
 - Documents command interface
@@ -208,12 +223,14 @@ Fix issue #$ARGUMENTS following our coding standards and best practices.
 ```
 
 **Usage:**
+
 ```
 > /fix-issue 123
 > /fix-issue 456
 ```
 
 **Expands to:**
+
 ```
 Fix issue #123 following our coding standards...
 Fix issue #456 following our coding standards...
@@ -234,11 +251,13 @@ After review, assign to $3 for follow-up.
 ```
 
 **Usage:**
+
 ```
 > /review-pr 123 high alice
 ```
 
 **Expands to:**
+
 ```
 Review pull request #123 with priority level high.
 After review, assign to alice for follow-up.
@@ -253,11 +272,13 @@ Deploy $1 to $2 environment with options: $3
 ```
 
 **Usage:**
+
 ```
 > /deploy api staging --force --skip-tests
 ```
 
 **Expands to:**
+
 ```
 Deploy api to staging environment with options: --force --skip-tests
 ```
@@ -275,12 +296,14 @@ argument-hint: [file-path]
 ---
 
 Review @$1 for:
+
 - Code quality
 - Best practices
 - Potential bugs
 ```
 
 **Usage:**
+
 ```
 > /review-file src/api/users.ts
 ```
@@ -295,6 +318,7 @@ Reference multiple files:
 Compare @src/old-version.js with @src/new-version.js
 
 Identify:
+
 - Breaking changes
 - New features
 - Bug fixes
@@ -308,6 +332,7 @@ Reference known files without arguments:
 Review @package.json and @tsconfig.json for consistency
 
 Ensure:
+
 - TypeScript version matches
 - Dependencies are aligned
 - Build configuration is correct
@@ -318,6 +343,7 @@ Ensure:
 Commands can execute bash commands inline to dynamically gather context before Claude processes the command. This is useful for including repository state, environment information, or project-specific context.
 
 **When to use:**
+
 - Include dynamic context (git status, environment vars, etc.)
 - Gather project/repository state
 - Build context-aware workflows
@@ -361,6 +387,7 @@ Organize commands in subdirectories:
 ```
 
 **Benefits:**
+
 - Logical grouping by category
 - Namespace shown in `/help`
 - Easier to find related commands
@@ -390,8 +417,8 @@ argument-hint: [pr-number]
 ---
 
 $IF($1,
-  Review PR #$1,
-  Please provide a PR number. Usage: /review-pr [number]
+Review PR #$1,
+Please provide a PR number. Usage: /review-pr [number]
 )
 ```
 
@@ -444,6 +471,7 @@ allowed-tools: Read, Bash(git:*)
 Files changed: !`git diff --name-only`
 
 Review each file for:
+
 1. Code quality and style
 2. Potential bugs or issues
 3. Test coverage
@@ -475,6 +503,7 @@ argument-hint: [source-file]
 ---
 
 Generate comprehensive documentation for @$1 including:
+
 - Function/class descriptions
 - Parameter documentation
 - Return value descriptions
@@ -502,23 +531,27 @@ PR #$1 Workflow:
 ## Troubleshooting
 
 **Command not appearing:**
+
 - Check file is in correct directory
 - Verify `.md` extension present
 - Ensure valid Markdown format
 - Restart Claude Code
 
 **Arguments not working:**
+
 - Verify `$1`, `$2` syntax correct
 - Check `argument-hint` matches usage
 - Ensure no extra spaces
 
 **Bash execution failing:**
+
 - Check `allowed-tools` includes Bash
 - Verify command syntax in backticks
 - Test command in terminal first
 - Check for required permissions
 
 **File references not working:**
+
 - Verify `@` syntax correct
 - Check file path is valid
 - Ensure Read tool allowed
@@ -531,6 +564,7 @@ PR #$1 Workflow:
 Plugin commands have access to `${CLAUDE_PLUGIN_ROOT}`, an environment variable that resolves to the plugin's absolute path.
 
 **Purpose:**
+
 - Reference plugin files portably
 - Execute plugin scripts
 - Load plugin configuration
@@ -553,19 +587,24 @@ Review results and report findings.
 
 ```markdown
 # Execute plugin script
+
 !`bash ${CLAUDE_PLUGIN_ROOT}/scripts/script.sh`
 
 # Load plugin configuration
+
 @${CLAUDE_PLUGIN_ROOT}/config/settings.json
 
 # Use plugin template
+
 @${CLAUDE_PLUGIN_ROOT}/templates/report.md
 
 # Access plugin resources
+
 @${CLAUDE_PLUGIN_ROOT}/docs/reference.md
 ```
 
 **Why use it:**
+
 - Works across all installations
 - Portable between systems
 - No hardcoded paths needed
@@ -586,12 +625,14 @@ plugin-name/
 ```
 
 **Namespace benefits:**
+
 - Logical command grouping
 - Shown in `/help` output
 - Avoid name conflicts
 - Organize related commands
 
 **Naming conventions:**
+
 - Use descriptive action names
 - Avoid generic names (test, run)
 - Consider plugin-specific prefix
@@ -661,17 +702,20 @@ argument-hint: [file-path]
 Initiate comprehensive review of @$1 using the code-reviewer agent.
 
 The agent will analyze:
+
 - Code structure
 - Security issues
 - Performance
 - Best practices
 
 Agent uses plugin resources:
+
 - ${CLAUDE_PLUGIN_ROOT}/config/rules.json
 - ${CLAUDE_PLUGIN_ROOT}/checklists/review.md
 ```
 
 **Key points:**
+
 - Agent must exist in `plugin/agents/` directory
 - Claude uses Task tool to launch agent
 - Document agent capabilities
@@ -690,6 +734,7 @@ argument-hint: [api-file]
 Document API in @$1 following plugin standards.
 
 Use the api-docs-standards skill to ensure:
+
 - Complete endpoint documentation
 - Consistent formatting
 - Example quality
@@ -699,6 +744,7 @@ Generate production-ready API docs.
 ```
 
 **Key points:**
+
 - Skill must exist in `plugin/skills/` directory
 - Mention skill name to trigger invocation
 - Document skill purpose
@@ -707,6 +753,7 @@ Generate production-ready API docs.
 ### Hook Coordination
 
 Design commands that work with plugin hooks:
+
 - Commands can prepare state for hooks to process
 - Hooks execute automatically on tool events
 - Commands should document expected hook behavior
@@ -743,6 +790,7 @@ Compile findings into report following template.
 ```
 
 **When to use:**
+
 - Complex multi-step workflows
 - Leverage multiple plugin capabilities
 - Require specialized analysis
@@ -763,10 +811,10 @@ argument-hint: [environment]
 Validate environment: !`echo "$1" | grep -E "^(dev|staging|prod)$" || echo "INVALID"`
 
 If $1 is valid environment:
-  Deploy to $1
+Deploy to $1
 Otherwise:
-  Explain valid environments: dev, staging, prod
-  Show usage: /deploy [environment]
+Explain valid environments: dev, staging, prod
+Show usage: /deploy [environment]
 ```
 
 ### File Existence Checks
@@ -780,11 +828,11 @@ argument-hint: [config-file]
 Check file exists: !`test -f $1 && echo "EXISTS" || echo "MISSING"`
 
 If file exists:
-  Process configuration: @$1
+Process configuration: @$1
 Otherwise:
-  Explain where to place config file
-  Show expected format
-  Provide example configuration
+Explain where to place config file
+Show expected format
+Provide example configuration
 ```
 
 ### Plugin Resource Validation
@@ -796,6 +844,7 @@ allowed-tools: Bash(test:*)
 ---
 
 Validate plugin setup:
+
 - Script: !`test -x ${CLAUDE_PLUGIN_ROOT}/bin/analyze && echo "✓" || echo "✗"`
 - Config: !`test -f ${CLAUDE_PLUGIN_ROOT}/config.json && echo "✓" || echo "✗"`
 
@@ -814,14 +863,15 @@ allowed-tools: Bash(*)
 Execute build: !`bash ${CLAUDE_PLUGIN_ROOT}/scripts/build.sh 2>&1 || echo "BUILD_FAILED"`
 
 If build succeeded:
-  Report success and output location
+Report success and output location
 If build failed:
-  Analyze error output
-  Suggest likely causes
-  Provide troubleshooting steps
+Analyze error output
+Suggest likely causes
+Provide troubleshooting steps
 ```
 
 **Best practices:**
+
 - Validate early in command
 - Provide helpful error messages
 - Suggest corrective actions