How do I install the Mcpb Manifest skill?

Run npx skillmds@latest add seangsisg/mcpb-manifest in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Mcpb Manifest skill do?

This skill should be used when the user asks to "configure manifest.json", "mcpb manifest spec", "manifest.json fields", "user_config in mcpb", "mcpb icon configuration", "set up manifest for desktop extension", "mcpb compatibility settings", "mcpb server types", "mcp_config variables", or needs detailed reference for the manifest.json file used in MCPB desktop extensions. Provides the complete field reference, user_config schema, server type examples, and variable substitution patterns. It is listed under AI & ML on SkillMD.

Is Mcpb Manifest safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Mcpb Manifest?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Mcpb Manifest free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Mcpb Manifest?

seanGSISG (@seangsisg) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Mcpb Manifest by seangsisg — Agent Skill

Name: Mcpb Manifest
Author: seanGSISG

Minimal manifest.json
Required Fields
Server Configuration
User Configuration
Optional Metadata Fields
Icons
Compatibility
Full Example manifest.json
Validate Your Manifest
Localization

MCPB manifest.json Reference

The manifest.json file is the required metadata descriptor for every MCPB bundle. It tells Claude Desktop what the extension does, how to run it, what tools it provides, and what configuration it needs.

Current spec version: 0.3 (use "manifest_version": "0.3")

Minimal manifest.json

The five required fields:

{
  "manifest_version": "0.3",
  "name": "my-extension",
  "version": "1.0.0",
  "description": "A brief description of what this extension does",
  "author": {
    "name": "Your Name"
  },
  "server": {
    "type": "node",
    "entry_point": "server/index.js",
    "mcp_config": {
      "command": "node",
      "args": ["${__dirname}/server/index.js"]
    }
  }
}

Required Fields

Field	Type	Description
`manifest_version`	string	Always `"0.3"` (current spec version)
`name`	string	Machine-readable identifier (used in CLI and APIs)
`version`	string	Semantic version (e.g., `"1.0.0"`)
`description`	string	Brief description shown in installation UI
`author.name`	string	Author's name (required within author object)
`server`	object	How to run the MCP server (see Server Configuration)

Server Configuration

Server Types

Type	Description
`"node"`	Node.js server; bundle `node_modules/` with the extension
`"python"`	Python server; bundle deps in `server/lib/` or `server/venv/`
`"binary"`	Pre-compiled executable, fully self-contained
`"uv"`	Python with UV runtime — experimental (v0.4+), small bundles

mcp_config

Defines the command Claude Desktop runs to start the server:

"server": {
  "type": "node",
  "entry_point": "server/index.js",
  "mcp_config": {
    "command": "node",
    "args": ["${__dirname}/server/index.js"],
    "env": {
      "API_KEY": "${user_config.api_key}"
    }
  }
}

Python example:

"server": {
  "type": "python",
  "entry_point": "server/main.py",
  "mcp_config": {
    "command": "python",
    "args": ["${__dirname}/server/main.py"],
    "env": {
      "PYTHONPATH": "${__dirname}/server/lib"
    }
  }
}

UV example (v0.4+):

"server": {
  "type": "uv",
  "entry_point": "src/server.py"
}

UV type: mcp_config is optional — host manages execution via pyproject.toml.

Variable Substitution in mcp_config

Variable	Replaced with
`${__dirname}`	Absolute path to the extension's install directory
`${HOME}`	User's home directory
`${DESKTOP}`	User's desktop directory
`${DOCUMENTS}`	User's documents directory
`${DOWNLOADS}`	User's downloads directory
`${pathSeparator}` or `${/}`	Platform path separator
`${user_config.KEY}`	User-provided value for config key KEY

Platform-Specific Overrides

"mcp_config": {
  "command": "server/my-server",
  "args": ["--config", "server/config.json"],
  "env": {},
  "platform_overrides": {
    "win32": {
      "command": "server/my-server.exe",
      "args": ["--config", "server/config-windows.json"]
    },
    "darwin": {
      "env": {
        "DYLD_LIBRARY_PATH": "server/lib"
      }
    }
  }
}

Note: For binary type, Claude Desktop automatically appends .exe on Windows.

User Configuration

user_config defines settings that Claude Desktop collects from the user via an auto-generated settings UI, then passes to your server at runtime.

Configuration Field Schema

Each key in user_config supports:

Property	Type	Description
`type`	string	`"string"`, `"boolean"`, `"number"`, `"file"`, `"directory"`
`title`	string	Label shown in the UI
`description`	string	Help text shown in the UI
`required`	boolean	Whether user must provide a value (default: `false`)
`default`	any	Default value (supports `${HOME}`, `${DESKTOP}`, `${DOCUMENTS}`)
`sensitive`	boolean	Mask input and store securely — for API keys/passwords (string only)
`multiple`	boolean	Allow multiple selections — for file/directory types (default: `false`)
`min` / `max`	number	Validation bounds — for number type only

All Config Types Example

"user_config": {
  "api_key": {
    "type": "string",
    "title": "API Key",
    "description": "Your authentication key",
    "sensitive": true,
    "required": true
  },
  "verbose_logging": {
    "type": "boolean",
    "title": "Verbose Logging",
    "description": "Enable detailed logging",
    "default": false
  },
  "max_results": {
    "type": "number",
    "title": "Maximum Results",
    "description": "Max items to return",
    "default": 10,
    "min": 1,
    "max": 100
  },
  "config_file": {
    "type": "file",
    "title": "Configuration File",
    "description": "Path to a JSON config file",
    "required": false
  },
  "allowed_directories": {
    "type": "directory",
    "title": "Allowed Directories",
    "description": "Directories the server can access",
    "multiple": true,
    "required": true,
    "default": ["${HOME}/Desktop", "${HOME}/Documents"]
  }
}

Referencing user_config Values

In mcp_config.args:

"args": [
  "${__dirname}/server/index.js",
  "--max=${user_config.max_results}",
  "${user_config.allowed_directories}"
]

In mcp_config.env:

"env": {
  "API_KEY": "${user_config.api_key}",
  "DEBUG": "${user_config.verbose_logging}"
}

Array expansion: When multiple: true, "${user_config.allowed_directories}" expands to separate args: ["/home/user/docs", "/home/user/projects"].

Optional Metadata Fields

Field	Description
`display_name`	Human-friendly name for UI (vs. machine `name`)
`long_description`	Detailed description (markdown supported)
`author.email`	Author's email
`author.url`	Author's website
`repository`	`{ "type": "git", "url": "..." }`
`homepage`	Extension homepage URL
`documentation`	Documentation URL
`support`	Issues/support URL
`keywords`	Array of search keywords
`license`	License identifier (e.g., `"MIT"`)
`privacy_policies`	Array of privacy policy URLs — required when connecting to external services
`tools`	Array of `{ "name": "...", "description": "..." }` — declares tools for directory listing
`tools_generated`	`true` if server generates additional tools at runtime
`prompts`	Array of prompt declarations
`screenshots`	Array of screenshot paths

Icons

Simple (single icon):

"icon": "icon.png"

Multiple variants (light/dark, multiple sizes):

"icons": [
  { "src": "assets/icon-16-light.png", "size": "16x16", "theme": "light" },
  { "src": "assets/icon-16-dark.png",  "size": "16x16", "theme": "dark" },
  { "src": "assets/icon-128.png",      "size": "128x128" }
]

Icon requirements: PNG format, transparency supported. Recommended: 512×512 main icon.

Compatibility

All fields optional — omit to support all platforms/runtimes:

"compatibility": {
  "claude_desktop": ">=1.0.0",
  "platforms": ["darwin", "win32"],
  "runtimes": {
    "node": ">=16.0.0"
  }
}

Field	Values
`claude_desktop`	Semver constraint (e.g., `">=0.10.0"`)
`platforms`	`"darwin"` (macOS), `"win32"` (Windows), `"linux"`
`runtimes.node`	Semver constraint for Node.js version
`runtimes.python`	Semver constraint for Python version

Binary extensions don't need runtimes. If platforms is omitted, all platforms are supported.

Full Example manifest.json

{
  "manifest_version": "0.3",
  "name": "my-extension",
  "display_name": "My Awesome Extension",
  "version": "1.0.0",
  "description": "Does amazing things with your data",
  "long_description": "A detailed description supporting **markdown**.",
  "author": {
    "name": "Your Name",
    "email": "you@example.com",
    "url": "https://your-site.com"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/you/my-extension.git"
  },
  "homepage": "https://your-site.com/my-extension",
  "documentation": "https://docs.your-site.com/my-extension",
  "support": "https://github.com/you/my-extension/issues",
  "icon": "icon.png",
  "keywords": ["productivity", "api", "automation"],
  "license": "MIT",
  "privacy_policies": ["https://your-site.com/privacy"],
  "server": {
    "type": "node",
    "entry_point": "server/index.js",
    "mcp_config": {
      "command": "node",
      "args": [
        "${__dirname}/server/index.js",
        "--workspace=${user_config.workspace_directory}"
      ],
      "env": {
        "API_KEY": "${user_config.api_key}"
      }
    }
  },
  "tools": [
    { "name": "search", "description": "Search your data" },
    { "name": "create_item", "description": "Create a new item" }
  ],
  "user_config": {
    "api_key": {
      "type": "string",
      "title": "API Key",
      "description": "Your API key",
      "sensitive": true,
      "required": true
    },
    "workspace_directory": {
      "type": "directory",
      "title": "Workspace",
      "description": "Working directory",
      "default": "${HOME}/Documents",
      "required": false
    }
  },
  "compatibility": {
    "claude_desktop": ">=0.10.0",
    "platforms": ["darwin", "win32"],
    "runtimes": {
      "node": ">=16.0.0"
    }
  }
}

Validate Your Manifest

mcpb validate manifest.json
# or
mcpb validate .

Always validate before packing. The validator checks against the official JSON schema.

Localization

For multi-language support, point to locale files:

"localization": {
  "resources": "mcpb-resources/${locale}.json",
  "default_locale": "en-US"
}

Localizable fields: description, display_name, long_description, author, tools, keywords. Values for the default locale stay in manifest.json; locale files only need overrides.

Mcpb Manifest

File contents

Table of Contents

MCPB manifest.json Reference

Minimal manifest.json

Required Fields

Server Configuration

Server Types

mcp_config

Variable Substitution in mcp_config

Platform-Specific Overrides

User Configuration

Configuration Field Schema

All Config Types Example

Referencing user_config Values

Optional Metadata Fields

Icons

Compatibility

Full Example manifest.json

Validate Your Manifest

Localization

Frequently asked questions

Mcpb Manifest

File contents

Table of Contents

MCPB manifest.json Reference

Minimal manifest.json

Required Fields

Server Configuration

Server Types

mcp_config

Variable Substitution in mcp_config

Platform-Specific Overrides

User Configuration

Configuration Field Schema

All Config Types Example

Referencing user_config Values

Optional Metadata Fields

Icons

Compatibility

Full Example manifest.json

Validate Your Manifest

Localization

Related skills

Frequently asked questions

How do I install the Mcpb Manifest skill?

What does the Mcpb Manifest skill do?

Is Mcpb Manifest safe to use?

Which AI agents work with Mcpb Manifest?

Is Mcpb Manifest free to use?

Who published Mcpb Manifest?