io.prefabapp/prefab
List, create and deploy your Prefab project templates from any MCP agent.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
prefab-mcpclaude mcp add prefab -- npx -y prefab-mcp@0.1.1{
"mcpServers": {
"prefab": {
"command": "npx",
"args": [
"-y",
"prefab-mcp@0.1.1"
]
}
}
}Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
prefab-mcp
An MCP server for Prefab, so an agent can see your templates and deploy one for you.
"Set up a new client folder for Northwind, autumn campaign, on my Desktop"
What it exposes
| Tool | Does |
|---|---|
list_templates | Every template, what it creates, what it asks for |
describe_template | One template in full: structure, placeholders, actions |
preview_deploy | What a deploy would create, and what values are still missing. Creates nothing |
deploy_template | Creates the folders, filling in the values given |
list_watched_folders | Folders Prefab is watching, and the rules on them |
list_globals | Library-wide placeholders, actions and value presets |
Setting it up
Works with any client that speaks MCP over stdio.
As a bundle - download prefab.mcpb from the
releases page and double-click it. Clients
that install MCP bundles, Claude Desktop among them, bring their own Node, so there is nothing else
to install.
From the command line (Claude Code, and anything with the same idea):
claude mcp add prefab -- npx -y prefab-mcp
In a config file - Cursor, Zed, and most others:
{
"mcpServers": {
"prefab": { "command": "npx", "args": ["-y", "prefab-mcp"] }
}
}Then switch on Let agents and scripts control Prefab in Prefab's Settings ▸ Permissions. It is off by default; reading your templates works without it, creating and deploying does not.
That switch arrives in Prefab 1.1.6. On an earlier version the reading tools work and the rest say so.
Requires macOS, Prefab installed and opened once, and Node 18+ (except for the .mcpb route).
How it works
Prefab is sandboxed and has no network access, so it cannot host anything. This server runs beside
it instead: it reads the library straight out of the app group
(~/Library/Group Containers/group.VFDG327T66.prefab) and asks the app to deploy through the
same prefab:// URL the Finder extension uses. Two consequences worth knowing:
- Prefab has to be running for a deploy. Reading works either way.
- The destination has to be a folder Prefab has been granted. macOS keeps a sandboxed app out
of your folders until you point it at one.
preview_deployanddeploy_templateboth check first and say so, rather than leaving a permission dialog on screen that an agent cannot answer. Grant folders in Prefab, under Settings ▸ Permissions.
Nothing here writes to Prefab's library. The app owns those files, and editing them behind its back would be overwritten the next time it saves.
Development
npm test # checks placeholder resolution matches the app's Swift, case for case npm run try '[["list_templates",{}]]' # call a tool the way a client does
src/resolve.js is a deliberate duplicate of RenamePattern.swift. If you change one, change the
other - npm test compiles the Swift and compares the two.
Frequently asked questions
What is io.prefabapp/prefab?
List, create and deploy your Prefab project templates from any MCP agent.
How do I install io.prefabapp/prefab?
It runs on your machine. In Claude Code: claude mcp add prefab -- npx -y prefab-mcp@0.1.1. For other clients, paste the JSON configuration from this page into their MCP settings.
Does io.prefabapp/prefab need an API key?
Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.
Is io.prefabapp/prefab open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains io.prefabapp/prefab?
It is published by davidjaykelly. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.