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Install a Servlet

Pre-requirements

This tutorial assumes you are already logged in to mcp.run, and have mcpx installed and authenticated on your system & is recognized by Claude Desktop or another MCP Client.

There are two ways you will find new servlets to install.

  1. via mcp.run, either by recommendation or searching the registry yourself.
  2. via Claude searching the registry if it realizes it could use a tool it doesn't currently have.

In either case, you will end up with a URL such as: https://mcp.run/nilslice/qr-code. This links you to a servlet detail page.

Servlet Pages​

Each servlet has its own unique page on mcp.run, that describes its capabilities and provides information about its requirements and author.

When a servlet is published, the author is responsible for providing these details. Please understand that servlet detail accuracy is entirely reliant on to the party who published it. We do not control what information is provided.

The "Input Schemas" section is derived from the servlet's code, but it is still up to the author of the servlet to accurately define these schemas and correctly implement them.

Installation​

When you find a servlet you would like to install, and have navigated to it's detail page, you will find a Install Servlet button next to its name.

When you click this button, assuming you are logged in, you will be asked to fill in some details about your installation:

1. Install as​

This field enables you to rename the servlet, which may help resolve a naming conflict, or simply give you flexibility to organize your servlets how you'd like. This will change the way the servlet is named inside Claude Desktop's MCP integration.

2. Config Variables​

This section contains author-defined values that the servlet may need to function properly. These values commonly include:

  • API Keys / Tokens
  • Environment variables
  • Usernames & passwords
  • URLs / service endpoints
Who has access to my information?

These values are only made available to the servlets you install.

No other mcp.run user will be able to see or use the values you submit here.

Note: these values are currently delivered to mcpx unencrypted, so be aware which device you are logged into via mcpx. If you are not on your own personal computer, you may expose a secret.

3. Required Permissions​

This section contains various system-level access requests defined by the servlet author. In order to read/write files on your computer, or make HTTP requests to external servers, you will need to approve or adjust the specified resources listed here.

Domain Access​

Many servlets will need to make network requests over the public Internet to access remote services. In these cases, you will need to approve network access to the requested domains / hosts listed by the servlet author. For example, if a servlet is going to get information from GitHub, it's likely the servlet will access api.github.com. You can simply approve that domain if listed.

Occasionally, a servlet will request *, meaning "all hosts". Be aware that this gives the servlet access to make requests to any server, including localhost.

Filesystem Access​

If a servlet needs to read/write to your filesystem, you have full control over where on your filesystem it can do so. A servlet author will publish the servlet with paths it expects to have access to. These requested paths will be hard-coded, but can be mapped to different paths on your system.

For example, you may see a hard-coded path like /etc. This means that the servlet code is going to try to read/write this file. The path you submit can be made more portable using provided replacement variables: ${HOME}, ${TEMP}, and ${ROOT}. Depending on your operating system, these will resolve to different locations.

You can also put any path you want as the value when you install a servlet. Just know that a servlet may not function properly if the files it needs are not at the mounted path you supply. e.g. if /etc is requested but you provide mapped access to ${HOME}/Downloads and the servlet expects to read /etc/ttys, then you'll probably see an error at runtime.

Note: if you don't see one or more of these installation detail sections for a servlet, it is because that servlet doesn't require that kind of configuration. Some servlets may not require any configuration at all.