mcp-client-capabilities

This package strives to be the most up-to-date database of all Model Context Protocol (MCP) clients and their capabilities, to enable MCP servers understand what features an MCP client supports and how to respond to it in order to provide the best user and agent experience. Unfortunately, the MCP protocol capability negotiation during the initial handshake is not sufficient for that—see Background bellow for details.

In other words, this package is the programmatic version of the community MCP clients table.

This package provides a JSON file called mcp-clients.json that lists all known MCP clients, their metadata and capabilities. It's a single JSON file to make it easy for multiple programming languages to access the data while enabling TypeScript type safety for the NPM package.

The JSON file contains an object where keys are client names and values an object with information about the MCP client:

{
  // Client name corresponds to `params.clientInfo.name` from the MCP client's `initialize` request, e.g. "ExampleClient"
  "<client-name>": {

    // Display name of the MCP client, e.g. "Example Client"
    title: string,
    
    // URL to the homepage of the client
    url: string,
    
    // Corresponds to `params.protocolVersion` from the MCP client's `initialize` request, e.g. "2024-11-05"
    protocolVersion: string,

    // Present if the client supports accessing server resources,
    // whether it can handle their dynamic changes, and whether it can subscribe to resource updates
    resources?: { listChanged?: boolean, subscribe?: boolean },

    // Present if the client supports accessing server prompts,
    // and whether it can handl