MetaMask MCP

Instructions

Implementation Reference

• src/tools/chainlist.ts:9-26 (handler)

  The execute handler fetches the chain list from chainlist.org/rpcs.json, parses it, and returns the JSON string in a structured content response.

  execute: async () => {
    const url = "https://chainlist.org/rpcs.json";
    const response = await fetch(url);
    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }
  
    const data = await response.json();
  
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(data),
        },
      ],
    };
  },

• src/tools/chainlist.ts:8-8 (schema)

  Zod schema defining empty input parameters for the tool.

  parameters: z.object({}),

• src/tools/chainlist.ts:4-28 (registration)

  Registers the 'get-chain-list' tool on the FastMCP server instance.

  export function registerChainlistTools(server: FastMCP): void {
    server.addTool({
      name: "get-chain-list",
      description: "Get a list of all chains information.",
      parameters: z.object({}),
      execute: async () => {
        const url = "https://chainlist.org/rpcs.json";
        const response = await fetch(url);
        if (!response.ok) {
          throw new Error(`HTTP error! status: ${response.status}`);
        }
  
        const data = await response.json();
  
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(data),
            },
          ],
        };
      },
    });
  };