MCPilot

Instructions

Implementation Reference

• packages/metamask-mcp/src/tools/sign-message.ts:14-33 (handler)

  The execute handler for the 'sign-message' tool. It extracts the message from args, calls wagmi's signMessage with the configured wagmiConfig, returns the signature hash as a JSON string in MCP content format, logs and rethrows errors.

  execute: async (args, { log }) => {
    try {
      const message = args.message
      const result = await signMessage(wagmiConfig, {
        message
      })
      return {
        content: [
          {
            type: "text",
            text: JSONStringify({
              hash: result
            }),
          },
        ],
      }
    } catch (error) {
      log.debug((error as Error).message)
      throw error;
    }

• packages/metamask-mcp/src/tools/sign-message.ts:11-13 (schema)

  Zod schema defining the input parameters for the tool: a single 'message' string.

  parameters: z.object({
    message: z.string(),
  }),

• packages/metamask-mcp/src/tools/sign-message.ts:7-36 (registration)

  The registerSignMessageTools function that defines and registers the 'sign-message' tool on the FastMCP server, including name, description, schema, and handler.

  export function registerSignMessageTools(server: FastMCP): void {
    server.addTool({
      name: "sign-message",
      description: "Sign messages",
      parameters: z.object({
        message: z.string(),
      }),
      execute: async (args, { log }) => {
        try {
          const message = args.message
          const result = await signMessage(wagmiConfig, {
            message
          })
          return {
            content: [
              {
                type: "text",
                text: JSONStringify({
                  hash: result
                }),
              },
            ],
          }
        } catch (error) {
          log.debug((error as Error).message)
          throw error;
        }
      },
    });
  };

• packages/metamask-mcp/src/index.ts:56-56 (registration)

  The call to registerSignMessageTools during server initialization in the main entry point.

  registerSignMessageTools(server);