sign-message
Sign messages using MetaMask wallet for blockchain interactions without exposing private keys. This tool enables secure message signing within AI-powered applications.
Instructions
Sign messages
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| message | Yes |
Implementation Reference
- 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; } - 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);