XMTP MCP Server

Instructions

Implementation Reference

• src/index.ts:250-294 (handler)

  The main handler function that implements the connect_xmtp tool logic: creates a wallet signer from private key, initializes XMTP Client, and stores it in state.

  private async connectXMTP(args: any) {
    try {
      const privateKey = args.privateKey || process.env.WALLET_KEY;
      const environment = args.environment || process.env.XMTP_ENV || "production";
  
      if (!privateKey) {
        throw new Error("Private key required. Provide via parameter or WALLET_KEY env variable.");
      }
  
      // Create proper EOA signer for XMTP using viem account (exact same as working debug script)
      const account = privateKeyToAccount(privateKey as `0x${string}`);
      const signer = {
        type: "EOA" as const,
        signMessage: async (message: string) => {
          const signature = await account.signMessage({ message });
          return toBytes(signature);
        },
        getIdentifier: () => {
          return {
            identifier: account.address,
            identifierKind: 0, // IdentifierKind.Ethereum
          };
        },
        getChainId: () => BigInt(1), // Ethereum mainnet as bigint
      };
  
      // Initialize XMTP client with proper signer
      this.state.client = await Client.create(signer, {
        env: environment as "local" | "dev" | "production",
      });
  
      this.state.walletAddress = account.address;
  
      return {
        content: [
          {
            type: "text",
            text: `Successfully connected to XMTP ${environment} network with address: ${account.address}`,
          },
        ],
      };
    } catch (error) {
      throw new Error(`XMTP connection failed: ${error}`);
    }
  }

• src/index.ts:113-131 (registration)

  Registers the connect_xmtp tool in the list of available tools, including name, description, and input schema.

  {
    name: "connect_xmtp",
    description: "Connect to XMTP network with wallet key",
    inputSchema: {
      type: "object",
      properties: {
        privateKey: {
          type: "string",
          description: "Wallet private key (optional, uses env WALLET_KEY if not provided)",
        },
        environment: {
          type: "string",
          description: "XMTP environment: local, dev, or production",
          enum: ["local", "dev", "production"],
          default: "production",
        },
      },
    },
  },

• src/index.ts:116-130 (schema)

  Defines the input schema for the connect_xmtp tool, specifying privateKey and environment parameters.

  inputSchema: {
    type: "object",
    properties: {
      privateKey: {
        type: "string",
        description: "Wallet private key (optional, uses env WALLET_KEY if not provided)",
      },
      environment: {
        type: "string",
        description: "XMTP environment: local, dev, or production",
        enum: ["local", "dev", "production"],
        default: "production",
      },
    },
  },

• src/index.ts:214-215 (handler)

  Dispatcher switch case that routes connect_xmtp tool calls to the connectXMTP handler.

  case "connect_xmtp":
    return await this.connectXMTP(args);