XMTP MCP Server

Instructions

Implementation Reference

• src/index.ts:296-337 (handler)

  The primary handler function for the 'send_message' tool. It checks if the XMTP client is connected, validates the recipient can receive messages, creates a direct message conversation, sends the message, syncs conversations, and returns a success response.

  private async sendMessage(args: any) {
    if (!this.state.client) {
      throw new Error("XMTP client not connected. Use connect_xmtp tool first.");
    }
  
    const { recipient, message } = args;
  
    try {
      // Create recipient identifier for XMTP operations
      const recipientIdentifier = {
        identifier: recipient,
        identifierKind: 0, // IdentifierKind.Ethereum
      };
      
      // Check if we can message this address (try both original and lowercase)
      const canMessage = await this.state.client.canMessage([recipientIdentifier]);
      const canMessageResult = canMessage.get(recipient) || canMessage.get(recipient.toLowerCase());
      if (!canMessageResult) {
        throw new Error(`Address ${recipient} is not on the XMTP network`);
      }
  
      // Create DM conversation with identifier (back to original method)  
      const conversation = await this.state.client.conversations.newDmWithIdentifier(recipientIdentifier);
      
      // Send message
      await conversation.send(message);
      
      // Sync to ensure message is propagated
      await this.state.client.conversations.syncAll();
  
      return {
        content: [
          {
            type: "text",
            text: `Message sent to ${recipient}: "${message}"`,
          },
        ],
      };
    } catch (error) {
      throw new Error(`Failed to send message: ${error}`);
    }
  }

• src/index.ts:132-149 (schema)

  The input schema and metadata for the 'send_message' tool, defining the required 'recipient' and 'message' parameters as strings.

  {
    name: "send_message",
    description: "Send a message to an address via XMTP",
    inputSchema: {
      type: "object",
      properties: {
        recipient: {
          type: "string",
          description: "Wallet address or ENS name to send message to",
        },
        message: {
          type: "string",
          description: "Message content to send",
        },
      },
      required: ["recipient", "message"],
    },
  },

• src/index.ts:217-218 (registration)

  The switch case registration in the CallToolRequestSchema handler that routes 'send_message' tool calls to the sendMessage method.

  case "send_message":
    return await this.sendMessage(args);