bsc-multisend-mcp

Instructions

Implementation Reference

• index.js:164-232 (handler)

  The handler function that executes the distributeToken tool. It handles ERC20 token distribution to multiple receivers by validating inputs, fetching token decimals, converting amounts, managing approvals, calling the contract's transferMultiToken method, and returning the transaction result.

  async ({ tokenAddress, receivers, amounts }) => {
    try {
      // Validate inputs
      if (receivers.length !== amounts.length) {
        return {
          content: [{ type: 'text', text: 'Receivers and amounts arrays must have the same length' }],
          isError: true
        };
      }
  
      // Initialize token contract
      const tokenContract = new ethers.Contract(tokenAddress, ERC20_ABI, wallet);
  
      // Query token decimals
      let decimals;
      try {
        decimals = await tokenContract.decimals();
      } catch (error) {
        return {
          content: [{ type: 'text', text: `Invalid ERC20 token: Unable to fetch decimals (${error.message})` }],
          isError: true
        };
      }
  
      // Convert amounts to token units
      const amountsUnits = amounts.map(amount => ethers.parseUnits(amount.toString(), decimals));
  
      // Calculate total amount needed
      const totalAmount = amountsUnits.reduce((sum, amount) => sum + BigInt(amount), BigInt(0));
  
      // Check allowance
      const allowance = await tokenContract.allowance(WALLET_ADDRESS, CONTRACT_ADDRESS);
      if (BigInt(allowance) < totalAmount) {
        // Approve the contract to spend tokens
        try {
          const approveTx = await tokenContract.approve(CONTRACT_ADDRESS, totalAmount, {
            gasLimit: await tokenContract.approve.estimateGas(CONTRACT_ADDRESS, totalAmount)
          });
          await approveTx.wait();
        } catch (error) {
          return {
            content: [{ type: 'text', text: `Failed to approve token spending: ${error.message}` }],
            isError: true
          };
        }
      }
  
      // Prepare and send transaction
      const tx = await contract.transferMultiToken(tokenAddress, receivers, amountsUnits, {
        gasLimit: await contract.transferMultiToken.estimateGas(tokenAddress, receivers, amountsUnits)
      });
  
      // Wait for transaction confirmation
      const receipt = await tx.wait();
  
      return {
        content: [{
          type: 'text',
          text: `Token distribution successful. Tx Hash: ${receipt.hash}`
        }],
        isError: false
      };
    } catch (error) {
      return {
        content: [{ type: 'text', text: `Error executing token distribution: ${error.message}` }],
        isError: true
      };
    }
  }

• index.js:155-163 (schema)

  Zod schema for validating inputs to the distributeToken tool: tokenAddress (ERC20 contract), receivers (array of addresses), amounts (array of positive numbers).

  z.object({
    tokenAddress: z.string().refine((val) => ethers.isAddress(val), {
      message: 'Invalid token address'
    }).describe('Address of the ERC20 token contract to distribute.'),
    receivers: z.array(z.string().refine((val) => ethers.isAddress(val), {
      message: 'Invalid BSC address'
    })).describe('Array of BSC addresses to receive tokens.'),
    amounts: z.array(z.number().positive('Amount must be positive')).describe('Array of token amounts (in tokens, e.g., 100.5) to send to each receiver.')
  }),

• index.js:152-233 (registration)

  Registration of the distributeToken tool on the MCP server, specifying name, description, input schema, and handler function.

  server.tool(
    'distributeToken',
    'Send ERC20 tokens to multiple addresses on BSC using the C98MultiSend contract.',
    z.object({
      tokenAddress: z.string().refine((val) => ethers.isAddress(val), {
        message: 'Invalid token address'
      }).describe('Address of the ERC20 token contract to distribute.'),
      receivers: z.array(z.string().refine((val) => ethers.isAddress(val), {
        message: 'Invalid BSC address'
      })).describe('Array of BSC addresses to receive tokens.'),
      amounts: z.array(z.number().positive('Amount must be positive')).describe('Array of token amounts (in tokens, e.g., 100.5) to send to each receiver.')
    }),
    async ({ tokenAddress, receivers, amounts }) => {
      try {
        // Validate inputs
        if (receivers.length !== amounts.length) {
          return {
            content: [{ type: 'text', text: 'Receivers and amounts arrays must have the same length' }],
            isError: true
          };
        }
  
        // Initialize token contract
        const tokenContract = new ethers.Contract(tokenAddress, ERC20_ABI, wallet);
  
        // Query token decimals
        let decimals;
        try {
          decimals = await tokenContract.decimals();
        } catch (error) {
          return {
            content: [{ type: 'text', text: `Invalid ERC20 token: Unable to fetch decimals (${error.message})` }],
            isError: true
          };
        }
  
        // Convert amounts to token units
        const amountsUnits = amounts.map(amount => ethers.parseUnits(amount.toString(), decimals));
  
        // Calculate total amount needed
        const totalAmount = amountsUnits.reduce((sum, amount) => sum + BigInt(amount), BigInt(0));
  
        // Check allowance
        const allowance = await tokenContract.allowance(WALLET_ADDRESS, CONTRACT_ADDRESS);
        if (BigInt(allowance) < totalAmount) {
          // Approve the contract to spend tokens
          try {
            const approveTx = await tokenContract.approve(CONTRACT_ADDRESS, totalAmount, {
              gasLimit: await tokenContract.approve.estimateGas(CONTRACT_ADDRESS, totalAmount)
            });
            await approveTx.wait();
          } catch (error) {
            return {
              content: [{ type: 'text', text: `Failed to approve token spending: ${error.message}` }],
              isError: true
            };
          }
        }
  
        // Prepare and send transaction
        const tx = await contract.transferMultiToken(tokenAddress, receivers, amountsUnits, {
          gasLimit: await contract.transferMultiToken.estimateGas(tokenAddress, receivers, amountsUnits)
        });
  
        // Wait for transaction confirmation
        const receipt = await tx.wait();
  
        return {
          content: [{
            type: 'text',
            text: `Token distribution successful. Tx Hash: ${receipt.hash}`
          }],
          isError: false
        };
      } catch (error) {
        return {
          content: [{ type: 'text', text: `Error executing token distribution: ${error.message}` }],
          isError: true
        };
      }
    }
  );