Alchemy MCP Server

Implementation Reference

• index.ts:183-210 (handler)

  The core handler function for the 'fetchAddressTransactionHistory' tool. It calls the alchemyApi helper, formats the transaction data (dates and ETH values), and returns a formatted JSON response or error message.

  }, async (params) => {  
    try {
      let result = await alchemyApi.getTransactionHistoryByMultichainAddress(params);
      // List the transaction hash when returning the result to the user
      const formattedTxns = result.transactions.map((transaction: any) => ({
        ...transaction,
        date: convertTimestampToDate(transaction.blockTimestamp),
        ethValue: convertWeiToEth(transaction.value)
      }));
  
      result.transactions = formattedTxns;
      return {
        content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
      };
    } catch (error) {
      if (error instanceof Error) {
        console.error('Error in getTransactionHistoryByMultichainAddress:', error);
        return {
          content: [{ type: "text", text: `Error: ${error.message}` }],
          isError: true     
        };
      }
      return {
        content: [{ type: "text", text: 'Unknown error occurred' }],
        isError: true
      };
    }
  });

• index.ts:176-182 (schema)

  Zod schema defining the input parameters for the tool: multi-chain addresses and pagination options (before, after, limit).

  addresses: z.array(z.object({
    address: z.string().describe('The wallet address to query. e.g. "0x1234567890123456789012345678901234567890"'),
    networks: z.array(z.string()).describe('The blockchain networks to query. e.g. ["eth-mainnet", "base-mainnet"]')
  })).describe('A list of wallet address and network pairs'),
  before: z.string().optional().describe('The cursor that points to the previous set of results. Use this to paginate through the results.'),
  after: z.string().optional().describe('The cursor that points to the next set of results. Use this to paginate through the results.'),
  limit: z.number().default(25).optional().describe('The number of results to return. Default is 25. Max is 100')

• index.ts:175-175 (registration)

  Registers the 'fetchAddressTransactionHistory' tool on the MCP server with the specified schema and handler.

  server.tool('fetchAddressTransactionHistory', {

• api/alchemyApi.ts:84-102 (helper)

  Helper function in alchemyApi that wraps the API call to Alchemy's multi-chain transaction history endpoint using the configured axios client.

  async getTransactionHistoryByMultichainAddress(params: MultiChainTransactionHistoryByAddress) {
    try {
      const { addresses, ...otherParams } = params;
      const client = createMultiChainTransactionHistoryClient();
      
      const response = await client.post('/by-address', {
        addresses: params.addresses.map((pair: AddressPair) => ({
          address: pair.address,  
          networks: pair.networks
        })),
        ...otherParams
      });
  
      return response.data;
    } catch (error) {
      console.error('Error fetching transaction history:', error);
      throw error;
    }
  },

• api/alchemyClients.ts:27-34 (helper)

  Factory function creating the axios HTTP client configured for Alchemy's transaction history API.

  export const createMultiChainTransactionHistoryClient = () => axios.create({
    baseURL: `https://api.g.alchemy.com/data/v1/${API_KEY}/transactions/history`,
    headers: {
        'accept': 'application/json',
        'content-type': 'application/json',
        'x-alchemy-client-breadcrumb': BREADCRUMB_HEADER
    },
  });