Alchemy MCP Server

Implementation Reference

• api/alchemyApi.ts:29-46 (handler)

  Main handler function that executes the tool logic by making a POST request to Alchemy's /prices/v1/{key}/tokens/by-address endpoint using the created axios client.

  async getTokenPriceByAddress(params: TokenPriceByAddress) {
    try {
      const client = createPricesClient();
      
      const response = await client.post('/by-address', {
        addresses: params.addresses.map((pair: TokenPriceByAddressPair) => ({
          address: pair.address,
          network: pair.network
        }))
      });
  
      console.log('Successfully fetched token price:', response.data);
      return response.data;
    } catch (error) {
      console.error('Error fetching token price:', error);
      throw error;
    }
  },

• index.ts:41-65 (registration)

  MCP tool registration using server.tool(), including Zod input schema and error-handling wrapper that calls the main handler and formats response.

  server.tool('fetchTokenPriceByAddress', {
    addresses: z.array(z.object({
      address: z.string().describe('The token contract address to query. e.g. "0x1234567890123456789012345678901234567890"'),
      network: z.string().describe('The blockchain network to query. e.g. "eth-mainnet" or "base-mainnet"')
    })).describe('A list of token contract address and network pairs'),
  }, async (params) => {
    try {
      const result = await alchemyApi.getTokenPriceByAddress(params);
      return {
        content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
      };
    } catch (error) {
      if (error instanceof Error) {
        console.error('Error in getTokenPriceByAddress:', error);
        return {
          content: [{ type: "text", text: `Error: ${error.message}` }],
          isError: true
        };
      }
      return {
        content: [{ type: "text", text: 'Unknown error occurred' }],
        isError: true
      };
    }
  });

• types/types.d.ts:6-13 (schema)

  TypeScript interface definitions for the tool's input parameters: TokenPriceByAddress and nested TokenPriceByAddressPair.

  export interface TokenPriceByAddress {
    addresses: TokenPriceByAddressPair[];
  }
  
  export interface TokenPriceByAddressPair {
    address: string;
    network: string;
  }

• api/alchemyClients.ts:9-16 (helper)

  Helper function to create an axios client configured for Alchemy Prices API, used in the handler to make HTTP requests.

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