mcp-coincap-jj

Instructions

Implementation Reference

• src/tools/price.ts:9-38 (handler)

  Main execution handler for the 'get-crypto-price' tool. Parses input using Zod schema, fetches cryptocurrency assets from CoinCap service, finds the matching asset, and returns formatted price information.

  export async function handleGetPrice(args: unknown) {
    const { symbol } = GetPriceArgumentsSchema.parse(args);
    const upperSymbol = symbol.toUpperCase();
  
    const assetsData = await getAssets();
    if (!assetsData) {
      return {
        content: [{ type: "text", text: "Failed to retrieve cryptocurrency data" }],
      };
    }
  
    const asset = assetsData.data.find(
      (a: { symbol: string; }) => a.symbol.toUpperCase() === upperSymbol
    );
  
    if (!asset) {
      return {
        content: [
          {
            type: "text",
            text: `Could not find cryptocurrency with symbol ${upperSymbol}`,
          },
        ],
      };
    }
  
    return {
      content: [{ type: "text", text: formatPriceInfo(asset) }],
    };
  }

• src/tools/price.ts:5-7 (schema)

  Zod schema used in the handler for validating the tool's input argument 'symbol'.

  export const GetPriceArgumentsSchema = z.object({
    symbol: z.string().min(1),
  });

• src/index.ts:31-44 (registration)

  Registration of the 'get-crypto-price' tool in the ListToolsRequestSchema handler, including name, description, and MCP-compatible input schema.

  {
    name: "get-crypto-price",
    description: "Get current price and 24h stats for a cryptocurrency",
    inputSchema: {
      type: "object",
      properties: {
        symbol: {
          type: "string",
          description: "Cryptocurrency symbol (e.g., BTC, ETH)",
        },
      },
      required: ["symbol"],
    },
  },

• src/index.ts:93-94 (registration)

  Dispatch logic in the CallToolRequestSchema handler that routes 'get-crypto-price' calls to the handleGetPrice function.

  case "get-crypto-price":
    return await handleGetPrice(args);