web3-mcp-server

Instructions

Implementation Reference

• src/tools/FetchQuote.ts:10-16 (handler)

  The primary handler function implementing the 'fetch_quote' tool logic. It destructures the slug option, fetches lightweight crypto data from CoinMarketCap service, and returns the current price from the statistics.

  export const fetchQuote = async (options: FetchQuoteOptions) => {
    const { slug } = options;
  
    const data = await getCryptoDataLite(slug);
  
    return data.data.statistics.price;
  };

• src/tools/FetchQuote.ts:5-8 (schema)

  Zod schema defining the input for fetch_quote: a required 'slug' string (e.g., token identifier). Includes the inferred TypeScript type.

  export const FetchQuoteSchema = z.object({
    slug: z.string(),
  });
  export type FetchQuoteOptions = z.infer<typeof FetchQuoteSchema>;

• src/index.ts:50-54 (registration)

  Registration of the 'fetch_quote' tool in the list returned by ListToolsRequestSchema, including name, description, and JSON schema for input validation.

  {
    name: "fetch_quote",
    description: "Get the price of a token",
    inputSchema: z.toJSONSchema(FetchQuoteSchema),
  },

• src/index.ts:142-155 (handler)

  Dispatcher handler in the main CallToolRequestSchema switch case. Parses arguments with the schema, invokes the fetchQuote handler, and formats the response as MCP tool content.

  case "fetch_quote": {
    const args = FetchQuoteSchema.parse(request.params.arguments);
    const result = await fetchQuote(args);
  
    return {
      content: [
        {
          type: "text",
          text: result.toString(),
          description: "The price of the token in USD",
        },
      ],
    };
  }