base-price-oracle-mcp

Instructions

Implementation Reference

• src/index.ts:422-470 (handler)

  The tool 'get_token_price' is registered here. The async function handles the logic: resolving decimals, finding pools, calculating prices across pools, and returning the best price in a JSON format.

  server.tool(
    "get_token_price",
    "Get current price of any Base token from on-chain DEX pools (Uniswap V2/V3, Aerodrome)",
    {
      token_address: z.string().describe("Token contract address on Base"),
      quote_currency: z.string().default("ETH").describe("Quote currency: ETH/WETH or a token address"),
    },
    async ({ token_address, quote_currency }) => {
      try {
        const quoteAddress = resolveQuote(quote_currency);
        const [tokenDecimals, quoteDecimals, tokenSymbol] = await Promise.all([
          getTokenDecimals(token_address),
          getTokenDecimals(quoteAddress),
          getTokenSymbol(token_address),
        ]);
  
        const pools = await findAllPools(token_address, quoteAddress);
        if (pools.length === 0) {
          return { content: [{ type: "text" as const, text: `No DEX pools found for ${token_address} paired with ${quote_currency} on Base.` }] };
        }
  
        const prices = pools.map((pool) => ({
          dex: pool.dex,
          pool: pool.address,
          price: calculatePrice(pool, tokenDecimals, quoteDecimals),
        }));
  
        const bestPool = prices.reduce((best, p) => (p.price > best.price ? p : best), prices[0]);
  
        const result = {
          token: token_address,
          symbol: tokenSymbol,
          quote: quote_currency.toUpperCase(),
          bestPrice: formatEth(bestPool.price),
          bestDex: bestPool.dex,
          allPools: prices.map((p) => ({
            dex: p.dex,
            pool: p.pool,
            price: formatEth(p.price),
          })),
        };
  
        return { content: [{ type: "text" as const, text: JSON.stringify(result, null, 2) }] };
      } catch (err: unknown) {
        const msg = err instanceof Error ? err.message : String(err);
        return { content: [{ type: "text" as const, text: `Error: ${msg}` }] };
      }
    }
  );