base-flash-arb-mcp

Instructions

Implementation Reference

• src/index.ts:516-635 (handler)

  The handler for the "detect_arb_opportunity" tool which compares token prices across different DEXes (Uniswap V2/V3, Aerodrome) to identify arbitrage opportunities.

  server.tool(
    "detect_arb_opportunity",
    "Compare token prices across Uniswap V2, Uniswap V3, and Aerodrome on Base. Find profitable arbitrage routes.",
    {
      token_address: z.string().describe("Token contract address on Base"),
      min_profit_bps: z
        .number()
        .default(50)
        .describe("Minimum profit in basis points (default 50 = 0.5%)"),
    },
    async ({ token_address, min_profit_bps }) => {
      try {
        const symbol = await getSymbol(token_address);
        const testAmount = ethers.parseEther("0.01"); // Test with 0.01 ETH
        const gasCost = await estimateGasCost();
  
        // Get all buy quotes
        const buyQuotes = await getAllBuyQuotes(token_address, testAmount);
        if (buyQuotes.length < 2) {
          return {
            content: [
              {
                type: "text" as const,
                text: JSON.stringify(
                  {
                    token: token_address,
                    symbol,
                    result: "INSUFFICIENT_ROUTES",
                    message: `Only ${buyQuotes.length} DEX route(s) found. Need at least 2 for cross-DEX arb.`,
                    availableRoutes: buyQuotes.map((q) => q.label),
                  },
                  null,
                  2
                ),
              },
            ],
          };
        }
  
        // Sort by best rate (most tokens per ETH)
        buyQuotes.sort((a, b) => (b.amountOut > a.amountOut ? 1 : -1));
        const bestBuy = buyQuotes[0];
  
        // Get sell quotes for the tokens we'd receive
        const sellQuotes = await getAllSellQuotes(
          token_address,
          bestBuy.amountOut
        );
  
        const opportunities = [];
  
        for (const sellQ of sellQuotes) {
          // Skip same route
          if (bestBuy.label === sellQ.label) continue;
  
          const ethOut = sellQ.amountOut;
          const profitWei = ethOut - testAmount;
          const profitAfterGas = profitWei - gasCost;
          const profitBps =
            testAmount > 0n
              ? Number((profitWei * 10000n) / testAmount)
              : 0;
  
          if (profitBps >= min_profit_bps) {
            opportunities.push({
              buyOn: bestBuy.label,
              sellOn: sellQ.label,
              ethIn: ethers.formatEther(testAmount),
              tokensReceived: bestBuy.amountOut.toString(),
              ethOut: ethers.formatEther(ethOut),
              grossProfitEth: ethers.formatEther(profitWei),
              gasCostEth: ethers.formatEther(gasCost),
              netProfitEth: ethers.formatEther(profitAfterGas),
              profitBps,
              profitable: profitAfterGas > 0n,
            });
          }
        }
  
        opportunities.sort(
          (a, b) =>
            parseFloat(b.netProfitEth) - parseFloat(a.netProfitEth)
        );
  
        return {
          content: [
            {
              type: "text" as const,
              text: JSON.stringify(
                {
                  token: token_address,
                  symbol,
                  testAmountEth: "0.01",
                  routesChecked: buyQuotes.length,
                  opportunitiesFound: opportunities.length,
                  opportunities,
                  allBuyQuotes: buyQuotes.map((q) => ({
                    label: q.label,
                    tokensOut: q.amountOut.toString(),
                  })),
                },
                null,
                2
              ),
            },
          ],
        };
      } catch (e) {
        return {
          content: [
            {
              type: "text" as const,
              text: `Error detecting arb: ${e instanceof Error ? e.message : String(e)}`,
            },
          ],
          isError: true,
        };
      }
    }
  );