Loyal Spark Loyalty Protocol

Instructions

Implementation Reference

• supabase/functions/loyalty-mcp/index.ts:214-276 (handler)

  The redeem_reward tool implementation, which verifies a token transfer on the Base network and creates a voucher.

  mcpServer.tool("redeem_reward", {
    description: "Redeem a reward by providing a verified token transfer transaction hash. Creates a voucher for the customer.",
    inputSchema: {
      type: "object" as const,
      properties: {
        reward_id: { type: "string", description: "UUID of the reward to redeem" },
        customer_address: { type: "string", description: "Wallet address of the customer who transferred tokens" },
        transaction_hash: { type: "string", description: "On-chain tx hash of the token transfer from customer to merchant" },
      },
      required: ["reward_id", "customer_address", "transaction_hash"],
    },
    handler: async ({ reward_id, customer_address, transaction_hash }: any) => {
      const err = authGuard(["read"]);
      if (err) return T(err);
      const d = db();
  
      const { data: reward } = await d.from("rewards").select("*").eq("id", reward_id).single();
      if (!reward) return T(JSON.stringify({ error: "Reward not found" }));
      if (reward.merchant_address.toLowerCase() !== agent.ownerAddress.toLowerCase()) return T(JSON.stringify({ error: "Reward not owned by you" }));
      if (!reward.is_active) return T(JSON.stringify({ error: "Reward is inactive" }));
  
      const { data: dup } = await d.from("vouchers").select("id").eq("transaction_hash", transaction_hash).maybeSingle();
      if (dup) return T(JSON.stringify({ error: "Voucher already exists for this transaction" }));
  
      // Verify tx on Base RPC
      const rpcUrl = "https://base-rpc.publicnode.com";
      const txHash = transaction_hash.startsWith("0x") ? transaction_hash : `0x${transaction_hash}`;
      let receipt: any = null;
      for (let i = 0; i < 5; i++) {
        const r = await fetch(rpcUrl, { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ jsonrpc: "2.0", id: 1, method: "eth_getTransactionReceipt", params: [txHash] }) });
        const j = (await r.json()) as any;
        receipt = j?.result;
        if (receipt) break;
        await new Promise(r => setTimeout(r, 2500));
      }
      if (!receipt) return T(JSON.stringify({ error: "Transaction not confirmed yet", retryable: true }));
      if (receipt.status && receipt.status !== "0x1") return T(JSON.stringify({ error: "Transaction failed on-chain" }));
  
      const ERC20 = "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef";
      const logs = Array.isArray(receipt.logs) ? receipt.logs : [];
      const ok = logs.some((l: any) => {
        const t = l?.topics || [];
        if ((l?.address || "").toLowerCase() !== reward.token_address.toLowerCase()) return false;
        if (t[0]?.toLowerCase() !== ERC20 || t.length < 3) return false;
        return `0x${t[1].slice(-40)}`.toLowerCase() === customer_address.toLowerCase() && `0x${t[2].slice(-40)}`.toLowerCase() === agent.ownerAddress.toLowerCase();
      });
      if (!ok) return T(JSON.stringify({ error: "Token transfer not verified in tx logs" }));
  
      const { data: prog } = await d.from("loyalty_programs").select("symbol").eq("token_address", reward.token_address.toLowerCase()).maybeSingle();
      const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
      const code = "LOYAL-" + Array.from({ length: 4 }, () => Array.from({ length: 4 }, () => chars.charAt(Math.floor(Math.random() * chars.length))).join("")).join("-");
  
      const { data: voucher, error: ve } = await d.from("vouchers").insert({
        code, reward_id: reward.id, reward_name: reward.name, reward_description: reward.description,
        token_address: reward.token_address.toLowerCase(), token_symbol: prog?.symbol || "TOKEN",
        customer_address: customer_address.toLowerCase(), merchant_address: agent.ownerAddress.toLowerCase(),
        status: "active", cost: reward.cost, transaction_hash,
      }).select().single();
      if (ve) return T(JSON.stringify({ error: ve.message }));
  
      return T(JSON.stringify({ voucher: { id: voucher.id, code: voucher.code, reward_name: voucher.reward_name, cost: voucher.cost, status: "active" } }));
    },
  });