add Synapse bridge plugin implementation

src/synapse-plugin.ts

@@ -0,0 +1,94 @@
+import axios from "axios";
+import { batchTx, BridgePlugin, BridgePluginParams, encodeApproveTx, rawTx } from "klaster-sdk";
+
+// Axios instance for base configuration
+const synapseClient = axios.create({
+  baseURL: "https://api.synapseprotocol.com",
+  headers: {
+    accept: "application/json",
+    "content-type": "application/json",
+  },
+});
+
+// Fetch bridge quote from Synapse
+/**
+ * Fetches the suggested route by Synapse based on bridge plugin parameters.
+ * @param params - BridgePluginParams containing token and chain information.
+ * @returns A promise resolving to the route data from Synapse.
+ */
+async function fetchBridgeQuote(params: BridgePluginParams) {
+  const response = await synapseClient.get("/bridge", {
+    params: {
+      fromChain: params.sourceChainId,
+      toChain: params.destinationChainId,
+      fromToken: params.sourceToken,
+      toToken: params.destinationToken,
+      amount: params.amount.toString(),
+      originUserAddress: params.account.getAddresses([params.sourceChainId]),
+      destAddress: params.account.getAddresses([params.destinationChainId]),
+    },
+  });
+
+  // Response is an array of possible routes, select the best one based on maxAmountOut
+  const routes = response.data;
+  if (!routes || routes.length === 0) {
+    throw new Error("No bridge routes available");
+  }
+
+  // Sort by maxAmountOut and select the best route
+  const bestRoute = routes.reduce((best: any, current: any) => {
+    const currentAmount = BigInt(current.maxAmountOut.hex);
+    const bestAmount = BigInt(best.maxAmountOut.hex);
+    return currentAmount > bestAmount ? current : best;
+  }, routes[0]);
+
+  return bestRoute;
+}
+
+// Prepare and send Synapse transaction
+/**
+ * Prepares and sends the Synapse transaction with the source and destination addresses.
+ * @param route - The route object returned from Synapse fetchBridgeQuote.
+ * @returns A promise resolving to the transaction data.
+ */
+function prepareTransactionData(route: any) {
+  return {
+    data: route.callData.data,
+    to: route.callData.to,
+    value: BigInt(route.callData.value.hex),
+    gasLimit: "250000", // Default gas limit, can be adjusted based on the chain
+  };
+}
+
+// Main Synapse Bridge Plugin
+export const synapseBridgePlugin: BridgePlugin = async (params: any) => {
+  // Fetch Synapse bridge quote
+  const routeData = await fetchBridgeQuote(params);
+
+  // Get transaction data
+  const transactionData = prepareTransactionData(routeData);
+
+  // Calculate the output amount on the destination chain
+  const receivedAmount = BigInt(routeData.maxAmountOut.hex);
+
+  // Create approval transaction for source token
+  const approvalTx = encodeApproveTx({
+    tokenAddress: params.sourceToken,
+    amount: params.amount,
+    recipient: transactionData.to,
+  });
+
+  // Create the transaction to initiate bridging
+  const callBridgeTx = rawTx({
+    to: transactionData.to,
+    data: transactionData.data,
+    value: transactionData.value,
+    gasLimit: transactionData.gasLimit,
+  });
+
+  // Return the batch of transactions
+  return {
+    receivedOnDestination: receivedAmount,
+    transactions: batchTx(params.sourceChainId, [approvalTx, callBridgeTx]),
+  };
+};