add support for okx

Author: dglowinski

.env.template

@@ -27,4 +27,7 @@ RPC_URL_31337=""
 LIFI_API_KEY=""
 ONEINCH_API_KEY=""
 PENDLE_API_KEY=""
-OPENOCEAN_API_KEY=""
+OPENOCEAN_API_KEY=""
+OKX_API_KEY=""
+OKX_PASSPHRASE=""
+OKX_SECRET_KEY=""

src/swapService/strategies/strategyBalmySDK.ts

@@ -13,10 +13,11 @@ import {
   type Address,
   type Hex,
   encodeAbiParameters,
+  getAddress,
   parseAbiParameters,
   parseUnits,
 } from "viem"
-import { SwapperMode } from "../interface"
+import { type SwapApiResponseMulticallItem, SwapperMode } from "../interface"
 import type { StrategyResult, SwapParams, SwapQuote } from "../types"
 import {
   SWAPPER_HANDLER_GENERIC,
@@ -26,6 +27,7 @@ import {
   buildApiResponseSwap,
   buildApiResponseVerifyDebtMax,
   calculateEstimatedAmountFrom,
+  encodeApproveMulticallItem,
   encodeSwapMulticallItem,
   isExactInRepay,
   matchParams,
@@ -110,6 +112,11 @@ export class StrategyBalmySDK {
             "open-ocean": {
               apiKey: String(process.env.OPENOCEAN_API_KEY),
             },
+            "okx-dex": {
+              apiKey: String(process.env.OKX_API_KEY),
+              secretKey: String(process.env.OKX_SECRET_KEY),
+              passphrase: String(process.env.OKX_PASSPHRASE),
+            },
           },
         },
       },
@@ -192,7 +199,18 @@ export class StrategyBalmySDK {
 
     if (!quote) throw new Error("Quote not found")
 
-    const multicallItems = [
+    const multicallItems: SwapApiResponseMulticallItem[] = []
+
+    if (quote.allowanceTarget) {
+      multicallItems.push(
+        encodeApproveMulticallItem(
+          swapParams.tokenIn.addressInfo,
+          quote.allowanceTarget,
+        ),
+      )
+    }
+
+    multicallItems.push(
       encodeSwapMulticallItem({
         handler: SWAPPER_HANDLER_GENERIC,
         mode: BigInt(SwapperMode.TARGET_DEBT),
@@ -205,7 +223,7 @@ export class StrategyBalmySDK {
         amountOut: swapParams.targetDebt,
         data: quote.data,
       }),
-    ]
+    )
 
     const swap = buildApiResponseSwap(swapParams.from, multicallItems)
 
@@ -390,7 +408,6 @@ export class StrategyBalmySDK {
     swapParams: SwapParams,
     sourcesFilter?: SourcesFilter,
   ) {
-    // TODO type
     const bestQuote = await this.sdk.quoteService.getBestQuote({
       request: this.#getSDKQuoteFromSwapParams(swapParams, sourcesFilter),
       config: {
@@ -441,6 +458,7 @@ export class StrategyBalmySDK {
       takerAddress: swapParams.from,
       recipient: swapParams.receiver,
       filters: sourcesFilter || this.config.sourcesFilter,
+      includeNonTransferSourcesWhenRecipientIsSet: true,
     }
   }
 
@@ -453,6 +471,13 @@ export class StrategyBalmySDK {
       sdkQuote.tx.data as Hex,
     ])
 
+    const sources = this.sdk.quoteService.supportedSources()
+    const shouldTransferToReceiver =
+      !sources[sdkQuote.source.id].supports.swapAndTransfer
+    const allowanceTarget = sdkQuote.source.allowanceTarget
+      ? getAddress(sdkQuote.source.allowanceTarget)
+      : undefined
+
     return {
       swapParams,
       amountIn: sdkQuote.sellAmount.amount,
@@ -461,6 +486,8 @@ export class StrategyBalmySDK {
       amountOutMin: sdkQuote.minBuyAmount.amount,
       data,
       protocol: sdkQuote.source.name,
+      shouldTransferToReceiver,
+      allowanceTarget,
     }
   }
 }

src/swapService/types.ts

@@ -35,6 +35,8 @@ export interface SwapQuote {
   amountOutMin?: bigint
   data: Hex
   protocol: string
+  shouldTransferToReceiver?: boolean
+  allowanceTarget?: Address
 }
 
 export interface StrategyResult {

src/swapService/utils.ts

@@ -8,6 +8,7 @@ import {
   encodeAbiParameters,
   encodeFunctionData,
   isAddressEqual,
+  maxUint256,
   parseAbiParameters,
   parseUnits,
   stringToHex,
@@ -157,8 +158,18 @@ export function buildApiResponseExactInputFromQuote(
   quote: SwapQuote,
 ): SwapApiResponse {
   const amountOutMin = applySlippage(quote.amountOut, swapParams.slippage)
+  const multicallItems: SwapApiResponseMulticallItem[] = []
+
+  if (quote.allowanceTarget) {
+    multicallItems.push(
+      encodeApproveMulticallItem(
+        swapParams.tokenIn.addressInfo,
+        quote.allowanceTarget,
+      ),
+    )
+  }
 
-  const multicallItems = [
+  multicallItems.push(
     encodeSwapMulticallItem({
       handler: SWAPPER_HANDLER_GENERIC,
       mode: BigInt(SwapperMode.EXACT_IN),
@@ -171,7 +182,17 @@ export function buildApiResponseExactInputFromQuote(
       amountOut: 0n, // ignored in exact in
       data: quote.data,
     }),
-  ]
+  )
+
+  if (quote.shouldTransferToReceiver) {
+    multicallItems.push(
+      encodeSweepMulticallItem(
+        swapParams.tokenOut.addressInfo,
+        0n,
+        swapParams.receiver,
+      ),
+    )
+  }
 
   const swap = buildApiResponseSwap(swapParams.from, multicallItems)
 
@@ -324,6 +345,46 @@ export const encodeRepayAndDepositMulticallItem = (
   }
 }
 
+export const encodeApproveMulticallItem = (
+  token: Address,
+  spender: Address,
+): SwapApiResponseMulticallItem => {
+  // TODO migrate to dedicated Swapper function when available
+
+  const abiItem = {
+    inputs: [
+      { name: "spender", type: "address" },
+      { name: "amount", type: "uint256" },
+    ],
+    name: "approve",
+    stateMutability: "nonpayable",
+    type: "function",
+  }
+
+  const functionData = encodeFunctionData({
+    abi: [abiItem],
+    args: [spender, maxUint256],
+  })
+
+  const data = encodeAbiParameters(parseAbiParameters("address, bytes"), [
+    token,
+    functionData,
+  ])
+
+  return encodeSwapMulticallItem({
+    handler: SWAPPER_HANDLER_GENERIC,
+    mode: SwapperMode.EXACT_IN,
+    account: zeroAddress,
+    tokenIn: zeroAddress,
+    tokenOut: zeroAddress,
+    vaultIn: zeroAddress,
+    accountIn: zeroAddress,
+    receiver: zeroAddress,
+    amountOut: 0n,
+    data,
+  })
+}
+
 export const getSwapper = (chainId: number) => {
   const swapper = contractBook.swapper.address[chainId] || ""
   if (!swapper) {