Implement 0x gasless swap plugin without approve

src/index.ts

@@ -9,6 +9,7 @@ import { makeGodexPlugin } from './swap/central/godex'
 import { makeLetsExchangePlugin } from './swap/central/letsexchange'
 import { makeSideshiftPlugin } from './swap/central/sideshift'
 import { makeSwapuzPlugin } from './swap/central/swapuz'
+import { make0xGaslessSwap } from './swap/defi/0x/0xGaslessSwap'
 import { make0xSwap } from './swap/defi/0x/0xSwap'
 import { makeCosmosIbcPlugin } from './swap/defi/cosmosIbc'
 import { makeLifiPlugin } from './swap/defi/lifi'
@@ -38,6 +39,7 @@ const plugins = {
   transfer: makeTransferPlugin,
   velodrome: makeVelodromePlugin,
   xrpdex,
+  zeroxgaslessswap: make0xGaslessSwap,
   zeroxswap: make0xSwap
 }
 

src/swap/defi/0x/0xGaslessSwap.ts

@@ -0,0 +1,125 @@
+import { add } from 'biggystring'
+import {
+  EdgeCorePluginFactory,
+  EdgeNetworkFee,
+  EdgeSwapApproveOptions,
+  EdgeSwapInfo,
+  EdgeSwapPlugin,
+  EdgeSwapQuote,
+  EdgeSwapResult
+} from 'edge-core-js/types'
+
+import { ZeroXApi } from './api'
+import { EXPIRATION_MS, NATIVE_TOKEN_ADDRESS } from './constants'
+import { asInitOptions } from './types'
+import { getCurrencyCode, getTokenAddress } from './util'
+
+const swapInfo: EdgeSwapInfo = {
+  displayName: '0x Gasless Swap',
+  pluginId: 'zeroxgaslessswap',
+  supportEmail: '[email protected]'
+}
+
+export const make0xGaslessSwap: EdgeCorePluginFactory = (
+  opts
+): EdgeSwapPlugin => {
+  const { io } = opts
+  const initOptions = asInitOptions(opts.initOptions)
+
+  const api = new ZeroXApi(io, initOptions.apiKey)
+
+  return {
+    swapInfo,
+    fetchSwapQuote: async (
+      swapRequest,
+      userSettings,
+      opts
+    ): Promise<EdgeSwapQuote> => {
+      // The fromWallet and toWallet must be of the same currency plugin
+      // type and therefore of the same network.
+      if (
+        swapRequest.fromWallet.currencyInfo.pluginId !==
+        swapRequest.toWallet.currencyInfo.pluginId
+      ) {
+        throw new Error('Swap between different networks is not supported')
+      }
+
+      const fromTokenAddress = getTokenAddress(
+        swapRequest.fromWallet,
+        swapRequest.fromTokenId
+      )
+      const fromCurrencyCode = getCurrencyCode(
+        swapRequest.fromWallet,
+        swapRequest.fromTokenId
+      )
+      const toTokenAddress = getTokenAddress(
+        swapRequest.toWallet,
+        swapRequest.toTokenId
+      )
+
+      if (swapRequest.quoteFor === 'max') {
+        throw new Error('Max quotes not supported')
+      }
+
+      // From wallet address
+      const {
+        publicAddress: fromWalletAddress
+      } = await swapRequest.fromWallet.getReceiveAddress({
+        tokenId: swapRequest.fromTokenId
+      })
+
+      // Amount request parameter/field name to use in the quote request
+      const amountField =
+        swapRequest.quoteFor === 'from' ? 'sellAmount' : 'buyAmount'
+
+      // Get quote from ZeroXApi
+      const chainId = api.getChainIdFromPluginId(
+        swapRequest.fromWallet.currencyInfo.pluginId
+      )
+      const apiSwapQuote = await api.gaslessSwapQuote(chainId, {
+        sellToken: fromTokenAddress ?? NATIVE_TOKEN_ADDRESS,
+        buyToken: toTokenAddress ?? NATIVE_TOKEN_ADDRESS,
+        takerAddress: fromWalletAddress,
+        [amountField]: swapRequest.nativeAmount
+      })
+
+      if (!apiSwapQuote.liquidityAvailable)
+        throw new Error('No liquidity available')
+
+      const { gasFee, zeroExFee } = apiSwapQuote.fees
+
+      if (
+        gasFee.feeToken.toLocaleLowerCase() !==
+          fromTokenAddress?.toLocaleLowerCase() ||
+        zeroExFee.feeToken.toLocaleLowerCase() !==
+          fromTokenAddress?.toLocaleLowerCase()
+      ) {
+        throw new Error(
+          'Quoted fees must be in the same token as the from token in the swap request'
+        )
+      }
+
+      const networkFee: EdgeNetworkFee = {
+        currencyCode: fromCurrencyCode,
+        nativeAmount: add(gasFee.feeAmount, zeroExFee.feeAmount)
+      }
+
+      return {
+        approve: async (
+          opts?: EdgeSwapApproveOptions
+        ): Promise<EdgeSwapResult> => {
+          throw new Error('Approve not yet implemented')
+        },
+        close: async () => {},
+        expirationDate: new Date(Date.now() + EXPIRATION_MS),
+        fromNativeAmount: apiSwapQuote.sellAmount,
+        isEstimate: false,
+        networkFee,
+        pluginId: swapInfo.pluginId,
+        request: swapRequest,
+        swapInfo: swapInfo,
+        toNativeAmount: apiSwapQuote.buyAmount
+      }
+    }
+  }
+}

src/swap/defi/0x/api.ts

@@ -4,7 +4,11 @@ import { FetchResponse } from 'serverlet'
 
 import {
   asErrorResponse,
+  asGaslessSwapQuoteResponse,
   asSwapQuoteResponse,
+  ChainId,
+  GaslessSwapQuoteRequest,
+  GaslessSwapQuoteResponse,
   SwapQuoteRequest,
   SwapQuoteResponse
 } from './apiTypes'
@@ -21,6 +25,32 @@ export class ZeroXApi {
     this.io = io
   }
 
+  /**
+   * Retrieves the ChainId based on the provided pluginId.
+   *
+   * @param pluginId The currency pluginId to retrieve the ChainId for.
+   * @returns The ChainId associated with the pluginId.
+   * @throws Error if the pluginId is not supported.
+   */
+  getChainIdFromPluginId(pluginId: string): ChainId {
+    switch (pluginId) {
+      case 'arbitrum':
+        return ChainId.Arbitrum
+      case 'base':
+        return ChainId.Base
+      case 'ethereum':
+        return ChainId.Ethereum
+      case 'optimism':
+        return ChainId.Optimism
+      case 'polygon':
+        return ChainId.Polygon
+      default:
+        throw new Error(
+          `ZeroXApi: Unsupported ChainId for currency plugin: '${pluginId}'`
+        )
+    }
+  }
+
   /**
    * Get the 0x API endpoint based on the currency plugin ID. The endpoint is
    * the appropriate 0x API server for a particular network (Ethereum, Polygon,
@@ -92,6 +122,46 @@ export class ZeroXApi {
 
     return responseData
   }
+
+  /**
+   * Retrieves a gasless swap quote from the API.
+   *
+   * @param {ChainId} chainId - The ID of the chain (see {@link getChainIdFromPluginId}).
+   * @param {GaslessSwapQuoteRequest} request - The request object containing
+   * the necessary parameters for the swap quote.
+   * @returns {Promise<GaslessSwapQuoteResponse>} - A promise that resolves to
+   * the gasless swap quote response.
+   */
+  async gaslessSwapQuote(
+    chainId: ChainId,
+    request: GaslessSwapQuoteRequest
+  ): Promise<GaslessSwapQuoteResponse> {
+    // Gasless API is only available on Ethereum network
+    const endpoint = this.getEndpointFromPluginId('ethereum')
+
+    const queryParams = requestToParams(request)
+    const queryString = new URLSearchParams(queryParams).toString()
+
+    const response = await this.io.fetch(
+      `${endpoint}/tx-relay/v1/swap/quote?${queryString}`,
+      {
+        headers: {
+          'content-type': 'application/json',
+          '0x-api-key': this.apiKey,
+          '0x-chain-id': chainId.toString()
+        }
+      }
+    )
+
+    if (!response.ok) {
+      await handledErrorResponse(response)
+    }
+
+    const responseText = await response.text()
+    const responseData = asGaslessSwapQuoteResponse(responseText)
+
+    return responseData
+  }
 }
 
 async function handledErrorResponse(response: FetchResponse): Promise<void> {