From 1fd17802fd6698c93c8d7b784f05f28feb6951fb Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Tue, 24 Mar 2026 15:19:50 +0100
Subject: [PATCH 01/14] feat(transaction-pay-controller): add HyperLiquid
 source quote support for Perps Withdraw

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../src/TransactionPayController.test.ts      |  13 +++
 .../src/TransactionPayController.ts           |   2 +
 .../strategy/relay/relay-max-gas-station.ts   |   8 +-
 .../src/strategy/relay/relay-quotes.test.ts   | 106 ++++++++++++++++++
 .../src/strategy/relay/relay-quotes.ts        |  69 ++++++++++--
 .../src/strategy/relay/relay-submit.ts        |   8 +-
 .../src/strategy/relay/types.ts               |  87 +++++++++++---
 .../transaction-pay-controller/src/types.ts   |  13 +++
 .../src/utils/quotes.test.ts                  |  20 ++++
 .../src/utils/quotes.ts                       |  12 +-
 10 files changed, 303 insertions(+), 35 deletions(-)

diff --git a/packages/transaction-pay-controller/src/TransactionPayController.test.ts b/packages/transaction-pay-controller/src/TransactionPayController.test.ts
index 09e1e3c99c8..f19bac3064e 100644
--- a/packages/transaction-pay-controller/src/TransactionPayController.test.ts
+++ b/packages/transaction-pay-controller/src/TransactionPayController.test.ts
@@ -149,6 +149,19 @@ describe('TransactionPayController', () => {
       ).toBe(true);
     });
 
+    it('updates isHyperliquidSource in state', () => {
+      const controller = createController();
+
+      controller.setTransactionConfig(TRANSACTION_ID_MOCK, (config) => {
+        config.isHyperliquidSource = true;
+      });
+
+      expect(
+        controller.state.transactionData[TRANSACTION_ID_MOCK]
+          .isHyperliquidSource,
+      ).toBe(true);
+    });
+
     it('triggers source amounts and quotes update when only isPostQuote changes', () => {
       const controller = createController();
 
diff --git a/packages/transaction-pay-controller/src/TransactionPayController.ts b/packages/transaction-pay-controller/src/TransactionPayController.ts
index 96938df0cd1..37ce1a19744 100644
--- a/packages/transaction-pay-controller/src/TransactionPayController.ts
+++ b/packages/transaction-pay-controller/src/TransactionPayController.ts
@@ -117,6 +117,7 @@ export class TransactionPayController extends BaseController<
       const config = {
         isMaxAmount: transactionData.isMaxAmount,
         isPostQuote: transactionData.isPostQuote,
+        isHyperliquidSource: transactionData.isHyperliquidSource,
         refundTo: transactionData.refundTo,
       };
 
@@ -124,6 +125,7 @@ export class TransactionPayController extends BaseController<
 
       transactionData.isMaxAmount = config.isMaxAmount;
       transactionData.isPostQuote = config.isPostQuote;
+      transactionData.isHyperliquidSource = config.isHyperliquidSource;
       transactionData.refundTo = config.refundTo;
     });
   }
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
index a318e02d3c6..54b9c4ecff9 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
@@ -1,3 +1,4 @@
+import type { Hex } from '@metamask/utils';
 import { createModuleLogger } from '@metamask/utils';
 import { BigNumber } from 'bignumber.js';
 
@@ -307,7 +308,12 @@ async function getGasCostFromQuoteOrGasStation(
     };
   }
 
-  const firstStepData = quote.original.steps[0]?.items[0]?.data;
+  const firstTxStep = quote.original.steps.find(
+    (step) => step.kind === 'transaction',
+  );
+  const firstStepData = firstTxStep?.items[0]?.data as
+    | { data: Hex; to: Hex; value?: string }
+    | undefined;
 
   if (!firstStepData) {
     return undefined;
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
index fb016e2cbf0..0263e990da8 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
@@ -1876,6 +1876,7 @@ describe('Relay Quotes Utils', () => {
               },
             },
           ],
+          kind: 'transaction',
         } as never);
 
         successfulFetchMock.mockResolvedValue({
@@ -2283,6 +2284,111 @@ describe('Relay Quotes Utils', () => {
       });
     });
 
+    describe('HyperLiquid source (isHyperliquidSource)', () => {
+      const HL_REQUEST: QuoteRequest = {
+        ...QUOTE_REQUEST_MOCK,
+        isHyperliquidSource: true,
+        isPostQuote: true,
+        sourceChainId: CHAIN_ID_ARBITRUM,
+        sourceTokenAddress: ARBITRUM_USDC_ADDRESS,
+        sourceTokenAmount: '100000000',
+      };
+
+      it('overrides source chain and token to HyperCore', async () => {
+        successfulFetchMock.mockResolvedValue({
+          json: async () => QUOTE_MOCK,
+        } as never);
+
+        await getRelayQuotes({
+          messenger,
+          requests: [HL_REQUEST],
+          transaction: TRANSACTION_META_MOCK,
+        });
+
+        const body = JSON.parse(
+          successfulFetchMock.mock.calls[0][1]?.body as string,
+        );
+
+        expect(body.originChainId).toBe(parseInt(CHAIN_ID_HYPERCORE, 16));
+        expect(body.originCurrency).toBe(
+          '0x00000000000000000000000000000000',
+        );
+      });
+
+      it('shifts source amount by 2 decimals (8→6)', async () => {
+        successfulFetchMock.mockResolvedValue({
+          json: async () => QUOTE_MOCK,
+        } as never);
+
+        await getRelayQuotes({
+          messenger,
+          requests: [HL_REQUEST],
+          transaction: TRANSACTION_META_MOCK,
+        });
+
+        const body = JSON.parse(
+          successfulFetchMock.mock.calls[0][1]?.body as string,
+        );
+
+        expect(body.amount).toBe('10000000000');
+      });
+
+      it('adds protocolVersion v2 to request body', async () => {
+        successfulFetchMock.mockResolvedValue({
+          json: async () => QUOTE_MOCK,
+        } as never);
+
+        await getRelayQuotes({
+          messenger,
+          requests: [HL_REQUEST],
+          transaction: TRANSACTION_META_MOCK,
+        });
+
+        const body = JSON.parse(
+          successfulFetchMock.mock.calls[0][1]?.body as string,
+        );
+
+        expect(body.protocolVersion).toBe('v2');
+      });
+
+      it('zeroes source network fees (gasless)', async () => {
+        successfulFetchMock.mockResolvedValue({
+          json: async () => QUOTE_MOCK,
+        } as never);
+
+        const result = await getRelayQuotes({
+          messenger,
+          requests: [HL_REQUEST],
+          transaction: TRANSACTION_META_MOCK,
+        });
+
+        const zeroAmount = { fiat: '0', human: '0', raw: '0', usd: '0' };
+
+        expect(result[0].fees.sourceNetwork.estimate).toStrictEqual(
+          zeroAmount,
+        );
+        expect(result[0].fees.sourceNetwork.max).toStrictEqual(zeroAmount);
+      });
+
+      it('uses Arbitrum USDC fiat rate for source', async () => {
+        successfulFetchMock.mockResolvedValue({
+          json: async () => QUOTE_MOCK,
+        } as never);
+
+        await getRelayQuotes({
+          messenger,
+          requests: [HL_REQUEST],
+          transaction: TRANSACTION_META_MOCK,
+        });
+
+        expect(getTokenFiatRateMock).toHaveBeenCalledWith(
+          expect.anything(),
+          ARBITRUM_USDC_ADDRESS,
+          CHAIN_ID_ARBITRUM,
+        );
+      });
+    });
+
     it('includes target network fee in quote', async () => {
       successfulFetchMock.mockResolvedValue({
         json: async () => QUOTE_MOCK,
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
index ee794aad7a2..108c30176be 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
@@ -2,6 +2,7 @@
 
 import { Interface } from '@ethersproject/abi';
 import { toHex } from '@metamask/controller-utils';
+import type { TransactionMeta } from '@metamask/transaction-controller';
 import type { Hex } from '@metamask/utils';
 import { createModuleLogger } from '@metamask/utils';
 import { BigNumber } from 'bignumber.js';
@@ -17,9 +18,9 @@ import type {
   RelayQuote,
   RelayQuoteMetamask,
   RelayQuoteRequest,
+  RelayTransactionStep,
 } from './types';
 import { TransactionPayStrategy } from '../..';
-import type { TransactionMeta } from '../../../../transaction-controller/src';
 import {
   ARBITRUM_USDC_ADDRESS,
   CHAIN_ID_ARBITRUM,
@@ -247,13 +248,19 @@ async function getSingleQuote(
       body.refundTo = request.refundTo;
     }
 
+    if (request.isHyperliquidSource) {
+      body.protocolVersion = 'v2';
+    }
+
     log('Request body', body);
 
     const quote = await fetchRelayQuote(messenger, body);
 
     log('Fetched relay quote', quote);
 
-    return await normalizeQuote(quote, request, fullRequest);
+    const normalized = await normalizeQuote(quote, request, fullRequest);
+
+    return normalized;
   } catch (error) {
     log('Error fetching relay quote', error);
     throw error;
@@ -323,8 +330,9 @@ async function processTransactions(
   requestBody.authorizationList = normalizedAuthorizationList;
   requestBody.tradeType = 'EXACT_OUTPUT';
 
-  const tokenTransferData = nestedTransactions?.find((nestedTx) =>
-    nestedTx.data?.startsWith(TOKEN_TRANSFER_FOUR_BYTE),
+  const tokenTransferData = nestedTransactions?.find(
+    (nestedTx: { data?: Hex }) =>
+      nestedTx.data?.startsWith(TOKEN_TRANSFER_FOUR_BYTE),
   )?.data;
 
   // If the transactions include a token transfer, change the recipient
@@ -389,6 +397,20 @@ function normalizeRequest(request: QuoteRequest): QuoteRequest {
     });
   }
 
+  // HyperLiquid withdrawal: source is HyperCore Perps USDC, not Arbitrum.
+  // Override source chain/token and set protocolVersion=v2 (required by Relay).
+  // Decimal shift: Perps USDC is 8 decimals, standard USDC is 6.
+  if (request.isHyperliquidSource) {
+    newRequest.sourceChainId = CHAIN_ID_HYPERCORE;
+    newRequest.sourceTokenAddress = '0x00000000000000000000000000000000';
+
+    if (newRequest.sourceTokenAmount) {
+      newRequest.sourceTokenAmount = new BigNumber(newRequest.sourceTokenAmount)
+        .shiftedBy(2)
+        .toString(10);
+    }
+  }
+
   return newRequest;
 }
 
@@ -537,7 +559,15 @@ function getFiatRates(
   sourceFiatRate: FiatRates;
   usdToFiatRate: BigNumber;
 } {
-  const { sourceChainId, sourceTokenAddress } = request;
+  // For HyperLiquid source, the normalized chain/token (HyperCore + Perps USDC)
+  // won't have a fiat rate entry. Use Arbitrum USDC instead since Perps USDC
+  // is pegged 1:1.
+  const sourceChainId = request.isHyperliquidSource
+    ? CHAIN_ID_ARBITRUM
+    : request.sourceChainId;
+  const sourceTokenAddress = request.isHyperliquidSource
+    ? ARBITRUM_USDC_ADDRESS
+    : request.sourceTokenAddress;
 
   const finalSourceTokenAddress =
     sourceChainId === CHAIN_ID_POLYGON &&
@@ -607,7 +637,25 @@ async function calculateSourceNetworkCost(
     };
   }
 
-  const relayParams = quote.steps
+  // HyperLiquid withdrawals are gasless -- the "deposit" step is an HL
+  // sendAsset (off-chain signature), not an on-chain transaction.
+  if (request.isHyperliquidSource) {
+    log('Zeroing network fees for HyperLiquid withdrawal (gasless)');
+
+    const zeroAmount = { fiat: '0', human: '0', raw: '0', usd: '0' };
+
+    return {
+      estimate: zeroAmount,
+      max: zeroAmount,
+      gasLimits: [],
+      is7702: false,
+    };
+  }
+
+  const txSteps = quote.steps.filter(
+    (step): step is RelayTransactionStep => step.kind === 'transaction',
+  );
+  const relayParams = txSteps
     .flatMap((step) => step.items)
     .map((item) => item.data);
 
@@ -777,7 +825,7 @@ async function calculateSourceNetworkCost(
  * @returns Total gas estimates and per-transaction gas limits.
  */
 async function calculateSourceNetworkGasLimit(
-  params: RelayQuote['steps'][0]['items'][0]['data'][],
+  params: RelayTransactionStep['items'][0]['data'][],
   messenger: TransactionPayControllerMessenger,
   fromOverride?: Hex,
 ): Promise<{
@@ -806,7 +854,7 @@ async function calculateSourceNetworkGasLimit(
 }
 
 function toRelayQuoteGasTransaction(
-  singleParams: RelayQuote['steps'][0]['items'][0]['data'],
+  singleParams: RelayTransactionStep['items'][0]['data'],
   fromOverride?: Hex,
 ): QuoteGasTransaction {
   return {
@@ -848,7 +896,9 @@ function combinePostQuoteGas(
   gasLimits: number[];
   is7702: boolean;
 } {
-  const nestedGas = transaction.nestedTransactions?.find((tx) => tx.gas)?.gas;
+  const nestedGas = transaction.nestedTransactions?.find(
+    (tx: { gas?: string }) => tx.gas,
+  )?.gas;
   const rawGas = nestedGas ?? transaction.txParams.gas;
   const originalTxGas = rawGas ? new BigNumber(rawGas).toNumber() : undefined;
 
@@ -920,7 +970,6 @@ function getTransferRecipient(data: Hex): Hex {
     .decodeFunctionData('transfer', data)
     .to.toLowerCase();
 }
-
 function getSubsidizedFeeAmountUsd(quote: RelayQuote): BigNumber {
   const subsidizedFee = quote.fees?.subsidized;
   const amountUsd = new BigNumber(subsidizedFee?.amountUsd ?? '0');
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts
index f4b6c396ee9..2e1d784f929 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts
@@ -19,6 +19,7 @@ import type {
   RelayExecuteRequest,
   RelayQuote,
   RelayStatusResponse,
+  RelayTransactionStep,
 } from './types';
 import { projectLogger } from '../../logger';
 import type {
@@ -216,7 +217,7 @@ async function waitForRelayCompletion(
  * @returns Normalized transaction parameters.
  */
 function normalizeParams(
-  params: RelayQuote['steps'][0]['items'][0]['data'],
+  params: RelayTransactionStep['items'][0]['data'],
   messenger: TransactionPayControllerMessenger,
 ): TransactionParams {
   const featureFlags = getFeatureFlags(messenger);
@@ -310,7 +311,10 @@ async function submitTransactions(
   messenger: TransactionPayControllerMessenger,
 ): Promise<Hex> {
   const { steps } = quote.original;
-  const params = steps.flatMap((step) => step.items).map((item) => item.data);
+  const txSteps = steps.filter(
+    (step): step is RelayTransactionStep => step.kind === 'transaction',
+  );
+  const params = txSteps.flatMap((step) => step.items).map((item) => item.data);
   const invalidKind = steps.find((step) => step.kind !== 'transaction')?.kind;
 
   if (invalidKind) {
diff --git a/packages/transaction-pay-controller/src/strategy/relay/types.ts b/packages/transaction-pay-controller/src/strategy/relay/types.ts
index 326f6cb9cc9..b70df29c983 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/types.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/types.ts
@@ -15,6 +15,8 @@ export type RelayQuoteRequest = {
   originChainId: number;
   originCurrency: Hex;
   originGasOverhead?: string;
+  /** Required for HyperLiquid withdrawals (value: 'v2'). */
+  protocolVersion?: string;
   recipient: Hex;
   refundTo?: Hex;
   slippageTolerance?: string;
@@ -74,28 +76,77 @@ export type RelayQuote = {
   };
   metamask: RelayQuoteMetamask;
   request: RelayQuoteRequest;
-  steps: {
-    id: string;
-    items: {
-      check: {
+  steps: (RelayTransactionStep | RelaySignatureStep)[];
+};
+
+export type RelayTransactionStep = {
+  id: string;
+  items: {
+    check: {
+      endpoint: string;
+      method: 'GET' | 'POST';
+    };
+    data: {
+      chainId: number;
+      data: Hex;
+      from: Hex;
+      gas?: string;
+      maxFeePerGas: string;
+      maxPriorityFeePerGas: string;
+      to: Hex;
+      value?: string;
+    };
+    status: 'complete' | 'incomplete';
+  }[];
+  kind: 'transaction';
+  requestId: string;
+};
+
+export type RelaySignatureStep = {
+  id: string;
+  items: {
+    data: {
+      sign: {
+        signatureKind: string;
+        domain: Record<string, unknown>;
+        types: Record<string, unknown>;
+        value: Record<string, unknown>;
+        primaryType: string;
+      };
+      post: {
         endpoint: string;
-        method: 'GET' | 'POST';
+        method: 'POST';
+        body: Record<string, unknown>;
       };
-      data: {
-        chainId: number;
-        data: Hex;
-        from: Hex;
-        gas?: string;
-        maxFeePerGas: string;
-        maxPriorityFeePerGas: string;
-        to: Hex;
-        value?: string;
+    };
+    status: 'complete' | 'incomplete';
+  }[];
+  kind: 'signature';
+  requestId: string;
+};
+
+/** HyperLiquid deposit step (sendAsset to Relay solver). */
+export type RelayHyperliquidDepositStep = {
+  id: string;
+  items: {
+    check: {
+      endpoint: string;
+      method: 'GET' | 'POST';
+    };
+    data: {
+      action: {
+        type: string;
+        parameters: Record<string, unknown>;
       };
-      status: 'complete' | 'incomplete';
-    }[];
-    kind: 'transaction';
-    requestId: string;
+      nonce: number;
+      eip712Types: Record<string, unknown>;
+      eip712PrimaryType: string;
+    };
+    status: 'complete' | 'incomplete';
   }[];
+  kind: 'transaction';
+  requestId: string;
+  depositAddress?: string;
 };
 
 type RelayQuoteMetamaskBase = {
diff --git a/packages/transaction-pay-controller/src/types.ts b/packages/transaction-pay-controller/src/types.ts
index 486cbaa52db..879b95bf629 100644
--- a/packages/transaction-pay-controller/src/types.ts
+++ b/packages/transaction-pay-controller/src/types.ts
@@ -83,6 +83,13 @@ export type TransactionConfig = {
    */
   isPostQuote?: boolean;
 
+  /**
+   * Whether the source of funds is HyperLiquid (HyperCore).
+   * When true, the Relay strategy uses the HyperLiquid 2-step withdrawal
+   * flow: (1) authorize nonce-mapping, (2) sendAsset to Relay solver.
+   */
+  isHyperliquidSource?: boolean;
+
   /**
    * Optional address to receive refunds if the Relay transaction fails.
    * When set, overrides the default refund recipient (EOA) in the Relay quote
@@ -164,6 +171,9 @@ export type TransactionData = {
    */
   isPostQuote?: boolean;
 
+  /** Whether the source of funds is HyperLiquid (HyperCore). */
+  isHyperliquidSource?: boolean;
+
   /**
    * Optional address to receive refunds if the Relay transaction fails.
    * When set, overrides the default refund recipient (EOA) in the Relay quote
@@ -324,6 +334,9 @@ export type QuoteRequest = {
   /** Whether this is a post-quote flow. */
   isPostQuote?: boolean;
 
+  /** Whether the source of funds is HyperLiquid (HyperCore). */
+  isHyperliquidSource?: boolean;
+
   /**
    * Optional address to receive refunds if the Relay transaction fails.
    * When set, overrides the default refund recipient (EOA) in the Relay quote
diff --git a/packages/transaction-pay-controller/src/utils/quotes.test.ts b/packages/transaction-pay-controller/src/utils/quotes.test.ts
index f582781019b..7e0953e7cc0 100644
--- a/packages/transaction-pay-controller/src/utils/quotes.test.ts
+++ b/packages/transaction-pay-controller/src/utils/quotes.test.ts
@@ -931,6 +931,26 @@ describe('Quotes Utils', () => {
       );
     });
 
+    it('passes isHyperliquidSource through to post-quote request', async () => {
+      await run({
+        transactionData: {
+          ...POST_QUOTE_TRANSACTION_DATA,
+          isHyperliquidSource: true,
+        },
+      });
+
+      expect(getQuotesMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          requests: [
+            expect.objectContaining({
+              isPostQuote: true,
+              isHyperliquidSource: true,
+            }),
+          ],
+        }),
+      );
+    });
+
     it('does not fetch quotes when sourceAmounts is empty (same-token filtered in source-amounts)', async () => {
       const sameTokenData: TransactionData = {
         ...POST_QUOTE_TRANSACTION_DATA,
diff --git a/packages/transaction-pay-controller/src/utils/quotes.ts b/packages/transaction-pay-controller/src/utils/quotes.ts
index 1621076e193..143f4b866fc 100644
--- a/packages/transaction-pay-controller/src/utils/quotes.ts
+++ b/packages/transaction-pay-controller/src/utils/quotes.ts
@@ -70,6 +70,7 @@ export async function updateQuotes(
   const {
     isMaxAmount,
     isPostQuote,
+    isHyperliquidSource,
     paymentToken: originalPaymentToken,
     refundTo,
     sourceAmounts,
@@ -95,6 +96,7 @@ export async function updateQuotes(
       from,
       isMaxAmount: isMaxAmount ?? false,
       isPostQuote,
+      isHyperliquidSource,
       paymentToken,
       refundTo,
       sourceAmounts,
@@ -266,6 +268,7 @@ function buildQuoteRequests({
   from,
   isMaxAmount,
   isPostQuote,
+  isHyperliquidSource,
   paymentToken,
   refundTo,
   sourceAmounts,
@@ -275,6 +278,7 @@ function buildQuoteRequests({
   from: Hex;
   isMaxAmount: boolean;
   isPostQuote?: boolean;
+  isHyperliquidSource?: boolean;
   paymentToken: TransactionPaymentToken | undefined;
   refundTo?: Hex;
   sourceAmounts: TransactionPaySourceAmount[] | undefined;
@@ -286,11 +290,10 @@ function buildQuoteRequests({
   }
 
   if (isPostQuote) {
-    // Post-quote flow: source = transaction's required token, target = paymentToken (destination)
-    // The user wants to receive the transaction output in paymentToken
     return buildPostQuoteRequests({
       from,
       isMaxAmount,
+      isHyperliquidSource,
       destinationToken: paymentToken,
       refundTo,
       sourceAmounts,
@@ -341,6 +344,7 @@ function buildQuoteRequests({
 function buildPostQuoteRequests({
   from,
   isMaxAmount,
+  isHyperliquidSource,
   destinationToken,
   refundTo,
   sourceAmounts,
@@ -348,6 +352,7 @@ function buildPostQuoteRequests({
 }: {
   from: Hex;
   isMaxAmount: boolean;
+  isHyperliquidSource?: boolean;
   destinationToken: TransactionPaymentToken;
   refundTo?: Hex;
   sourceAmounts: TransactionPaySourceAmount[] | undefined;
@@ -376,13 +381,12 @@ function buildPostQuoteRequests({
     from,
     isMaxAmount,
     isPostQuote: true,
+    isHyperliquidSource,
     refundTo,
     sourceBalanceRaw: sourceAmount.sourceBalanceRaw,
     sourceTokenAmount: sourceAmount.sourceAmountRaw,
     sourceChainId: sourceAmount.sourceChainId,
     sourceTokenAddress: sourceAmount.sourceTokenAddress,
-    // For post-quote flows, use EXACT_INPUT - user specifies how much to send,
-    // and we show them how much they'll receive after fees
     targetAmountMinimum: '0',
     targetChainId: destinationToken.chainId,
     targetTokenAddress: destinationToken.address,

From 020736f7806379709ef7a1f2f34259de2b691b3d Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Tue, 24 Mar 2026 15:36:44 +0100
Subject: [PATCH 02/14] Refactoring

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../transaction-pay-controller/src/constants.ts   |  7 ++++++-
 .../src/strategy/relay/relay-quotes.ts            | 15 +++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/packages/transaction-pay-controller/src/constants.ts b/packages/transaction-pay-controller/src/constants.ts
index dffbcdc9cb2..801bc751baa 100644
--- a/packages/transaction-pay-controller/src/constants.ts
+++ b/packages/transaction-pay-controller/src/constants.ts
@@ -14,6 +14,11 @@ export const ARBITRUM_USDC_ADDRESS =
 export const POLYGON_USDCE_ADDRESS =
   '0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174' as Hex;
 
+export const HYPERCORE_USDC_ADDRESS = '0x00000000000000000000000000000000';
+
+// HyperCore Perps USDC uses 8 decimals vs standard USDC's 6.
+export const HYPERCORE_USDC_DECIMAL_SHIFT = 2;
+
 export const STABLECOINS: Record<Hex, Hex[]> = {
   // Mainnet
   '0x1': [
@@ -29,7 +34,7 @@ export const STABLECOINS: Record<Hex, Hex[]> = {
     '0xa219439258ca9da29e9cc4ce5596924745e12b93', // USDT
   ],
   [CHAIN_ID_POLYGON]: [POLYGON_USDCE_ADDRESS.toLowerCase() as Hex],
-  [CHAIN_ID_HYPERCORE]: ['0x00000000000000000000000000000000'], // USDC
+  [CHAIN_ID_HYPERCORE]: [HYPERCORE_USDC_ADDRESS], // USDC
 };
 
 export enum TransactionPayStrategy {
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
index 108c30176be..49c85220cec 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
@@ -26,6 +26,8 @@ import {
   CHAIN_ID_ARBITRUM,
   CHAIN_ID_HYPERCORE,
   CHAIN_ID_POLYGON,
+  HYPERCORE_USDC_ADDRESS,
+  HYPERCORE_USDC_DECIMAL_SHIFT,
   NATIVE_TOKEN_ADDRESS,
   STABLECOINS,
 } from '../../constants';
@@ -258,9 +260,7 @@ async function getSingleQuote(
 
     log('Fetched relay quote', quote);
 
-    const normalized = await normalizeQuote(quote, request, fullRequest);
-
-    return normalized;
+    return await normalizeQuote(quote, request, fullRequest);
   } catch (error) {
     log('Error fetching relay quote', error);
     throw error;
@@ -386,9 +386,9 @@ function normalizeRequest(request: QuoteRequest): QuoteRequest {
 
   if (isHyperliquidDeposit) {
     newRequest.targetChainId = CHAIN_ID_HYPERCORE;
-    newRequest.targetTokenAddress = '0x00000000000000000000000000000000';
+    newRequest.targetTokenAddress = HYPERCORE_USDC_ADDRESS;
     newRequest.targetAmountMinimum = new BigNumber(request.targetAmountMinimum)
-      .shiftedBy(2)
+      .shiftedBy(HYPERCORE_USDC_DECIMAL_SHIFT)
       .toString(10);
 
     log('Converting Arbitrum Hyperliquid deposit to direct deposit', {
@@ -399,14 +399,13 @@ function normalizeRequest(request: QuoteRequest): QuoteRequest {
 
   // HyperLiquid withdrawal: source is HyperCore Perps USDC, not Arbitrum.
   // Override source chain/token and set protocolVersion=v2 (required by Relay).
-  // Decimal shift: Perps USDC is 8 decimals, standard USDC is 6.
   if (request.isHyperliquidSource) {
     newRequest.sourceChainId = CHAIN_ID_HYPERCORE;
-    newRequest.sourceTokenAddress = '0x00000000000000000000000000000000';
+    newRequest.sourceTokenAddress = HYPERCORE_USDC_ADDRESS;
 
     if (newRequest.sourceTokenAmount) {
       newRequest.sourceTokenAmount = new BigNumber(newRequest.sourceTokenAmount)
-        .shiftedBy(2)
+        .shiftedBy(HYPERCORE_USDC_DECIMAL_SHIFT)
         .toString(10);
     }
   }

From 80deaf39d1316ca86fdbea445bdcf4b4f132ad91 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 11:37:07 +0100
Subject: [PATCH 03/14] Add casting

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../src/strategy/relay/relay-max-gas-station.ts           | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
index 54b9c4ecff9..1724e7785e6 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
@@ -6,7 +6,7 @@ import {
   getGasStationEligibility,
   getGasStationCostInSourceTokenRaw,
 } from './gas-station';
-import type { RelayQuote } from './types';
+import type { RelayQuote, RelayTransactionStep } from './types';
 import { projectLogger } from '../../logger';
 import type {
   PayStrategyGetQuotesRequest,
@@ -309,11 +309,9 @@ async function getGasCostFromQuoteOrGasStation(
   }
 
   const firstTxStep = quote.original.steps.find(
-    (step) => step.kind === 'transaction',
+    (step): step is RelayTransactionStep => step.kind === 'transaction',
   );
-  const firstStepData = firstTxStep?.items[0]?.data as
-    | { data: Hex; to: Hex; value?: string }
-    | undefined;
+  const firstStepData = firstTxStep?.items[0]?.data;
 
   if (!firstStepData) {
     return undefined;

From 7448595b6652c5c1afc173b8dead90ed745bda3e Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 11:41:02 +0100
Subject: [PATCH 04/14] Remove protocolVersion v2

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../src/strategy/relay/relay-quotes.test.ts    | 18 ------------------
 .../src/strategy/relay/relay-quotes.ts         |  4 ----
 2 files changed, 22 deletions(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
index 0263e990da8..5dc19613758 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
@@ -2333,24 +2333,6 @@ describe('Relay Quotes Utils', () => {
         expect(body.amount).toBe('10000000000');
       });
 
-      it('adds protocolVersion v2 to request body', async () => {
-        successfulFetchMock.mockResolvedValue({
-          json: async () => QUOTE_MOCK,
-        } as never);
-
-        await getRelayQuotes({
-          messenger,
-          requests: [HL_REQUEST],
-          transaction: TRANSACTION_META_MOCK,
-        });
-
-        const body = JSON.parse(
-          successfulFetchMock.mock.calls[0][1]?.body as string,
-        );
-
-        expect(body.protocolVersion).toBe('v2');
-      });
-
       it('zeroes source network fees (gasless)', async () => {
         successfulFetchMock.mockResolvedValue({
           json: async () => QUOTE_MOCK,
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
index 49c85220cec..a42dba748c1 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
@@ -250,10 +250,6 @@ async function getSingleQuote(
       body.refundTo = request.refundTo;
     }
 
-    if (request.isHyperliquidSource) {
-      body.protocolVersion = 'v2';
-    }
-
     log('Request body', body);
 
     const quote = await fetchRelayQuote(messenger, body);

From ede9dfccce667f24451fa8fab0a0d1c463e7b387 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 11:43:30 +0100
Subject: [PATCH 05/14] Code cleanup

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../src/strategy/relay/relay-quotes.ts                   | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
index a42dba748c1..3bf3cf1e610 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
@@ -326,9 +326,8 @@ async function processTransactions(
   requestBody.authorizationList = normalizedAuthorizationList;
   requestBody.tradeType = 'EXACT_OUTPUT';
 
-  const tokenTransferData = nestedTransactions?.find(
-    (nestedTx: { data?: Hex }) =>
-      nestedTx.data?.startsWith(TOKEN_TRANSFER_FOUR_BYTE),
+  const tokenTransferData = nestedTransactions?.find((nestedTx) =>
+    nestedTx.data?.startsWith(TOKEN_TRANSFER_FOUR_BYTE),
   )?.data;
 
   // If the transactions include a token transfer, change the recipient
@@ -891,9 +890,7 @@ function combinePostQuoteGas(
   gasLimits: number[];
   is7702: boolean;
 } {
-  const nestedGas = transaction.nestedTransactions?.find(
-    (tx: { gas?: string }) => tx.gas,
-  )?.gas;
+  const nestedGas = transaction.nestedTransactions?.find((tx) => tx.gas)?.gas;
   const rawGas = nestedGas ?? transaction.txParams.gas;
   const originalTxGas = rawGas ? new BigNumber(rawGas).toNumber() : undefined;
 

From 7cd1b8e35ebc1751678c2aeff183b0b157bf80a1 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 11:49:36 +0100
Subject: [PATCH 06/14] Define HYPERCORE_USDC_DECIMALS and USDC_DECIMALS, use
 it for a decimal shift

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 packages/transaction-pay-controller/src/constants.ts       | 4 ++--
 .../src/strategy/relay/relay-quotes.ts                     | 7 ++++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/transaction-pay-controller/src/constants.ts b/packages/transaction-pay-controller/src/constants.ts
index 801bc751baa..5a097ee85dc 100644
--- a/packages/transaction-pay-controller/src/constants.ts
+++ b/packages/transaction-pay-controller/src/constants.ts
@@ -16,8 +16,8 @@ export const POLYGON_USDCE_ADDRESS =
 
 export const HYPERCORE_USDC_ADDRESS = '0x00000000000000000000000000000000';
 
-// HyperCore Perps USDC uses 8 decimals vs standard USDC's 6.
-export const HYPERCORE_USDC_DECIMAL_SHIFT = 2;
+export const HYPERCORE_USDC_DECIMALS = 8;
+export const USDC_DECIMALS = 6;
 
 export const STABLECOINS: Record<Hex, Hex[]> = {
   // Mainnet
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
index 3bf3cf1e610..92b5c33642c 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
@@ -27,8 +27,9 @@ import {
   CHAIN_ID_HYPERCORE,
   CHAIN_ID_POLYGON,
   HYPERCORE_USDC_ADDRESS,
-  HYPERCORE_USDC_DECIMAL_SHIFT,
+  HYPERCORE_USDC_DECIMALS,
   NATIVE_TOKEN_ADDRESS,
+  USDC_DECIMALS,
   STABLECOINS,
 } from '../../constants';
 import { projectLogger } from '../../logger';
@@ -383,7 +384,7 @@ function normalizeRequest(request: QuoteRequest): QuoteRequest {
     newRequest.targetChainId = CHAIN_ID_HYPERCORE;
     newRequest.targetTokenAddress = HYPERCORE_USDC_ADDRESS;
     newRequest.targetAmountMinimum = new BigNumber(request.targetAmountMinimum)
-      .shiftedBy(HYPERCORE_USDC_DECIMAL_SHIFT)
+      .shiftedBy(HYPERCORE_USDC_DECIMALS - USDC_DECIMALS)
       .toString(10);
 
     log('Converting Arbitrum Hyperliquid deposit to direct deposit', {
@@ -400,7 +401,7 @@ function normalizeRequest(request: QuoteRequest): QuoteRequest {
 
     if (newRequest.sourceTokenAmount) {
       newRequest.sourceTokenAmount = new BigNumber(newRequest.sourceTokenAmount)
-        .shiftedBy(HYPERCORE_USDC_DECIMAL_SHIFT)
+        .shiftedBy(HYPERCORE_USDC_DECIMALS - USDC_DECIMALS)
         .toString(10);
     }
   }

From 715baf6e63b9058bf137356efcf0cdc1b8398a80 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 11:50:59 +0100
Subject: [PATCH 07/14] Update the steps type

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 packages/transaction-pay-controller/src/strategy/relay/types.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/types.ts b/packages/transaction-pay-controller/src/strategy/relay/types.ts
index b70df29c983..78b32277f68 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/types.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/types.ts
@@ -76,7 +76,7 @@ export type RelayQuote = {
   };
   metamask: RelayQuoteMetamask;
   request: RelayQuoteRequest;
-  steps: (RelayTransactionStep | RelaySignatureStep)[];
+  steps: (RelayTransactionStep | RelaySignatureStep | RelayHyperliquidDepositStep)[];
 };
 
 export type RelayTransactionStep = {

From e03373c9a8fb9d6f5e9eaa8bff82ff78571b5d6c Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 11:52:52 +0100
Subject: [PATCH 08/14] Alphabetical order

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 packages/transaction-pay-controller/src/types.ts | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/packages/transaction-pay-controller/src/types.ts b/packages/transaction-pay-controller/src/types.ts
index 879b95bf629..723150c1da2 100644
--- a/packages/transaction-pay-controller/src/types.ts
+++ b/packages/transaction-pay-controller/src/types.ts
@@ -73,6 +73,13 @@ export type TransactionPayControllerGetStateAction = ControllerGetStateAction<
 
 /** Configurable properties of a transaction. */
 export type TransactionConfig = {
+  /**
+   * Whether the source of funds is HyperLiquid (HyperCore).
+   * When true, the Relay strategy uses the HyperLiquid 2-step withdrawal
+   * flow: (1) authorize nonce-mapping, (2) sendAsset to Relay solver.
+   */
+  isHyperliquidSource?: boolean;
+
   /** Whether the user has selected the maximum amount. */
   isMaxAmount?: boolean;
 
@@ -83,13 +90,6 @@ export type TransactionConfig = {
    */
   isPostQuote?: boolean;
 
-  /**
-   * Whether the source of funds is HyperLiquid (HyperCore).
-   * When true, the Relay strategy uses the HyperLiquid 2-step withdrawal
-   * flow: (1) authorize nonce-mapping, (2) sendAsset to Relay solver.
-   */
-  isHyperliquidSource?: boolean;
-
   /**
    * Optional address to receive refunds if the Relay transaction fails.
    * When set, overrides the default refund recipient (EOA) in the Relay quote

From d9825b91fd58a264d81380720b93af2f051d61a3 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 12:01:07 +0100
Subject: [PATCH 09/14] =?UTF-8?q?Allow=20=E2=80=9Csignature=E2=80=9D=20as?=
 =?UTF-8?q?=20a=20valid=20step?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../src/strategy/relay/relay-submit.ts                      | 5 ++++-
 .../transaction-pay-controller/src/strategy/relay/types.ts  | 6 +++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts
index 2e1d784f929..9ae6846e53c 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-submit.ts
@@ -315,7 +315,10 @@ async function submitTransactions(
     (step): step is RelayTransactionStep => step.kind === 'transaction',
   );
   const params = txSteps.flatMap((step) => step.items).map((item) => item.data);
-  const invalidKind = steps.find((step) => step.kind !== 'transaction')?.kind;
+  const SUPPORTED_STEP_KINDS = ['transaction', 'signature'];
+  const invalidKind = steps.find(
+    (step) => !SUPPORTED_STEP_KINDS.includes(step.kind),
+  )?.kind;
 
   if (invalidKind) {
     throw new Error(`Unsupported step kind: ${invalidKind}`);
diff --git a/packages/transaction-pay-controller/src/strategy/relay/types.ts b/packages/transaction-pay-controller/src/strategy/relay/types.ts
index 78b32277f68..c12b886b1ae 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/types.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/types.ts
@@ -76,7 +76,11 @@ export type RelayQuote = {
   };
   metamask: RelayQuoteMetamask;
   request: RelayQuoteRequest;
-  steps: (RelayTransactionStep | RelaySignatureStep | RelayHyperliquidDepositStep)[];
+  steps: (
+    | RelayTransactionStep
+    | RelaySignatureStep
+    | RelayHyperliquidDepositStep
+  )[];
 };
 
 export type RelayTransactionStep = {

From c489044cb79dfd7d6d3eedf0f5e6dbcc9b61a6a1 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 12:04:57 +0100
Subject: [PATCH 10/14] Fix linting

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../src/strategy/relay/relay-quotes.test.ts               | 8 ++------
 packages/transaction-pay-controller/src/utils/quotes.ts   | 2 ++
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
index 5dc19613758..1dde69160fc 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
@@ -2310,9 +2310,7 @@ describe('Relay Quotes Utils', () => {
         );
 
         expect(body.originChainId).toBe(parseInt(CHAIN_ID_HYPERCORE, 16));
-        expect(body.originCurrency).toBe(
-          '0x00000000000000000000000000000000',
-        );
+        expect(body.originCurrency).toBe('0x00000000000000000000000000000000');
       });
 
       it('shifts source amount by 2 decimals (8→6)', async () => {
@@ -2346,9 +2344,7 @@ describe('Relay Quotes Utils', () => {
 
         const zeroAmount = { fiat: '0', human: '0', raw: '0', usd: '0' };
 
-        expect(result[0].fees.sourceNetwork.estimate).toStrictEqual(
-          zeroAmount,
-        );
+        expect(result[0].fees.sourceNetwork.estimate).toStrictEqual(zeroAmount);
         expect(result[0].fees.sourceNetwork.max).toStrictEqual(zeroAmount);
       });
 
diff --git a/packages/transaction-pay-controller/src/utils/quotes.ts b/packages/transaction-pay-controller/src/utils/quotes.ts
index 143f4b866fc..ed5c122effb 100644
--- a/packages/transaction-pay-controller/src/utils/quotes.ts
+++ b/packages/transaction-pay-controller/src/utils/quotes.ts
@@ -256,6 +256,7 @@ export async function refreshQuotes(
  * @param request - Request parameters.
  * @param request.from - Address from which the transaction is sent.
  * @param request.isMaxAmount - Whether the transaction is a maximum amount transaction.
+ * @param request.isHyperliquidSource - Whether the source of funds is HyperLiquid.
  * @param request.isPostQuote - Whether this is a post-quote flow.
  * @param request.paymentToken - Payment token (source for standard flows, destination for post-quote).
  * @param request.refundTo - Optional address to receive refunds if the Relay transaction fails.
@@ -335,6 +336,7 @@ function buildQuoteRequests({
  * @param request - Request parameters.
  * @param request.from - Address from which the transaction is sent.
  * @param request.isMaxAmount - Whether the transaction is a maximum amount transaction.
+ * @param request.isHyperliquidSource - Whether the source of funds is HyperLiquid.
  * @param request.destinationToken - Destination token (paymentToken in post-quote mode).
  * @param request.refundTo - Optional address to receive refunds if the Relay transaction fails.
  * @param request.sourceAmounts - Source amounts for the transaction (includes source token info).

From 6d53ed69a874d3049d0920509d56a56fcf3ec42d Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 13:55:35 +0100
Subject: [PATCH 11/14] Resolve Bugbot comment and linting

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 .../strategy/relay/relay-max-gas-station.ts   |  1 -
 .../src/strategy/relay/relay-quotes.test.ts   | 73 ++++++++++---------
 .../src/strategy/relay/relay-quotes.ts        |  1 -
 3 files changed, 37 insertions(+), 38 deletions(-)

diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
index 1724e7785e6..1abbaad082c 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts
@@ -1,4 +1,3 @@
-import type { Hex } from '@metamask/utils';
 import { createModuleLogger } from '@metamask/utils';
 import { BigNumber } from 'bignumber.js';
 
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
index 1dde69160fc..85ca5bfa33e 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.test.ts
@@ -8,7 +8,7 @@ import type { Hex } from '@metamask/utils';
 import { cloneDeep } from 'lodash';
 
 import { getRelayQuotes } from './relay-quotes';
-import type { RelayQuote } from './types';
+import type { RelayQuote, RelayTransactionStep } from './types';
 import { getDefaultRemoteFeatureFlagControllerState } from '../../../../remote-feature-flag-controller/src/remote-feature-flag-controller';
 import {
   ARBITRUM_USDC_ADDRESS,
@@ -87,6 +87,31 @@ const QUOTE_REQUEST_MOCK: QuoteRequest = {
   targetTokenAddress: '0x1234567890123456789012345678901234567890',
 };
 
+const STEP_MOCK: RelayTransactionStep = {
+  id: 'swap',
+  requestId: '0x1',
+  kind: 'transaction',
+  items: [
+    {
+      check: {
+        endpoint: '/test',
+        method: 'GET',
+      },
+      data: {
+        chainId: 1,
+        data: '0x123' as Hex,
+        from: FROM_MOCK,
+        gas: '21000',
+        maxFeePerGas: '1000000000',
+        maxPriorityFeePerGas: '2000000000',
+        to: '0x2' as Hex,
+        value: '300000',
+      },
+      status: 'complete',
+    },
+  ],
+};
+
 const QUOTE_MOCK = {
   details: {
     currencyIn: {
@@ -117,32 +142,8 @@ const QUOTE_MOCK = {
     gasLimits: [21000],
     is7702: false,
   },
-  steps: [
-    {
-      id: 'swap',
-      items: [
-        {
-          check: {
-            endpoint: '/test',
-            method: 'GET',
-          },
-          data: {
-            chainId: 1,
-            data: '0x123' as Hex,
-            from: FROM_MOCK,
-            gas: '21000',
-            maxFeePerGas: '1000000000',
-            maxPriorityFeePerGas: '2000000000',
-            to: '0x2' as Hex,
-            value: '300000',
-          },
-          status: 'complete',
-        },
-      ],
-      kind: 'transaction',
-    },
-  ],
-} as RelayQuote;
+  steps: [STEP_MOCK],
+} as RelayQuote & { steps: RelayTransactionStep[] };
 
 const DELEGATION_RESULT_MOCK = {
   authorizationList: [
@@ -897,13 +898,13 @@ describe('Relay Quotes Utils', () => {
         ...QUOTE_MOCK,
         steps: [
           {
-            ...QUOTE_MOCK.steps[0],
+            ...STEP_MOCK,
             items: [
-              QUOTE_MOCK.steps[0].items[0],
+              STEP_MOCK.items[0],
               {
-                ...QUOTE_MOCK.steps[0].items[0],
+                ...STEP_MOCK.items[0],
                 data: {
-                  ...QUOTE_MOCK.steps[0].items[0].data,
+                  ...STEP_MOCK.items[0].data,
                   gas: '30000',
                 },
               },
@@ -956,13 +957,13 @@ describe('Relay Quotes Utils', () => {
         ...QUOTE_MOCK,
         steps: [
           {
-            ...QUOTE_MOCK.steps[0],
+            ...STEP_MOCK,
             items: [
-              QUOTE_MOCK.steps[0].items[0],
+              STEP_MOCK.items[0],
               {
-                ...QUOTE_MOCK.steps[0].items[0],
+                ...STEP_MOCK.items[0],
                 data: {
-                  ...QUOTE_MOCK.steps[0].items[0].data,
+                  ...STEP_MOCK.items[0].data,
                   gas: '30000',
                 },
               },
@@ -2932,7 +2933,7 @@ describe('Relay Quotes Utils', () => {
       quoteMock.steps[0].items = [
         {
           ...quoteMock.steps[0].items[0],
-          data: {},
+          data: {} as RelayTransactionStep['items'][0]['data'],
         },
       ];
 
diff --git a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
index 92b5c33642c..8ad148cbf13 100644
--- a/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
+++ b/packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts
@@ -394,7 +394,6 @@ function normalizeRequest(request: QuoteRequest): QuoteRequest {
   }
 
   // HyperLiquid withdrawal: source is HyperCore Perps USDC, not Arbitrum.
-  // Override source chain/token and set protocolVersion=v2 (required by Relay).
   if (request.isHyperliquidSource) {
     newRequest.sourceChainId = CHAIN_ID_HYPERCORE;
     newRequest.sourceTokenAddress = HYPERCORE_USDC_ADDRESS;

From f38d4c8a4f02772fc32bcfe254850532156bc76b Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 14:19:58 +0100
Subject: [PATCH 12/14] Linting

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 eslint-suppressions.json | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/eslint-suppressions.json b/eslint-suppressions.json
index 03a7bc55bf6..f02e6062810 100644
--- a/eslint-suppressions.json
+++ b/eslint-suppressions.json
@@ -1734,11 +1734,6 @@
       "count": 2
     }
   },
-  "packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts": {
-    "import-x/no-relative-packages": {
-      "count": 1
-    }
-  },
   "packages/transaction-pay-controller/src/utils/source-amounts.ts": {
     "import-x/no-relative-packages": {
       "count": 1
@@ -1848,4 +1843,4 @@
       "count": 1
     }
   }
-}
+}
\ No newline at end of file

From 36571e1164be8275622ce256586d1df2f73a16ad Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 14:38:47 +0100
Subject: [PATCH 13/14] Linting

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 eslint-suppressions.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eslint-suppressions.json b/eslint-suppressions.json
index f02e6062810..613fc19879e 100644
--- a/eslint-suppressions.json
+++ b/eslint-suppressions.json
@@ -1843,4 +1843,4 @@
       "count": 1
     }
   }
-}
\ No newline at end of file
+}

From 581aa2041d62e79fc6404fc831aebf6eed3ed464 Mon Sep 17 00:00:00 2001
From: dan437 <80175477+dan437@users.noreply.github.com>
Date: Wed, 25 Mar 2026 15:00:15 +0100
Subject: [PATCH 14/14] Update changelog

Signed-off-by: dan437 <80175477+dan437@users.noreply.github.com>
---
 packages/transaction-pay-controller/CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/transaction-pay-controller/CHANGELOG.md b/packages/transaction-pay-controller/CHANGELOG.md
index 9e639bc0db9..b7504fd7480 100644
--- a/packages/transaction-pay-controller/CHANGELOG.md
+++ b/packages/transaction-pay-controller/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add HyperLiquid source quote support for Relay strategy ([#8285](https://github.com/MetaMask/core/pull/8285))
+
 ### Changed
 
 - Bump `@metamask/assets-controller` from `^3.1.0` to `^3.1.1` ([#8298](https://github.com/MetaMask/core/pull/8298))