feat(perps): add configurable slippage controls

app/scripts/controllers/perps/perps-stream-bridge.test.ts

@@ -717,6 +717,36 @@ describe('PerpsStreamBridge', () => {
       expect(emit).toHaveBeenCalledWith('orderBook', { bids: [], asks: [] });
     });
 
+    it('forwards levels / nSigFigs / mantissa to the controller', async () => {
+      const controller = createMockController();
+      const { bridge } = createBridge({
+        controller: controller as unknown as PerpsController,
+      });
+      const api = bridge.bridgeApi();
+
+      await (
+        api.perpsActivateOrderBookStream as (p: {
+          symbol: string;
+          levels?: number;
+          nSigFigs?: 2 | 3 | 4 | 5;
+          mantissa?: 2 | 5;
+        }) => Promise<void>
+      )({
+        symbol: 'ETH',
+        levels: 25,
+        nSigFigs: 4,
+        mantissa: 5,
+      });
+
+      expect(controller.subscribeToOrderBook).toHaveBeenCalledWith({
+        symbol: 'ETH',
+        levels: 25,
+        nSigFigs: 4,
+        mantissa: 5,
+        callback: expect.any(Function),
+      });
+    });
+
     it('deactivateOrderBookStream tears down order book subscription', async () => {
       const controller = createMockController();
       const unsub = jest.fn();

app/scripts/controllers/perps/perps-stream-bridge.ts

@@ -217,10 +217,20 @@ export class PerpsStreamBridge {
       perpsDeactivatePriceStream: () => {
         this.#tearDownChannel('prices');
       },
-      perpsActivateOrderBookStream: async ({ symbol }: { symbol: string }) => {
+      perpsActivateOrderBookStream: async ({
+        symbol,
+        levels,
+        nSigFigs,
+        mantissa,
+      }: {
+        symbol: string;
+        levels?: number;
+        nSigFigs?: 2 | 3 | 4 | 5;
+        mantissa?: 2 | 5;
+      }) => {
         await this.#initAndActivate();
         if (this.#isConnectionAlive()) {
-          this.#activateOrderBookStream(symbol);
+          this.#activateOrderBookStream({ symbol, levels, nSigFigs, mantissa });
         }
       },
       perpsDeactivateOrderBookStream: () => {
@@ -586,12 +596,18 @@ export class PerpsStreamBridge {
     );
   }
 
-  #activateOrderBookStream(symbol: string): void {
+  #activateOrderBookStream(params: {
+    symbol: string;
+    levels?: number;
+    nSigFigs?: 2 | 3 | 4 | 5;
+    mantissa?: 2 | 5;
+  }): void {
+    const { symbol } = params;
     this.#tearDownChannel('orderBook');
     if (symbol) {
       this.#addDynamicSubscription('orderBook', () =>
         this.#controller.subscribeToOrderBook({
-          symbol,
+          ...params,
           callback: (data: unknown) => this.#emit('orderBook', data),
         }),
       );

app/scripts/messenger-client-init/perps-controller-init.test.ts

@@ -102,6 +102,8 @@ jest.mock('@metamask/perps-controller', () => ({
     clearPendingTransactionRequests: jest.fn(),
     saveOrderBookGrouping: jest.fn(),
     getOrderBookGrouping: jest.fn(),
+    getMaxSlippage: jest.fn(),
+    setMaxSlippage: jest.fn(),
     getActiveProvider: jest.fn().mockReturnValue({
       getUserHistory: jest.fn(),
       getUserNonFundingLedgerUpdates: jest.fn(),
@@ -581,6 +583,8 @@ describe('PerpsControllerInit', () => {
       ],
       ['perpsSaveOrderBookGrouping', 'saveOrderBookGrouping'],
       ['perpsGetOrderBookGrouping', 'getOrderBookGrouping'],
+      ['perpsGetMaxSlippage', 'getMaxSlippage'],
+      ['perpsSetMaxSlippage', 'setMaxSlippage'],
       ['perpsClearDepositResult', 'clearDepositResult'],
       ['perpsClearWithdrawResult', 'clearWithdrawResult'],
       ['perpsGetBlockExplorerUrl', 'getBlockExplorerUrl'],

app/scripts/messenger-client-init/perps-controller-init.ts

@@ -184,6 +184,8 @@ type PerpsActionName =
   | 'perpsClearPendingTransactionRequests'
   | 'perpsSaveOrderBookGrouping'
   | 'perpsGetOrderBookGrouping'
+  | 'perpsGetMaxSlippage'
+  | 'perpsSetMaxSlippage'
   | 'perpsGetUserHistory'
   | 'perpsClearDepositResult'
   | 'perpsClearWithdrawResult'
@@ -468,6 +470,8 @@ function getApi(
       messengerClient.saveOrderBookGrouping.bind(messengerClient),
     perpsGetOrderBookGrouping:
       messengerClient.getOrderBookGrouping.bind(messengerClient),
+    perpsGetMaxSlippage: messengerClient.getMaxSlippage.bind(messengerClient),
+    perpsSetMaxSlippage: messengerClient.setMaxSlippage.bind(messengerClient),
 
     // -- Provider passthrough (read-guard) --
     perpsGetUserHistory: read(

shared/constants/perps-events.ts

@@ -45,6 +45,10 @@ export const PERPS_EVENT_PROPERTY = {
   SCREEN_NAME: 'screen_name',
   ACTION_TYPE: 'action_type',
   ORDER_TIMESTAMP: 'order_timestamp',
+  MAX_SLIPPAGE_PCT: 'max_slippage_pct',
+  MAX_SLIPPAGE_SOURCE: 'max_slippage_source',
+  ESTIMATED_SLIPPAGE_PCT: 'estimated_slippage_pct',
+  SETTING_TYPE: 'setting_type',
 } as const;
 
 export const PERPS_EVENT_VALUE = {
@@ -78,6 +82,9 @@ export const PERPS_EVENT_VALUE = {
     CLOSE_ALL_TAPPED: 'close_all_tapped',
     CLOSE_ALL_CONFIRMED: 'close_all_confirmed',
     CLOSE_ALL_CANCELLED: 'close_all_cancelled',
+    SLIPPAGE_CONFIG_OPENED: 'slippage_config_opened',
+    SLIPPAGE_CONFIG_CHANGED: 'slippage_config_changed',
+    SLIPPAGE_LIMIT_BLOCKED_ORDER: 'slippage_limit_blocked_order',
   },
   BUTTON_CLICKED: {
     DEPOSIT: 'deposit',
@@ -147,6 +154,13 @@ export const PERPS_EVENT_VALUE = {
     FUNDING: 'funding',
     DEPOSITS: 'deposits',
   },
+  MAX_SLIPPAGE_SOURCE: {
+    DEFAULT: 'default',
+    USER_CONFIGURED: 'user_configured',
+  },
+  SETTING_TYPE: {
+    SLIPPAGE: 'slippage',
+  },
 } as const;
 
 export enum PerpsAnalyticsEvent {

test/e2e/feature-flags/feature-flag-registry.ts

@@ -2261,6 +2261,17 @@ export const FEATURE_FLAG_REGISTRY: Record<string, FeatureFlagRegistryEntry> = {
     status: FeatureFlagStatus.Active,
   },
 
+  perpsSlippageConfig2: {
+    name: 'perpsSlippageConfig2',
+    type: FeatureFlagType.Remote,
+    inProd: true,
+    productionDefault: {
+      enabled: true,
+      minimumVersion: '13.30.0',
+    },
+    status: FeatureFlagStatus.Active,
+  },
+
   vipProgramEnabled: {
     name: 'vipProgramEnabled',
     type: FeatureFlagType.Remote,

test/e2e/tests/perps/perps-fixture-config.ts

@@ -92,6 +92,13 @@ const PERPS_ELIGIBLE_REMOTE_FEATURE_FLAGS = {
   confirmations_pay_post_quote: PERPS_WITHDRAW_CONFIRMATION_DISABLED_FLAG,
   perpsEnabledVersion: { enabled: true, minimumVersion: '0.0.0' },
   perpsPerpTradingGeoBlockedCountriesV2: { blockedRegions: [] },
+  // Disable the configurable max-slippage controls in the generic Perps E2E
+  // fixture. When enabled, market-order submit is gated on a live order-book
+  // slippage estimate (usePerpsEstimatedSlippage) that the lifecycle WS mock
+  // does not feed, leaving submit-order-button permanently disabled. The flag
+  // is on in production (registry value), so it stays registered; tests that
+  // need the slippage UI can opt in explicitly. Covered by unit tests + recipe.
+  perpsSlippageConfig2: { enabled: false, minimumVersion: '0.0.0' },
 };
 
 /**
@@ -258,6 +265,13 @@ async function mockEligibleFeatureFlags(server: Mockttp): Promise<void> {
     // eslint-disable-next-line @typescript-eslint/naming-convention
     confirmations_pay: { name: 'empty' },
     perpsPerpTradingGeoBlockedCountriesV2: { blockedRegions: [] },
+    // Mirror the seeded controller state: the background
+    // RemoteFeatureFlagController refetches /v1/flags on load and would
+    // otherwise overwrite the seeded `enabled: false` with the production
+    // default (`enabled: true`), re-enabling slippage gating and leaving
+    // market submit disabled without order-book estimates.
+    perpsSlippageConfig2:
+      PERPS_ELIGIBLE_REMOTE_FEATURE_FLAGS.perpsSlippageConfig2,
   });
   await server
     .forGet('https://client-config.api.cx.metamask.io/v1/flags')

test/mocks/metamask-perps-controller.js

@@ -128,11 +128,68 @@ const mockPerpsErrorCodes = new Proxy(
   { get: (_target, prop) => String(prop) },
 );
 
+const mockOrderSlippageConfig = {
+  DefaultMarketSlippageBps: 300,
+  DefaultTpslSlippageBps: 1000,
+  DefaultLimitSlippageBps: 100,
+};
+
+const mockMaxSlippageBounds = {
+  MinBps: 10,
+  MaxBps: 1000,
+  StepBps: 10,
+};
+
+const mockPerformanceConfig = {
+  SlippageEstimateThrottleMs: 250,
+  SlippageEstimateBookLevels: 10,
+};
+
+const mockTradingDefaults = {
+  leverage: 3,
+  marginPercent: 10,
+  takeProfitPercent: 0.3,
+  stopLossPercent: 0.1,
+  amount: {
+    mainnet: 10,
+    testnet: 10,
+  },
+};
+
+/**
+ * Simplified max-amount helper for unit tests (matches controller shape; omits
+ * position-size rounding details that are covered by controller tests).
+ *
+ * @param {object} params
+ * @param {number} params.spendableBalance
+ * @param {number} params.assetPrice
+ * @param {number} params.assetSzDecimals
+ * @param {number} params.leverage
+ * @returns {number}
+ */
+function mockGetMaxAllowedAmount({
+  spendableBalance,
+  assetPrice,
+  assetSzDecimals,
+  leverage,
+}) {
+  if (spendableBalance === 0 || !assetPrice || assetSzDecimals === undefined) {
+    return 0;
+  }
+  return Math.max(0, Math.floor(spendableBalance * leverage * 0.99));
+}
+
 module.exports = {
   PERPS_EVENT_PROPERTY: mockPerpsEventPropertyKeys,
   PERPS_EVENT_VALUE: mockPerpsEventValueLiterals,
   PerpsAnalyticsEvent: mockPerpsAnalyticsEventNames,
   PERPS_ERROR_CODES: mockPerpsErrorCodes,
+  ORDER_SLIPPAGE_CONFIG: mockOrderSlippageConfig,
+  MAX_SLIPPAGE_BOUNDS: mockMaxSlippageBounds,
+  PERFORMANCE_CONFIG: mockPerformanceConfig,
+  TRADING_DEFAULTS: mockTradingDefaults,
+  getMaxAllowedAmount: mockGetMaxAllowedAmount,
+  BASIS_POINTS_DIVISOR: 10000,
   MARKET_CATEGORIES: mockMarketCategories,
   isHip3Market: mockIsHip3Market,
   getMarketTypeFilter: mockGetMarketTypeFilter,

ui/components/app/perps/close-position/close-position-modal.test.tsx

@@ -56,6 +56,7 @@ jest.mock('../../../../../shared/lib/perps-formatters', () => ({
 }));
 
 jest.mock('@metamask/perps-controller', () => ({
+  ...jest.requireActual('@metamask/perps-controller'),
   PERPS_ERROR_CODES: {
     CLIENT_NOT_INITIALIZED: 'CLIENT_NOT_INITIALIZED',
     CLIENT_REINITIALIZING: 'CLIENT_REINITIALIZING',

ui/components/app/perps/constants/slippageConfig.test.ts

@@ -0,0 +1,26 @@
+import {
+  PERPS_SLIPPAGE_DEFAULT_BPS,
+  PERPS_SLIPPAGE_MAX_BPS,
+  PERPS_SLIPPAGE_MIN_BPS,
+  PERPS_SLIPPAGE_STEP_BPS,
+  bpsToPercent,
+  percentToBps,
+} from './slippageConfig';
+
+describe('slippageConfig constants', () => {
+  it('uses controller default of 3%', () => {
+    expect(PERPS_SLIPPAGE_DEFAULT_BPS).toBe(300);
+    expect(bpsToPercent(PERPS_SLIPPAGE_DEFAULT_BPS)).toBe(3);
+  });
+
+  it('exposes 0.1% to 10% bounds in 0.1% steps', () => {
+    expect(bpsToPercent(PERPS_SLIPPAGE_MIN_BPS)).toBe(0.1);
+    expect(bpsToPercent(PERPS_SLIPPAGE_MAX_BPS)).toBe(10);
+    expect(bpsToPercent(PERPS_SLIPPAGE_STEP_BPS)).toBe(0.1);
+  });
+
+  it('converts percent and bps', () => {
+    expect(percentToBps(3)).toBe(300);
+    expect(bpsToPercent(300)).toBe(3);
+  });
+});