diff --git a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/approve-builder-fee.ts b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/approve-builder-fee.ts
new file mode 100644
index 000000000..bf716394c
--- /dev/null
+++ b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/approve-builder-fee.ts
@@ -0,0 +1,30 @@
+import * as hyperliquid from '@nktkas/hyperliquid';
+import { approveBuilderFee, SuccessResponse } from '@nktkas/hyperliquid/api/exchange';
+import { LitActionPkpEthersWallet } from './lit-action-pkp-ethers-wallet';
+import { DEFAULT_BUILDER } from '../constants';
+
+export async function approveBuilderFeeAction({
+  transport,
+  pkpPublicKey,
+  useTestnet = false,
+}: {
+  transport: hyperliquid.HttpTransport;
+  pkpPublicKey: string;
+  useTestnet?: boolean;
+}): Promise<SuccessResponse> {
+  const pkpWallet = new LitActionPkpEthersWallet(pkpPublicKey);
+
+  const response = await Lit.Actions.runOnce(
+    { waitForResponse: true, name: 'HyperLiquidApproveBuilderFee' },
+    async () => {
+      return JSON.stringify(
+        await approveBuilderFee(
+          { transport, wallet: pkpWallet },
+          { builder: DEFAULT_BUILDER.address, maxFeeRate: DEFAULT_BUILDER.maxFeeRate },
+        ),
+      );
+    },
+  );
+
+  return JSON.parse(response) as SuccessResponse;
+}
diff --git a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-perp-order.ts b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-perp-order.ts
index c1affb57e..db33d887f 100644
--- a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-perp-order.ts
+++ b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-perp-order.ts
@@ -10,6 +10,7 @@ import { signL1Action } from '@nktkas/hyperliquid/signing';
 import { bigIntReplacer } from '@lit-protocol/vincent-ability-sdk';
 
 import { LitActionPkpEthersWallet } from './lit-action-pkp-ethers-wallet';
+import { DEFAULT_BUILDER } from '../constants';
 
 export type TimeInForce = 'Gtc' | 'Ioc' | 'Alo';
 
@@ -140,6 +141,8 @@ export async function executePerpOrder({
       ? { limit: { tif: 'FrontendMarket' } }
       : { limit: { tif: orderType.tif } };
 
+  const builderConfig = DEFAULT_BUILDER;
+
   // Construct order action
   const orderAction = parser(OrderRequest.entries.action)({
     type: 'order',
@@ -151,6 +154,10 @@ export async function executePerpOrder({
         s: params.size,
         r: params.reduceOnly ?? false, // reduce only (true to close positions, false for opening)
         t: orderTypeField,
+        builder: {
+          b: builderConfig.address,
+          f: builderConfig.fee,
+        },
       },
     ],
     grouping: 'na',
diff --git a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-spot-order.ts b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-spot-order.ts
index f9c24e012..fe8ffa42c 100644
--- a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-spot-order.ts
+++ b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/execute-spot-order.ts
@@ -5,6 +5,7 @@ import { signL1Action } from '@nktkas/hyperliquid/signing';
 import { bigIntReplacer } from '@lit-protocol/vincent-ability-sdk';
 
 import { LitActionPkpEthersWallet } from './lit-action-pkp-ethers-wallet';
+import { DEFAULT_BUILDER } from '../constants';
 
 export type TimeInForce = 'Gtc' | 'Ioc' | 'Alo';
 
@@ -77,6 +78,8 @@ export async function executeSpotOrder({
       ? { limit: { tif: 'FrontendMarket' } }
       : { limit: { tif: orderType.tif } };
 
+  const builderConfig = DEFAULT_BUILDER;
+
   // Construct order action
   const orderAction = parser(OrderRequest.entries.action)({
     type: 'order',
@@ -88,6 +91,10 @@ export async function executeSpotOrder({
         s: params.size,
         r: false, // reduce only (false for spot)
         t: orderTypeField,
+        builder: {
+          b: builderConfig.address,
+          f: builderConfig.fee,
+        },
       },
     ],
     grouping: 'na',
diff --git a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/index.ts b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/index.ts
index d27f7aa51..3d95b8ae2 100644
--- a/packages/apps/ability-hyperliquid/src/lib/ability-helpers/index.ts
+++ b/packages/apps/ability-hyperliquid/src/lib/ability-helpers/index.ts
@@ -5,3 +5,4 @@ export { sendDepositTx } from './send-deposit-tx';
 export { transferUsdcTo } from './transfer-usdc-to';
 export { executeSpotOrder } from './execute-spot-order';
 export { executePerpOrder } from './execute-perp-order';
+export { approveBuilderFeeAction } from './approve-builder-fee';
diff --git a/packages/apps/ability-hyperliquid/src/lib/constants.ts b/packages/apps/ability-hyperliquid/src/lib/constants.ts
new file mode 100644
index 000000000..940a63688
--- /dev/null
+++ b/packages/apps/ability-hyperliquid/src/lib/constants.ts
@@ -0,0 +1,6 @@
+export const DEFAULT_BUILDER = {
+  address: '0x132Db5f531Ba38628F1640683354229daE04E8e6',
+  /** 0.05% expressed in 0.1 bps units (500 * 0.0001% = 0.05%). */
+  fee: 500,
+  maxFeeRate: '0.05%',
+};
diff --git a/packages/apps/ability-hyperliquid/src/lib/schemas.ts b/packages/apps/ability-hyperliquid/src/lib/schemas.ts
index c174ededd..d2c8d0202 100644
--- a/packages/apps/ability-hyperliquid/src/lib/schemas.ts
+++ b/packages/apps/ability-hyperliquid/src/lib/schemas.ts
@@ -10,6 +10,7 @@ export const actionTypeSchema = z.enum([
   'perpShort',
   'cancelOrder',
   'cancelAllOrdersForSymbol',
+  'approveBuilder',
 ]);
 
 export const depositParamsSchema = z.object({
@@ -153,6 +154,7 @@ export const abilityParamsSchema = z
       if (data.action === 'perpLong' || data.action === 'perpShort') return !!data.perp;
       if (data.action === 'cancelOrder') return !!data.cancelOrder;
       if (data.action === 'cancelAllOrdersForSymbol') return !!data.cancelAllOrdersForSymbol;
+      if (data.action === 'approveBuilder') return true;
       return false;
     },
     {
@@ -196,4 +198,8 @@ export const executeSuccessSchema = z.object({
     .any()
     .optional()
     .describe('Cancel result (for spotCancelOrder/spotCancelAll action)'),
+  builderApproval: z
+    .any()
+    .optional()
+    .describe('Builder approval result (for approveBuilder action)'),
 });
diff --git a/packages/apps/ability-hyperliquid/src/lib/types.ts b/packages/apps/ability-hyperliquid/src/lib/types.ts
index 95a7f5c8a..a119f8599 100644
--- a/packages/apps/ability-hyperliquid/src/lib/types.ts
+++ b/packages/apps/ability-hyperliquid/src/lib/types.ts
@@ -11,6 +11,7 @@ export enum HyperliquidAction {
   PERP_SHORT = 'perpShort',
   CANCEL_ORDER = 'cancelOrder',
   CANCEL_ALL_ORDERS_FOR_SYMBOL = 'cancelAllOrdersForSymbol',
+  APPROVE_BUILDER = 'approveBuilder',
 }
 
 /**
diff --git a/packages/apps/ability-hyperliquid/src/lib/vincent-ability.ts b/packages/apps/ability-hyperliquid/src/lib/vincent-ability.ts
index b817ad6a6..f785b019b 100644
--- a/packages/apps/ability-hyperliquid/src/lib/vincent-ability.ts
+++ b/packages/apps/ability-hyperliquid/src/lib/vincent-ability.ts
@@ -28,6 +28,7 @@ import {
   cancelOrder,
   cancelAllOrdersForSymbol,
   executePerpOrder,
+  approveBuilderFeeAction,
 } from './ability-helpers';
 import {
   depositPrechecks,
@@ -227,6 +228,10 @@ export const vincentAbility = createVincentAbility({
         return succeed({ action });
       }
 
+      case HyperliquidAction.APPROVE_BUILDER: {
+        return succeed({ action });
+      }
+
       default:
         return fail({ action, reason: `Unknown action: ${action}` });
     }
@@ -441,6 +446,19 @@ export const vincentAbility = createVincentAbility({
           });
         }
 
+        case HyperliquidAction.APPROVE_BUILDER: {
+          const result = await approveBuilderFeeAction({
+            transport,
+            pkpPublicKey: delegatorPkpInfo.publicKey,
+            useTestnet,
+          });
+
+          return succeed({
+            action,
+            builderApproval: result,
+          });
+        }
+
         default:
           return fail({ action, reason: `Unknown action: ${action}` });
       }