diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index bdd2dac..0dd74f3 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -2,7 +2,7 @@ module.exports = {
     extends: ['plugin:@typescript-eslint/recommended'],
     parser: '@typescript-eslint/parser',
     parserOptions: {
-        project: "./tsconfig.json",
+        project: './tsconfig.json',
         tsconfigRootDir: __dirname,
         emcaVersion: 2018,
         sourceType: 'module',
@@ -11,11 +11,24 @@ module.exports = {
     root: true,
     rules: {
         '@typescript-eslint/no-explicit-any': 'off',
-        "tsdoc/syntax": "warn",
-        "require-jsdoc": "warn",
-        "jsdoc/check-tag-names": "off",
-        "jsdoc/require-param-type": "off",
-        "jsdoc/require-returns-type": "off",
-        "jsdoc/empty-tags": "off"
-    }
-};
+        '@typescript-eslint/member-delimiter-style': [
+            'warn',
+            {
+                multiline: {
+                    delimiter: 'comma',
+                    requireLast: true,
+                },
+                singleline: {
+                    delimiter: 'comma',
+                    requireLast: false,
+                },
+            },
+        ],
+        'tsdoc/syntax': 'warn',
+        'require-jsdoc': 'warn',
+        'jsdoc/check-tag-names': 'off',
+        'jsdoc/require-param-type': 'off',
+        'jsdoc/require-returns-type': 'off',
+        'jsdoc/empty-tags': 'off',
+    },
+}
diff --git a/.gitignore b/.gitignore
index 6aa0b9d..cb26d38 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ build
 .idea/
 *.log
 .env
+.vscode
diff --git a/src/api/interfaces.ts b/src/api/interfaces.ts
index 8de7220..11e4665 100644
--- a/src/api/interfaces.ts
+++ b/src/api/interfaces.ts
@@ -44,7 +44,7 @@ export type IEventHistoryEntry = {
         logs?: Array<LogParams>,
         gasUsed: string,
         mevGasPrice: string,
-    }
+    },
 }
 
 /**
@@ -85,7 +85,16 @@ export interface TransactionOptions {
     hints?: HintPreferences,
     /** Maximum block number for the transaction to be included in. */
     maxBlockNumber?: number,
+    /** Builders that are allowed to receive this tx. See [flashbots docs](https://github.com/flashbots/dowg/blob/main/builder-registrations.json) for supported builders. */
     builders?: string[],
+    /** Specifies how refund should be paid if tx is used by another searcher. */
+    refund?: Array<{
+         /** The address that receives this portion of the refund. */
+         address: string,
+         /** Percentage of refund to be paid to `address`. Set this to `100` unless splitting refunds between multiple recipients. */
+         percent: number,
+    }>,
+    
 }
 
 /**
@@ -128,12 +137,12 @@ export interface BundleParams {
     privacy?: {
         /** Data fields from bundle transactions to be shared with searchers on MEV-Share. */
         hints?: HintPreferences,
-        /** Builders that are allowed to receive this bundle. See [mev-share spec](https://github.com/flashbots/mev-share/blob/main/builders/registration.json) for supported builders. */
+        /** Builders that are allowed to receive this bundle. See [flashbots docs](https://github.com/flashbots/dowg/blob/main/builder-registrations.json) for supported builders. */
         builders?: Array<string>,
     },
     metadata?: {
         originId?: string,
-    }
+    },
 }
 
 /** Response received from MEV-Share API */
diff --git a/src/api/mungers.ts b/src/api/mungers.ts
index 5b00de8..803b66d 100644
--- a/src/api/mungers.ts
+++ b/src/api/mungers.ts
@@ -44,6 +44,9 @@ export function mungePrivateTxParams(signedTx: string, options?: TransactionOpti
                 hints: extractSpecifiedHints(options.hints),
             },
             builders: options?.builders,
+            validity: options?.refund && {
+                refund: options.refund
+            }
         },
     }]
 }