diff --git a/src/resources/beta/threads/messages.ts b/src/resources/beta/threads/messages.ts
index f17b8508d..68fee1a94 100644
--- a/src/resources/beta/threads/messages.ts
+++ b/src/resources/beta/threads/messages.ts
@@ -369,12 +369,12 @@ export interface Message {
 
 export namespace Message {
   export interface Attachment {
-    add_to?: Array<'file_search' | 'code_interpreter'>;
-
     /**
      * The ID of the file to attach to the message.
      */
     file_id?: string;
+
+    tools?: Array<'file_search' | 'code_interpreter'>;
   }
 
   /**
@@ -523,12 +523,12 @@ export interface MessageCreateParams {
 
 export namespace MessageCreateParams {
   export interface Attachment {
-    add_to?: Array<'file_search' | 'code_interpreter'>;
-
     /**
      * The ID of the file to attach to the message.
      */
     file_id?: string;
+
+    tools?: Array<'file_search' | 'code_interpreter'>;
   }
 }
 
diff --git a/src/resources/beta/threads/runs/runs.ts b/src/resources/beta/threads/runs/runs.ts
index 48cfac546..d48619fba 100644
--- a/src/resources/beta/threads/runs/runs.ts
+++ b/src/resources/beta/threads/runs/runs.ts
@@ -775,12 +775,12 @@ export namespace RunCreateParams {
 
   export namespace AdditionalMessage {
     export interface Attachment {
-      add_to?: Array<'file_search' | 'code_interpreter'>;
-
       /**
        * The ID of the file to attach to the message.
        */
       file_id?: string;
+
+      tools?: Array<'file_search' | 'code_interpreter'>;
     }
   }
 
@@ -1023,12 +1023,12 @@ export namespace RunCreateAndPollParams {
 
   export namespace AdditionalMessage {
     export interface Attachment {
-      add_to?: Array<'file_search' | 'code_interpreter'>;
-
       /**
        * The ID of the file to attach to the message.
        */
       file_id?: string;
+
+      tools?: Array<'file_search' | 'code_interpreter'>;
     }
   }
 
@@ -1224,12 +1224,12 @@ export namespace RunCreateAndStreamParams {
 
   export namespace AdditionalMessage {
     export interface Attachment {
-      add_to?: Array<'file_search' | 'code_interpreter'>;
-
       /**
        * The ID of the file to attach to the message.
        */
       file_id?: string;
+
+      tools?: Array<'file_search' | 'code_interpreter'>;
     }
   }
 
@@ -1425,12 +1425,12 @@ export namespace RunStreamParams {
 
   export namespace AdditionalMessage {
     export interface Attachment {
-      add_to?: Array<'file_search' | 'code_interpreter'>;
-
       /**
        * The ID of the file to attach to the message.
        */
       file_id?: string;
+
+      tools?: Array<'file_search' | 'code_interpreter'>;
     }
   }
 
diff --git a/src/resources/beta/threads/threads.ts b/src/resources/beta/threads/threads.ts
index 6f1e761de..5f325d33a 100644
--- a/src/resources/beta/threads/threads.ts
+++ b/src/resources/beta/threads/threads.ts
@@ -313,12 +313,12 @@ export namespace ThreadCreateParams {
 
   export namespace Message {
     export interface Attachment {
-      add_to?: Array<'file_search' | 'code_interpreter'>;
-
       /**
        * The ID of the file to attach to the message.
        */
       file_id?: string;
+
+      tools?: Array<'file_search' | 'code_interpreter'>;
     }
   }
 
@@ -648,12 +648,12 @@ export namespace ThreadCreateAndRunParams {
 
     export namespace Message {
       export interface Attachment {
-        add_to?: Array<'file_search' | 'code_interpreter'>;
-
         /**
          * The ID of the file to attach to the message.
          */
         file_id?: string;
+
+        tools?: Array<'file_search' | 'code_interpreter'>;
       }
     }
 
@@ -994,12 +994,12 @@ export namespace ThreadCreateAndRunPollParams {
 
     export namespace Message {
       export interface Attachment {
-        add_to?: Array<'file_search' | 'code_interpreter'>;
-
         /**
          * The ID of the file to attach to the message.
          */
         file_id?: string;
+
+        tools?: Array<'file_search' | 'code_interpreter'>;
       }
     }
 
@@ -1319,12 +1319,12 @@ export namespace ThreadCreateAndRunStreamParams {
 
     export namespace Message {
       export interface Attachment {
-        add_to?: Array<'file_search' | 'code_interpreter'>;
-
         /**
          * The ID of the file to attach to the message.
          */
         file_id?: string;
+
+        tools?: Array<'file_search' | 'code_interpreter'>;
       }
     }
 
diff --git a/tests/api-resources/beta/threads/messages.test.ts b/tests/api-resources/beta/threads/messages.test.ts
index a0a025869..61ccebe9f 100644
--- a/tests/api-resources/beta/threads/messages.test.ts
+++ b/tests/api-resources/beta/threads/messages.test.ts
@@ -25,9 +25,9 @@ describe('resource messages', () => {
       content: 'x',
       role: 'user',
       attachments: [
-        { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-        { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-        { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+        { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+        { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+        { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
       ],
       metadata: {},
     });
diff --git a/tests/api-resources/beta/threads/runs/runs.test.ts b/tests/api-resources/beta/threads/runs/runs.test.ts
index 4a3743ca0..ea9c0761e 100644
--- a/tests/api-resources/beta/threads/runs/runs.test.ts
+++ b/tests/api-resources/beta/threads/runs/runs.test.ts
@@ -29,9 +29,9 @@ describe('resource runs', () => {
           role: 'user',
           content: 'x',
           attachments: [
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
           ],
           metadata: {},
         },
@@ -39,9 +39,9 @@ describe('resource runs', () => {
           role: 'user',
           content: 'x',
           attachments: [
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
           ],
           metadata: {},
         },
@@ -49,9 +49,9 @@ describe('resource runs', () => {
           role: 'user',
           content: 'x',
           attachments: [
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-            { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+            { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
           ],
           metadata: {},
         },
diff --git a/tests/api-resources/beta/threads/threads.test.ts b/tests/api-resources/beta/threads/threads.test.ts
index 0a5f70af4..6a697865b 100644
--- a/tests/api-resources/beta/threads/threads.test.ts
+++ b/tests/api-resources/beta/threads/threads.test.ts
@@ -37,9 +37,9 @@ describe('resource threads', () => {
               role: 'user',
               content: 'x',
               attachments: [
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
               ],
               metadata: {},
             },
@@ -47,9 +47,9 @@ describe('resource threads', () => {
               role: 'user',
               content: 'x',
               attachments: [
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
               ],
               metadata: {},
             },
@@ -57,9 +57,9 @@ describe('resource threads', () => {
               role: 'user',
               content: 'x',
               attachments: [
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-                { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+                { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
               ],
               metadata: {},
             },
@@ -153,9 +153,9 @@ describe('resource threads', () => {
             role: 'user',
             content: 'x',
             attachments: [
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
             ],
             metadata: {},
           },
@@ -163,9 +163,9 @@ describe('resource threads', () => {
             role: 'user',
             content: 'x',
             attachments: [
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
             ],
             metadata: {},
           },
@@ -173,9 +173,9 @@ describe('resource threads', () => {
             role: 'user',
             content: 'x',
             attachments: [
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
-              { file_id: 'string', add_to: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
+              { file_id: 'string', tools: ['file_search', 'code_interpreter'] },
             ],
             metadata: {},
           },