diff --git a/codex-rs/app-server-protocol/src/protocol/v2.rs b/codex-rs/app-server-protocol/src/protocol/v2.rs
index d23ef3bf56..209c184c8c 100644
--- a/codex-rs/app-server-protocol/src/protocol/v2.rs
+++ b/codex-rs/app-server-protocol/src/protocol/v2.rs
@@ -252,7 +252,7 @@ pub struct FeedbackUploadResponse {
 
 // Thread APIs
 
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ThreadStartParams {
@@ -280,7 +280,7 @@ pub struct ThreadStartResponse {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ThreadResumeParams {
-    pub thread: Thread,
+    pub thread_id: String,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -294,7 +294,7 @@ pub struct ThreadResumeResponse {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ThreadArchiveParams {
-    pub thread: Thread,
+    pub thread_id: String,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
diff --git a/codex-rs/app-server/src/codex_message_processor.rs b/codex-rs/app-server/src/codex_message_processor.rs
index fd2f4069cc..d0b558266e 100644
--- a/codex-rs/app-server/src/codex_message_processor.rs
+++ b/codex-rs/app-server/src/codex_message_processor.rs
@@ -1050,7 +1050,7 @@ impl CodexMessageProcessor {
 
     async fn thread_archive(&self, request_id: RequestId, params: ThreadArchiveParams) {
         // Resolve conversation id from v2 thread id string.
-        let conversation_id = match ConversationId::from_string(&params.thread.id) {
+        let conversation_id = match ConversationId::from_string(&params.thread_id) {
             Ok(id) => id,
             Err(err) => {
                 let error = JSONRPCErrorError {
@@ -1307,7 +1307,7 @@ impl CodexMessageProcessor {
 
     async fn thread_resume(&self, request_id: RequestId, params: ThreadResumeParams) {
         // Convert thread id string into ConversationId.
-        let conversation_id = match ConversationId::from_string(&params.thread.id) {
+        let conversation_id = match ConversationId::from_string(&params.thread_id) {
             Ok(id) => id,
             Err(err) => {
                 let error = JSONRPCErrorError {
diff --git a/codex-rs/app-server/tests/suite/v2/thread_archive.rs b/codex-rs/app-server/tests/suite/v2/thread_archive.rs
index eb65f4419c..345580ca32 100644
--- a/codex-rs/app-server/tests/suite/v2/thread_archive.rs
+++ b/codex-rs/app-server/tests/suite/v2/thread_archive.rs
@@ -51,7 +51,7 @@ async fn thread_archive_moves_rollout_into_archived_directory() -> Result<()> {
     // Archive the thread.
     let archive_id = mcp
         .send_thread_archive_request(ThreadArchiveParams {
-            thread: thread.clone(),
+            thread_id: thread.id.clone(),
         })
         .await?;
     let archive_resp: JSONRPCResponse = timeout(
diff --git a/codex-rs/app-server/tests/suite/v2/thread_resume.rs b/codex-rs/app-server/tests/suite/v2/thread_resume.rs
index c503d8138e..bde3f8d982 100644
--- a/codex-rs/app-server/tests/suite/v2/thread_resume.rs
+++ b/codex-rs/app-server/tests/suite/v2/thread_resume.rs
@@ -39,7 +39,7 @@ async fn thread_resume_returns_existing_thread() -> Result<()> {
     // Resume it via v2 API.
     let resume_id = mcp
         .send_thread_resume_request(ThreadResumeParams {
-            thread: thread.clone(),
+            thread_id: thread.id.clone(),
         })
         .await?;
     let resume_resp: JSONRPCResponse = timeout(