diff --git a/codex-rs/app-server-client/src/lib.rs b/codex-rs/app-server-client/src/lib.rs
index 0911cc448d..c2228de20c 100644
--- a/codex-rs/app-server-client/src/lib.rs
+++ b/codex-rs/app-server-client/src/lib.rs
@@ -378,6 +378,7 @@ impl InProcessClientStartArgs {
     pub fn initialize_params(&self) -> InitializeParams {
         let capabilities = InitializeCapabilities {
             experimental_api: self.experimental_api,
+            request_attestation: false,
             opt_out_notification_methods: if self.opt_out_notification_methods.is_empty() {
                 None
             } else {
diff --git a/codex-rs/app-server-client/src/remote.rs b/codex-rs/app-server-client/src/remote.rs
index d75534c160..4a4426a260 100644
--- a/codex-rs/app-server-client/src/remote.rs
+++ b/codex-rs/app-server-client/src/remote.rs
@@ -73,6 +73,7 @@ impl RemoteAppServerConnectArgs {
     fn initialize_params(&self) -> InitializeParams {
         let capabilities = InitializeCapabilities {
             experimental_api: self.experimental_api,
+            request_attestation: false,
             opt_out_notification_methods: if self.opt_out_notification_methods.is_empty() {
                 None
             } else {