diff --git a/codex-rs/app-server/src/message_processor.rs b/codex-rs/app-server/src/message_processor.rs
index e80e1790f..de4418f0e 100644
--- a/codex-rs/app-server/src/message_processor.rs
+++ b/codex-rs/app-server/src/message_processor.rs
@@ -49,6 +49,7 @@ use codex_core::default_client::set_default_originator;
 use codex_feedback::CodexFeedback;
 use codex_protocol::ThreadId;
 use codex_protocol::protocol::SessionSource;
+use futures::FutureExt;
 use tokio::sync::broadcast;
 use tokio::time::Duration;
 use tokio::time::timeout;
@@ -386,8 +387,12 @@ impl MessageProcessor {
                 .await;
             }
             other => {
+                // Box the delegated future so this wrapper's async state machine does not
+                // inline the full `CodexMessageProcessor::process_request` future, which
+                // can otherwise push worker-thread stack usage over the edge.
                 self.codex_message_processor
                     .process_request(connection_id, other)
+                    .boxed()
                     .await;
             }
         }