diff --git a/src-tauri/src/acp/connection.rs b/src-tauri/src/acp/connection.rs
index 5f1af15..146216d 100644
--- a/src-tauri/src/acp/connection.rs
+++ b/src-tauri/src/acp/connection.rs
@@ -477,6 +477,24 @@ fn ensure_codex_mode_option(options: &mut Vec<SessionConfigOptionInfo>) {
     });
 }
 
+/// Claude Code does not support the "auto" value for config options.
+/// Strip any option whose value is "auto" from the flat and grouped lists,
+/// and update `current_value` to the first remaining option when it was "auto".
+fn strip_auto_config_values(options: &mut Vec<SessionConfigOptionInfo>) {
+    for opt in options.iter_mut() {
+        let SessionConfigKindInfo::Select(ref mut select) = opt.kind;
+        select.options.retain(|o| o.value != "auto");
+        for group in &mut select.groups {
+            group.options.retain(|o| o.value != "auto");
+        }
+        if select.current_value == "auto" {
+            if let Some(first) = select.options.first() {
+                select.current_value = first.value.clone();
+            }
+        }
+    }
+}
+
 fn emit_session_config_options_values(
     connection_id: &str,
     emitter: &EventEmitter,
@@ -487,6 +505,9 @@ fn emit_session_config_options_values(
     if agent_type == AgentType::Codex {
         ensure_codex_mode_option(&mut mapped);
     }
+    if agent_type == AgentType::ClaudeCode {
+        strip_auto_config_values(&mut mapped);
+    }
     crate::web::event_bridge::emit_event(
         emitter,
         "acp://event",
@@ -1072,6 +1093,9 @@ async fn set_session_config_option(
     config_id: String,
     value_id: String,
 ) -> Result<(), sacp::Error> {
+    if agent_type == AgentType::ClaudeCode && value_id == "auto" {
+        return Ok(());
+    }
     let req = SetSessionConfigOptionRequest::new(session_id.clone(), config_id, value_id);
     let untyped_req = UntypedMessage::new("session/set_config_option", req).map_err(|e| {
         sacp::util::internal_error(format!("Failed to build config option request: {e}"))