make cached web_search client-side default

codex-rs/core/src/client.rs

@@ -655,13 +655,11 @@ fn build_responses_headers(
     let mut headers = experimental_feature_headers(config);
     headers.insert(
         WEB_SEARCH_ELIGIBLE_HEADER,
-        HeaderValue::from_static(
-            if matches!(config.web_search_mode, Some(WebSearchMode::Disabled)) {
-                "false"
-            } else {
-                "true"
-            },
-        ),
+        HeaderValue::from_static(if config.web_search_mode == WebSearchMode::Disabled {
+            "false"
+        } else {
+            "true"
+        }),
     );
     if let Some(turn_state) = turn_state
         && let Some(state) = turn_state.get()

codex-rs/core/src/codex.rs

@@ -2824,7 +2824,7 @@ async fn spawn_review_thread(
     let tools_config = ToolsConfig::new(&ToolsConfigParams {
         model_info: &review_model_info,
         features: &review_features,
-        web_search_mode: Some(review_web_search_mode),
+        web_search_mode: review_web_search_mode,
     });
 
     let review_prompt = resolved.prompt.clone();
@@ -2836,7 +2836,7 @@ async fn spawn_review_thread(
     let mut per_turn_config = (*config).clone();
     per_turn_config.model = Some(model.clone());
     per_turn_config.features = review_features.clone();
-    per_turn_config.web_search_mode = Some(review_web_search_mode);
+    per_turn_config.web_search_mode = review_web_search_mode;
 
     let otel_manager = parent_turn_context
         .client

codex-rs/core/src/config/mod.rs

@@ -304,8 +304,8 @@ pub struct Config {
     /// model info's default preference.
     pub include_apply_patch_tool: bool,
 
-    /// Explicit or feature-derived web search mode.
-    pub web_search_mode: Option<WebSearchMode>,
+    /// Explicit or feature-derived web search mode. Defaults to cached.
+    pub web_search_mode: WebSearchMode,
 
     /// If set to `true`, used only the experimental unified exec tool.
     pub use_experimental_unified_exec_tool: bool,
@@ -1205,17 +1205,17 @@ fn resolve_web_search_mode(
     config_toml: &ConfigToml,
     config_profile: &ConfigProfile,
     features: &Features,
-) -> Option<WebSearchMode> {
+) -> WebSearchMode {
     if let Some(mode) = config_profile.web_search.or(config_toml.web_search) {
-        return Some(mode);
+        return mode;
     }
     if features.enabled(Feature::WebSearchCached) {
-        return Some(WebSearchMode::Cached);
+        return WebSearchMode::Cached;
     }
     if features.enabled(Feature::WebSearchRequest) {
-        return Some(WebSearchMode::Live);
+        return WebSearchMode::Live;
     }
-    None
+    WebSearchMode::Cached
 }
 
 impl Config {
@@ -2264,12 +2264,15 @@ trust_level = "trusted"
     }
 
     #[test]
-    fn web_search_mode_uses_none_if_unset() {
+    fn web_search_mode_defaults_to_cached_if_unset() {
         let cfg = ConfigToml::default();
         let profile = ConfigProfile::default();
         let features = Features::with_defaults();
 
-        assert_eq!(resolve_web_search_mode(&cfg, &profile, &features), None);
+        assert_eq!(
+            resolve_web_search_mode(&cfg, &profile, &features),
+            WebSearchMode::Cached
+        );
     }
 
     #[test]
@@ -2284,7 +2287,7 @@ trust_level = "trusted"
 
         assert_eq!(
             resolve_web_search_mode(&cfg, &profile, &features),
-            Some(WebSearchMode::Live)
+            WebSearchMode::Live
         );
     }
 
@@ -2300,7 +2303,7 @@ trust_level = "trusted"
 
         assert_eq!(
             resolve_web_search_mode(&cfg, &profile, &features),
-            Some(WebSearchMode::Disabled)
+            WebSearchMode::Disabled
         );
     }
 
@@ -3737,7 +3740,7 @@ model_verbosity = "high"
                 forced_chatgpt_workspace_id: None,
                 forced_login_method: None,
                 include_apply_patch_tool: false,
-                web_search_mode: None,
+                web_search_mode: WebSearchMode::Cached,
                 use_experimental_unified_exec_tool: false,
                 ghost_snapshot: GhostSnapshotConfig::default(),
                 features: Features::with_defaults(),
@@ -3820,7 +3823,7 @@ model_verbosity = "high"
             forced_chatgpt_workspace_id: None,
             forced_login_method: None,
             include_apply_patch_tool: false,
-            web_search_mode: None,
+            web_search_mode: WebSearchMode::Cached,
             use_experimental_unified_exec_tool: false,
             ghost_snapshot: GhostSnapshotConfig::default(),
             features: Features::with_defaults(),
@@ -3918,7 +3921,7 @@ model_verbosity = "high"
             forced_chatgpt_workspace_id: None,
             forced_login_method: None,
             include_apply_patch_tool: false,
-            web_search_mode: None,
+            web_search_mode: WebSearchMode::Cached,
             use_experimental_unified_exec_tool: false,
             ghost_snapshot: GhostSnapshotConfig::default(),
             features: Features::with_defaults(),
@@ -4002,7 +4005,7 @@ model_verbosity = "high"
             forced_chatgpt_workspace_id: None,
             forced_login_method: None,
             include_apply_patch_tool: false,
-            web_search_mode: None,
+            web_search_mode: WebSearchMode::Cached,
             use_experimental_unified_exec_tool: false,
             ghost_snapshot: GhostSnapshotConfig::default(),
             features: Features::with_defaults(),

codex-rs/core/src/tasks/review.rs

@@ -86,7 +86,7 @@ async fn start_review_conversation(
     let mut sub_agent_config = config.as_ref().clone();
     // Carry over review-only feature restrictions so the delegate cannot
     // re-enable blocked tools (web search, view image).
-    sub_agent_config.web_search_mode = Some(WebSearchMode::Disabled);
+    sub_agent_config.web_search_mode = WebSearchMode::Disabled;
 
     // Set explicit review rubric for the sub-agent
     sub_agent_config.base_instructions = Some(crate::REVIEW_PROMPT.to_string());