diff --git a/codex-rs/core/src/client_common.rs b/codex-rs/core/src/client_common.rs
index 1fb3b7b47..135166919 100644
--- a/codex-rs/core/src/client_common.rs
+++ b/codex-rs/core/src/client_common.rs
@@ -155,12 +155,11 @@ fn strip_total_output_header(output: &str) -> Option<(&str, u32)> {
 pub(crate) mod tools {
     use crate::tools::spec::JsonSchema;
     use codex_protocol::config_types::WebSearchContextSize;
-    use codex_protocol::config_types::WebSearchFilters;
-    use codex_protocol::config_types::WebSearchUserLocation;
+    use codex_protocol::config_types::WebSearchFilters as ConfigWebSearchFilters;
+    use codex_protocol::config_types::WebSearchUserLocation as ConfigWebSearchUserLocation;
     use codex_protocol::config_types::WebSearchUserLocationType;
     use serde::Deserialize;
     use serde::Serialize;
-    use serde::Serializer;
 
     /// When serialized as JSON, this produces a valid "Tool" in the OpenAI
     /// Responses API.
@@ -181,16 +180,10 @@ pub(crate) mod tools {
         WebSearch {
             #[serde(skip_serializing_if = "Option::is_none")]
             external_web_access: Option<bool>,
-            #[serde(
-                skip_serializing_if = "Option::is_none",
-                serialize_with = "serialize_web_search_filters"
-            )]
-            filters: Option<WebSearchFilters>,
-            #[serde(
-                skip_serializing_if = "Option::is_none",
-                serialize_with = "serialize_web_search_user_location"
-            )]
-            user_location: Option<WebSearchUserLocation>,
+            #[serde(skip_serializing_if = "Option::is_none")]
+            filters: Option<ResponsesApiWebSearchFilters>,
+            #[serde(skip_serializing_if = "Option::is_none")]
+            user_location: Option<ResponsesApiWebSearchUserLocation>,
             #[serde(skip_serializing_if = "Option::is_none")]
             search_context_size: Option<WebSearchContextSize>,
             #[serde(skip_serializing_if = "Option::is_none")]
@@ -212,63 +205,43 @@ pub(crate) mod tools {
         }
     }
 
-    fn serialize_web_search_filters<S>(
-        filters: &Option<WebSearchFilters>,
-        serializer: S,
-    ) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        match filters {
-            Some(filters) => {
-                #[derive(Serialize)]
-                struct SerializableWebSearchFilters<'a> {
-                    #[serde(skip_serializing_if = "Option::is_none")]
-                    allowed_domains: Option<&'a Vec<String>>,
-                }
+    #[derive(Debug, Clone, Serialize, PartialEq)]
+    pub(crate) struct ResponsesApiWebSearchFilters {
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub(crate) allowed_domains: Option<Vec<String>>,
+    }
 
-                SerializableWebSearchFilters {
-                    allowed_domains: filters.allowed_domains.as_ref(),
-                }
-                .serialize(serializer)
+    impl From<ConfigWebSearchFilters> for ResponsesApiWebSearchFilters {
+        fn from(filters: ConfigWebSearchFilters) -> Self {
+            Self {
+                allowed_domains: filters.allowed_domains,
             }
-            None => serializer.serialize_none(),
         }
     }
 
-    fn serialize_web_search_user_location<S>(
-        user_location: &Option<WebSearchUserLocation>,
-        serializer: S,
-    ) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        match user_location {
-            Some(user_location) => {
-                #[derive(Serialize)]
-                struct SerializableWebSearchUserLocation<'a> {
-                    #[serde(rename = "type")]
-                    r#type: WebSearchUserLocationType,
-                    #[serde(skip_serializing_if = "Option::is_none")]
-                    country: Option<&'a String>,
-                    #[serde(skip_serializing_if = "Option::is_none")]
-                    region: Option<&'a String>,
-                    #[serde(skip_serializing_if = "Option::is_none")]
-                    city: Option<&'a String>,
-                    #[serde(skip_serializing_if = "Option::is_none")]
-                    timezone: Option<&'a String>,
-                }
+    #[derive(Debug, Clone, Serialize, PartialEq)]
+    pub(crate) struct ResponsesApiWebSearchUserLocation {
+        #[serde(rename = "type")]
+        pub(crate) r#type: WebSearchUserLocationType,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub(crate) country: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub(crate) region: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub(crate) city: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub(crate) timezone: Option<String>,
+    }
 
-                SerializableWebSearchUserLocation {
-                    r#type: user_location.r#type,
-                    country: user_location.country.as_ref(),
-                    region: user_location.region.as_ref(),
-                    city: user_location.city.as_ref(),
-                    timezone: user_location.timezone.as_ref(),
-                }
-                .serialize(serializer)
+    impl From<ConfigWebSearchUserLocation> for ResponsesApiWebSearchUserLocation {
+        fn from(user_location: ConfigWebSearchUserLocation) -> Self {
+            Self {
+                r#type: user_location.r#type,
+                country: user_location.country,
+                region: user_location.region,
+                city: user_location.city,
+                timezone: user_location.timezone,
             }
-            None => serializer.serialize_none(),
         }
     }
 
diff --git a/codex-rs/core/src/tools/spec.rs b/codex-rs/core/src/tools/spec.rs
index f3cec19a1..219484c44 100644
--- a/codex-rs/core/src/tools/spec.rs
+++ b/codex-rs/core/src/tools/spec.rs
@@ -2017,11 +2017,11 @@ pub(crate) fn build_specs(
             filters: config
                 .web_search_config
                 .as_ref()
-                .and_then(|cfg| cfg.filters.clone()),
+                .and_then(|cfg| cfg.filters.clone().map(Into::into)),
             user_location: config
                 .web_search_config
                 .as_ref()
-                .and_then(|cfg| cfg.user_location.clone()),
+                .and_then(|cfg| cfg.user_location.clone().map(Into::into)),
             search_context_size: config
                 .web_search_config
                 .as_ref()
@@ -2766,8 +2766,12 @@ mod tests {
             tool.spec,
             ToolSpec::WebSearch {
                 external_web_access: Some(true),
-                filters: web_search_config.filters,
-                user_location: web_search_config.user_location,
+                filters: web_search_config
+                    .filters
+                    .map(crate::client_common::tools::ResponsesApiWebSearchFilters::from),
+                user_location: web_search_config
+                    .user_location
+                    .map(crate::client_common::tools::ResponsesApiWebSearchUserLocation::from),
                 search_context_size: web_search_config.search_context_size,
                 search_content_types: None,
             }