diff --git a/internal/translator/codex/openai/responses/codex_openai-responses_request.go b/internal/translator/codex/openai/responses/codex_openai-responses_request.go
index 360c037f8b..13c336b658 100644
--- a/internal/translator/codex/openai/responses/codex_openai-responses_request.go
+++ b/internal/translator/codex/openai/responses/codex_openai-responses_request.go
@@ -3,6 +3,7 @@ package responses
 import (
 	"fmt"
 
+	log "github.com/sirupsen/logrus"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 )
@@ -39,6 +40,7 @@ func ConvertOpenAIResponsesRequestToCodex(modelName string, inputRawJSON []byte,
 
 	// Convert role "system" to "developer" in input array to comply with Codex API requirements.
 	rawJSON = convertSystemRoleToDeveloper(rawJSON)
+	rawJSON = normalizeCodexBuiltinTools(rawJSON)
 
 	return rawJSON
 }
@@ -82,3 +84,59 @@ func convertSystemRoleToDeveloper(rawJSON []byte) []byte {
 
 	return result
 }
+
+// normalizeCodexBuiltinTools rewrites legacy/preview built-in tool variants to the
+// stable names expected by the current Codex upstream.
+func normalizeCodexBuiltinTools(rawJSON []byte) []byte {
+	result := rawJSON
+
+	tools := gjson.GetBytes(result, "tools")
+	if tools.IsArray() {
+		toolArray := tools.Array()
+		for i := 0; i < len(toolArray); i++ {
+			typePath := fmt.Sprintf("tools.%d.type", i)
+			result = normalizeCodexBuiltinToolAtPath(result, typePath)
+		}
+	}
+
+	result = normalizeCodexBuiltinToolAtPath(result, "tool_choice.type")
+
+	toolChoiceTools := gjson.GetBytes(result, "tool_choice.tools")
+	if toolChoiceTools.IsArray() {
+		toolArray := toolChoiceTools.Array()
+		for i := 0; i < len(toolArray); i++ {
+			typePath := fmt.Sprintf("tool_choice.tools.%d.type", i)
+			result = normalizeCodexBuiltinToolAtPath(result, typePath)
+		}
+	}
+
+	return result
+}
+
+func normalizeCodexBuiltinToolAtPath(rawJSON []byte, path string) []byte {
+	currentType := gjson.GetBytes(rawJSON, path).String()
+	normalizedType := normalizeCodexBuiltinToolType(currentType)
+	if normalizedType == "" {
+		return rawJSON
+	}
+
+	updated, err := sjson.SetBytes(rawJSON, path, normalizedType)
+	if err != nil {
+		return rawJSON
+	}
+
+	log.Debugf("codex responses: normalized builtin tool type at %s from %q to %q", path, currentType, normalizedType)
+	return updated
+}
+
+// normalizeCodexBuiltinToolType centralizes the current known Codex Responses
+// built-in tool alias compatibility. If Codex introduces more legacy aliases,
+// extend this helper instead of adding path-specific rewrite logic elsewhere.
+func normalizeCodexBuiltinToolType(toolType string) string {
+	switch toolType {
+	case "web_search_preview", "web_search_preview_2025_03_11":
+		return "web_search"
+	default:
+		return ""
+	}
+}
diff --git a/internal/translator/codex/openai/responses/codex_openai-responses_request_test.go b/internal/translator/codex/openai/responses/codex_openai-responses_request_test.go
index a2ede1b874..3b48a76e04 100644
--- a/internal/translator/codex/openai/responses/codex_openai-responses_request_test.go
+++ b/internal/translator/codex/openai/responses/codex_openai-responses_request_test.go
@@ -264,6 +264,52 @@ func TestConvertSystemRoleToDeveloper_AssistantRole(t *testing.T) {
 	}
 }
 
+func TestConvertOpenAIResponsesRequestToCodex_NormalizesWebSearchPreview(t *testing.T) {
+	inputJSON := []byte(`{
+		"model": "gpt-5.4-mini",
+		"input": "find latest OpenAI model news",
+		"tools": [
+			{"type": "web_search_preview_2025_03_11"}
+		],
+		"tool_choice": {
+			"type": "allowed_tools",
+			"tools": [
+				{"type": "web_search_preview"},
+				{"type": "web_search_preview_2025_03_11"}
+			]
+		}
+	}`)
+
+	output := ConvertOpenAIResponsesRequestToCodex("gpt-5.4-mini", inputJSON, false)
+
+	if got := gjson.GetBytes(output, "tools.0.type").String(); got != "web_search" {
+		t.Fatalf("tools.0.type = %q, want %q: %s", got, "web_search", string(output))
+	}
+	if got := gjson.GetBytes(output, "tool_choice.type").String(); got != "allowed_tools" {
+		t.Fatalf("tool_choice.type = %q, want %q: %s", got, "allowed_tools", string(output))
+	}
+	if got := gjson.GetBytes(output, "tool_choice.tools.0.type").String(); got != "web_search" {
+		t.Fatalf("tool_choice.tools.0.type = %q, want %q: %s", got, "web_search", string(output))
+	}
+	if got := gjson.GetBytes(output, "tool_choice.tools.1.type").String(); got != "web_search" {
+		t.Fatalf("tool_choice.tools.1.type = %q, want %q: %s", got, "web_search", string(output))
+	}
+}
+
+func TestConvertOpenAIResponsesRequestToCodex_NormalizesTopLevelToolChoicePreviewAlias(t *testing.T) {
+	inputJSON := []byte(`{
+		"model": "gpt-5.4-mini",
+		"input": "find latest OpenAI model news",
+		"tool_choice": {"type": "web_search_preview_2025_03_11"}
+	}`)
+
+	output := ConvertOpenAIResponsesRequestToCodex("gpt-5.4-mini", inputJSON, false)
+
+	if got := gjson.GetBytes(output, "tool_choice.type").String(); got != "web_search" {
+		t.Fatalf("tool_choice.type = %q, want %q: %s", got, "web_search", string(output))
+	}
+}
+
 func TestUserFieldDeletion(t *testing.T) {
 	inputJSON := []byte(`{  
 		"model": "gpt-5.2",