feat(xai): support namespace tools and enhance tool normalization logic

- Added `namespace` tool type support, enabling nested tools to be normalized and moved to the top level.
- Refactored tool normalization logic into `normalizeXAITool` for reusability and clarity.
- Updated `xai_executor` test cases to validate namespace tool handling and nested tool normalization.

internal/runtime/executor/xai_executor.go

@@ -34,6 +34,7 @@ const (
 	xaiCustomToolType           = "custom"
 	xaiFunctionToolType         = "function"
 	xaiImageGenerationToolType  = "image_generation"
+	xaiNamespaceToolType        = "namespace"
 	xaiToolSearchType           = "tool_search"
 	xaiWebSearchToolType        = "web_search"
 	xaiImagesGenerationsPath    = "/images/generations"
@@ -664,30 +665,34 @@ func normalizeXAITools(body []byte) []byte {
 	filtered := []byte(`[]`)
 	for _, tool := range tools.Array() {
 		toolType := tool.Get("type").String()
-		if toolType == xaiToolSearchType || toolType == xaiImageGenerationToolType {
+		if toolType == xaiNamespaceToolType {
 			changed = true
+			if namespaceTools := tool.Get("tools"); namespaceTools.IsArray() {
+				for _, nestedTool := range namespaceTools.Array() {
+					nestedRaw, nestedChanged, ok := normalizeXAITool(nestedTool)
+					if !ok {
+						return body
+					}
+					changed = changed || nestedChanged
+					if len(nestedRaw) == 0 {
+						continue
+					}
+					updated, errSet := sjson.SetRawBytes(filtered, "-1", nestedRaw)
+					if errSet != nil {
+						return body
+					}
+					filtered = updated
+				}
+			}
 			continue
 		}
-		raw := []byte(tool.Raw)
-		if toolType == xaiCustomToolType {
-			if tool.Get("name").String() == "apply_patch" {
-				changed = true
-				continue
-			}
-			updatedTool, errSet := sjson.SetBytes(raw, "type", xaiFunctionToolType)
-			if errSet != nil {
-				return body
-			}
-			raw = updatedTool
-			changed = true
+		raw, toolChanged, ok := normalizeXAITool(tool)
+		if !ok {
+			return body
 		}
-		if toolType == xaiWebSearchToolType && tool.Get("external_web_access").Exists() {
-			updatedTool, errDel := sjson.DeleteBytes(raw, "external_web_access")
-			if errDel != nil {
-				return body
-			}
-			raw = updatedTool
-			changed = true
+		changed = changed || toolChanged
+		if len(raw) == 0 {
+			continue
 		}
 		updated, errSet := sjson.SetRawBytes(filtered, "-1", raw)
 		if errSet != nil {
@@ -705,6 +710,35 @@ func normalizeXAITools(body []byte) []byte {
 	return updated
 }
 
+func normalizeXAITool(tool gjson.Result) ([]byte, bool, bool) {
+	toolType := tool.Get("type").String()
+	changed := false
+	if toolType == xaiToolSearchType || toolType == xaiImageGenerationToolType {
+		return nil, true, true
+	}
+	raw := []byte(tool.Raw)
+	if toolType == xaiCustomToolType {
+		if tool.Get("name").String() == "apply_patch" {
+			return nil, true, true
+		}
+		updatedTool, errSet := sjson.SetBytes(raw, "type", xaiFunctionToolType)
+		if errSet != nil {
+			return nil, false, false
+		}
+		raw = updatedTool
+		changed = true
+	}
+	if toolType == xaiWebSearchToolType && tool.Get("external_web_access").Exists() {
+		updatedTool, errDel := sjson.DeleteBytes(raw, "external_web_access")
+		if errDel != nil {
+			return nil, false, false
+		}
+		raw = updatedTool
+		changed = true
+	}
+	return raw, changed, true
+}
+
 func normalizeXAIInputReasoningItems(body []byte) []byte {
 	input := gjson.GetBytes(body, "input")
 	if !input.Exists() || !input.IsArray() {

internal/runtime/executor/xai_executor_test.go

@@ -55,7 +55,7 @@ func TestXAIExecutorExecuteShapesResponsesRequest(t *testing.T) {
 
 	_, err := exec.Execute(context.Background(), auth, cliproxyexecutor.Request{
 		Model:   "grok-4.3",
-		Payload: []byte(`{"model":"grok-4.3","input":[{"type":"reasoning","summary":[{"type":"summary_text","text":"test"}],"content":null,"encrypted_content":null},{"role":"user","content":"hello"}],"include":["reasoning.encrypted_content"],"reasoning":{"effort":"high"},"tools":[{"type":"tool_search"},{"type":"image_generation"},{"type":"custom","name":"apply_patch"},{"type":"custom","name":"custom_lookup"},{"type":"function","name":"lookup"},{"type":"web_search","external_web_access":true,"search_content_types":["text","image"]}]}`),
+		Payload: []byte(`{"model":"grok-4.3","input":[{"type":"reasoning","summary":[{"type":"summary_text","text":"test"}],"content":null,"encrypted_content":null},{"role":"user","content":"hello"}],"include":["reasoning.encrypted_content"],"reasoning":{"effort":"high"},"tools":[{"type":"tool_search"},{"type":"image_generation"},{"type":"custom","name":"apply_patch"},{"type":"custom","name":"custom_lookup"},{"type":"function","name":"lookup"},{"type":"web_search","external_web_access":true,"search_content_types":["text","image"]},{"type":"namespace","name":"codex_app","description":"Tools in the codex_app namespace.","tools":[{"type":"function","name":"automation_update"},{"type":"custom","name":"namespace_custom"},{"type":"tool_search"}]}]}`),
 	}, cliproxyexecutor.Options{
 		SourceFormat: sdktranslator.FormatOpenAIResponse,
 		Stream:       false,
@@ -101,9 +101,11 @@ func TestXAIExecutorExecuteShapesResponsesRequest(t *testing.T) {
 		t.Fatalf("input.0.summary.0.text = %q, want test; body=%s", got, string(gotBody))
 	}
 	tools := gjson.GetBytes(gotBody, "tools").Array()
-	if len(tools) != 3 {
-		t.Fatalf("tools length = %d, want 3; body=%s", len(tools), string(gotBody))
+	if len(tools) != 5 {
+		t.Fatalf("tools length = %d, want 5; body=%s", len(tools), string(gotBody))
 	}
+	foundAutomationUpdate := false
+	foundNamespaceCustom := false
 	for i, tool := range tools {
 		toolType := tool.Get("type").String()
 		if toolType == "image_generation" {
@@ -115,6 +117,12 @@ func TestXAIExecutorExecuteShapesResponsesRequest(t *testing.T) {
 		if got := tool.Get("name").String(); got == "apply_patch" {
 			t.Fatalf("tools.%d.name = apply_patch, want removed; body=%s", i, string(gotBody))
 		}
+		switch tool.Get("name").String() {
+		case "automation_update":
+			foundAutomationUpdate = true
+		case "namespace_custom":
+			foundNamespaceCustom = true
+		}
 		if toolType == "web_search" {
 			if tool.Get("external_web_access").Exists() {
 				t.Fatalf("tools.%d.external_web_access exists, want removed; body=%s", i, string(gotBody))
@@ -124,6 +132,12 @@ func TestXAIExecutorExecuteShapesResponsesRequest(t *testing.T) {
 			}
 		}
 	}
+	if !foundAutomationUpdate {
+		t.Fatalf("namespace function tool was not moved to top-level tools; body=%s", string(gotBody))
+	}
+	if !foundNamespaceCustom {
+		t.Fatalf("namespace custom tool was not moved to top-level tools; body=%s", string(gotBody))
+	}
 	for _, include := range gjson.GetBytes(gotBody, "include").Array() {
 		if include.String() == "reasoning.encrypted_content" {
 			t.Fatalf("xai request must not ask for encrypted reasoning content: %s", string(gotBody))
@@ -192,7 +206,7 @@ func TestXAIExecutorExecuteStreamFiltersToolSearchTool(t *testing.T) {
 
 	result, err := exec.ExecuteStream(context.Background(), auth, cliproxyexecutor.Request{
 		Model:   "grok-4.3",
-		Payload: []byte(`{"model":"grok-4.3","input":[{"type":"reasoning","summary":[{"type":"summary_text","text":"test"}],"content":null,"encrypted_content":null},{"role":"user","content":"hello"}],"tools":[{"type":"tool_search"},{"type":"image_generation"},{"type":"custom","name":"apply_patch"},{"type":"custom","name":"custom_lookup"},{"type":"function","name":"lookup"},{"type":"web_search","external_web_access":true,"search_content_types":["text","image"]}]}`),
+		Payload: []byte(`{"model":"grok-4.3","input":[{"type":"reasoning","summary":[{"type":"summary_text","text":"test"}],"content":null,"encrypted_content":null},{"role":"user","content":"hello"}],"tools":[{"type":"tool_search"},{"type":"image_generation"},{"type":"custom","name":"apply_patch"},{"type":"custom","name":"custom_lookup"},{"type":"function","name":"lookup"},{"type":"web_search","external_web_access":true,"search_content_types":["text","image"]},{"type":"namespace","name":"codex_app","description":"Tools in the codex_app namespace.","tools":[{"type":"function","name":"automation_update"},{"type":"custom","name":"namespace_custom"},{"type":"tool_search"}]}]}`),
 	}, cliproxyexecutor.Options{
 		SourceFormat: sdktranslator.FormatOpenAIResponse,
 		Stream:       true,
@@ -207,8 +221,8 @@ func TestXAIExecutorExecuteStreamFiltersToolSearchTool(t *testing.T) {
 	}
 
 	tools := gjson.GetBytes(gotBody, "tools").Array()
-	if len(tools) != 3 {
-		t.Fatalf("tools length = %d, want 3; body=%s", len(tools), string(gotBody))
+	if len(tools) != 5 {
+		t.Fatalf("tools length = %d, want 5; body=%s", len(tools), string(gotBody))
 	}
 	if gjson.GetBytes(gotBody, "input.0.content").Exists() {
 		t.Fatalf("input.0.content exists, want removed; body=%s", string(gotBody))
@@ -219,6 +233,8 @@ func TestXAIExecutorExecuteStreamFiltersToolSearchTool(t *testing.T) {
 	if got := gjson.GetBytes(gotBody, "input.0.summary.0.text").String(); got != "test" {
 		t.Fatalf("input.0.summary.0.text = %q, want test; body=%s", got, string(gotBody))
 	}
+	foundAutomationUpdate := false
+	foundNamespaceCustom := false
 	for i, tool := range tools {
 		toolType := tool.Get("type").String()
 		if toolType == "image_generation" {
@@ -230,6 +246,12 @@ func TestXAIExecutorExecuteStreamFiltersToolSearchTool(t *testing.T) {
 		if got := tool.Get("name").String(); got == "apply_patch" {
 			t.Fatalf("tools.%d.name = apply_patch, want removed; body=%s", i, string(gotBody))
 		}
+		switch tool.Get("name").String() {
+		case "automation_update":
+			foundAutomationUpdate = true
+		case "namespace_custom":
+			foundNamespaceCustom = true
+		}
 		if toolType == "web_search" {
 			if tool.Get("external_web_access").Exists() {
 				t.Fatalf("tools.%d.external_web_access exists, want removed; body=%s", i, string(gotBody))
@@ -239,6 +261,12 @@ func TestXAIExecutorExecuteStreamFiltersToolSearchTool(t *testing.T) {
 			}
 		}
 	}
+	if !foundAutomationUpdate {
+		t.Fatalf("namespace function tool was not moved to top-level tools; body=%s", string(gotBody))
+	}
+	if !foundNamespaceCustom {
+		t.Fatalf("namespace custom tool was not moved to top-level tools; body=%s", string(gotBody))
+	}
 }
 
 func TestXAIExecutorExecuteImagesUsesImagesEndpoint(t *testing.T) {