Fix Codex template context override

Author: liyuyang

sdk/api/handlers/openai/codex_client_models.go

@@ -53,6 +53,7 @@ func buildCodexClientModels(models []map[string]any) []map[string]any {
 
 		if template, ok := templates[id]; ok {
 			entry := cloneCodexClientModelMap(template)
+			applyCodexClientContextWindowOverride(entry, id, model)
 			sanitizeCodexClientReasoningMetadata(entry)
 			applyCodexClientVisibilityOverride(entry, id)
 			result = append(result, entry)
@@ -97,6 +98,20 @@ func loadCodexClientModelTemplates() (map[string]map[string]any, map[string]any,
 	return codexClientModelTemplates, codexClientDefaultTemplate, codexClientModelTemplatesErr
 }
 
+func applyCodexClientContextWindowOverride(entry map[string]any, id string, model map[string]any) {
+	contextWindow := intModelValue(model, "context_length")
+	if contextWindow <= 0 {
+		if info := registry.LookupModelInfo(id); info != nil {
+			contextWindow = info.ContextLength
+		}
+	}
+	if contextWindow <= 0 {
+		return
+	}
+	entry["context_window"] = contextWindow
+	entry["max_context_window"] = contextWindow
+}
+
 func applyCodexClientModelMetadata(entry map[string]any, id string, model map[string]any) {
 	info := registry.LookupModelInfo(id)
 

sdk/api/handlers/openai/codex_client_models_test.go

@@ -0,0 +1,25 @@
+package openai
+
+import "testing"
+
+func TestBuildCodexClientModelsAppliesContextLengthToTemplateModel(t *testing.T) {
+	models := buildCodexClientModels([]map[string]any{{
+		"id":             "gpt-5.4",
+		"object":         "model",
+		"owned_by":       "heybox",
+		"context_length": 700000,
+	}})
+
+	if len(models) != 1 {
+		t.Fatalf("models len = %d, want 1", len(models))
+	}
+	if got := intModelValue(models[0], "context_window"); got != 700000 {
+		t.Fatalf("context_window = %d, want 700000", got)
+	}
+	if got := intModelValue(models[0], "max_context_window"); got != 700000 {
+		t.Fatalf("max_context_window = %d, want 700000", got)
+	}
+	if _, ok := models[0]["apply_patch_tool_type"]; !ok {
+		t.Fatal("expected template metadata to be preserved")
+	}
+}