diff --git a/internal/tools/openclaw.go b/internal/tools/openclaw.go
index 1c1aec4..6dcf099 100644
--- a/internal/tools/openclaw.go
+++ b/internal/tools/openclaw.go
@@ -129,7 +129,7 @@ func writeOpenClawViaCLISequential(providerBlock map[string]any, modelsCatalog m
 		providerName + "/" + reg.Coding().Slug,
 		providerName + "/" + reg.Sub().Slug,
 	})
-	cmd = exec.Command("openclaw", "config", "set", "agents.defaults.model.fallbacks", string(fallbacksJSON))
+	cmd = exec.Command("openclaw", "config", "set", "--merge", "agents.defaults.model.fallbacks", string(fallbacksJSON))
 	if out, err := cmd.CombinedOutput(); err != nil {
 		return fmt.Errorf("openclaw config set agents.defaults.model.fallbacks: %s: %w", string(out), err)
 	}
@@ -139,7 +139,7 @@ func writeOpenClawViaCLISequential(providerBlock map[string]any, modelsCatalog m
 	if err != nil {
 		return fmt.Errorf("marshal models catalog: %w", err)
 	}
-	cmd = exec.Command("openclaw", "config", "set", "agents.defaults.models", string(modelsJSON))
+	cmd = exec.Command("openclaw", "config", "set", "--merge", "agents.defaults.models", string(modelsJSON))
 	if out, err := cmd.CombinedOutput(); err != nil {
 		return fmt.Errorf("openclaw config set agents.defaults.models: %s: %w", string(out), err)
 	}
@@ -177,15 +177,10 @@ func writeOpenClawViaCLI(apiKey string, reg *models.Registry) error {
 	// Check OpenClaw version to determine which approach to use
 	version := getOpenClawVersion()
 	if isBatchJSONSupported(version) {
-		// Use --batch-json to set all config in a single CLI call (~3s vs ~12s sequential).
+		// Use --batch-json for the fields that don't conflict with existing user config.
 		batchOps := []map[string]any{
 			{"path": "models.providers.kimchi", "value": providerBlock},
 			{"path": "agents.defaults.model.primary", "value": providerName + "/" + reg.Main().Slug},
-			{"path": "agents.defaults.model.fallbacks", "value": []string{
-				providerName + "/" + reg.Coding().Slug,
-				providerName + "/" + reg.Sub().Slug,
-			}},
-			{"path": "agents.defaults.models", "value": modelsCatalog},
 		}
 
 		batchJSON, err := json.Marshal(batchOps)
@@ -197,6 +192,26 @@ func writeOpenClawViaCLI(apiKey string, reg *models.Registry) error {
 		if out, err := cmd.CombinedOutput(); err != nil {
 			return fmt.Errorf("openclaw config set: %s: %w", string(out), err)
 		}
+
+		// Merge fallbacks so existing entries are preserved.
+		fallbacksJSON, _ := json.Marshal([]string{
+			providerName + "/" + reg.Coding().Slug,
+			providerName + "/" + reg.Sub().Slug,
+		})
+		cmd = exec.Command("openclaw", "config", "set", "--merge", "agents.defaults.model.fallbacks", string(fallbacksJSON))
+		if out, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("openclaw config set --merge agents.defaults.model.fallbacks: %s: %w", string(out), err)
+		}
+
+		// Merge models catalog so existing entries are preserved.
+		modelsJSON, err := json.Marshal(modelsCatalog)
+		if err != nil {
+			return fmt.Errorf("marshal models catalog: %w", err)
+		}
+		cmd = exec.Command("openclaw", "config", "set", "--merge", "agents.defaults.models", string(modelsJSON))
+		if out, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("openclaw config set --merge agents.defaults.models: %s: %w", string(out), err)
+		}
 	} else {
 		// Fall back to sequential calls for older versions
 		if err := writeOpenClawViaCLISequential(providerBlock, modelsCatalog, reg); err != nil {
@@ -310,13 +325,25 @@ func writeOpenClawDirect(scope config.ConfigScope, apiKey string, reg *models.Re
 	if defaults == nil {
 		defaults = make(map[string]any)
 	}
-	defaults["model"] = map[string]any{
-		"primary":   providerName + "/" + reg.Main().Slug,
-		"fallbacks": []any{providerName + "/" + reg.Coding().Slug, providerName + "/" + reg.Sub().Slug},
+	// Merge into model config to preserve existing keys like temperature, max_tokens.
+	modelMap, _ := defaults["model"].(map[string]any)
+	if modelMap == nil {
+		modelMap = make(map[string]any)
+	}
+	modelMap["primary"] = providerName + "/" + reg.Main().Slug
+	// Merge fallbacks so existing entries are preserved.
+	existingFallbacks, _ := modelMap["fallbacks"].([]any)
+	modelMap["fallbacks"] = append(existingFallbacks,
+		providerName+"/"+reg.Coding().Slug,
+		providerName+"/"+reg.Sub().Slug,
+	)
+	defaults["model"] = modelMap
+
+	// Merge into the allowed models catalog, preserving existing entries.
+	modelsCatalog, _ := defaults["models"].(map[string]any)
+	if modelsCatalog == nil {
+		modelsCatalog = make(map[string]any)
 	}
-
-	// Add models to the allowed models catalog.
-	modelsCatalog := make(map[string]any)
 	for _, m := range reg.All() {
 		modelsCatalog[providerName+"/"+m.Slug] = map[string]any{"alias": m.DisplayName}
 	}
diff --git a/scripts/install.sh b/scripts/install.sh
index f17cff2..13f4a56 100644
--- a/scripts/install.sh
+++ b/scripts/install.sh
@@ -74,4 +74,11 @@ echo -e "${GREEN}✓ Installed kimchi to ${INSTALL_PATH}${NC}"
 echo ""
 echo -e "${BLUE}Launching Kimchi...${NC}"
 echo ""
-exec "$INSTALL_PATH"
+if [ -t 0 ]; then
+	exec "$INSTALL_PATH"
+elif [ -c /dev/tty ]; then
+	exec "$INSTALL_PATH" < /dev/tty
+else
+	echo ""
+	echo -e "${BLUE}Run 'kimchi' to get started.${NC}"
+fi