feat(grpc): add explicit PermifyClient type for gRPC client factory

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@permify/permify-node",
-  "version": "1.1.2",
+  "version": "1.1.3",
   "description": "Permify Node Client",
   "main": "dist/src/index.js",
   "types": "dist/src/index.d.ts",

src/grpc/clients.ts

@@ -1,4 +1,5 @@
-import { ClientMiddleware, createChannel, createClientFactory, ChannelCredentials } from 'nice-grpc';
+import { ClientMiddleware, createChannel, createClientFactory, ChannelCredentials, RawClient } from 'nice-grpc';
+import type { FromTsProtoServiceDefinition, TsProtoServiceDefinition } from 'nice-grpc/lib/service-definitions/ts-proto';
 import {
     PermissionDefinition,
     SchemaDefinition,
@@ -9,6 +10,22 @@ import {
 } from './generated/base/v1/service';
 import { Config } from './config';
 
+// Helper type to extract the client type from a service definition
+type ClientFromDefinition<T extends TsProtoServiceDefinition> = RawClient<FromTsProtoServiceDefinition<T>>;
+
+/**
+ * Return type for the Permify gRPC client.
+ * This explicit type ensures proper type preservation through export layers.
+ */
+export type PermifyClient = {
+    permission: ClientFromDefinition<typeof PermissionDefinition>;
+    schema: ClientFromDefinition<typeof SchemaDefinition>;
+    data: ClientFromDefinition<typeof DataDefinition>;
+    bundle: ClientFromDefinition<typeof BundleDefinition>;
+    tenancy: ClientFromDefinition<typeof TenancyDefinition>;
+    watch: ClientFromDefinition<typeof WatchDefinition>;
+};
+
 /**
  * Create a new gRPC service client for Permify.
  * The client can be configured with multiple client interceptors. For authentication interceptors,
@@ -19,7 +36,7 @@ import { Config } from './config';
  *
  * @returns A new gRPC service client for the Permission API of Permify.
  */
-export function newClient(conf: Config, ...interceptors: ClientMiddleware[]) {
+export function newClient(conf: Config, ...interceptors: ClientMiddleware[]): PermifyClient {
     const channel = conf.insecure
         ? createChannel(conf.endpoint, ChannelCredentials.createInsecure())
         : createChannel(conf.endpoint, ChannelCredentials.createSsl(conf.cert, conf.pk, conf.certChain));