---
slug: grpc-dart
title: gRPC protoc Dart Client
---
[](https://youtu.be/fDARSMNlt50)
## Dart protoc generated GrpcServiceClient TodoWorld Example
Install [x dotnet tool](/dotnet-tool):
:::sh
dotnet tool install --global x
:::
Install [stagehand](https://pub.dev/packages/stagehand):
:::sh
pub global activate stagehand
:::
Create a new Dart Console App:
:::sh
stagehand console-full
:::
Add required dependencies to **pubspec.yaml**:
```yaml
dependencies:
fixnum: ^0.10.11
async: ^2.2.0
protobuf: ^1.0.1
grpc: ^2.1.3
```
Install dependencies:
:::sh
pub get
:::
### Generate protoc Dart gRPC Client
Add protoc generated TodoWorld DTOs and gRPC GrpcServiceClient to `lib/` folder:
:::sh
x proto-dart https://todoworld.servicestack.net -out lib
:::
### Dart protoc gRPC insecure Example
Use protoc generated DTOs and `GrpcServiceClient` to call TodoWorld gRPC Service in `bin/main.dart`:
```dart
import 'dart:io';
import 'package:grpc/grpc.dart';
import 'package:TodoWorld/services.pb.dart';
import 'package:TodoWorld/services.pbgrpc.dart';
void main(List args) async {
var client = GrpcServicesClient(ClientChannel('todoworld.servicestack.net', port:5054,
options:ChannelOptions(credentials: ChannelCredentials.insecure())));
var response = await client.getHello(Hello()..name = 'gRPC Dart');
print(response.result);
exit(0);
}
```
Override `bin/main.dart` with the above Dart Example:
:::sh
npx add-in todoworld-dart -out bin
:::
Run example:
:::sh
dart run
:::
### Dart protoc gRPC SSL Example
Download TodoWorld SSL Certificate used for its gRPC HTTP/2 Services:
:::sh
x get https://todoworld.servicestack.net/grpc.crt
:::
Use certificate when initializing `GrpcServicesClient`:
```dart
import 'dart:io';
import 'package:grpc/grpc.dart';
import 'package:TodoWorld/services.pb.dart';
import 'package:TodoWorld/services.pbgrpc.dart';
void main(List args) async {
var client = GrpcServicesClient(ClientChannel('todoworld.servicestack.net', port:50051,
options:ChannelOptions(credentials: ChannelCredentials.secure(
certificates: File('grpc.crt').readAsBytesSync(),
authority: 'todoworld.servicestack.net'))));
var response = await client.getHello(Hello()..name = 'gRPC Dart');
print(response.result);
exit(0);
}
```
Override `bin/main.dart` with the above Dart Example:
:::sh
npx add-in todoworld-dart-ssl -out bin
:::
Run example:
:::sh
dart run
:::
### Dart Local Development gRPC SSL CRUD Example
```dart
import 'dart:convert';
import 'dart:io';
import 'package:grpc/grpc.dart';
import 'package:todoworld/services.pb.dart';
import 'package:todoworld/services.pbgrpc.dart';
GrpcServicesClient createClient({CallOptions options}) {
return GrpcServicesClient(ClientChannel('localhost', port:5001,
options:ChannelOptions(credentials: ChannelCredentials.secure(
certificates: File('../certs/dev.crt').readAsBytesSync(),
authority: 'localhost'))), options:options);
}
void main(List args) async {
var client = createClient();
await client.postResetTodos(ResetTodos());
//POST /todos
var todo = (await client.postCreateTodo(CreateTodo()..title = 'ServiceStack')).result;
print('new todo Id: ${todo.id}, Title: ${todo.title}');
//GET /todos
var all = await client.callGetTodos(GetTodos());
print('todos: ${all.results.length}');
//GET /todos/1
todo = (await client.callGetTodo(GetTodo()..id = todo.id)).result;
print('get todo Id: ${todo.id}, Title: ${todo.title}');
//PUT /todos/1
await client.putUpdateTodo(UpdateTodo()..id = todo.id..title = 'gRPC');
//GET /todos/1
todo = (await client.callGetTodo(GetTodo()..id = todo.id)).result;
print('get todo Id: ${todo.id}, Title: ${todo.title}');
//DELETE /todos/1
await client.callDeleteTodo(DeleteTodo()..id = todo.id);
//GET /todos
all = await client.callGetTodos(GetTodos());
print('todos: ${all.results.length}');
}
```
### Dart Server Events gRPC Server Stream Example
Consume [ServiceStack Server Events](/server-events) from gRPC Server Stream API:
```dart
var stream = client.serverStreamServerEvents(StreamServerEvents()..channels.add('todos'));
await for (var r in stream) {
var obj = jsonDecode(r.json);
if (r.selector.startsWith('todos')) {
if (obj is Map) {
print('EVENT ${r.selector} [${r.channel}]: #${obj['id']} ${obj['title']}');
} else {
print('EVENT ${r.selector} [${r.channel}]: ${obj}');
}
} else {
print('EVENT ${r.selector} ${r.channels}: #${obj['userId']} ${obj['displayName']}');
}
}
```
### Dart gRPC Server Stream Files Example
```dart
var stream = client.serverStreamFiles(StreamFiles()..paths.addAll([
'/js/ss-utils.js',
'/js/hot-loader.js',
'/js/hot-fileloader.js',
]));
await for (var file in stream) {
var text = utf8.decode(file.body);
print('FILE ${file.name} (${file.length}): ${text.substring(0, text.length < 50 ? text.length : 50)} ...');
}
```
### Dart gRPC Authenticated Request Example
Depending on what Authentication Providers are available will determine how you can Authenticate and whether the
`AuthenticateResponse` will return a [stateless Bearer Token](/auth/authentication-and-authorization#authentication-per-request-auth-providers)
that can be used to Authenticate instead of a Server Session Id.
Here's an example of authenticating with the common Credentials Auth and authenticating with either the
[Session Id](/auth/sessions) or JWT Bearer Token (if [JWT is enabled](/auth/jwt-authprovider)):
```dart
// Authenticate user Username/Password Credentials Auth
var authResponse = await client.postAuthenticate(Authenticate()..provider='credentials'
..userName=userOrEmail..password=password);
// If using Session Auth
var authClient = createClient(options:CallOptions(metadata:{ 'X-ss-id': authResponse.sessionId }));
// If using Bearer Token stateless Auth Providers (e.g. JWT or API Key):
const bearerToken = authResponse.bearerToken; // or JWT or API Key
var authClient = createClient(options:CallOptions(metadata:{ 'Authorization': 'Bearer ${bearerToken}' }));
// Use authClient to make Authenticated Requests:
var response = await authClient.getHelloSecure(HelloSecure()..name = 'Authenticated gRPC Dart!');
print(response.result);
```
Refer to [/clients/dart](https://github.com/NetCoreApps/todo-world/tree/master/clients/dart)
for a complete example project.