Dart callables

.github/workflows/test_dart.yml

@@ -43,14 +43,15 @@ jobs:
         with:
           sdk: ${{ matrix.dart-version }}
 
-      - name: HTTPS Time Server - Install dependencies
-        working-directory: ./Dart/quickstarts/https-time-server
-        run: dart pub get
-
-      - name: HTTPS Time Server - Format
-        working-directory: ./Dart/quickstarts/https-time-server
-        run: dart format --set-exit-if-changed .
-
-      - name: HTTPS Time Server - Analyze
-        working-directory: ./Dart/quickstarts/https-time-server
-        run: dart analyze .
+      - name: Test Dart Samples
+        run: |
+          set -e
+          for dir in $(find Dart -name pubspec.yaml -exec dirname {} \;); do
+            echo "::group::Testing $dir"
+            cd "$dir"
+            dart pub get
+            dart format --set-exit-if-changed .
+            dart analyze .
+            cd - > /dev/null
+            echo "::endgroup::"
+          done

Dart/quickstarts/callable-functions-streaming/.gitignore

@@ -0,0 +1,5 @@
+.dart_tool/
+.packages
+build/
+*.dart_tool
+pubspec.lock

Dart/quickstarts/callable-functions-streaming/README.md

@@ -0,0 +1,31 @@
+# Firebase SDK for Cloud Functions Quickstart - Callable Functions Streaming
+
+This quickstart demonstrates how to send requests to a server-side function and _stream_ a response to a client SDK using Dart.
+
+[Read more about Cloud Functions for Firebase](https://firebase.google.com/docs/functions/)
+
+
+## Frontend Client
+
+You can find the frontend code in [`../../../Node/quickstarts/callable-functions-streaming/website`](../../../Node/quickstarts/callable-functions-streaming/website).
+
+**IMPORTANT NOTE**: Due to limitations during the experimental release of Dart support in Cloud Functions for Firebase, the code in the website must be modified. Instead of using `httpsCallable`, you must use [`httpsCallableFromURL`](https://firebase.google.com/docs/reference/js/functions.md#httpscallablefromurl_7af6987) and pass the full function url (`https://<function-name-and-hash>.run.app` or the emulator equivalent), which can be found in the Cloud console or the emulator logs.
+
+
+## Deploy the app to prod
+
+First you need to get the `dart` dependencies of the functions:
+
+```bash
+dart pub get
+```
+
+Deploy to Firebase using the following command:
+
+```bash
+firebase deploy --only functions
+```
+
+## License
+
+© Google, 2026. Licensed under an [Apache-2](../../../LICENSE) license.

Dart/quickstarts/callable-functions-streaming/bin/server.dart

@@ -0,0 +1,92 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// [START full-sample]
+// Dependencies for callable functions.
+import 'dart:convert';
+import 'dart:math';
+
+import 'package:firebase_functions/firebase_functions.dart';
+import 'package:http/http.dart' as http;
+
+/// Gets the weather from the national weather service
+/// https://www.weather.gov/documentation/services-web-api
+Future<dynamic> weatherForecastApi(num lat, num lng) async {
+  final resp = await http.get(
+    Uri.parse('https://api.weather.gov/points/$lat,$lng'),
+  );
+
+  if (resp.statusCode >= 400) {
+    return 'error: ${resp.statusCode}';
+  }
+
+  final pointData = jsonDecode(resp.body) as Map<String, dynamic>;
+  final forecastUrl = pointData['properties']['forecast'] as String;
+  final forecastResp = await http.get(Uri.parse(forecastUrl));
+
+  if (forecastResp.statusCode >= 400) {
+    return 'error: ${forecastResp.statusCode}';
+  }
+
+  // add an artificial wait to emphasize stream-iness
+  final randomWait = Random().nextDouble() * 1500;
+  await Future<void>.delayed(Duration(milliseconds: randomWait.toInt()));
+
+  return jsonDecode(forecastResp.body);
+}
+
+void main(List<String> args) async {
+  await fireUp(args, (firebase) {
+    // [START streaming-callable]
+    firebase.https.onCall(name: 'getForecast', (request, response) async {
+      final data = request.data as Map<String, Object?>?;
+      final locations = data?['locations'] as List<dynamic>?;
+
+      if (locations == null || locations.isEmpty) {
+        throw InvalidArgumentError('Missing locations to forecast');
+      }
+
+      // fetch forecast data for all requested locations
+      final allRequests = locations.map((location) async {
+        if (location case {
+          'latitude': num latitude,
+          'longitude': num longitude,
+        }) {
+          final forecast = await weatherForecastApi(latitude, longitude);
+          final result = {
+            'latitude': latitude,
+            'longitude': longitude,
+            'forecast': forecast,
+          };
+
+          // clients that support streaming will have each
+          // forecast streamed to them as they complete
+          if (request.acceptsStreaming) {
+            await response.sendChunk(result);
+          }
+
+          return result;
+        }
+
+        throw InvalidArgumentError('Invalid location format');
+      });
+
+      // Return the full set of data to all clients
+      return CallableResult(await Future.wait(allRequests));
+    });
+    // [END streaming-callable]
+  });
+}
+
+// [END full-sample]

Dart/quickstarts/callable-functions-streaming/firebase.json

@@ -0,0 +1,6 @@
+{
+  "functions": {
+    "source": ".",
+    "codebase": "dart-quickstarts-callable-functions-streaming"
+  }
+}

Dart/quickstarts/callable-functions-streaming/pubspec.yaml

@@ -0,0 +1,33 @@
+name: callable_functions_streaming
+description: Streaming callable examples for Firebase Functions for Dart
+publish_to: none
+
+environment:
+  sdk: ^3.11.0
+
+dependencies:
+  firebase_functions:
+    git:
+      url: https://github.com/firebase/firebase-functions-dart
+      ref: main
+  http: ^1.2.0
+
+dev_dependencies:
+  build_runner: ^2.10.5
+  lints: ^6.0.0
+
+dependency_overrides:
+  firebase_functions:
+    git:
+      url: https://github.com/firebase/firebase-functions-dart
+      ref: main
+  dart_firebase_admin:
+    git:
+      url: https://github.com/firebase/firebase-admin-dart
+      path: packages/dart_firebase_admin
+      ref: main
+  google_cloud_firestore:
+    git:
+      url: https://github.com/firebase/firebase-admin-dart
+      path: packages/google_cloud_firestore
+      ref: main

Dart/quickstarts/callable-functions/.gitignore

@@ -0,0 +1,5 @@
+.dart_tool/
+.packages
+build/
+*.dart_tool
+pubspec.lock

Dart/quickstarts/callable-functions/README.md

@@ -0,0 +1,29 @@
+# Firebase SDK for Cloud Functions Quickstart - Callable Functions
+
+This quickstart demonstrates how to send requests to a server-side function and get a response back using one of the Client SDKs.
+
+## Introduction
+
+The function `addNumbers` Returns the sum of two numbers.
+
+Further reading:
+
+ - [Read more about Cloud Functions for Firebase](https://firebase.google.com/docs/functions/)
+
+## Deploy the app to prod
+
+First you need to get the `dart` dependencies of the functions:
+
+```bash
+dart pub get
+```
+
+Deploy to Firebase using the following command:
+
+```bash
+firebase deploy --only functions
+```
+
+## License
+
+© Google, 2026. Licensed under an [Apache-2](../../../LICENSE) license.

Dart/quickstarts/callable-functions/bin/server.dart

@@ -0,0 +1,70 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// [START imports]
+// Dependencies for callable functions.
+import 'package:firebase_functions/firebase_functions.dart';
+// [END imports]
+
+void main(List<String> args) async {
+  await fireUp(args, (firebase) {
+    // [START allAdd]
+    // [START addFunctionTrigger]
+    // Adds two numbers to each other.
+    firebase.https.onCall(name: 'addNumbers', (request, response) async {
+      // [END addFunctionTrigger]
+      // [START readAddData]
+      // Numbers passed from the client.
+      final data = request.data as Map<String, Object?>?;
+      final firstNumber = data?['firstNumber'];
+      final secondNumber = data?['secondNumber'];
+      // [END readAddData]
+
+      // [START addHttpsError]
+      // Checking that attributes are present and are numbers.
+      if (firstNumber is! num || secondNumber is! num) {
+        // Throwing an HttpsError so that the client gets the error details.
+        throw InvalidArgumentError(
+          'The function must be called with two arguments "firstNumber" and "secondNumber" which must both be numbers.',
+        );
+      }
+      // [END addHttpsError]
+
+      // [START authIntegration]
+      // Authentication / user information is automatically added to the request.
+      final uid = request.auth?.uid;
+      final token = request.auth?.token;
+      final name = token?['name'];
+      final picture = token?['picture'];
+      final email = token?['email'];
+
+      // Use variables to suppress 'unused' lint warnings
+      print(
+        'User details: uid=$uid, name=$name, picture=$picture, email=$email',
+      );
+      // [END authIntegration]
+
+      // [START returnAddData]
+      // returning result.
+      return CallableResult({
+        'firstNumber': firstNumber,
+        'secondNumber': secondNumber,
+        'operator': '+',
+        'operationResult': firstNumber + secondNumber,
+      });
+      // [END returnAddData]
+    });
+    // [END allAdd]
+  });
+}

Dart/quickstarts/callable-functions/firebase.json

@@ -0,0 +1,6 @@
+{
+  "functions": {
+    "source": ".",
+    "codebase": "dart-quickstarts-callable-functions"
+  }
+}

Dart/quickstarts/callable-functions/pubspec.yaml

@@ -0,0 +1,32 @@
+name: callable_functions
+description: Callable examples for Firebase Functions for Dart
+publish_to: none
+
+environment:
+  sdk: ^3.11.0
+
+dependencies:
+  firebase_functions:
+    git:
+      url: https://github.com/firebase/firebase-functions-dart
+      ref: main
+
+dev_dependencies:
+  build_runner: ^2.10.5
+  lints: ^6.0.0
+
+dependency_overrides:
+  firebase_functions:
+    git:
+      url: https://github.com/firebase/firebase-functions-dart
+      ref: main
+  dart_firebase_admin:
+      git:
+        url: https://github.com/firebase/firebase-admin-dart
+        path: packages/dart_firebase_admin
+        ref: main
+  google_cloud_firestore:
+      git:
+        url: https://github.com/firebase/firebase-admin-dart
+        path: packages/google_cloud_firestore
+        ref: main

README.md

@@ -31,10 +31,16 @@ This quickstart sample demonstrates using **Cloud Functions** triggered by **Fir
 
 ### Quickstart: Add numbers and sanitize text with callable functions
 
+- [Dart](/Dart/quickstarts/callable-functions/)
 - [Node 2nd gen](/Node/quickstarts/callable-functions/)
 - [Python](/Python/quickstarts/callable-functions)
 - [Node 1st gen](/Node-1st-gen/quickstarts/callable-functions/)
 
+### Quickstart: Stream responses with callable functions
+
+- [Dart](/Dart/quickstarts/callable-functions-streaming/)
+- [Node 2nd gen](/Node/quickstarts/callable-functions-streaming/)
+
 ### HTTPS trigger quickstart: Time Server
 
 - [Dart](/Dart/quickstarts/https-time-server/)