From e985e0d1cc9556a6628d11a2b2599795b23f74c4 Mon Sep 17 00:00:00 2001
From: Guillaume Bernos <guillaume@bernos.dev>
Date: Mon, 8 Jun 2026 14:10:39 +0200
Subject: [PATCH] fix(ai): firebase_ai server template image inputs passed as
 InlineDataPart were serialized as normal generative inlineData

---
 .../firebase_ai/lib/src/base_model.dart       | 27 ++++++++++++++++--
 .../test/server_template_test.dart            | 28 +++++++++++++++++++
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/packages/firebase_ai/firebase_ai/lib/src/base_model.dart b/packages/firebase_ai/firebase_ai/lib/src/base_model.dart
index f02bc723b580..96972eb5dafb 100644
--- a/packages/firebase_ai/firebase_ai/lib/src/base_model.dart
+++ b/packages/firebase_ai/firebase_ai/lib/src/base_model.dart
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:firebase_app_check/firebase_app_check.dart';
 import 'package:firebase_auth/firebase_auth.dart';
@@ -375,7 +376,7 @@ abstract class BaseTemplateApiClientModel extends BaseApiClientModel {
       T Function(Map<String, Object?>) parse) {
     Map<String, Object?> body = {};
     if (inputs != null) {
-      body['inputs'] = inputs;
+      body['inputs'] = _serializeTemplateInputs(inputs);
     }
     if (history != null) {
       body['history'] = history.map((c) => c.toJson()).toList();
@@ -405,7 +406,7 @@ abstract class BaseTemplateApiClientModel extends BaseApiClientModel {
       T Function(Map<String, Object?>) parse) {
     Map<String, Object?> body = {};
     if (inputs != null) {
-      body['inputs'] = inputs;
+      body['inputs'] = _serializeTemplateInputs(inputs);
     }
     if (history != null) {
       body['history'] = history.map((c) => c.toJson()).toList();
@@ -428,4 +429,26 @@ abstract class BaseTemplateApiClientModel extends BaseApiClientModel {
   /// Returns the template name for the given [templateId].
   String templateName(String templateId) =>
       _templateUri.templateName(templateId);
+
+  Map<String, Object?> _serializeTemplateInputs(Map<String, Object?> inputs) {
+    return inputs.map((key, value) {
+      return MapEntry(key, _serializeTemplateInputValue(value));
+    });
+  }
+
+  Object? _serializeTemplateInputValue(Object? value) {
+    return switch (value) {
+      InlineDataPart(:final mimeType, :final bytes) => {
+          'isInline': true,
+          'mimeType': mimeType,
+          'contents': base64Encode(bytes),
+        },
+      Map<Object?, Object?>() => value.map((key, nestedValue) {
+          return MapEntry(key, _serializeTemplateInputValue(nestedValue));
+        }),
+      List<Object?>() =>
+        value.map(_serializeTemplateInputValue).toList(growable: false),
+      _ => value,
+    };
+  }
 }
diff --git a/packages/firebase_ai/firebase_ai/test/server_template_test.dart b/packages/firebase_ai/firebase_ai/test/server_template_test.dart
index 71d0905a7424..1dbde35afc0c 100644
--- a/packages/firebase_ai/firebase_ai/test/server_template_test.dart
+++ b/packages/firebase_ai/firebase_ai/test/server_template_test.dart
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import 'dart:convert';
+import 'dart:typed_data';
 
 import 'package:firebase_ai/firebase_ai.dart';
 import 'package:firebase_ai/src/base_model.dart';
@@ -86,6 +87,33 @@ void main() {
       expect(response.text, 'Some response');
     });
 
+    test('generateContent serializes inline image inputs', () async {
+      final mockHttp = MockClient((request) async {
+        final body = jsonDecode(request.body) as Map<String, Object?>;
+        expect(body['inputs'], {
+          'screenshot': {
+            'isInline': true,
+            'mimeType': 'image/jpeg',
+            'contents': base64Encode([1, 2, 3]),
+          },
+        });
+        return http.Response(jsonEncode(_arbitraryGenerateContentResponse), 200,
+            headers: {'content-type': 'application/json'});
+      });
+
+      final model = createModel(mockHttp);
+      final response = await model.generateContent(
+        templateId,
+        inputs: {
+          'screenshot': InlineDataPart(
+            'image/jpeg',
+            Uint8List.fromList([1, 2, 3]),
+          ),
+        },
+      );
+      expect(response.text, 'Some response');
+    });
+
     test('generateContent with TemplateToolConfig passes retrievalConfig',
         () async {
       final mockHttp = MockClient((request) async {