diff --git a/packages/celest/lib/celest.dart b/packages/celest/lib/celest.dart
index 960cd3f..34e24de 100644
--- a/packages/celest/lib/celest.dart
+++ b/packages/celest/lib/celest.dart
@@ -19,10 +19,12 @@ export 'src/config/config_values.dart';
 /// Core
 export 'src/core/annotations.dart';
 export 'src/core/cloud_widget.dart';
-export 'src/core/context.dart';
 export 'src/core/environment.dart';
 export 'src/core/project.dart';
 
+/// Data
+export 'src/data/database.dart';
+
 /// Functions
 export 'src/functions/cloud_api.dart';
 export 'src/functions/cloud_function.dart';
diff --git a/packages/celest/lib/src/core/context.dart b/packages/celest/lib/src/core/context.dart
index 8eb776c..b8420d1 100644
--- a/packages/celest/lib/src/core/context.dart
+++ b/packages/celest/lib/src/core/context.dart
@@ -23,7 +23,8 @@ import 'package:shelf/shelf.dart' as shelf;
 Context get context => Context.current;
 
 /// {@template celest.runtime.celest_context}
-/// A per-request context object which propogates request information and common accessors to the Celest server environment.
+/// A per-request context object which propogates request information and common
+/// accessors to the Celest server environment.
 /// {@endtemplate}
 final class Context {
   /// {@macro celest.runtime.celest_context}
diff --git a/packages/celest/lib/src/runtime/auth/supabase/supabase_token_verifier.dart b/packages/celest/lib/src/runtime/auth/supabase/supabase_token_verifier.dart
index 1a7a33e..9e549a9 100644
--- a/packages/celest/lib/src/runtime/auth/supabase/supabase_token_verifier.dart
+++ b/packages/celest/lib/src/runtime/auth/supabase/supabase_token_verifier.dart
@@ -2,6 +2,7 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:celest/celest.dart';
+import 'package:celest/src/core/context.dart';
 import 'package:celest/src/runtime/auth/jwt/base64_raw_url.dart';
 import 'package:crypto_keys/crypto_keys.dart'
     show AlgorithmIdentifier, Signature, SymmetricKey;
diff --git a/packages/celest/lib/src/runtime/configuration.dart b/packages/celest/lib/src/runtime/configuration.dart
index 9b1815e..a87425a 100644
--- a/packages/celest/lib/src/runtime/configuration.dart
+++ b/packages/celest/lib/src/runtime/configuration.dart
@@ -44,22 +44,27 @@ Future<Map<String, Object?>?> _loadJsonFromFileSystem(
 }
 
 /// Configures the environment in which Celest is running.
-Future<void> configure() async {
+Future<void> configure({
+  ResolvedProject? config,
+}) async {
   configureLogging();
 
   final rootContext = Context.root;
 
-  final configJson = _loadJsonFromEnv(rootContext) ??
-      await _loadJsonFromFileSystem(rootContext);
-  if (configJson == null) {
-    throw StateError(
-      'No project configuration found. Create a celest.json file and set '
-      'CELEST_CONFIG with its path or CELEST_CONFIG_JSON with its contents.',
-    );
+  if (config == null) {
+    final configJson = _loadJsonFromEnv(rootContext) ??
+        await _loadJsonFromFileSystem(rootContext);
+    if (configJson == null) {
+      throw StateError(
+        'No project configuration found. Create a celest.json file and set '
+        'CELEST_CONFIG with its path or CELEST_CONFIG_JSON with its contents.',
+      );
+    }
+
+    final configPb = pb.ResolvedProject()..mergeFromProto3Json(configJson);
+    config = ResolvedProject.fromProto(configPb);
   }
 
-  final configPb = pb.ResolvedProject()..mergeFromProto3Json(configJson);
-  final config = ResolvedProject.fromProto(configPb);
   Logger.root
     ..config('Loaded project configuration')
     ..config(config);
diff --git a/packages/celest/lib/src/runtime/gcp/gcp.dart b/packages/celest/lib/src/runtime/gcp/gcp.dart
index 7152628..1d61d83 100644
--- a/packages/celest/lib/src/runtime/gcp/gcp.dart
+++ b/packages/celest/lib/src/runtime/gcp/gcp.dart
@@ -1,7 +1,7 @@
 @internal
 library;
 
-import 'package:celest/celest.dart';
+import 'package:celest/src/core/context.dart';
 import 'package:google_cloud/google_cloud.dart';
 import 'package:meta/meta.dart';
 
diff --git a/packages/celest/lib/src/runtime/http/cloud_middleware.dart b/packages/celest/lib/src/runtime/http/cloud_middleware.dart
index ad0886a..edbabf3 100644
--- a/packages/celest/lib/src/runtime/http/cloud_middleware.dart
+++ b/packages/celest/lib/src/runtime/http/cloud_middleware.dart
@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:math';
 
 import 'package:celest/celest.dart';
+import 'package:celest/src/core/context.dart';
 import 'package:celest/src/runtime/http/middleware.dart';
 import 'package:celest/src/runtime/json_utils.dart';
 import 'package:celest_core/_internal.dart';
diff --git a/packages/celest/lib/src/runtime/http/logging.dart b/packages/celest/lib/src/runtime/http/logging.dart
index 4acd754..0dd584e 100644
--- a/packages/celest/lib/src/runtime/http/logging.dart
+++ b/packages/celest/lib/src/runtime/http/logging.dart
@@ -6,7 +6,7 @@ import 'dart:convert';
 import 'dart:developer' as developer;
 import 'dart:io';
 
-import 'package:celest/celest.dart';
+import 'package:celest/src/core/context.dart';
 import 'package:celest/src/runtime/gcp/gcp.dart';
 import 'package:celest_core/_internal.dart';
 import 'package:cloud_http/cloud_http.dart';
diff --git a/packages/celest/lib/src/runtime/serve.dart b/packages/celest/lib/src/runtime/serve.dart
index 6e1d093..6570dd8 100644
--- a/packages/celest/lib/src/runtime/serve.dart
+++ b/packages/celest/lib/src/runtime/serve.dart
@@ -6,13 +6,16 @@ import 'dart:io';
 
 import 'package:async/async.dart';
 import 'package:celest/celest.dart';
+import 'package:celest/src/core/context.dart';
 import 'package:celest/src/runtime/configuration.dart';
 import 'package:celest/src/runtime/gcp/gcp.dart';
 import 'package:celest/src/runtime/http/cloud_middleware.dart';
 import 'package:celest/src/runtime/http/middleware.dart';
 import 'package:celest/src/runtime/json_utils.dart';
 import 'package:celest/src/runtime/sse/sse_handler.dart';
+import 'package:celest_ast/celest_ast.dart' as ast;
 import 'package:celest_core/_internal.dart';
+import 'package:logging/logging.dart';
 import 'package:shelf/shelf.dart' hide Middleware;
 import 'package:shelf/shelf_io.dart' as shelf_io;
 import 'package:shelf_router/shelf_router.dart';
@@ -31,14 +34,30 @@ part 'targets.dart';
 const int defaultCelestPort = 7777;
 
 /// Serves [targets] on a local HTTP server.
-Future<void> serve({
+///
+/// If [setup] is provided, it is called before the service starts with the root
+/// [Context]. This can be used to configure dependencies and environment
+/// parameters for the service.
+Future<CelestService> serve({
   required Map<String, CloudFunctionTarget> targets,
+  ast.ResolvedProject? config,
+  FutureOr<void> Function(Context context)? setup,
 }) async {
-  await configure();
+  await configure(
+    config: config,
+  );
   final projectId = await googleCloudProject();
   if (projectId != null) {
     Context.root.put(googleCloudProjectKey, projectId);
   }
+  if (setup != null) {
+    try {
+      await setup(Context.root);
+    } on Object catch (e, st) {
+      Logger.root.severe('Failed to setup', e, st);
+      rethrow;
+    }
+  }
   final router = Router()..get('/v1/healthz', (_) => Response.ok('OK'));
   for (final MapEntry(key: route, value: target) in targets.entries) {
     target._apply(router, route);
@@ -61,10 +80,38 @@ Future<void> serve({
     poweredByHeader: 'Celest, the Flutter cloud platform',
   );
   print('Serving on http://localhost:$port');
-  await StreamGroup.merge([
-    ProcessSignal.sigint.watch(),
-    if (!Platform.isWindows) ProcessSignal.sigterm.watch(),
-  ]).first;
-  print('Shutting down...');
-  await server.close();
+  unawaited(
+    StreamGroup.merge([
+      ProcessSignal.sigint.watch(),
+      if (!Platform.isWindows) ProcessSignal.sigterm.watch(),
+    ]).first.then((signal) {
+      print('Received signal $signal');
+      return server.close(force: true);
+    }),
+  );
+  return CelestService._(server);
+}
+
+/// {@template celest.runtime.celest_service}
+/// A running instance of a Celest service.
+/// {@endtemplate}
+final class CelestService {
+  /// {@macro celest.runtime.celest_service}
+  CelestService._(this._server);
+
+  final HttpServer _server;
+
+  /// The address of the running service.
+  InternetAddress get address => _server.address;
+
+  /// The port on which Celest is running.
+  int get port => _server.port;
+
+  /// Closes the Celest service.
+  Future<void> close({
+    bool force = false,
+  }) {
+    print('Shutting down...');
+    return _server.close(force: force);
+  }
 }
diff --git a/packages/celest/test/runtime/serve_test.dart b/packages/celest/test/runtime/serve_test.dart
new file mode 100644
index 0000000..a3a7ab8
--- /dev/null
+++ b/packages/celest/test/runtime/serve_test.dart
@@ -0,0 +1,63 @@
+@TestOn('vm')
+library;
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:celest/src/core/context.dart';
+import 'package:celest/src/runtime/serve.dart';
+import 'package:celest_ast/celest_ast.dart';
+import 'package:pub_semver/pub_semver.dart';
+import 'package:test/test.dart';
+
+final config = ResolvedProject(
+  projectId: 'test',
+  environmentId: 'local',
+  sdkConfig: SdkConfiguration(
+    celest: Version.parse('1.0.0'),
+    dart: Sdk(
+      type: SdkType.dart,
+      version: Version.parse(Platform.version.split(' ').first),
+    ),
+  ),
+);
+
+void main() {
+  group('serve', () {
+    test('calls setup', () async {
+      Context.root = Context.current;
+
+      final setupCompleter = Completer<void>();
+      final service = await serve(
+        config: config,
+        targets: {},
+        setup: setupCompleter.complete,
+      );
+      addTearDown(service.close);
+      expect(
+        setupCompleter.future.timeout(const Duration(seconds: 1)),
+        completes,
+      );
+    });
+
+    test('fails to start server if setup fails', () async {
+      Context.root = Context.current;
+
+      final service = serve(
+        config: config,
+        targets: {},
+        setup: (_) => throw StateError('Failed to setup'),
+      );
+      await expectLater(
+        service,
+        throwsA(
+          isA<StateError>().having(
+            (e) => e.message,
+            'message',
+            'Failed to setup',
+          ),
+        ),
+      );
+    });
+  });
+}
diff --git a/packages/celest_ast/lib/src/sdk_configuration.dart b/packages/celest_ast/lib/src/sdk_configuration.dart
index c4bb936..e8502c8 100644
--- a/packages/celest_ast/lib/src/sdk_configuration.dart
+++ b/packages/celest_ast/lib/src/sdk_configuration.dart
@@ -28,8 +28,8 @@ abstract class SdkConfiguration
     required Version celest,
     required Sdk dart,
     Sdk? flutter,
-    required SdkType targetSdk,
-    required Iterable<FeatureFlag> featureFlags,
+    SdkType targetSdk = SdkType.dart,
+    Iterable<FeatureFlag> featureFlags = const [],
   }) {
     return _$SdkConfiguration._(
       celest: celest,