feat: getFlowDefinition wrapper + FlowInputDef DTO (v0.15.0)

Surface the new platform RPC `GetFlowDefinition` as a typed
Dart method so Studio (and other GUI clients) can render an
input form before calling `runSavedFlow`. Each declared input
arrives as a `FlowInputDef` with the verbatim type tag from
the flow YAML — usually `text`, `bytes`, `json`, or `file`.

Regenerated proto bindings to pick up the new
`GetFlowDefinitionRequest`, `FlowDefinition`, and
`FlowInputSpec` message types.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/src/generated/fai/v1/hub.pb.dart

@@ -1351,6 +1351,170 @@ class RunSavedFlowRequest extends $pb.GeneratedMessage {
   $pb.PbMap<$core.String, $4.Payload> get inputs => $_getMap(1);
 }
 
+class GetFlowDefinitionRequest extends $pb.GeneratedMessage {
+  factory GetFlowDefinitionRequest({
+    $core.String? name,
+  }) {
+    final $result = create();
+    if (name != null) {
+      $result.name = name;
+    }
+    return $result;
+  }
+  GetFlowDefinitionRequest._() : super();
+  factory GetFlowDefinitionRequest.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
+  factory GetFlowDefinitionRequest.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
+
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'GetFlowDefinitionRequest', package: const $pb.PackageName(_omitMessageNames ? '' : 'fai.v1'), createEmptyInstance: create)
+    ..aOS(1, _omitFieldNames ? '' : 'name')
+    ..hasRequiredFields = false
+  ;
+
+  @$core.Deprecated('See https://github.com/google/protobuf.dart/issues/998.')
+  GetFlowDefinitionRequest clone() => GetFlowDefinitionRequest()..mergeFromMessage(this);
+  @$core.Deprecated('See https://github.com/google/protobuf.dart/issues/998.')
+  GetFlowDefinitionRequest copyWith(void Function(GetFlowDefinitionRequest) updates) => super.copyWith((message) => updates(message as GetFlowDefinitionRequest)) as GetFlowDefinitionRequest;
+
+  $pb.BuilderInfo get info_ => _i;
+
+  @$core.pragma('dart2js:noInline')
+  static GetFlowDefinitionRequest create() => GetFlowDefinitionRequest._();
+  GetFlowDefinitionRequest createEmptyInstance() => create();
+  static $pb.PbList<GetFlowDefinitionRequest> createRepeated() => $pb.PbList<GetFlowDefinitionRequest>();
+  @$core.pragma('dart2js:noInline')
+  static GetFlowDefinitionRequest getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<GetFlowDefinitionRequest>(create);
+  static GetFlowDefinitionRequest? _defaultInstance;
+
+  @$pb.TagNumber(1)
+  $core.String get name => $_getSZ(0);
+  @$pb.TagNumber(1)
+  set name($core.String v) { $_setString(0, v); }
+  @$pb.TagNumber(1)
+  $core.bool hasName() => $_has(0);
+  @$pb.TagNumber(1)
+  void clearName() => $_clearField(1);
+}
+
+/// Parsed shape of a saved flow. Currently surfaces only the
+/// declared inputs — that is what Studio needs to render its
+/// run-flow form. Fields can grow (steps, outputs) without
+/// breaking older clients.
+class FlowDefinition extends $pb.GeneratedMessage {
+  factory FlowDefinition({
+    $core.String? name,
+    $core.Iterable<FlowInputSpec>? inputs,
+  }) {
+    final $result = create();
+    if (name != null) {
+      $result.name = name;
+    }
+    if (inputs != null) {
+      $result.inputs.addAll(inputs);
+    }
+    return $result;
+  }
+  FlowDefinition._() : super();
+  factory FlowDefinition.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
+  factory FlowDefinition.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
+
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'FlowDefinition', package: const $pb.PackageName(_omitMessageNames ? '' : 'fai.v1'), createEmptyInstance: create)
+    ..aOS(1, _omitFieldNames ? '' : 'name')
+    ..pc<FlowInputSpec>(2, _omitFieldNames ? '' : 'inputs', $pb.PbFieldType.PM, subBuilder: FlowInputSpec.create)
+    ..hasRequiredFields = false
+  ;
+
+  @$core.Deprecated('See https://github.com/google/protobuf.dart/issues/998.')
+  FlowDefinition clone() => FlowDefinition()..mergeFromMessage(this);
+  @$core.Deprecated('See https://github.com/google/protobuf.dart/issues/998.')
+  FlowDefinition copyWith(void Function(FlowDefinition) updates) => super.copyWith((message) => updates(message as FlowDefinition)) as FlowDefinition;
+
+  $pb.BuilderInfo get info_ => _i;
+
+  @$core.pragma('dart2js:noInline')
+  static FlowDefinition create() => FlowDefinition._();
+  FlowDefinition createEmptyInstance() => create();
+  static $pb.PbList<FlowDefinition> createRepeated() => $pb.PbList<FlowDefinition>();
+  @$core.pragma('dart2js:noInline')
+  static FlowDefinition getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<FlowDefinition>(create);
+  static FlowDefinition? _defaultInstance;
+
+  @$pb.TagNumber(1)
+  $core.String get name => $_getSZ(0);
+  @$pb.TagNumber(1)
+  set name($core.String v) { $_setString(0, v); }
+  @$pb.TagNumber(1)
+  $core.bool hasName() => $_has(0);
+  @$pb.TagNumber(1)
+  void clearName() => $_clearField(1);
+
+  /// Declared input keys plus their declared type tag, exactly
+  /// as the flow YAML's `inputs:` section spelled them. Common
+  /// values: "text", "bytes", "json", "file".
+  @$pb.TagNumber(2)
+  $pb.PbList<FlowInputSpec> get inputs => $_getList(1);
+}
+
+class FlowInputSpec extends $pb.GeneratedMessage {
+  factory FlowInputSpec({
+    $core.String? name,
+    $core.String? type,
+  }) {
+    final $result = create();
+    if (name != null) {
+      $result.name = name;
+    }
+    if (type != null) {
+      $result.type = type;
+    }
+    return $result;
+  }
+  FlowInputSpec._() : super();
+  factory FlowInputSpec.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
+  factory FlowInputSpec.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
+
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'FlowInputSpec', package: const $pb.PackageName(_omitMessageNames ? '' : 'fai.v1'), createEmptyInstance: create)
+    ..aOS(1, _omitFieldNames ? '' : 'name')
+    ..aOS(2, _omitFieldNames ? '' : 'type')
+    ..hasRequiredFields = false
+  ;
+
+  @$core.Deprecated('See https://github.com/google/protobuf.dart/issues/998.')
+  FlowInputSpec clone() => FlowInputSpec()..mergeFromMessage(this);
+  @$core.Deprecated('See https://github.com/google/protobuf.dart/issues/998.')
+  FlowInputSpec copyWith(void Function(FlowInputSpec) updates) => super.copyWith((message) => updates(message as FlowInputSpec)) as FlowInputSpec;
+
+  $pb.BuilderInfo get info_ => _i;
+
+  @$core.pragma('dart2js:noInline')
+  static FlowInputSpec create() => FlowInputSpec._();
+  FlowInputSpec createEmptyInstance() => create();
+  static $pb.PbList<FlowInputSpec> createRepeated() => $pb.PbList<FlowInputSpec>();
+  @$core.pragma('dart2js:noInline')
+  static FlowInputSpec getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<FlowInputSpec>(create);
+  static FlowInputSpec? _defaultInstance;
+
+  /// Input key (the name the flow YAML uses).
+  @$pb.TagNumber(1)
+  $core.String get name => $_getSZ(0);
+  @$pb.TagNumber(1)
+  set name($core.String v) { $_setString(0, v); }
+  @$pb.TagNumber(1)
+  $core.bool hasName() => $_has(0);
+  @$pb.TagNumber(1)
+  void clearName() => $_clearField(1);
+
+  /// Declared type tag from the flow YAML — opaque string so
+  /// the wire stays stable as the type system grows.
+  @$pb.TagNumber(2)
+  $core.String get type => $_getSZ(1);
+  @$pb.TagNumber(2)
+  set type($core.String v) { $_setString(1, v); }
+  @$pb.TagNumber(2)
+  $core.bool hasType() => $_has(1);
+  @$pb.TagNumber(2)
+  void clearType() => $_clearField(2);
+}
+
 class SearchStoreRequest extends $pb.GeneratedMessage {
   factory SearchStoreRequest({
     $core.String? query,

lib/src/generated/fai/v1/hub.pbgrpc.dart

@@ -155,6 +155,10 @@ class HubAdminClient extends $grpc.Client {
       '/fai.v1.HubAdmin/RunSavedFlow',
       ($0.RunSavedFlowRequest value) => value.writeToBuffer(),
       ($core.List<$core.int> value) => $0.SubmitResponse.fromBuffer(value));
+  static final _$getFlowDefinition = $grpc.ClientMethod<$0.GetFlowDefinitionRequest, $0.FlowDefinition>(
+      '/fai.v1.HubAdmin/GetFlowDefinition',
+      ($0.GetFlowDefinitionRequest value) => value.writeToBuffer(),
+      ($core.List<$core.int> value) => $0.FlowDefinition.fromBuffer(value));
   static final _$searchStore = $grpc.ClientMethod<$0.SearchStoreRequest, $0.StoreSearchResponse>(
       '/fai.v1.HubAdmin/SearchStore',
       ($0.SearchStoreRequest value) => value.writeToBuffer(),
@@ -317,6 +321,13 @@ class HubAdminClient extends $grpc.Client {
     return $createUnaryCall(_$runSavedFlow, request, options: options);
   }
 
+  /// Return the parsed structure of a saved flow (declared
+  /// inputs + their type tags) so a client can render an
+  /// input form before calling RunSavedFlow.
+  $grpc.ResponseFuture<$0.FlowDefinition> getFlowDefinition($0.GetFlowDefinitionRequest request, {$grpc.CallOptions? options}) {
+    return $createUnaryCall(_$getFlowDefinition, request, options: options);
+  }
+
   /// Search the bundled (and Phase 1+: federated) store index for
   /// modules matching a query.
   $grpc.ResponseFuture<$0.StoreSearchResponse> searchStore($0.SearchStoreRequest request, {$grpc.CallOptions? options}) {
@@ -593,6 +604,13 @@ abstract class HubAdminServiceBase extends $grpc.Service {
         false,
         ($core.List<$core.int> value) => $0.RunSavedFlowRequest.fromBuffer(value),
         ($0.SubmitResponse value) => value.writeToBuffer()));
+    $addMethod($grpc.ServiceMethod<$0.GetFlowDefinitionRequest, $0.FlowDefinition>(
+        'GetFlowDefinition',
+        getFlowDefinition_Pre,
+        false,
+        false,
+        ($core.List<$core.int> value) => $0.GetFlowDefinitionRequest.fromBuffer(value),
+        ($0.FlowDefinition value) => value.writeToBuffer()));
     $addMethod($grpc.ServiceMethod<$0.SearchStoreRequest, $0.StoreSearchResponse>(
         'SearchStore',
         searchStore_Pre,
@@ -837,6 +855,10 @@ abstract class HubAdminServiceBase extends $grpc.Service {
     return runSavedFlow($call, await $request);
   }
 
+  $async.Future<$0.FlowDefinition> getFlowDefinition_Pre($grpc.ServiceCall $call, $async.Future<$0.GetFlowDefinitionRequest> $request) async {
+    return getFlowDefinition($call, await $request);
+  }
+
   $async.Future<$0.StoreSearchResponse> searchStore_Pre($grpc.ServiceCall $call, $async.Future<$0.SearchStoreRequest> $request) async {
     return searchStore($call, await $request);
   }
@@ -965,6 +987,7 @@ abstract class HubAdminServiceBase extends $grpc.Service {
   $async.Future<$0.DeleteFlowResponse> deleteFlow($grpc.ServiceCall call, $0.DeleteFlowRequest request);
   $async.Future<$0.FlowList> listFlows($grpc.ServiceCall call, $1.Empty request);
   $async.Future<$0.SubmitResponse> runSavedFlow($grpc.ServiceCall call, $0.RunSavedFlowRequest request);
+  $async.Future<$0.FlowDefinition> getFlowDefinition($grpc.ServiceCall call, $0.GetFlowDefinitionRequest request);
   $async.Future<$0.StoreSearchResponse> searchStore($grpc.ServiceCall call, $0.SearchStoreRequest request);
   $async.Future<$0.InstallModuleResponse> installModule($grpc.ServiceCall call, $0.InstallModuleRequest request);
   $async.Future<$0.UninstallModuleResponse> uninstallModule($grpc.ServiceCall call, $0.UninstallModuleRequest request);

lib/src/generated/fai/v1/hub.pbjson.dart

@@ -374,6 +374,46 @@ final $typed_data.Uint8List runSavedFlowRequestDescriptor = $convert.base64Decod
     'bnB1dHNFbnRyeRIQCgNrZXkYASABKAlSA2tleRIlCgV2YWx1ZRgCIAEoCzIPLmZhaS52MS5QYX'
     'lsb2FkUgV2YWx1ZToCOAE=');
 
+@$core.Deprecated('Use getFlowDefinitionRequestDescriptor instead')
+const GetFlowDefinitionRequest$json = {
+  '1': 'GetFlowDefinitionRequest',
+  '2': [
+    {'1': 'name', '3': 1, '4': 1, '5': 9, '10': 'name'},
+  ],
+};
+
+/// Descriptor for `GetFlowDefinitionRequest`. Decode as a `google.protobuf.DescriptorProto`.
+final $typed_data.Uint8List getFlowDefinitionRequestDescriptor = $convert.base64Decode(
+    'ChhHZXRGbG93RGVmaW5pdGlvblJlcXVlc3QSEgoEbmFtZRgBIAEoCVIEbmFtZQ==');
+
+@$core.Deprecated('Use flowDefinitionDescriptor instead')
+const FlowDefinition$json = {
+  '1': 'FlowDefinition',
+  '2': [
+    {'1': 'name', '3': 1, '4': 1, '5': 9, '10': 'name'},
+    {'1': 'inputs', '3': 2, '4': 3, '5': 11, '6': '.fai.v1.FlowInputSpec', '10': 'inputs'},
+  ],
+};
+
+/// Descriptor for `FlowDefinition`. Decode as a `google.protobuf.DescriptorProto`.
+final $typed_data.Uint8List flowDefinitionDescriptor = $convert.base64Decode(
+    'Cg5GbG93RGVmaW5pdGlvbhISCgRuYW1lGAEgASgJUgRuYW1lEi0KBmlucHV0cxgCIAMoCzIVLm'
+    'ZhaS52MS5GbG93SW5wdXRTcGVjUgZpbnB1dHM=');
+
+@$core.Deprecated('Use flowInputSpecDescriptor instead')
+const FlowInputSpec$json = {
+  '1': 'FlowInputSpec',
+  '2': [
+    {'1': 'name', '3': 1, '4': 1, '5': 9, '10': 'name'},
+    {'1': 'type', '3': 2, '4': 1, '5': 9, '10': 'type'},
+  ],
+};
+
+/// Descriptor for `FlowInputSpec`. Decode as a `google.protobuf.DescriptorProto`.
+final $typed_data.Uint8List flowInputSpecDescriptor = $convert.base64Decode(
+    'Cg1GbG93SW5wdXRTcGVjEhIKBG5hbWUYASABKAlSBG5hbWUSEgoEdHlwZRgCIAEoCVIEdHlwZQ'
+    '==');
+
 @$core.Deprecated('Use searchStoreRequestDescriptor instead')
 const SearchStoreRequest$json = {
   '1': 'SearchStoreRequest',

lib/src/hub_client.dart

@@ -466,6 +466,19 @@ class HubClient {
     return r.flows;
   }
 
+  /// Return the parsed input schema of a saved flow so a GUI
+  /// client can render an input form before calling
+  /// [runSavedFlow]. Each entry's `type` is the verbatim type
+  /// tag from the flow YAML (`text`, `bytes`, `json`, `file`,
+  /// or anything else the flow author put there).
+  Future<List<FlowInputDef>> getFlowDefinition(String name) async {
+    final req = pb.GetFlowDefinitionRequest()..name = name;
+    final resp = await _admin.getFlowDefinition(req);
+    return resp.inputs
+        .map((spec) => FlowInputDef(name: spec.name, type: spec.type))
+        .toList();
+  }
+
   /// Run a saved flow by name with the supplied named inputs.
   /// Two input shapes are supported in the same call so a
   /// flow that mixes text and binary inputs (e.g. extract
@@ -503,3 +516,17 @@ class HubClient {
     await _channel.shutdown();
   }
 }
+
+/// One declared input in a saved flow's `inputs:` section.
+/// Returned by [HubClient.getFlowDefinition] so GUI clients
+/// can build a typed run-flow form. The [type] field carries
+/// the flow YAML's verbatim type tag — opaque to the SDK so
+/// the type system can grow without an SDK release.
+class FlowInputDef {
+  /// Input key (the name the flow YAML uses).
+  final String name;
+  /// Type tag — typically `text`, `bytes`, `json`, or `file`.
+  final String type;
+
+  const FlowInputDef({required this.name, required this.type});
+}