diff --git a/src/modules/__tests__/json-rx.spec.ts b/src/modules/__tests__/json-rx.spec.ts
new file mode 100644
index 00000000..bd09100b
--- /dev/null
+++ b/src/modules/__tests__/json-rx.spec.ts
@@ -0,0 +1,9 @@
+import {SchemaOf, t} from '../../type';
+import {Message, NotificationMessage} from '../json-rx';
+
+test('...', () => {
+  console.log(NotificationMessage + '');
+  type adasfsad = SchemaOf<typeof NotificationMessage.type>;
+  type asdf = t.infer<typeof NotificationMessage.type>;
+  // console.log(Message + '');
+});
diff --git a/src/modules/json-rx.ts b/src/modules/json-rx.ts
new file mode 100644
index 00000000..504430d2
--- /dev/null
+++ b/src/modules/json-rx.ts
@@ -0,0 +1,109 @@
+import {ModuleType} from "../type";
+
+export const enum CompactMessageType {
+  RequestData = 0,
+  RequestComplete = 1,
+  RequestError = 2,
+  RequestUnsubscribe = 3,
+
+  ResponseData = 4,
+  ResponseComplete = 5,
+  ResponseError = 6,
+  ResponseUnsubscribe = 7,
+
+  Notification = 8,
+}
+
+
+export const system = new ModuleType();
+const t = system.t;
+
+// export const CompactMsgId = t.num.format('u32').alias('CompactMsgId');
+const MethodName = t.str.min(1).max(32).format('ascii').alias('MethodName');
+
+export const NotificationMessage = t.tuple(
+  t.Key('type', t.con(8)),
+  t.Key('method', t.Ref<typeof MethodName>('MethodName')),
+  t.KeyOpt('data', t.any),
+).alias('NotificationMessage');
+
+export const RequestDataMessage = t.Or(
+  t.tuple(
+    t.con(CompactMessageType.RequestData),
+    t.num.format('u32'),
+    t.Ref<typeof MethodName>('MethodName'),
+  ),
+  t.tuple(
+    t.con(CompactMessageType.RequestData),
+    t.num.format('u32'),
+    t.Ref<typeof MethodName>('MethodName'),
+    t.any,
+  ),
+).options({
+  discriminator: ['?', ['eq', ['len', ['$', '']], 2], 0, 1],
+}).alias('RequestDataMessage');
+
+export const RequestCompleteMessage = t.Or(
+  t.tuple(
+    t.con(CompactMessageType.RequestComplete),
+    t.num.format('u32'),
+    t.Ref<typeof MethodName>('MethodName'),
+  ),
+  t.tuple(
+    t.con(CompactMessageType.RequestComplete),
+    t.num.format('u32'),
+    t.Ref<typeof MethodName>('MethodName'),
+    t.any,
+  ),
+).options({
+  discriminator: ['?', ['eq', ['len', ['$', '']], 2], 0, 1],
+}).alias('RequestCompleteMessage');
+
+export const RequestErrorMessage = t.tuple(
+  t.con(CompactMessageType.RequestError),
+  t.num.format('u32'),
+  t.Ref<typeof MethodName>('MethodName'),
+  t.any,
+).alias('RequestErrorMessage');
+
+export const RequestUnsubscribeMessage = t.tuple(
+  t.con(CompactMessageType.RequestUnsubscribe),
+  t.num.format('u32'),
+).alias('RequestUnsubscribeMessage');
+
+export const ResponseDataMessage = t.tuple(
+  t.con(CompactMessageType.ResponseData),
+  t.num.format('u32'),
+  t.any,
+).alias('ResponseDataMessage');
+
+export const ResponseCompleteMessage = t.tuple(
+  t.con(CompactMessageType.ResponseComplete),
+  t.num.format('u32'),
+  t.any,
+).alias('ResponseCompleteMessage');
+
+export const ResponseErrorMessage = t.tuple(
+  t.con(CompactMessageType.ResponseError),
+  t.num.format('u32'),
+  t.any,
+).alias('ResponseErrorMessage');
+
+export const ResponseUnsubscribeMessage = t.tuple(
+  t.con(CompactMessageType.ResponseUnsubscribe),
+  t.num.format('u32'),
+).alias('ResponseUnsubscribeMessage');
+
+export const Message = t.Or(
+  NotificationMessage.type,
+  RequestDataMessage.type,
+  RequestCompleteMessage.type,
+  RequestErrorMessage.type,
+  RequestUnsubscribeMessage.type,
+  ResponseDataMessage.type,
+  ResponseCompleteMessage.type,
+  ResponseErrorMessage.type,
+  ResponseUnsubscribeMessage.type,
+).alias('Message');
+
+export const messageBatch = t.array(Message).alias('MessageBatch');
diff --git a/src/schema/schema.ts b/src/schema/schema.ts
index 950d6330..82a508dc 100644
--- a/src/schema/schema.ts
+++ b/src/schema/schema.ts
@@ -489,19 +489,21 @@ export type TypeOfValue<T> = T extends BoolSchema
           ]
         : T extends ConSchema<infer U>
           ? U
-          : T extends KeySchema<infer K, infer V>
-            ? TypeOf<V>
-            : T extends ObjSchema<infer F>
-              ? NoEmptyInterface<TypeFields<Mutable<F>>>
-              : T extends MapSchema<infer U>
-                ? Record<string, TypeOf<U>>
-                : T extends BinSchema
-                  ? Uint8Array
-                  : T extends FnSchema<infer Req, infer Res, infer Ctx>
-                    ? (req: TypeOf<Req>, ctx: Ctx) => UndefToVoid<TypeOf<Res>> | Promise<UndefToVoid<TypeOf<Res>>>
-                    : T extends FnRxSchema<infer Req, infer Res, infer Ctx>
-                      ? (req$: Observable<TypeOf<Req>>, ctx: Ctx) => Observable<UndefToVoid<TypeOf<Res>>>
-                      : never;
+          : T extends OptKeySchema<infer K, infer V>
+            ? (TypeOf<V> | undefined)
+            : T extends KeySchema<infer K, infer V>
+              ? TypeOf<V>
+              : T extends ObjSchema<infer F>
+                ? NoEmptyInterface<TypeFields<Mutable<F>>>
+                : T extends MapSchema<infer U>
+                  ? Record<string, TypeOf<U>>
+                  : T extends BinSchema
+                    ? Uint8Array
+                    : T extends FnSchema<infer Req, infer Res, infer Ctx>
+                      ? (req: TypeOf<Req>, ctx: Ctx) => UndefToVoid<TypeOf<Res>> | Promise<UndefToVoid<TypeOf<Res>>>
+                      : T extends FnRxSchema<infer Req, infer Res, infer Ctx>
+                        ? (req$: Observable<TypeOf<Req>>, ctx: Ctx) => Observable<UndefToVoid<TypeOf<Res>>>
+                        : never;
 
 export type TypeOfMap<M extends Record<string, Schema>> = {
   [K in keyof M]: TypeOf<M[K]>;
diff --git a/src/type/TypeBuilder.ts b/src/type/TypeBuilder.ts
index 9034acb7..80397e25 100644
--- a/src/type/TypeBuilder.ts
+++ b/src/type/TypeBuilder.ts
@@ -1,6 +1,6 @@
 import * as schema from '../schema';
 import * as classes from './classes';
-import type {Type, TypeOfAlias} from './types';
+import type {TypeRef, TypeRefToType, Type, TypeOfAlias} from './types';
 
 const {s} = schema;
 
@@ -76,7 +76,7 @@ export class TypeBuilder {
 
   // --------------------------------------------------------------- shorthands
 
-  public readonly or = <F extends Type[]>(...types: F) => this.Or(...types);
+  public readonly or = <F extends TypeRef<any>[]>(...types: F) => this.Or(...types);
   public readonly undefined = () => this.undef;
   public readonly null = () => this.nil;
   public readonly boolean = () => this.bool;
@@ -94,7 +94,11 @@ export class TypeBuilder {
       options,
     );
 
-  public readonly tuple = <F extends Type[]>(...types: F) => this.Tuple(types);
+  public readonly tuple = <F extends TypeRef<any>[]>(...types: F) => this.Tuple(types);
+
+  protected typeRefToType = <T extends Type>(type: TypeRef<T>): TypeRefToType<T> => {
+    return typeof type === 'function' ? (type() as TypeRefToType<T>) : (type as TypeRefToType<T>);
+  };
 
   /**
    * Creates an object type with the specified properties. This is a shorthand for
@@ -117,10 +121,10 @@ export class TypeBuilder {
    * @param record A mapping of property names to types.
    * @returns An object type.
    */
-  public readonly object = <R extends Record<string, Type>>(record: R): classes.ObjType<RecordToFields<R>> => {
+  public readonly object = <R extends Record<string, TypeRef<any>>>(record: R): classes.ObjType<RecordToFields<{[K in keyof R]: TypeRefToType<R[K]>}>> => {
     const keys: classes.KeyType<any, any>[] = [];
-    for (const [key, value] of Object.entries(record)) keys.push(this.Key(key, value));
-    return new classes.ObjType<RecordToFields<R>>(keys as any).sys(this.system);
+    for (const [key, value] of Object.entries(record)) keys.push(this.Key(key, this.typeRefToType(value)));
+    return new classes.ObjType<RecordToFields<{[K in keyof R]: TypeRefToType<R[K]>}>>(keys as any).sys(this.system);
   };
 
   /**
diff --git a/src/type/__tests__/type-ref.spec.ts b/src/type/__tests__/type-ref.spec.ts
new file mode 100644
index 00000000..3920ab37
--- /dev/null
+++ b/src/type/__tests__/type-ref.spec.ts
@@ -0,0 +1,24 @@
+import {ModuleType} from '../classes/ModuleType';
+import {ResolveType} from '../types';
+
+test('...', () => {
+  const mod = new ModuleType();
+  const t = mod.t;
+
+  const Str = t.str;
+  const Obj = t.object({
+    x: () => Str,
+  });
+
+  type asdf = ResolveType<typeof Obj>;
+  t.Array(Str);
+
+  const Node = t.object({
+    value: t.any,
+    key: t.str,
+    left: () => Node,
+    right: () => Node,
+  });
+
+
+});
diff --git a/src/type/classes/ObjType.ts b/src/type/classes/ObjType.ts
index a9a687af..eb62589b 100644
--- a/src/type/classes/ObjType.ts
+++ b/src/type/classes/ObjType.ts
@@ -35,20 +35,35 @@ export class KeyType<K extends string, V extends Type> extends AbsType<schema.Ke
   }
 }
 
-export class KeyOptType<K extends string, V extends Type> extends KeyType<K, V> {
+export class KeyOptType<K extends string, V extends Type> extends AbsType<schema.OptKeySchema<K, SchemaOf<V>>> {
   public readonly optional: boolean = true;
 
   constructor(
     public readonly key: K,
     public readonly val: V,
   ) {
-    super(key, val);
-    (this as any).schema = schema.s.KeyOpt(key, schema.s.any) as any;
+    super(schema.s.KeyOpt(key, schema.s.any) as any);
+  }
+
+  public getSchema(): schema.OptKeySchema<K, SchemaOf<V>> {
+    return {
+      ...this.schema,
+      value: this.val.getSchema() as any,
+    };
+  }
+
+  public getOptions(): schema.Optional<schema.KeySchema<K, SchemaOf<V>>> {
+    const {kind, key, value, optional, ...options} = this.schema;
+    return options as any;
   }
 
   protected toStringTitle(): string {
     return JSON.stringify(this.key) + '?';
   }
+
+  public toString(tab: string = ''): string {
+    return super.toString(tab) + printTree(tab + ' ', [(tab) => this.val.toString(tab)]);
+  }
 }
 
 export class ObjType<
@@ -113,7 +128,7 @@ export class ObjType<
 
   public getField<K extends keyof schema.TypeOf<schema.ObjSchema<SchemaOfObjectFields<F>>>>(
     key: K,
-  ): KeyType<string, Type> | undefined {
+  ): KeyType<string, Type> | KeyOptType<string, Type> | undefined {
     return this.keys.find((f) => f.key === key);
   }
 
diff --git a/src/type/classes/RefType.ts b/src/type/classes/RefType.ts
index 5e735586..67a95abc 100644
--- a/src/type/classes/RefType.ts
+++ b/src/type/classes/RefType.ts
@@ -3,12 +3,16 @@ import type {SchemaOf, Type} from '../types';
 import {AbsType} from './AbsType';
 
 export class RefType<T extends Type = any> extends AbsType<schema.RefSchema<SchemaOf<T>>> {
-  constructor(ref: string) {
-    super(schema.s.Ref<SchemaOf<T>>(ref));
+  protected _ref: string | (() => string);
+
+  constructor(ref: string | (() => string)) {
+    super(schema.s.Ref<SchemaOf<T>>(typeof ref === 'function' ? 'lazy' : ref));
+    this._ref = ref;
   }
 
   public ref(): string {
-    return this.schema.ref;
+    const _ref = this._ref;
+    return typeof _ref === 'function' ? _ref() : _ref;
   }
 
   public getOptions(): schema.Optional<schema.RefSchema<SchemaOf<T>>> {
@@ -20,8 +24,14 @@ export class RefType<T extends Type = any> extends AbsType<schema.RefSchema<Sche
     return this.getSystem().resolve(this.ref()).type as Type;
   }
 
+  public getSchema() {
+    const _ref = this._ref;
+    const ref = typeof _ref === 'function' ? _ref() : _ref;
+    return {...super.getSchema(), ref} as any;
+  }
+
   public toStringTitle(tab: string = ''): string {
     const options = this.toStringOptions();
-    return `${super.toStringTitle()} → [${this.schema.ref}]` + (options ? ` ${options}` : '');
+    return `${super.toStringTitle()} → [${this.ref()}]` + (options ? ` ${options}` : '');
   }
 }
diff --git a/src/type/types.ts b/src/type/types.ts
index 219666b2..faa09ff9 100644
--- a/src/type/types.ts
+++ b/src/type/types.ts
@@ -24,6 +24,9 @@ export type Type =
   | classes.FnType<any, any, any>
   | classes.FnRxType<any, any, any>;
 
+export type TypeRef<T extends Type> = T | (() => AliasType<any, T>)
+export type TypeRefToType<T extends TypeRef<Type>> = T extends () => infer U ? U : T;
+
 export type SchemaOf<T extends Type | Type[]> = T extends BaseType<infer U> ? U : never;
 export type SchemaOfMap<M extends Record<string, Type>> = {
   [K in keyof M]: SchemaOf<M[K]>;
diff --git a/src/value/ObjValue.ts b/src/value/ObjValue.ts
index 47807733..835e4810 100644
--- a/src/value/ObjValue.ts
+++ b/src/value/ObjValue.ts
@@ -56,12 +56,11 @@ export class ObjValue<T extends classes.ObjType<any>> extends Value<T> implement
 
   public add<K extends string, V extends classes.Type>(
     key: K,
-    type: V | ((t: TypeBuilder) => V),
+    type: V,
     data: classes.ResolveType<V>,
   ) {
     const system = (this.type as classes.ObjType<any>).getSystem();
     const t = system.t;
-    type = typeof type === 'function' ? type(t) : type;
     return this.field(t.Key(key, type), data);
   }