diff --git a/packages/api-metadata/src/consts/types.ts b/packages/api-metadata/src/consts/types.ts
index b5ae655a70..0b6337437c 100644
--- a/packages/api-metadata/src/consts/types.ts
+++ b/packages/api-metadata/src/consts/types.ts
@@ -3,10 +3,10 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { Codec } from '@polkadot/types/types';
-import { ModuleConstantMetadata as MetaV7 } from '@polkadot/types/Metadata/v6/Constants';
+import { ModuleConstantMetadataV7 } from '@polkadot/types/interfaces';
 
 export interface ConstantCodec extends Codec {
-  meta: MetaV7;
+  meta: ModuleConstantMetadataV7;
 }
 
 export type ModuleConstants = Record<string, Codec>;
diff --git a/packages/api-metadata/src/extrinsics/fromMetadata/createUnchecked.ts b/packages/api-metadata/src/extrinsics/fromMetadata/createUnchecked.ts
index 071396e9a6..c869c12bf0 100644
--- a/packages/api-metadata/src/extrinsics/fromMetadata/createUnchecked.ts
+++ b/packages/api-metadata/src/extrinsics/fromMetadata/createUnchecked.ts
@@ -2,10 +2,9 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Call } from '@polkadot/types/interfaces';
+import { Call, FunctionMetadataV7 } from '@polkadot/types/interfaces';
 import { CallFunction } from '@polkadot/types/types';
 
-import { FunctionMetadata } from '@polkadot/types/Metadata/v7/Calls';
 import { createType } from '@polkadot/types';
 import { assert, stringCamelCase } from '@polkadot/util';
 
@@ -22,7 +21,7 @@ export default function createDescriptor (
   section: string,
   sectionIndex: number,
   methodIndex: number,
-  callMetadata: FunctionMetadata
+  callMetadata: FunctionMetadataV7
 ): CallFunction {
   const callIndex = new Uint8Array([sectionIndex, methodIndex]);
   const expectedArgs = callMetadata.args;
diff --git a/packages/types/src/Metadata/v0/Calls.ts b/packages/types/src/Metadata/v0/Calls.ts
deleted file mode 100644
index 0b571a5f9b..0000000000
--- a/packages/types/src/Metadata/v0/Calls.ts
+++ /dev/null
@@ -1,62 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import Struct from '../../codec/Struct';
-import Vec from '../../codec/Vec';
-import Text from '../../primitive/Text';
-import U16 from '../../primitive/U16';
-
-export class OuterDispatchCall extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      prefix: Text,
-      index: U16
-    }, value);
-  }
-
-  /**
-   * @description The [[U16]] index for the call
-   */
-  public get index (): U16 {
-    return this.get('index') as U16;
-  }
-
-  /**
-   * @description The name for the call
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-
-  /**
-   * @description The call prefix (or section)
-   */
-  public get prefix (): Text {
-    return this.get('prefix') as Text;
-  }
-}
-
-export class OuterDispatchMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      calls: Vec.with(OuterDispatchCall)
-    }, value);
-  }
-
-  /**
-   * @description The [[OuterDispathCall]] wrapped
-   */
-  public get calls (): Vec<OuterDispatchCall> {
-    return this.get('calls') as Vec<OuterDispatchCall>;
-  }
-
-  /**
-   * @description The name for the dispatch
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-}
diff --git a/packages/types/src/Metadata/v0/Events.ts b/packages/types/src/Metadata/v0/Events.ts
index ce910bf45c..6c8db4b03f 100644
--- a/packages/types/src/Metadata/v0/Events.ts
+++ b/packages/types/src/Metadata/v0/Events.ts
@@ -2,72 +2,23 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV0 } from '../../interfaces/metadata/types';
+
 import Struct from '../../codec/Struct';
 import Tuple from '../../codec/Tuple';
 import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
-import Type from '../../primitive/Type';
-
-export class EventMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      args: Vec.with(Type),
-      documentation: Vec.with(Text)
-    }, value);
-  }
-
-  /**
-   * @description The arguments of [[Type]]
-   */
-  public get args (): Vec<Type> {
-    return this.get('args') as Vec<Type>;
-  }
-
-  /**
-   * @description The arguments of [[Type]]
-   * @deprecated Use `.args` instead
-   */
-  public get arguments (): Vec<Type> {
-    return this.args;
-  }
-
-  /**
-   * @description The [[Text]] documentation
-   */
-  public get documentation (): Vec<Text> {
-    return this.get('documentation') as Vec<Text>;
-  }
-
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
-  /**
-   * @description The name for the event
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-}
 
 export class OuterEventEventMetadata extends Tuple {
   public constructor (value?: any) {
-    super({
-      Text,
-      'Vec<EventMetadata>': Vec.with(EventMetadata)
-    }, value);
+    super(['Text', 'Vec<EventMetadataV0>'], value);
   }
 
   /**
    * @description The [[EventMetadata]]
    */
-  public get events (): Vec<EventMetadata> {
-    return this[1] as Vec<EventMetadata>;
+  public get events (): Vec<EventMetadataV0> {
+    return this[1] as Vec<EventMetadataV0>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v0/Metadata.ts b/packages/types/src/Metadata/v0/Metadata.ts
index 42093f7d8a..18e9ab53be 100644
--- a/packages/types/src/Metadata/v0/Metadata.ts
+++ b/packages/types/src/Metadata/v0/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { OuterDispatchMetadataV0, OuterDispatchCallV0 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import { hexToU8a, isHex, isU8a } from '@polkadot/util';
@@ -10,9 +11,8 @@ import Compact from '../../codec/Compact';
 import Struct from '../../codec/Struct';
 import Vec from '../../codec/Vec';
 import { flattenUniq, validateTypes } from '../util';
-import { OuterDispatchMetadata, OuterDispatchCall } from './Calls';
 import { OuterEventMetadata, OuterEventEventMetadata } from './Events';
-import { RuntimeModuleMetadata } from './Modules';
+import { RuntimeModuleMetadataV0 } from './Modules';
 
 // Decodes the runtime metadata as passed through from the `state_getMetadata` call.
 
@@ -21,12 +21,12 @@ import { RuntimeModuleMetadata } from './Modules';
  * @description
  * The runtime metadata as a decoded structure
  */
-export default class MetadataV0 extends Struct implements MetadataInterface<RuntimeModuleMetadata> {
+export default class MetadataV0 extends Struct implements MetadataInterface<RuntimeModuleMetadataV0> {
   public constructor (value?: any) {
     super({
       outerEvent: OuterEventMetadata,
-      modules: Vec.with(RuntimeModuleMetadata),
-      outerDispatch: OuterDispatchMetadata
+      modules: Vec.with(RuntimeModuleMetadataV0),
+      outerDispatch: 'OuterDispatchMetadataV0'
     }, MetadataV0.decodeMetadata(value));
   }
 
@@ -55,8 +55,8 @@ export default class MetadataV0 extends Struct implements MetadataInterface<Runt
   /**
    * @description Wrapped [[OuterDispatchCall]]
    */
-  public get calls (): Vec<OuterDispatchCall> {
-    return (this.get('outerDispatch') as OuterDispatchMetadata).calls;
+  public get calls (): Vec<OuterDispatchCallV0> {
+    return (this.get('outerDispatch') as OuterDispatchMetadataV0).calls;
   }
 
   /**
@@ -69,14 +69,14 @@ export default class MetadataV0 extends Struct implements MetadataInterface<Runt
   /**
    * @description Wrapped [[RuntimeModuleMetadata]]
    */
-  public get modules (): Vec<RuntimeModuleMetadata> {
-    return this.get('modules') as Vec<RuntimeModuleMetadata>;
+  public get modules (): Vec<RuntimeModuleMetadataV0> {
+    return this.get('modules') as Vec<RuntimeModuleMetadataV0>;
   }
 
   private get argNames (): string[][][] {
-    return this.modules.map((modul): string[][] =>
-      modul.module.call.functions.map((fn): string[] =>
-        fn.args.map((argument): string => argument.type.toString())
+    return this.modules.map(({ module: { call: { functions } } }): string[][] =>
+      functions.map(({ args }): string[] =>
+        args.map((arg): string => arg.type.toString())
       )
     );
   }
@@ -92,10 +92,10 @@ export default class MetadataV0 extends Struct implements MetadataInterface<Runt
   private get storageNames (): string[][][] {
     return this.modules.map((modul): string[][] =>
       modul.storage.isSome
-        ? modul.storage.unwrap().functions.map((fn): string[] =>
-          fn.type.isMap
-            ? [fn.type.asMap.key.toString(), fn.type.asMap.value.toString()]
-            : [fn.type.asType.toString()]
+        ? modul.storage.unwrap().functions.map(({ type }): string[] =>
+          type.isMap
+            ? [type.asMap.key.toString(), type.asMap.value.toString()]
+            : [type.asType.toString()]
         )
         : []
     );
diff --git a/packages/types/src/Metadata/v0/Modules.ts b/packages/types/src/Metadata/v0/Modules.ts
index 71e8e9a726..0ef2c819fd 100644
--- a/packages/types/src/Metadata/v0/Modules.ts
+++ b/packages/types/src/Metadata/v0/Modules.ts
@@ -2,152 +2,28 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { ModuleMetadataV0 } from '../../interfaces/types';
+
 import Option from '../../codec/Option';
 import Struct from '../../codec/Struct';
-import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
-import Type from '../../primitive/Type';
-import U16 from '../../primitive/U16';
 
-import { StorageMetadata } from './Storage';
+import { StorageMetadataV0 } from './Storage';
 
-export class FunctionArgumentMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      type: Type
-    }, value);
-  }
-
-  /**
-   * @description The argument name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-
-  /**
-   * @description The [[Type]]
-   */
-  public get type (): Type {
-    return this.get('type') as Type;
-  }
-}
-
-export class FunctionMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      id: U16,
-      name: Text,
-      args: Vec.with(FunctionArgumentMetadata),
-      documentation: Vec.with(Text)
-    }, value);
-  }
-
-  /**
-   * @description The arguments of [[Type]]
-   */
-  public get args (): Vec<FunctionArgumentMetadata> {
-    return this.get('args') as Vec<FunctionArgumentMetadata>;
-  }
-
-  /**
-   * @description The [[FunctionArgumentMetadata]] for arguments
-   * @deprecated Use `.args` instead
-   */
-  public get arguments (): Vec<FunctionArgumentMetadata> {
-    return this.get('arguments') as Vec<FunctionArgumentMetadata>;
-  }
-
-  /**
-   * @description The [[Text]] documentation
-   */
-  public get documentation (): Vec<Text> {
-    return this.get('documentation') as Vec<Text>;
-  }
-
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
-  /**
-   * @description The `[sectionIndex, methodIndex]` call id
-   */
-  public get id (): U16 {
-    return this.get('id') as U16;
-  }
-
-  /**
-   * @description The call name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-}
-
-export class CallMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      functions: Vec.with(FunctionMetadata)
-    }, value);
-  }
-
-  /**
-   * @description The functions available as [[FunctionMetadata]]
-   */
-  public get functions (): Vec<FunctionMetadata> {
-    return this.get('functions') as Vec<FunctionMetadata>;
-  }
-
-  /**
-   * @description The section name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-}
-export class ModuleMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      call: CallMetadata
-    }, value);
-  }
-
-  /**
-   * @description The calls as [[FunctionMetadata]]
-   */
-  public get call (): CallMetadata {
-    return this.get('call') as CallMetadata;
-  }
-
-  /**
-   * @description The name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-}
-
-export class RuntimeModuleMetadata extends Struct {
+export class RuntimeModuleMetadataV0 extends Struct {
   public constructor (value?: any) {
     super({
       prefix: Text,
-      module: ModuleMetadata,
-      storage: Option.with(StorageMetadata)
+      module: 'ModuleMetadataV0',
+      storage: Option.with(StorageMetadataV0)
     }, value);
   }
 
   /**
-   * @description The [[ModuleMetadata]]
+   * @description The [[ModuleMetadataV0]]
    */
-  public get module (): ModuleMetadata {
-    return this.get('module') as ModuleMetadata;
+  public get module (): ModuleMetadataV0 {
+    return this.get('module') as ModuleMetadataV0;
   }
 
   /**
@@ -158,9 +34,9 @@ export class RuntimeModuleMetadata extends Struct {
   }
 
   /**
-   * @description The optional [[StorageMetadata]]
+   * @description The optional [[StorageMetadataV0]]
    */
-  public get storage (): Option<StorageMetadata> {
-    return this.get('storage') as Option<StorageMetadata>;
+  public get storage (): Option<StorageMetadataV0> {
+    return this.get('storage') as Option<StorageMetadataV0>;
   }
 }
diff --git a/packages/types/src/Metadata/v0/Storage.ts b/packages/types/src/Metadata/v0/Storage.ts
index efa714f05d..4d1a00c68c 100644
--- a/packages/types/src/Metadata/v0/Storage.ts
+++ b/packages/types/src/Metadata/v0/Storage.ts
@@ -145,14 +145,6 @@ export class StorageFunctionMetadata extends Struct {
     }, value);
   }
 
-  /**
-   * @description The default value of the storage function
-   * @deprecated Use `.fallback` instead.
-   */
-  public get default (): Bytes {
-    return this.fallback;
-  }
-
   /**
    * @description The default value of the storage function
    */
@@ -167,14 +159,6 @@ export class StorageFunctionMetadata extends Struct {
     return this.get('documentation') as Vec<Text>;
   }
 
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
   /**
    * @description The key name
    */
@@ -197,7 +181,7 @@ export class StorageFunctionMetadata extends Struct {
   }
 }
 
-export class StorageMetadata extends Struct {
+export class StorageMetadataV0 extends Struct {
   public constructor (value?: any) {
     super({
       prefix: Text,
diff --git a/packages/types/src/Metadata/v0/toV1.ts b/packages/types/src/Metadata/v0/toV1.ts
index 8f113304f3..65957629ed 100644
--- a/packages/types/src/Metadata/v0/toV1.ts
+++ b/packages/types/src/Metadata/v0/toV1.ts
@@ -3,32 +3,31 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV1, FunctionMetadataV1 } from '../../interfaces/metadata/types';
 import { stringUpperFirst } from '@polkadot/util';
 
 import { Option, Vec } from '../../codec';
 import MetadataV0 from './Metadata';
-import { RuntimeModuleMetadata } from './Modules';
+import { RuntimeModuleMetadataV0 } from './Modules';
 import { Text } from '../../primitive';
-import { FunctionMetadata } from '../v1/Calls';
-import { EventMetadata } from '../v1/Events';
 import MetadataV1, { ModuleMetadata as ModuleMetadataV1 } from '../v1/Metadata';
 import { StorageFunctionMetadata } from '../v1/Storage';
 
-function toV1Calls (modul: RuntimeModuleMetadata): Option<FunctionMetadata> {
+function toV1Calls (modul: RuntimeModuleMetadataV0): Option<FunctionMetadataV1> {
   return modul.module.call.functions.length === 0
-    ? new Option(Vec.with(FunctionMetadata))
-    : new Option(Vec.with(FunctionMetadata), modul.module.call.functions);
+    ? new Option(Vec.with('FunctionMetadataV1'))
+    : new Option(Vec.with('FunctionMetadataV1'), modul.module.call.functions);
 }
 
-function toV1Events (metadataV0: MetadataV0, prefix: Text): Option<EventMetadata> {
+function toV1Events (metadataV0: MetadataV0, prefix: Text): Option<EventMetadataV1> {
   const events = metadataV0.events.find((event): boolean => event.name.eq(prefix));
 
   return events
-    ? new Option(Vec.with(EventMetadata), events.events)
-    : new Option(Vec.with(EventMetadata));
+    ? new Option(Vec.with('EventMetadataV1'), events.events)
+    : new Option(Vec.with('EventMetadataV1'));
 }
 
-function toV1Storage (modul: RuntimeModuleMetadata): Option<StorageFunctionMetadata> {
+function toV1Storage (modul: RuntimeModuleMetadataV0): Option<StorageFunctionMetadata> {
   return modul.storage.isNone
     ? new Option(Vec.with(StorageFunctionMetadata))
     : new Option(
diff --git a/packages/types/src/Metadata/v1/Calls.ts b/packages/types/src/Metadata/v1/Calls.ts
deleted file mode 100644
index 6ccea3a4a1..0000000000
--- a/packages/types/src/Metadata/v1/Calls.ts
+++ /dev/null
@@ -1,75 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import Struct from '../../codec/Struct';
-import Vec from '../../codec/Vec';
-import Text from '../../primitive/Text';
-import Type from '../../primitive/Type';
-
-export class FunctionArgumentMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      type: Type
-    }, value);
-  }
-
-  /**
-   * @description The argument name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-
-  /**
-   * @description The [[Type]]
-   */
-  public get type (): Type {
-    return this.get('type') as Type;
-  }
-}
-
-/**
- * @name FunctionMetadata
- * @description
- * The definition of a call
- */
-export class FunctionMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      args: Vec.with(FunctionArgumentMetadata),
-      documentation: Vec.with(Text)
-    }, value);
-  }
-
-  /**
-   * @description The [[FunctionArgumentMetadata]] for arguments
-   */
-  public get args (): Vec<FunctionArgumentMetadata> {
-    return this.get('args') as Vec<FunctionArgumentMetadata>;
-  }
-
-  /**
-   * @description The [[Text]] documentation
-   */
-  public get documentation (): Vec<Text> {
-    return this.get('documentation') as Vec<Text>;
-  }
-
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
-  /**
-   * @description The call name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-}
diff --git a/packages/types/src/Metadata/v1/Events.ts b/packages/types/src/Metadata/v1/Events.ts
deleted file mode 100644
index ba9078cdf1..0000000000
--- a/packages/types/src/Metadata/v1/Events.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V0 and V1
-export { EventMetadata } from '../v0/Events';
diff --git a/packages/types/src/Metadata/v1/Metadata.ts b/packages/types/src/Metadata/v1/Metadata.ts
index 7aeb6477ad..561b887584 100644
--- a/packages/types/src/Metadata/v1/Metadata.ts
+++ b/packages/types/src/Metadata/v1/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV1, FunctionMetadataV1 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,8 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { EventMetadata } from './Events';
 import { StorageFunctionMetadata } from './Storage';
 
 /**
@@ -25,23 +24,23 @@ export class ModuleMetadata extends Struct {
       name: Text,
       prefix: Text,
       storage: Option.with(Vec.with(StorageFunctionMetadata)),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata))
+      calls: Option.with(Vec.with('FunctionMetadataV1')),
+      events: Option.with(Vec.with('EventMetadataV1'))
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV1>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV1>>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV1>> {
+    return this.get('events') as Option<Vec<EventMetadataV1>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v2/Calls.ts b/packages/types/src/Metadata/v2/Calls.ts
deleted file mode 100644
index 8e3ef477f3..0000000000
--- a/packages/types/src/Metadata/v2/Calls.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V1 and V2
-export {
-  FunctionArgumentMetadata,
-  FunctionMetadata
-} from '../v1/Calls';
diff --git a/packages/types/src/Metadata/v2/Events.ts b/packages/types/src/Metadata/v2/Events.ts
deleted file mode 100644
index de53bb4245..0000000000
--- a/packages/types/src/Metadata/v2/Events.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V1 and V2
-export { EventMetadata } from '../v1/Events';
diff --git a/packages/types/src/Metadata/v2/Metadata.ts b/packages/types/src/Metadata/v2/Metadata.ts
index 11de70f068..daac92633d 100644
--- a/packages/types/src/Metadata/v2/Metadata.ts
+++ b/packages/types/src/Metadata/v2/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV2, FunctionMetadataV2 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,8 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { EventMetadata } from './Events';
 import { StorageFunctionMetadata } from './Storage';
 
 /**
@@ -25,23 +24,23 @@ export class ModuleMetadata extends Struct {
       name: Text,
       prefix: Text,
       storage: Option.with(Vec.with(StorageFunctionMetadata)),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata))
+      calls: Option.with(Vec.with('FunctionMetadataV2')),
+      events: Option.with(Vec.with('EventMetadataV2'))
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV2>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV2>>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV2>> {
+    return this.get('events') as Option<Vec<EventMetadataV2>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v2/Storage.ts b/packages/types/src/Metadata/v2/Storage.ts
index 0969282e70..94e8732413 100644
--- a/packages/types/src/Metadata/v2/Storage.ts
+++ b/packages/types/src/Metadata/v2/Storage.ts
@@ -132,14 +132,6 @@ export class StorageFunctionMetadata extends Struct {
     }, value);
   }
 
-  /**
-   * @description The default value of the storage function
-   * @deprecated Use `.fallback` instead.
-   */
-  public get default (): Bytes {
-    return this.fallback;
-  }
-
   /**
    * @description The [[Text]] documentation
    */
@@ -147,14 +139,6 @@ export class StorageFunctionMetadata extends Struct {
     return this.get('documentation') as Vec<Text>;
   }
 
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
   /**
    * @description The [[Bytes]] fallback default
    */
diff --git a/packages/types/src/Metadata/v3/Calls.ts b/packages/types/src/Metadata/v3/Calls.ts
deleted file mode 100644
index 9911bcdbd2..0000000000
--- a/packages/types/src/Metadata/v3/Calls.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V2 and V3
-export {
-  FunctionArgumentMetadata,
-  FunctionMetadata
-} from '../v2/Calls';
diff --git a/packages/types/src/Metadata/v3/Events.ts b/packages/types/src/Metadata/v3/Events.ts
deleted file mode 100644
index f81e45b6c6..0000000000
--- a/packages/types/src/Metadata/v3/Events.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V2 and V3
-export { EventMetadata } from '../v2/Events';
diff --git a/packages/types/src/Metadata/v3/Metadata.ts b/packages/types/src/Metadata/v3/Metadata.ts
index e4b452d7a9..c29407f3de 100644
--- a/packages/types/src/Metadata/v3/Metadata.ts
+++ b/packages/types/src/Metadata/v3/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV3, FunctionMetadataV3 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,8 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { EventMetadata } from './Events';
 import { StorageFunctionMetadata } from './Storage';
 
 /**
@@ -25,23 +24,23 @@ export class ModuleMetadata extends Struct {
       name: Text,
       prefix: Text,
       storage: Option.with(Vec.with(StorageFunctionMetadata)),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata))
+      calls: Option.with(Vec.with('FunctionMetadataV3')),
+      events: Option.with(Vec.with('EventMetadataV3'))
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV3>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV3>>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV3>> {
+    return this.get('events') as Option<Vec<EventMetadataV3>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v3/Storage.ts b/packages/types/src/Metadata/v3/Storage.ts
index f3cde893ba..0b6b2bac34 100644
--- a/packages/types/src/Metadata/v3/Storage.ts
+++ b/packages/types/src/Metadata/v3/Storage.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { DoubleMapTypeV3 } from '../../interfaces/metadata/types';
 import { AnyNumber } from '../../types';
 
 import { assert } from '@polkadot/util';
@@ -11,12 +12,7 @@ import Struct from '../../codec/Struct';
 import Vec from '../../codec/Vec';
 import Bytes from '../../primitive/Bytes';
 import Text from '../../primitive/Text';
-import Type from '../../primitive/Type';
-import {
-  MapType,
-  PlainType,
-  StorageFunctionModifier
-} from '../v2/Storage';
+import { MapType, PlainType, StorageFunctionModifier } from '../v2/Storage';
 
 // Re-export classes that haven't changed between V2 and V3
 export {
@@ -25,61 +21,22 @@ export {
   StorageFunctionModifier
 };
 
-export class DoubleMapType extends Struct {
-  public constructor (value?: any) {
-    super({
-      key1: Type,
-      key2: Type,
-      value: Type,
-      key2Hasher: Text
-    }, value);
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get key1 (): Type {
-    return this.get('key1') as Type;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get key2 (): Type {
-    return this.get('key2') as Type;
-  }
-
-  /**
-   * @description The hashing algorithm used to hash key2, as [[Text]]
-   */
-  public get key2Hasher (): Text {
-    return this.get('key2Hasher') as Text;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get value (): Type {
-    return this.get('value') as Type;
-  }
-}
-
 export class StorageFunctionType extends Enum {
   public constructor (value?: any, index?: number) {
     super({
       PlainType,
       MapType,
-      DoubleMapType
+      DoubleMapType: 'DoubleMapTypeV3'
     }, value, index);
   }
 
   /**
    * @description The value as a mapped value
    */
-  public get asDoubleMap (): DoubleMapType {
+  public get asDoubleMap (): DoubleMapTypeV3 {
     assert(this.isDoubleMap, `Cannot convert '${this.type}' via asDoubleMap`);
 
-    return this.value as DoubleMapType;
+    return this.value as DoubleMapTypeV3;
   }
 
   /**
@@ -165,14 +122,6 @@ export class StorageFunctionMetadata extends Struct {
     }, value);
   }
 
-  /**
-   * @description The default value of the storage function
-   * @deprecated Use `.fallback` instead.
-   */
-  public get default (): Bytes {
-    return this.fallback;
-  }
-
   /**
    * @description The [[Text]] documentation
    */
@@ -180,14 +129,6 @@ export class StorageFunctionMetadata extends Struct {
     return this.get('documentation') as Vec<Text>;
   }
 
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
   /**
    * @description The [[Bytes]] fallback default
    */
diff --git a/packages/types/src/Metadata/v3/toV4.ts b/packages/types/src/Metadata/v3/toV4.ts
index b5e3ef8ee8..45c5c4a1fe 100644
--- a/packages/types/src/Metadata/v3/toV4.ts
+++ b/packages/types/src/Metadata/v3/toV4.ts
@@ -2,12 +2,12 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Option, Vec } from '../../codec';
+import { createType, Option, Vec } from '../../codec';
 import MetadataV3 from './Metadata';
 import StorageHasher from '../../primitive/StorageHasher';
 import MetadataV4 from '../v4';
 import { ModuleMetadata as ModuleMetadataV4 } from '../v4/Metadata';
-import { DoubleMapType, MapType, StorageFunctionMetadata, StorageFunctionType } from '../v4/Storage';
+import { MapType, StorageFunctionMetadata, StorageFunctionType } from '../v4/Storage';
 import { StorageFunctionMetadata as StorageFunctionMetadataV3 } from './Storage';
 
 /**
@@ -28,7 +28,7 @@ function toV4StorageFunction (storageFn: StorageFunctionMetadataV3): StorageFunc
         value: type.asMap.value,
         isLinked: type.asMap.isLinked
       }), 1]
-      : [new DoubleMapType({
+      : [createType('DoubleMapTypeV4', {
         hasher: new StorageHasher('Twox128'),
         key1: type.asDoubleMap.key1,
         key2: type.asDoubleMap.key2,
@@ -49,9 +49,9 @@ function toV4StorageFunction (storageFn: StorageFunctionMetadataV3): StorageFunc
  * Convert from MetadataV3 to MetadataV4
  * See https://github.com/paritytech/substrate/pull/2268 for details
  */
-export default function toV4 (metadataV3: MetadataV3): MetadataV4 {
+export default function toV4 ({ modules }: MetadataV3): MetadataV4 {
   return new MetadataV4({
-    modules: metadataV3.modules.map(({ calls, events, name, prefix, storage }): ModuleMetadataV4 =>
+    modules: modules.map(({ calls, events, name, prefix, storage }): ModuleMetadataV4 =>
       new ModuleMetadataV4({
         calls,
         events,
diff --git a/packages/types/src/Metadata/v4/Calls.ts b/packages/types/src/Metadata/v4/Calls.ts
deleted file mode 100644
index 24ee13dc04..0000000000
--- a/packages/types/src/Metadata/v4/Calls.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V3 and V4
-export {
-  FunctionArgumentMetadata,
-  FunctionMetadata
-} from '../v3/Calls';
diff --git a/packages/types/src/Metadata/v4/Events.ts b/packages/types/src/Metadata/v4/Events.ts
deleted file mode 100644
index 689efe418e..0000000000
--- a/packages/types/src/Metadata/v4/Events.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V3 and V4
-export { EventMetadata } from '../v3/Events';
diff --git a/packages/types/src/Metadata/v4/Metadata.ts b/packages/types/src/Metadata/v4/Metadata.ts
index e90f149061..c601e993d0 100644
--- a/packages/types/src/Metadata/v4/Metadata.ts
+++ b/packages/types/src/Metadata/v4/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV4, FunctionMetadataV4 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,8 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { EventMetadata } from './Events';
 import { StorageFunctionMetadata } from './Storage';
 
 /**
@@ -25,23 +24,23 @@ export class ModuleMetadata extends Struct {
       name: Text,
       prefix: Text,
       storage: Option.with(Vec.with(StorageFunctionMetadata)),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata))
+      calls: Option.with(Vec.with('FunctionMetadataV4')),
+      events: Option.with(Vec.with('EventMetadataV4'))
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV4>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV4>>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV4>> {
+    return this.get('events') as Option<Vec<EventMetadataV4>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v4/Storage.ts b/packages/types/src/Metadata/v4/Storage.ts
index cd301a81c0..6d59787ce8 100644
--- a/packages/types/src/Metadata/v4/Storage.ts
+++ b/packages/types/src/Metadata/v4/Storage.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { DoubleMapTypeV4 } from '../../interfaces/metadata/types';
 import { AnyNumber } from '../../types';
 
 import { assert } from '@polkadot/util';
@@ -61,69 +62,22 @@ export class MapType extends Struct {
   }
 }
 
-export class DoubleMapType extends Struct {
-  public constructor (value?: any) {
-    super({
-      hasher: StorageHasher,
-      key1: Type,
-      key2: Type,
-      value: Type,
-      key2Hasher: Text
-    }, value);
-  }
-
-  /**
-   * @description The hashing algorithm used to hash keys, as [[StorageHasher]]
-   */
-  public get hasher (): StorageHasher {
-    return this.get('hasher') as StorageHasher;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get key1 (): Type {
-    return this.get('key1') as Type;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get key2 (): Type {
-    return this.get('key2') as Type;
-  }
-
-  /**
-   * @description The hashing algorithm used to hash key2, as [[Text]]
-   */
-  public get key2Hasher (): Text {
-    return this.get('key2Hasher') as Text;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get value (): Type {
-    return this.get('value') as Type;
-  }
-}
-
 export class StorageFunctionType extends Enum {
   public constructor (value?: any, index?: number) {
     super({
       PlainType,
       MapType,
-      DoubleMapType
+      DoubleMapType: 'DoubleMapTypeV4'
     }, value, index);
   }
 
   /**
    * @description The value as a mapped value
    */
-  public get asDoubleMap (): DoubleMapType {
+  public get asDoubleMap (): DoubleMapTypeV4 {
     assert(this.isDoubleMap, `Cannot convert '${this.type}' via asDoubleMap`);
 
-    return this.value as DoubleMapType;
+    return this.value as DoubleMapTypeV4;
   }
 
   /**
@@ -209,14 +163,6 @@ export class StorageFunctionMetadata extends Struct {
     }, value);
   }
 
-  /**
-   * @description The default value of the storage function
-   * @deprecated Use `.fallback` instead.
-   */
-  public get default (): Bytes {
-    return this.fallback;
-  }
-
   /**
    * @description The default value of the storage function
    */
@@ -231,14 +177,6 @@ export class StorageFunctionMetadata extends Struct {
     return this.get('documentation') as Vec<Text>;
   }
 
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
   /**
    * @description The key name
    */
diff --git a/packages/types/src/Metadata/v4/toV5.ts b/packages/types/src/Metadata/v4/toV5.ts
index d652b3718d..63117a2469 100644
--- a/packages/types/src/Metadata/v4/toV5.ts
+++ b/packages/types/src/Metadata/v4/toV5.ts
@@ -4,13 +4,13 @@
 
 import { assert } from '@polkadot/util';
 
-import { Option, Vec } from '../../codec';
+import { createType, Option, Vec } from '../../codec';
 import Text from '../../primitive/Text';
 import MetadataV4 from './Metadata';
 import StorageHasher from '../../primitive/StorageHasher';
 import MetadataV5 from '../v5';
 import { ModuleMetadata as ModuleMetadataV5 } from '../v5/Metadata';
-import { DoubleMapType, StorageFunctionMetadata, StorageFunctionType } from '../v5/Storage';
+import { StorageFunctionMetadata, StorageFunctionType } from '../v5/Storage';
 import { StorageFunctionMetadata as StorageFunctionMetadataV4 } from './Storage';
 
 const hasherMap: Map<string, string> = new Map([
@@ -38,7 +38,7 @@ function toV5StorageFunction (storageFn: StorageFunctionMetadataV4): StorageFunc
     ? [type, 0]
     : type.isMap
       ? [type.asMap, 1]
-      : [new DoubleMapType({
+      : [createType('DoubleMapTypeV5', {
         hasher: type.asDoubleMap.hasher,
         key1: type.asDoubleMap.key1,
         key2: type.asDoubleMap.key2,
@@ -59,9 +59,9 @@ function toV5StorageFunction (storageFn: StorageFunctionMetadataV4): StorageFunc
  * Convert from MetadataV4 to MetadataV5
  * See https://github.com/paritytech/substrate/pull/2836/files for details
  */
-export default function toV5 (metadataV4: MetadataV4): MetadataV5 {
+export default function toV5 ({ modules }: MetadataV4): MetadataV5 {
   return new MetadataV5({
-    modules: metadataV4.modules.map(({ calls, events, name, prefix, storage }): ModuleMetadataV5 =>
+    modules: modules.map(({ calls, events, name, prefix, storage }): ModuleMetadataV5 =>
       new ModuleMetadataV5({
         name,
         prefix,
diff --git a/packages/types/src/Metadata/v5/Calls.ts b/packages/types/src/Metadata/v5/Calls.ts
deleted file mode 100644
index 83a2f37fee..0000000000
--- a/packages/types/src/Metadata/v5/Calls.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V4 and V5
-export {
-  FunctionArgumentMetadata,
-  FunctionMetadata
-} from '../v4/Calls';
diff --git a/packages/types/src/Metadata/v5/Events.ts b/packages/types/src/Metadata/v5/Events.ts
deleted file mode 100644
index 751e2d5f16..0000000000
--- a/packages/types/src/Metadata/v5/Events.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V4 and V5
-export { EventMetadata } from '../v4/Events';
diff --git a/packages/types/src/Metadata/v5/Metadata.ts b/packages/types/src/Metadata/v5/Metadata.ts
index e59f5effe5..6417cd80e1 100644
--- a/packages/types/src/Metadata/v5/Metadata.ts
+++ b/packages/types/src/Metadata/v5/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV5, FunctionMetadataV5 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,8 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { EventMetadata } from './Events';
 import { StorageFunctionMetadata } from './Storage';
 
 /**
@@ -25,23 +24,23 @@ export class ModuleMetadata extends Struct {
       name: Text,
       prefix: Text,
       storage: Option.with(Vec.with(StorageFunctionMetadata)),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata))
+      calls: Option.with(Vec.with('FunctionMetadataV5')),
+      events: Option.with(Vec.with('EventMetadataV5'))
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV5>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV5>>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV5>> {
+    return this.get('events') as Option<Vec<EventMetadataV5>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v5/Storage.ts b/packages/types/src/Metadata/v5/Storage.ts
index 29c0a056de..d628311742 100644
--- a/packages/types/src/Metadata/v5/Storage.ts
+++ b/packages/types/src/Metadata/v5/Storage.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { DoubleMapTypeV5 } from '../../interfaces/metadata/types';
 import { AnyNumber } from '../../types';
 
 import { assert } from '@polkadot/util';
@@ -10,9 +11,7 @@ import Enum from '../../codec/Enum';
 import Struct from '../../codec/Struct';
 import Vec from '../../codec/Vec';
 import Bytes from '../../primitive/Bytes';
-import StorageHasher from '../../primitive/StorageHasher';
 import Text from '../../primitive/Text';
-import Type from '../../primitive/Type';
 import { MapType, PlainType, StorageFunctionModifier } from '../v4/Storage';
 
 // Re-export classes that haven't changed between V4 and V5
@@ -22,69 +21,22 @@ export {
   StorageFunctionModifier
 };
 
-export class DoubleMapType extends Struct {
-  public constructor (value?: any) {
-    super({
-      hasher: StorageHasher,
-      key1: Type,
-      key2: Type,
-      value: Type,
-      key2Hasher: StorageHasher
-    }, value);
-  }
-
-  /**
-   * @description The hashing algorithm used to hash keys, as [[StorageHasher]]
-   */
-  public get hasher (): StorageHasher {
-    return this.get('hasher') as StorageHasher;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get key1 (): Type {
-    return this.get('key1') as Type;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get key2 (): Type {
-    return this.get('key2') as Type;
-  }
-
-  /**
-   * @description The hashing algorithm used to hash key2, as [[StorageHasher]]
-   */
-  public get key2Hasher (): StorageHasher {
-    return this.get('key2Hasher') as StorageHasher;
-  }
-
-  /**
-   * @description The mapped key as [[Type]]
-   */
-  public get value (): Type {
-    return this.get('value') as Type;
-  }
-}
-
 export class StorageFunctionType extends Enum {
   public constructor (value?: any, index?: number) {
     super({
       PlainType,
       MapType,
-      DoubleMapType
+      DoubleMapType: 'DoubleMapTypeV5'
     }, value, index);
   }
 
   /**
    * @description The value as a mapped value
    */
-  public get asDoubleMap (): DoubleMapType {
+  public get asDoubleMap (): DoubleMapTypeV5 {
     assert(this.isDoubleMap, `Cannot convert '${this.type}' via asDoubleMap`);
 
-    return this.value as DoubleMapType;
+    return this.value as DoubleMapTypeV5;
   }
 
   /**
@@ -170,14 +122,6 @@ export class StorageFunctionMetadata extends Struct {
     }, value);
   }
 
-  /**
-   * @description The default value of the storage function
-   * @deprecated Use `.fallback` instead.
-   */
-  public get default (): Bytes {
-    return this.fallback;
-  }
-
   /**
    * @description The default value of the storage function
    */
@@ -192,14 +136,6 @@ export class StorageFunctionMetadata extends Struct {
     return this.get('documentation') as Vec<Text>;
   }
 
-  /**
-   * @description The [[Text]] documentation
-   * @deprecated Use `.documentation` instead.
-   */
-  public get docs (): Vec<Text> {
-    return this.documentation;
-  }
-
   /**
    * @description The key name
    */
diff --git a/packages/types/src/Metadata/v5/toV6.ts b/packages/types/src/Metadata/v5/toV6.ts
index 5c74874600..d9320b69a3 100644
--- a/packages/types/src/Metadata/v5/toV6.ts
+++ b/packages/types/src/Metadata/v5/toV6.ts
@@ -10,9 +10,9 @@ import { ModuleMetadata as ModuleMetadataV6 } from '../v6/Metadata';
  * Convert from MetadataV5 to MetadataV6
  * See https://github.com/polkadot-js/api/issues/1043 for details
  */
-export default function toV6 (metadataV5: MetadataV5): MetadataV6 {
+export default function toV6 ({ modules }: MetadataV5): MetadataV6 {
   return new MetadataV6({
-    modules: metadataV5.modules.map(({ calls, events, name, prefix, storage }): ModuleMetadataV6 =>
+    modules: modules.map(({ calls, events, name, prefix, storage }): ModuleMetadataV6 =>
       new ModuleMetadataV6({
         calls,
         constants: [],
diff --git a/packages/types/src/Metadata/v6/Calls.ts b/packages/types/src/Metadata/v6/Calls.ts
deleted file mode 100644
index 4bcfba4c5f..0000000000
--- a/packages/types/src/Metadata/v6/Calls.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V5 and V6
-export {
-  FunctionArgumentMetadata,
-  FunctionMetadata
-} from '../v5/Calls';
diff --git a/packages/types/src/Metadata/v6/Constants.ts b/packages/types/src/Metadata/v6/Constants.ts
deleted file mode 100644
index 2ce2839d03..0000000000
--- a/packages/types/src/Metadata/v6/Constants.ts
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import Bytes from '../../primitive/Bytes';
-import Text from '../../primitive/Text';
-import Type from '../../primitive/Type';
-import Struct from '../../codec/Struct';
-import Vec from '../../codec/Vec';
-
-export class ModuleConstantMetadata extends Struct {
-  public constructor (value?: any) {
-    super({
-      name: Text,
-      type: Type,
-      value: Bytes,
-      documentation: Vec.with(Text)
-    }, value);
-  }
-
-  /**
-   * @description The argument name
-   */
-  public get name (): Text {
-    return this.get('name') as Text;
-  }
-
-  /**
-   * @description The [[Type]]
-   */
-  public get type (): Type {
-    return this.get('type') as Type;
-  }
-
-  /**
-   * @description The value as [[Bytes]]
-   */
-  public get value (): Bytes {
-    return this.get('value') as Bytes;
-  }
-
-  /**
-   * @description The documentation
-   */
-  public get documentation (): Vec<Text> {
-    return this.get('documentation') as Vec<Text>;
-  }
-}
diff --git a/packages/types/src/Metadata/v6/Events.ts b/packages/types/src/Metadata/v6/Events.ts
deleted file mode 100644
index 6d426706ff..0000000000
--- a/packages/types/src/Metadata/v6/Events.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V5 and V6
-export { EventMetadata } from '../v5/Events';
diff --git a/packages/types/src/Metadata/v6/Metadata.ts b/packages/types/src/Metadata/v6/Metadata.ts
index a1b5308191..b277648d45 100644
--- a/packages/types/src/Metadata/v6/Metadata.ts
+++ b/packages/types/src/Metadata/v6/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV6, FunctionMetadataV6, ModuleConstantMetadataV6 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,9 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { ModuleConstantMetadata } from './Constants';
-import { EventMetadata } from './Events';
 import { StorageEntryMetadata } from './Storage';
 
 /**
@@ -26,31 +24,31 @@ export class ModuleMetadata extends Struct {
       name: Text,
       prefix: Text,
       storage: Option.with(Vec.with(StorageEntryMetadata)),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata)),
-      constants: Vec.with(ModuleConstantMetadata)
+      calls: Option.with(Vec.with('FunctionMetadataV6')),
+      events: Option.with(Vec.with('EventMetadataV6')),
+      constants: Vec.with('ModuleConstantMetadataV6')
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV6>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV6>>;
   }
 
   /**
    * @description the module constants
    */
-  public get constants (): Vec<ModuleConstantMetadata> {
-    return this.get('constants') as Vec<ModuleConstantMetadata>;
+  public get constants (): Vec<ModuleConstantMetadataV6> {
+    return this.get('constants') as Vec<ModuleConstantMetadataV6>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV6>> {
+    return this.get('events') as Option<Vec<EventMetadataV6>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v6/Storage.ts b/packages/types/src/Metadata/v6/Storage.ts
index 5e6ce35515..322eb553ee 100644
--- a/packages/types/src/Metadata/v6/Storage.ts
+++ b/packages/types/src/Metadata/v6/Storage.ts
@@ -2,13 +2,12 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { DoubleMapType, MapType, PlainType, StorageFunctionMetadata, StorageFunctionMetadataValue, StorageFunctionModifier, StorageFunctionType } from '../v5/Storage';
+import { MapType, PlainType, StorageFunctionMetadata, StorageFunctionMetadataValue, StorageFunctionModifier, StorageFunctionType } from '../v5/Storage';
 
 // Re-export classes that haven't changed between V5 and V6
 export {
   MapType,
   PlainType,
-  DoubleMapType,
   StorageFunctionMetadata as StorageEntryMetadata,
   StorageFunctionMetadataValue as StorageEntryMetadataValue,
   StorageFunctionModifier as StorageEntryModifier,
diff --git a/packages/types/src/Metadata/v7/Calls.ts b/packages/types/src/Metadata/v7/Calls.ts
deleted file mode 100644
index 78f24dc3ea..0000000000
--- a/packages/types/src/Metadata/v7/Calls.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V6 & V7
-export {
-  FunctionArgumentMetadata,
-  FunctionMetadata
-} from '../v6/Calls';
diff --git a/packages/types/src/Metadata/v7/Constants.ts b/packages/types/src/Metadata/v7/Constants.ts
deleted file mode 100644
index d40c72093d..0000000000
--- a/packages/types/src/Metadata/v7/Constants.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V6 & V7
-export {
-  ModuleConstantMetadata
-} from '../v6/Constants';
diff --git a/packages/types/src/Metadata/v7/Events.ts b/packages/types/src/Metadata/v7/Events.ts
deleted file mode 100644
index a968d99a61..0000000000
--- a/packages/types/src/Metadata/v7/Events.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright 2017-2019 @polkadot/types authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-// Re-export classes that haven't changed between V6 & V7
-export {
-  EventMetadata
-} from '../v6/Events';
diff --git a/packages/types/src/Metadata/v7/Metadata.ts b/packages/types/src/Metadata/v7/Metadata.ts
index c74af7bb87..ae22e46a7f 100644
--- a/packages/types/src/Metadata/v7/Metadata.ts
+++ b/packages/types/src/Metadata/v7/Metadata.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { EventMetadataV7, FunctionMetadataV7, ModuleConstantMetadataV7 } from '../../interfaces/metadata/types';
 import { MetadataInterface } from '../types';
 
 import Option from '../../codec/Option';
@@ -10,9 +11,6 @@ import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
 import { flattenUniq, validateTypes } from '../util';
 
-import { FunctionMetadata } from './Calls';
-import { ModuleConstantMetadata } from './Constants';
-import { EventMetadata } from './Events';
 import { StorageMetadata } from './Storage';
 
 /**
@@ -25,31 +23,31 @@ export class ModuleMetadata extends Struct {
     super({
       name: Text,
       storage: Option.with(StorageMetadata),
-      calls: Option.with(Vec.with(FunctionMetadata)),
-      events: Option.with(Vec.with(EventMetadata)),
-      constants: Vec.with(ModuleConstantMetadata)
+      calls: Option.with(Vec.with('FunctionMetadataV7')),
+      events: Option.with(Vec.with('EventMetadataV7')),
+      constants: Vec.with('ModuleConstantMetadataV7')
     }, value);
   }
 
   /**
    * @description the module calls
    */
-  public get calls (): Option<Vec<FunctionMetadata>> {
-    return this.get('calls') as Option<Vec<FunctionMetadata>>;
+  public get calls (): Option<Vec<FunctionMetadataV7>> {
+    return this.get('calls') as Option<Vec<FunctionMetadataV7>>;
   }
 
   /**
    * @description the module constants
    */
-  public get constants (): Vec<ModuleConstantMetadata> {
-    return this.get('constants') as Vec<ModuleConstantMetadata>;
+  public get constants (): Vec<ModuleConstantMetadataV7> {
+    return this.get('constants') as Vec<ModuleConstantMetadataV7>;
   }
 
   /**
    * @description the module events
    */
-  public get events (): Option<Vec<EventMetadata>> {
-    return this.get('events') as Option<Vec<EventMetadata>>;
+  public get events (): Option<Vec<EventMetadataV7>> {
+    return this.get('events') as Option<Vec<EventMetadataV7>>;
   }
 
   /**
diff --git a/packages/types/src/Metadata/v7/Storage.ts b/packages/types/src/Metadata/v7/Storage.ts
index 1d9d727a8e..458ede2025 100644
--- a/packages/types/src/Metadata/v7/Storage.ts
+++ b/packages/types/src/Metadata/v7/Storage.ts
@@ -5,13 +5,12 @@
 import Struct from '../../codec/Struct';
 import Vec from '../../codec/Vec';
 import Text from '../../primitive/Text';
-import { DoubleMapType, MapType, PlainType, StorageEntryMetadata, StorageEntryMetadataValue, StorageEntryModifier, StorageEntryType } from '../v6/Storage';
+import { MapType, PlainType, StorageEntryMetadata, StorageEntryMetadataValue, StorageEntryModifier, StorageEntryType } from '../v6/Storage';
 
 // Re-export classes that haven't changed between V6 and V7
 export {
   MapType,
   PlainType,
-  DoubleMapType,
   StorageEntryMetadata,
   StorageEntryMetadataValue,
   StorageEntryModifier,
diff --git a/packages/types/src/interfaceRegistry.ts b/packages/types/src/interfaceRegistry.ts
index 254d6d1bd2..bd70075d06 100644
--- a/packages/types/src/interfaceRegistry.ts
+++ b/packages/types/src/interfaceRegistry.ts
@@ -24,6 +24,7 @@ import { TreasuryProposal } from './interfaces/treasury';
 import { BlockAttestations, IncludedBlocks, MoreAttestations } from './interfaces/attestations';
 import { EcdsaSignature, EthereumAddress } from './interfaces/claims';
 import { AttestedCandidate, AuctionIndex, BalanceUpload, Bidder, CandidateReceipt, CollatorSignature, EgressQueueRoot, HeadData, IncomingParachain, IncomingParachainDeploy, IncomingParachainFixed, LeasePeriod, LeasePeriodOf, NewBidder, ParaId, ParaIdOf, ParachainDispatchOrigin, SlotRange, SubId, UpwardMessage, ValidatorIndex, ValidityAttestation, ValidityVote, WinningData, WinningDataEntry } from './interfaces/parachains';
+import { CallMetadataV0, DoubleMapTypeV3, DoubleMapTypeV4, DoubleMapTypeV5, DoubleMapTypeV6, DoubleMapTypeV7, EventMetadataV0, EventMetadataV1, EventMetadataV2, EventMetadataV3, EventMetadataV4, EventMetadataV5, EventMetadataV6, EventMetadataV7, FunctionArgumentMetadataV0, FunctionArgumentMetadataV1, FunctionArgumentMetadataV2, FunctionArgumentMetadataV3, FunctionArgumentMetadataV4, FunctionArgumentMetadataV5, FunctionArgumentMetadataV6, FunctionArgumentMetadataV7, FunctionMetadataV0, FunctionMetadataV1, FunctionMetadataV2, FunctionMetadataV3, FunctionMetadataV4, FunctionMetadataV5, FunctionMetadataV6, FunctionMetadataV7, ModuleConstantMetadataV6, ModuleConstantMetadataV7, ModuleMetadataV0, OuterDispatchCallV0, OuterDispatchMetadataV0 } from './interfaces/metadata';
 import { ApiId, ChainProperties, ExtrinsicOrHash, ExtrinsicStatus, Health, KeyValueOption, NetworkState, PeerInfo, RuntimeVersion, RuntimeVersionApi, StorageChangeSet } from './interfaces/rpc';
 
 export interface InterfaceRegistry {
@@ -625,6 +626,111 @@ export interface InterfaceRegistry {
   WinningData: WinningData;
   'Option<WinningData>': Option<WinningData>;
   'Vec<WinningData>': Vec<WinningData>;
+  CallMetadataV0: CallMetadataV0;
+  'Option<CallMetadataV0>': Option<CallMetadataV0>;
+  'Vec<CallMetadataV0>': Vec<CallMetadataV0>;
+  EventMetadataV0: EventMetadataV0;
+  'Option<EventMetadataV0>': Option<EventMetadataV0>;
+  'Vec<EventMetadataV0>': Vec<EventMetadataV0>;
+  FunctionArgumentMetadataV0: FunctionArgumentMetadataV0;
+  'Option<FunctionArgumentMetadataV0>': Option<FunctionArgumentMetadataV0>;
+  'Vec<FunctionArgumentMetadataV0>': Vec<FunctionArgumentMetadataV0>;
+  FunctionMetadataV0: FunctionMetadataV0;
+  'Option<FunctionMetadataV0>': Option<FunctionMetadataV0>;
+  'Vec<FunctionMetadataV0>': Vec<FunctionMetadataV0>;
+  ModuleMetadataV0: ModuleMetadataV0;
+  'Option<ModuleMetadataV0>': Option<ModuleMetadataV0>;
+  'Vec<ModuleMetadataV0>': Vec<ModuleMetadataV0>;
+  OuterDispatchCallV0: OuterDispatchCallV0;
+  'Option<OuterDispatchCallV0>': Option<OuterDispatchCallV0>;
+  'Vec<OuterDispatchCallV0>': Vec<OuterDispatchCallV0>;
+  OuterDispatchMetadataV0: OuterDispatchMetadataV0;
+  'Option<OuterDispatchMetadataV0>': Option<OuterDispatchMetadataV0>;
+  'Vec<OuterDispatchMetadataV0>': Vec<OuterDispatchMetadataV0>;
+  EventMetadataV1: EventMetadataV1;
+  'Option<EventMetadataV1>': Option<EventMetadataV1>;
+  'Vec<EventMetadataV1>': Vec<EventMetadataV1>;
+  FunctionArgumentMetadataV1: FunctionArgumentMetadataV1;
+  'Option<FunctionArgumentMetadataV1>': Option<FunctionArgumentMetadataV1>;
+  'Vec<FunctionArgumentMetadataV1>': Vec<FunctionArgumentMetadataV1>;
+  FunctionMetadataV1: FunctionMetadataV1;
+  'Option<FunctionMetadataV1>': Option<FunctionMetadataV1>;
+  'Vec<FunctionMetadataV1>': Vec<FunctionMetadataV1>;
+  EventMetadataV2: EventMetadataV2;
+  'Option<EventMetadataV2>': Option<EventMetadataV2>;
+  'Vec<EventMetadataV2>': Vec<EventMetadataV2>;
+  FunctionArgumentMetadataV2: FunctionArgumentMetadataV2;
+  'Option<FunctionArgumentMetadataV2>': Option<FunctionArgumentMetadataV2>;
+  'Vec<FunctionArgumentMetadataV2>': Vec<FunctionArgumentMetadataV2>;
+  FunctionMetadataV2: FunctionMetadataV2;
+  'Option<FunctionMetadataV2>': Option<FunctionMetadataV2>;
+  'Vec<FunctionMetadataV2>': Vec<FunctionMetadataV2>;
+  DoubleMapTypeV3: DoubleMapTypeV3;
+  'Option<DoubleMapTypeV3>': Option<DoubleMapTypeV3>;
+  'Vec<DoubleMapTypeV3>': Vec<DoubleMapTypeV3>;
+  EventMetadataV3: EventMetadataV3;
+  'Option<EventMetadataV3>': Option<EventMetadataV3>;
+  'Vec<EventMetadataV3>': Vec<EventMetadataV3>;
+  FunctionArgumentMetadataV3: FunctionArgumentMetadataV3;
+  'Option<FunctionArgumentMetadataV3>': Option<FunctionArgumentMetadataV3>;
+  'Vec<FunctionArgumentMetadataV3>': Vec<FunctionArgumentMetadataV3>;
+  FunctionMetadataV3: FunctionMetadataV3;
+  'Option<FunctionMetadataV3>': Option<FunctionMetadataV3>;
+  'Vec<FunctionMetadataV3>': Vec<FunctionMetadataV3>;
+  DoubleMapTypeV4: DoubleMapTypeV4;
+  'Option<DoubleMapTypeV4>': Option<DoubleMapTypeV4>;
+  'Vec<DoubleMapTypeV4>': Vec<DoubleMapTypeV4>;
+  EventMetadataV4: EventMetadataV4;
+  'Option<EventMetadataV4>': Option<EventMetadataV4>;
+  'Vec<EventMetadataV4>': Vec<EventMetadataV4>;
+  FunctionArgumentMetadataV4: FunctionArgumentMetadataV4;
+  'Option<FunctionArgumentMetadataV4>': Option<FunctionArgumentMetadataV4>;
+  'Vec<FunctionArgumentMetadataV4>': Vec<FunctionArgumentMetadataV4>;
+  FunctionMetadataV4: FunctionMetadataV4;
+  'Option<FunctionMetadataV4>': Option<FunctionMetadataV4>;
+  'Vec<FunctionMetadataV4>': Vec<FunctionMetadataV4>;
+  DoubleMapTypeV5: DoubleMapTypeV5;
+  'Option<DoubleMapTypeV5>': Option<DoubleMapTypeV5>;
+  'Vec<DoubleMapTypeV5>': Vec<DoubleMapTypeV5>;
+  EventMetadataV5: EventMetadataV5;
+  'Option<EventMetadataV5>': Option<EventMetadataV5>;
+  'Vec<EventMetadataV5>': Vec<EventMetadataV5>;
+  FunctionArgumentMetadataV5: FunctionArgumentMetadataV5;
+  'Option<FunctionArgumentMetadataV5>': Option<FunctionArgumentMetadataV5>;
+  'Vec<FunctionArgumentMetadataV5>': Vec<FunctionArgumentMetadataV5>;
+  FunctionMetadataV5: FunctionMetadataV5;
+  'Option<FunctionMetadataV5>': Option<FunctionMetadataV5>;
+  'Vec<FunctionMetadataV5>': Vec<FunctionMetadataV5>;
+  DoubleMapTypeV6: DoubleMapTypeV6;
+  'Option<DoubleMapTypeV6>': Option<DoubleMapTypeV6>;
+  'Vec<DoubleMapTypeV6>': Vec<DoubleMapTypeV6>;
+  EventMetadataV6: EventMetadataV6;
+  'Option<EventMetadataV6>': Option<EventMetadataV6>;
+  'Vec<EventMetadataV6>': Vec<EventMetadataV6>;
+  FunctionArgumentMetadataV6: FunctionArgumentMetadataV6;
+  'Option<FunctionArgumentMetadataV6>': Option<FunctionArgumentMetadataV6>;
+  'Vec<FunctionArgumentMetadataV6>': Vec<FunctionArgumentMetadataV6>;
+  FunctionMetadataV6: FunctionMetadataV6;
+  'Option<FunctionMetadataV6>': Option<FunctionMetadataV6>;
+  'Vec<FunctionMetadataV6>': Vec<FunctionMetadataV6>;
+  ModuleConstantMetadataV6: ModuleConstantMetadataV6;
+  'Option<ModuleConstantMetadataV6>': Option<ModuleConstantMetadataV6>;
+  'Vec<ModuleConstantMetadataV6>': Vec<ModuleConstantMetadataV6>;
+  DoubleMapTypeV7: DoubleMapTypeV7;
+  'Option<DoubleMapTypeV7>': Option<DoubleMapTypeV7>;
+  'Vec<DoubleMapTypeV7>': Vec<DoubleMapTypeV7>;
+  EventMetadataV7: EventMetadataV7;
+  'Option<EventMetadataV7>': Option<EventMetadataV7>;
+  'Vec<EventMetadataV7>': Vec<EventMetadataV7>;
+  FunctionArgumentMetadataV7: FunctionArgumentMetadataV7;
+  'Option<FunctionArgumentMetadataV7>': Option<FunctionArgumentMetadataV7>;
+  'Vec<FunctionArgumentMetadataV7>': Vec<FunctionArgumentMetadataV7>;
+  FunctionMetadataV7: FunctionMetadataV7;
+  'Option<FunctionMetadataV7>': Option<FunctionMetadataV7>;
+  'Vec<FunctionMetadataV7>': Vec<FunctionMetadataV7>;
+  ModuleConstantMetadataV7: ModuleConstantMetadataV7;
+  'Option<ModuleConstantMetadataV7>': Option<ModuleConstantMetadataV7>;
+  'Vec<ModuleConstantMetadataV7>': Vec<ModuleConstantMetadataV7>;
   ApiId: ApiId;
   'Option<ApiId>': Option<ApiId>;
   'Vec<ApiId>': Vec<ApiId>;
diff --git a/packages/types/src/interfaces/definitions.ts b/packages/types/src/interfaces/definitions.ts
index 45460f2bea..6c712b32e4 100644
--- a/packages/types/src/interfaces/definitions.ts
+++ b/packages/types/src/interfaces/definitions.ts
@@ -29,5 +29,6 @@ export { default as attestations } from './attestations/definitions';
 export { default as claims } from './claims/definitions';
 export { default as parachains } from './parachains/definitions';
 
-// pull in rpc last, assuming that is uses info from above
+// pull in metadata & rpc last, assuming that is uses info from above
+export { default as metadata } from './metadata/definitions';
 export { default as rpc } from './rpc/definitions';
diff --git a/packages/types/src/interfaces/metadata/definitions.ts b/packages/types/src/interfaces/metadata/definitions.ts
new file mode 100644
index 0000000000..1b1ed629f4
--- /dev/null
+++ b/packages/types/src/interfaces/metadata/definitions.ts
@@ -0,0 +1,109 @@
+// Copyright 2017-2019 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export default {
+  types: {
+    // v0
+    CallMetadataV0: {
+      name: 'Text',
+      functions: 'Vec<FunctionMetadataV0>'
+    },
+    EventMetadataV0: {
+      name: 'Text',
+      args: 'Vec<Type>',
+      documentation: 'Vec<Text>'
+    },
+    FunctionArgumentMetadataV0: {
+      name: 'Text',
+      type: 'Type'
+    },
+    FunctionMetadataV0: {
+      id: 'u16',
+      name: 'Text',
+      args: 'Vec<FunctionArgumentMetadataV0>',
+      documentation: 'Vec<Text>'
+    },
+    ModuleMetadataV0: {
+      name: 'Text',
+      call: 'CallMetadataV0'
+    },
+    OuterDispatchCallV0: {
+      name: 'Text',
+      prefix: 'Text',
+      index: 'u16'
+    },
+    OuterDispatchMetadataV0: {
+      name: 'Text',
+      calls: 'Vec<OuterDispatchCallV0>'
+    },
+
+    // v1
+    EventMetadataV1: 'EventMetadataV0',
+    FunctionArgumentMetadataV1: 'FunctionArgumentMetadataV0',
+    FunctionMetadataV1: {
+      name: 'Text',
+      args: 'Vec<FunctionArgumentMetadataV1>',
+      documentation: 'Vec<Text>'
+    },
+
+    // v2
+    EventMetadataV2: 'EventMetadataV1',
+    FunctionArgumentMetadataV2: 'FunctionArgumentMetadataV1',
+    FunctionMetadataV2: 'FunctionMetadataV1',
+
+    // v3
+    DoubleMapTypeV3: {
+      key1: 'Type',
+      key2: 'Type',
+      value: 'Type',
+      key2Hasher: 'Text'
+    },
+    EventMetadataV3: 'EventMetadataV2',
+    FunctionArgumentMetadataV3: 'FunctionArgumentMetadataV2',
+    FunctionMetadataV3: 'FunctionMetadataV2',
+
+    // v4
+    DoubleMapTypeV4: {
+      hasher: 'StorageHasher',
+      key1: 'Type',
+      key2: 'Type',
+      value: 'Type',
+      key2Hasher: 'Text'
+    },
+    EventMetadataV4: 'EventMetadataV3',
+    FunctionArgumentMetadataV4: 'FunctionArgumentMetadataV3',
+    FunctionMetadataV4: 'FunctionMetadataV3',
+
+    // v5
+    DoubleMapTypeV5: {
+      hasher: 'StorageHasher',
+      key1: 'Type',
+      key2: 'Type',
+      value: 'Type',
+      key2Hasher: 'StorageHasher'
+    },
+    EventMetadataV5: 'EventMetadataV4',
+    FunctionArgumentMetadataV5: 'FunctionArgumentMetadataV4',
+    FunctionMetadataV5: 'FunctionMetadataV4',
+
+    // v6
+    DoubleMapTypeV6: 'DoubleMapTypeV5',
+    EventMetadataV6: 'EventMetadataV5',
+    FunctionArgumentMetadataV6: 'FunctionArgumentMetadataV5',
+    FunctionMetadataV6: 'FunctionMetadataV5',
+    ModuleConstantMetadataV6: {
+      name: 'Text',
+      type: 'Type',
+      value: 'Bytes',
+      documentation: 'Vec<Text>'
+    },
+
+    // v7
+    DoubleMapTypeV7: 'DoubleMapTypeV6',
+    EventMetadataV7: 'EventMetadataV6',
+    FunctionArgumentMetadataV7: 'FunctionArgumentMetadataV6',
+    FunctionMetadataV7: 'FunctionMetadataV6',
+    ModuleConstantMetadataV7: 'ModuleConstantMetadataV6'
+  }
+};
diff --git a/packages/types/src/interfaces/metadata/index.ts b/packages/types/src/interfaces/metadata/index.ts
new file mode 100644
index 0000000000..05fdc138ff
--- /dev/null
+++ b/packages/types/src/interfaces/metadata/index.ts
@@ -0,0 +1,4 @@
+// Auto-generated via `yarn build:interfaces`, do not edit
+/* eslint-disable @typescript-eslint/no-empty-interface */
+
+export * from './types';
diff --git a/packages/types/src/interfaces/metadata/types.ts b/packages/types/src/interfaces/metadata/types.ts
new file mode 100644
index 0000000000..10a3779503
--- /dev/null
+++ b/packages/types/src/interfaces/metadata/types.ts
@@ -0,0 +1,200 @@
+// Auto-generated via `yarn build:interfaces`, do not edit
+/* eslint-disable @typescript-eslint/no-empty-interface */
+
+import { Struct, Vec } from '../../codec';
+import { Bytes, StorageHasher, Text, Type, u16 } from '../../primitive';
+
+/** Struct */
+export interface CallMetadataV0 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Vec<FunctionMetadataV0> */
+  readonly functions: Vec<FunctionMetadataV0>;
+}
+
+/** Struct */
+export interface DoubleMapTypeV3 extends Struct {
+  /** Type */
+  readonly key1: Type;
+  /** Type */
+  readonly key2: Type;
+  /** Type */
+  readonly value: Type;
+  /** Text */
+  readonly key2Hasher: Text;
+}
+
+/** Struct */
+export interface DoubleMapTypeV4 extends Struct {
+  /** StorageHasher */
+  readonly hasher: StorageHasher;
+  /** Type */
+  readonly key1: Type;
+  /** Type */
+  readonly key2: Type;
+  /** Type */
+  readonly value: Type;
+  /** Text */
+  readonly key2Hasher: Text;
+}
+
+/** Struct */
+export interface DoubleMapTypeV5 extends Struct {
+  /** StorageHasher */
+  readonly hasher: StorageHasher;
+  /** Type */
+  readonly key1: Type;
+  /** Type */
+  readonly key2: Type;
+  /** Type */
+  readonly value: Type;
+  /** StorageHasher */
+  readonly key2Hasher: StorageHasher;
+}
+
+/** DoubleMapTypeV5 */
+export type DoubleMapTypeV6 = DoubleMapTypeV5;
+
+/** DoubleMapTypeV6 */
+export type DoubleMapTypeV7 = DoubleMapTypeV6;
+
+/** Struct */
+export interface EventMetadataV0 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Vec<Type> */
+  readonly args: Vec<Type>;
+  /** Vec<Text> */
+  readonly documentation: Vec<Text>;
+}
+
+/** EventMetadataV0 */
+export type EventMetadataV1 = EventMetadataV0;
+
+/** EventMetadataV1 */
+export type EventMetadataV2 = EventMetadataV1;
+
+/** EventMetadataV2 */
+export type EventMetadataV3 = EventMetadataV2;
+
+/** EventMetadataV3 */
+export type EventMetadataV4 = EventMetadataV3;
+
+/** EventMetadataV4 */
+export type EventMetadataV5 = EventMetadataV4;
+
+/** EventMetadataV5 */
+export type EventMetadataV6 = EventMetadataV5;
+
+/** EventMetadataV6 */
+export type EventMetadataV7 = EventMetadataV6;
+
+/** Struct */
+export interface FunctionArgumentMetadataV0 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Type */
+  readonly type: Type;
+}
+
+/** FunctionArgumentMetadataV0 */
+export type FunctionArgumentMetadataV1 = FunctionArgumentMetadataV0;
+
+/** FunctionArgumentMetadataV1 */
+export type FunctionArgumentMetadataV2 = FunctionArgumentMetadataV1;
+
+/** FunctionArgumentMetadataV2 */
+export type FunctionArgumentMetadataV3 = FunctionArgumentMetadataV2;
+
+/** FunctionArgumentMetadataV3 */
+export type FunctionArgumentMetadataV4 = FunctionArgumentMetadataV3;
+
+/** FunctionArgumentMetadataV4 */
+export type FunctionArgumentMetadataV5 = FunctionArgumentMetadataV4;
+
+/** FunctionArgumentMetadataV5 */
+export type FunctionArgumentMetadataV6 = FunctionArgumentMetadataV5;
+
+/** FunctionArgumentMetadataV6 */
+export type FunctionArgumentMetadataV7 = FunctionArgumentMetadataV6;
+
+/** Struct */
+export interface FunctionMetadataV0 extends Struct {
+  /** u16 */
+  readonly id: u16;
+  /** Text */
+  readonly name: Text;
+  /** Vec<FunctionArgumentMetadataV0> */
+  readonly args: Vec<FunctionArgumentMetadataV0>;
+  /** Vec<Text> */
+  readonly documentation: Vec<Text>;
+}
+
+/** Struct */
+export interface FunctionMetadataV1 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Vec<FunctionArgumentMetadataV1> */
+  readonly args: Vec<FunctionArgumentMetadataV1>;
+  /** Vec<Text> */
+  readonly documentation: Vec<Text>;
+}
+
+/** FunctionMetadataV1 */
+export type FunctionMetadataV2 = FunctionMetadataV1;
+
+/** FunctionMetadataV2 */
+export type FunctionMetadataV3 = FunctionMetadataV2;
+
+/** FunctionMetadataV3 */
+export type FunctionMetadataV4 = FunctionMetadataV3;
+
+/** FunctionMetadataV4 */
+export type FunctionMetadataV5 = FunctionMetadataV4;
+
+/** FunctionMetadataV5 */
+export type FunctionMetadataV6 = FunctionMetadataV5;
+
+/** FunctionMetadataV6 */
+export type FunctionMetadataV7 = FunctionMetadataV6;
+
+/** Struct */
+export interface ModuleConstantMetadataV6 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Type */
+  readonly type: Type;
+  /** Bytes */
+  readonly value: Bytes;
+  /** Vec<Text> */
+  readonly documentation: Vec<Text>;
+}
+
+/** ModuleConstantMetadataV6 */
+export type ModuleConstantMetadataV7 = ModuleConstantMetadataV6;
+
+/** Struct */
+export interface ModuleMetadataV0 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** CallMetadataV0 */
+  readonly call: CallMetadataV0;
+}
+
+/** Struct */
+export interface OuterDispatchCallV0 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Text */
+  readonly prefix: Text;
+  /** u16 */
+  readonly index: u16;
+}
+
+/** Struct */
+export interface OuterDispatchMetadataV0 extends Struct {
+  /** Text */
+  readonly name: Text;
+  /** Vec<OuterDispatchCallV0> */
+  readonly calls: Vec<OuterDispatchCallV0>;
+}
diff --git a/packages/types/src/interfaces/types.ts b/packages/types/src/interfaces/types.ts
index addf3f6b4d..0050d4a5b9 100644
--- a/packages/types/src/interfaces/types.ts
+++ b/packages/types/src/interfaces/types.ts
@@ -22,4 +22,5 @@ export * from './treasury/types';
 export * from './attestations/types';
 export * from './claims/types';
 export * from './parachains/types';
+export * from './metadata/types';
 export * from './rpc/types';
diff --git a/packages/types/src/primitive/Extrinsic/Extrinsic.ts b/packages/types/src/primitive/Extrinsic/Extrinsic.ts
index 531db2aa57..b7d4601991 100644
--- a/packages/types/src/primitive/Extrinsic/Extrinsic.ts
+++ b/packages/types/src/primitive/Extrinsic/Extrinsic.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { FunctionMetadataV7 } from '../../interfaces/metadata/types';
 import { Balance, Index } from '../../interfaces/runtime';
 import { AnyU8a, ArgsDef, Codec, ExtrinsicPayloadValue, IExtrinsic, IHash, IKeyringPair, SignatureOptions } from '../../types';
 
@@ -9,7 +10,6 @@ import { assert, isHex, isU8a, u8aConcat, u8aToHex, u8aToU8a } from '@polkadot/u
 
 import Base from '../../codec/Base';
 import Compact from '../../codec/Compact';
-import { FunctionMetadata } from '../../Metadata/v7/Calls';
 import Address from '../Generic/Address';
 import Call from '../Generic/Call';
 import ExtrinsicV1, { ExtrinsicValueV1 } from './v1/Extrinsic';
@@ -160,9 +160,9 @@ export default class Extrinsic extends Base<ExtrinsicV1 | ExtrinsicV2 | Extrinsi
   }
 
   /**
-   * @description The [[FunctionMetadata]] that describes the extrinsic
+   * @description The [[FunctionMetadataV7]] that describes the extrinsic
    */
-  public get meta (): FunctionMetadata {
+  public get meta (): FunctionMetadataV7 {
     return this.method.meta;
   }
 
diff --git a/packages/types/src/primitive/Generic/Call.ts b/packages/types/src/primitive/Generic/Call.ts
index 3f792813f8..b15749c08f 100644
--- a/packages/types/src/primitive/Generic/Call.ts
+++ b/packages/types/src/primitive/Generic/Call.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { FunctionArgumentMetadataV7, FunctionMetadataV7 } from '../../interfaces/metadata';
 import { AnyU8a, ArgsDef, CallFunction, Codec, IMethod, ModulesWithCalls } from '../../types';
 
 import { assert, isHex, isObject, isU8a, u8aToU8a } from '@polkadot/util';
@@ -9,7 +10,6 @@ import { assert, isHex, isObject, isU8a, u8aToU8a } from '@polkadot/util';
 import { getTypeDef, getTypeClass } from '../../codec/create';
 import Struct from '../../codec/Struct';
 import U8aFixed from '../../codec/U8aFixed';
-import { FunctionMetadata as FunctionMetadataV7, FunctionArgumentMetadata } from '../../Metadata/v7/Calls';
 
 interface DecodeMethodInput {
   args: any;
@@ -115,7 +115,7 @@ export default class Call extends Struct implements IMethod {
   }
 
   // If the extrinsic function has an argument of type `Origin`, we ignore it
-  public static filterOrigin (meta?: FunctionMetadataV7): FunctionArgumentMetadata[] {
+  public static filterOrigin (meta?: FunctionMetadataV7): FunctionArgumentMetadataV7[] {
     // FIXME should be `arg.type !== Origin`, but doesn't work...
     return meta
       ? meta.args.filter(({ type }): boolean =>
diff --git a/packages/types/src/primitive/Generic/Event.ts b/packages/types/src/primitive/Generic/Event.ts
index 79fda8fb0c..61995fd733 100644
--- a/packages/types/src/primitive/Generic/Event.ts
+++ b/packages/types/src/primitive/Generic/Event.ts
@@ -3,6 +3,7 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { TypeDef } from '../../codec/types';
+import { EventMetadataV7 } from '../../interfaces/metadata';
 import { EventId } from '../../interfaces/system';
 import { Constructor, Codec } from '../../types';
 
@@ -12,7 +13,6 @@ import { getTypeClass, getTypeDef } from '../../codec/create';
 import Struct from '../../codec/Struct';
 import Tuple from '../../codec/Tuple';
 import Metadata from '../../Metadata';
-import { EventMetadata as EventMetadataV7 } from '../../Metadata/v7/Events';
 import Null from '../Null';
 
 const EventTypes: Record<string, Constructor<EventData>> = {};
diff --git a/packages/types/src/types.ts b/packages/types/src/types.ts
index d47e9521f3..5ffcc0aeb0 100644
--- a/packages/types/src/types.ts
+++ b/packages/types/src/types.ts
@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { FunctionMetadataV7 } from './interfaces/metadata';
 import { Balance, Index } from './interfaces/runtime';
 
 import BN from 'bn.js';
@@ -9,7 +10,6 @@ import BN from 'bn.js';
 import Compact from './codec/Compact';
 import U8a from './codec/U8a';
 import { InterfaceRegistry } from './interfaceRegistry';
-import { FunctionMetadata } from './Metadata/v7/Calls';
 import Call from './primitive/Generic/Call';
 import Address from './primitive/Generic/Address';
 
@@ -20,7 +20,7 @@ export type InterfaceTypes = keyof InterfaceRegistry;
 export interface CallFunction {
   (...args: any[]): Call;
   callIndex: Uint8Array;
-  meta: FunctionMetadata;
+  meta: FunctionMetadataV7;
   method: string;
   section: string;
   toJSON: () => any;
@@ -162,7 +162,7 @@ export interface IMethod extends Codec {
   readonly data: Uint8Array;
   readonly hash: IHash;
   readonly hasOrigin: boolean;
-  readonly meta: FunctionMetadata;
+  readonly meta: FunctionMetadataV7;
 }
 
 interface ExtrinsicSignatureBase {