diff --git a/README.md b/README.md
index ab529bc99..24134744f 100644
--- a/README.md
+++ b/README.md
@@ -36,14 +36,19 @@ event, there's a method to attach a listener function.
 // Listen for an event from the Events API
 app.event(eventType, fn);
 
-// Listen for an action from a block element (buttons, menus, etc), dialog submission, message action, or legacy action
+// Listen for an action from a block element (buttons, menus, etc)
 app.action(actionId, fn);
+// Listen for dialog submission, message action, or legacy action
+app.action({ callback_id: callbackId }, fn);
 
 // Listen for a slash command
 app.command(commandName, fn);
 
 // Listen for options requests (from menus with an external data source)
 app.options(actionId, fn);
+
+// Listen for modal view requests
+app.view(callbackId, fn);
 ```
 
 There's a special method that's provided as a convenience to handle Events API events with the type `message`. Also, you
diff --git a/src/types/actions/block-action.ts b/src/types/actions/block-action.ts
index 4e56b23fc..511cb67d1 100644
--- a/src/types/actions/block-action.ts
+++ b/src/types/actions/block-action.ts
@@ -20,7 +20,8 @@ export type BlockElementAction =
   | MultiExternalSelectAction
   | OverflowAction
   | DatepickerAction
-  | RadioButtonsAction;
+  | RadioButtonsAction
+  | CheckboxesAction;
 
 /**
  * Any action from Slack's interactive elements
@@ -185,6 +186,15 @@ export interface RadioButtonsAction extends BasicElementAction<'radio_buttons'>
   confirm?: Confirmation;
 }
 
+/**
+ * An action from a checkboxes element
+ */
+export interface CheckboxesAction extends BasicElementAction<'checkboxes'> {
+  selected_options: Option[];
+  initial_options?: Option[];
+  confirm?: Confirmation;
+}
+
 /**
  * A Slack Block Kit element action wrapped in the standard metadata.
  *
diff --git a/src/types/view/index.ts b/src/types/view/index.ts
index 411df4d51..af86548db 100644
--- a/src/types/view/index.ts
+++ b/src/types/view/index.ts
@@ -1,5 +1,6 @@
 import { StringIndexed } from '../helpers';
-import { RespondArguments, AckFn } from '../utilities';
+import { AckFn } from '../utilities';
+import { View } from '@slack/types';
 
 /**
  * Known view action types
@@ -13,7 +14,7 @@ export interface SlackViewMiddlewareArgs<ViewActionType extends SlackViewAction
   payload: ViewOutput;
   view: this['payload'];
   body: ViewActionType;
-  ack: AckFn<string | RespondArguments>;
+  ack: ViewAckFn<ViewActionType>;
 }
 
 interface PlainTextElementOutput {
@@ -80,7 +81,13 @@ export interface ViewOutput {
   blocks: StringIndexed; // TODO: should this just be any?
   close: PlainTextElementOutput | null;
   submit: PlainTextElementOutput | null;
-  state: object; // TODO: this should probably be expanded in the future
+  state: {
+    values: {
+      [blockId: string]: {
+        [actionId: string]: any; // TODO: a union of all the input elements' output payload
+      };
+    };
+  };
   hash: string;
   private_metadata: string;
   root_view_id: string | null;
@@ -89,3 +96,37 @@ export interface ViewOutput {
   notify_on_close: boolean;
   external_id?: string;
 }
+
+export interface ViewUpdateResponseAction {
+  response_action: 'update';
+  view: View;
+}
+
+export interface ViewPushResponseAction {
+  response_action: 'push';
+  view: View;
+}
+
+export interface ViewClearResponseAction {
+  response_action: 'clear';
+}
+
+export interface ViewErrorsResponseAction {
+  response_action: 'errors';
+  errors: {
+    [blockId: string]: string;
+  };
+}
+
+export type ViewResponseAction =
+  ViewUpdateResponseAction | ViewPushResponseAction | ViewClearResponseAction | ViewErrorsResponseAction;
+
+/**
+ * Type function which given a view action `VA` returns a corresponding type for the `ack()` function. The function is
+ * used to acknowledge the receipt (and possibly signal failure) of an view submission or closure from a listener or
+ * middleware.
+ */
+type ViewAckFn<VA extends SlackViewAction = SlackViewAction> =
+  VA extends ViewSubmitAction ? AckFn<ViewResponseAction> :
+  // ViewClosedActions can only be acknowledged, there are no arguments
+  AckFn<void>;