diff --git a/lib/types/activity-types.js b/lib/types/activity-types.js
--- a/lib/types/activity-types.js
+++ b/lib/types/activity-types.js
@@ -9,6 +9,12 @@
   +threadID: string,
   +latestMessage: ?string,
 };
+export const activityUpdateValidator: TInterface<ActivityUpdate> =
+  tShape<ActivityUpdate>({
+    focus: t.Boolean,
+    threadID: tID,
+    latestMessage: t.maybe(tID),
+  });
 
 export type UpdateActivityRequest = {
   +updates: $ReadOnlyArray<ActivityUpdate>,
diff --git a/lib/types/entry-types.js b/lib/types/entry-types.js
--- a/lib/types/entry-types.js
+++ b/lib/types/entry-types.js
@@ -3,7 +3,11 @@
 import t, { type TInterface } from 'tcomb';
 
 import { type Platform, isWebPlatform } from './device-types.js';
-import { type CalendarFilter, defaultCalendarFilters } from './filter-types.js';
+import {
+  type CalendarFilter,
+  calendarFilterValidator,
+  defaultCalendarFilters,
+} from './filter-types.js';
 import type { RawMessageInfo } from './message-types.js';
 import type {
   ServerCreateUpdatesResponse,
@@ -73,6 +77,13 @@
   +filters: $ReadOnlyArray<CalendarFilter>,
 };
 
+export const calendarQueryValidator: TInterface<CalendarQuery> =
+  tShape<CalendarQuery>({
+    startDate: t.String,
+    endDate: t.String,
+    filters: t.list(calendarFilterValidator),
+  });
+
 export const defaultCalendarQuery = (
   platform: ?Platform,
   timeZone?: ?string,
diff --git a/lib/types/filter-types.js b/lib/types/filter-types.js
--- a/lib/types/filter-types.js
+++ b/lib/types/filter-types.js
@@ -1,6 +1,9 @@
 // @flow
 
+import t, { type TUnion } from 'tcomb';
+
 import type { ResolvedThreadInfo } from './thread-types.js';
+import { tID, tShape, tString } from '../utils/validation-utils.js';
 
 export const calendarThreadFilterTypes = Object.freeze({
   THREAD_LIST: 'threads',
@@ -16,6 +19,14 @@
 };
 export type CalendarFilter = { +type: 'not_deleted' } | CalendarThreadFilter;
 
+export const calendarFilterValidator: TUnion<CalendarFilter> = t.union([
+  tShape<CalendarThreadFilter>({
+    type: tString('threads'),
+    threadIDs: t.list(tID),
+  }),
+  tShape({ type: tString('not_deleted') }),
+]);
+
 export const defaultCalendarFilters: $ReadOnlyArray<CalendarFilter> = [
   { type: calendarThreadFilterTypes.NOT_DELETED },
 ];
diff --git a/lib/types/socket-types.js b/lib/types/socket-types.js
--- a/lib/types/socket-types.js
+++ b/lib/types/socket-types.js
@@ -5,6 +5,7 @@
 
 import {
   type ActivityUpdate,
+  activityUpdateValidator,
   type UpdateActivityResult,
   updateActivityResultValidator,
 } from './activity-types.js';
@@ -14,6 +15,7 @@
   type RawEntryInfo,
   rawEntryInfoValidator,
   type CalendarQuery,
+  calendarQueryValidator,
   defaultCalendarQuery,
 } from './entry-types.js';
 import {
@@ -473,6 +475,21 @@
   +lateResponses: $ReadOnlyArray<number>,
   +showDisconnectedBar: boolean,
 };
+export const connectionInfoValidator: TInterface<ConnectionInfo> =
+  tShape<ConnectionInfo>({
+    status: t.enums.of([
+      'connecting',
+      'connected',
+      'reconnecting',
+      'disconnecting',
+      'forcedDisconnecting',
+      'disconnected',
+    ]),
+    queuedActivityUpdates: t.list(activityUpdateValidator),
+    actualizedCalendarQuery: calendarQueryValidator,
+    lateResponses: t.list(t.Number),
+    showDisconnectedBar: t.Boolean,
+  });
 export const defaultConnectionInfo = (
   platform: Platform,
   timeZone?: ?string,