diff --git a/keyserver/src/session/cookies.js b/keyserver/src/session/cookies.js
index 2be9a0b64..5915b392b 100644
--- a/keyserver/src/session/cookies.js
+++ b/keyserver/src/session/cookies.js
@@ -1,845 +1,846 @@
 // @flow
 
 import crypto from 'crypto';
 import type { $Response, $Request } from 'express';
 import invariant from 'invariant';
 import bcrypt from 'twin-bcrypt';
 import url from 'url';
 
 import { hasMinCodeVersion } from 'lib/shared/version-utils.js';
 import type { Shape } from 'lib/types/core.js';
 import type { SignedIdentityKeysBlob } from 'lib/types/crypto-types.js';
+import { isWebPlatform } from 'lib/types/device-types.js';
 import type { Platform, PlatformDetails } from 'lib/types/device-types.js';
 import type { CalendarQuery } from 'lib/types/entry-types.js';
 import {
   type ServerSessionChange,
   cookieLifetime,
   cookieSources,
   type CookieSource,
   cookieTypes,
   sessionIdentifierTypes,
   type SessionIdentifierType,
 } from 'lib/types/session-types.js';
 import type { SIWESocialProof } from 'lib/types/siwe-types.js';
 import type { InitialClientSocketMessage } from 'lib/types/socket-types.js';
 import type { UserInfo } from 'lib/types/user-types.js';
 import { values } from 'lib/utils/objects.js';
 import { promiseAll } from 'lib/utils/promises.js';
 
 import { Viewer } from './viewer.js';
 import type { AnonymousViewerData, UserViewerData } from './viewer.js';
 import createIDs from '../creators/id-creator.js';
 import { createSession } from '../creators/session-creator.js';
 import { dbQuery, SQL } from '../database/database.js';
 import { deleteCookie } from '../deleters/cookie-deleters.js';
 import { handleAsyncPromise } from '../responders/handlers.js';
 import { clearDeviceToken } from '../updaters/device-token-updaters.js';
 import { updateThreadMembers } from '../updaters/thread-updaters.js';
 import { assertSecureRequest } from '../utils/security-utils.js';
 import {
   type AppURLFacts,
   getAppURLFactsFromRequestURL,
 } from '../utils/urls.js';
 
 function cookieIsExpired(lastUsed: number) {
   return lastUsed + cookieLifetime <= Date.now();
 }
 
 type SessionParameterInfo = {
   isSocket: boolean,
   sessionID: ?string,
   sessionIdentifierType: SessionIdentifierType,
   ipAddress: string,
   userAgent: ?string,
 };
 
 type FetchViewerResult =
   | { type: 'valid', viewer: Viewer }
   | InvalidFetchViewerResult;
 
 type InvalidFetchViewerResult =
   | {
       type: 'nonexistant',
       cookieName: ?string,
       cookieSource: ?CookieSource,
       sessionParameterInfo: SessionParameterInfo,
     }
   | {
       type: 'invalidated',
       cookieName: string,
       cookieID: string,
       cookieSource: CookieSource,
       sessionParameterInfo: SessionParameterInfo,
       platformDetails: ?PlatformDetails,
       deviceToken: ?string,
     };
 
 async function fetchUserViewer(
   cookie: string,
   cookieSource: CookieSource,
   sessionParameterInfo: SessionParameterInfo,
 ): Promise<FetchViewerResult> {
   const [cookieID, cookiePassword] = cookie.split(':');
   if (!cookieID || !cookiePassword) {
     return {
       type: 'nonexistant',
       cookieName: cookieTypes.USER,
       cookieSource,
       sessionParameterInfo,
     };
   }
 
   const query = SQL`
     SELECT hash, user, last_used, platform, device_token, versions
     FROM cookies
     WHERE id = ${cookieID} AND user IS NOT NULL
   `;
   const [[result], allSessionInfo] = await Promise.all([
     dbQuery(query),
     fetchSessionInfo(sessionParameterInfo, cookieID),
   ]);
   if (result.length === 0) {
     return {
       type: 'nonexistant',
       cookieName: cookieTypes.USER,
       cookieSource,
       sessionParameterInfo,
     };
   }
 
   let sessionID = null,
     sessionInfo = null;
   if (allSessionInfo) {
     ({ sessionID, ...sessionInfo } = allSessionInfo);
   }
 
   const cookieRow = result[0];
   let platformDetails = null;
   if (cookieRow.versions) {
     const versions = JSON.parse(cookieRow.versions);
     platformDetails = {
       platform: cookieRow.platform,
       codeVersion: versions.codeVersion,
       stateVersion: versions.stateVersion,
     };
   } else {
     platformDetails = { platform: cookieRow.platform };
   }
   const deviceToken = cookieRow.device_token;
 
   if (
     !bcrypt.compareSync(cookiePassword, cookieRow.hash) ||
     cookieIsExpired(cookieRow.last_used)
   ) {
     return {
       type: 'invalidated',
       cookieName: cookieTypes.USER,
       cookieID,
       cookieSource,
       sessionParameterInfo,
       platformDetails,
       deviceToken,
     };
   }
   const userID = cookieRow.user.toString();
   const viewer = new Viewer({
     isSocket: sessionParameterInfo.isSocket,
     loggedIn: true,
     id: userID,
     platformDetails,
     deviceToken,
     userID,
     cookieSource,
     cookieID,
     cookiePassword,
     sessionIdentifierType: sessionParameterInfo.sessionIdentifierType,
     sessionID,
     sessionInfo,
     isScriptViewer: false,
     ipAddress: sessionParameterInfo.ipAddress,
     userAgent: sessionParameterInfo.userAgent,
   });
   return { type: 'valid', viewer };
 }
 
 async function fetchAnonymousViewer(
   cookie: string,
   cookieSource: CookieSource,
   sessionParameterInfo: SessionParameterInfo,
 ): Promise<FetchViewerResult> {
   const [cookieID, cookiePassword] = cookie.split(':');
   if (!cookieID || !cookiePassword) {
     return {
       type: 'nonexistant',
       cookieName: cookieTypes.ANONYMOUS,
       cookieSource,
       sessionParameterInfo,
     };
   }
 
   const query = SQL`
     SELECT last_used, hash, platform, device_token, versions
     FROM cookies
     WHERE id = ${cookieID} AND user IS NULL
   `;
   const [[result], allSessionInfo] = await Promise.all([
     dbQuery(query),
     fetchSessionInfo(sessionParameterInfo, cookieID),
   ]);
   if (result.length === 0) {
     return {
       type: 'nonexistant',
       cookieName: cookieTypes.ANONYMOUS,
       cookieSource,
       sessionParameterInfo,
     };
   }
 
   let sessionID = null,
     sessionInfo = null;
   if (allSessionInfo) {
     ({ sessionID, ...sessionInfo } = allSessionInfo);
   }
 
   const cookieRow = result[0];
   let platformDetails = null;
   if (cookieRow.platform && cookieRow.versions) {
     const versions = JSON.parse(cookieRow.versions);
     platformDetails = {
       platform: cookieRow.platform,
       codeVersion: versions.codeVersion,
       stateVersion: versions.stateVersion,
     };
   } else if (cookieRow.platform) {
     platformDetails = { platform: cookieRow.platform };
   }
   const deviceToken = cookieRow.device_token;
 
   if (
     !bcrypt.compareSync(cookiePassword, cookieRow.hash) ||
     cookieIsExpired(cookieRow.last_used)
   ) {
     return {
       type: 'invalidated',
       cookieName: cookieTypes.ANONYMOUS,
       cookieID,
       cookieSource,
       sessionParameterInfo,
       platformDetails,
       deviceToken,
     };
   }
   const viewer = new Viewer({
     isSocket: sessionParameterInfo.isSocket,
     loggedIn: false,
     id: cookieID,
     platformDetails,
     deviceToken,
     cookieSource,
     cookieID,
     cookiePassword,
     sessionIdentifierType: sessionParameterInfo.sessionIdentifierType,
     sessionID,
     sessionInfo,
     isScriptViewer: false,
     ipAddress: sessionParameterInfo.ipAddress,
     userAgent: sessionParameterInfo.userAgent,
   });
   return { type: 'valid', viewer };
 }
 
 type SessionInfo = {
   +sessionID: ?string,
   +lastValidated: number,
   +lastUpdate: number,
   +calendarQuery: CalendarQuery,
 };
 async function fetchSessionInfo(
   sessionParameterInfo: SessionParameterInfo,
   cookieID: string,
 ): Promise<?SessionInfo> {
   const { sessionID } = sessionParameterInfo;
   const session = sessionID !== undefined ? sessionID : cookieID;
   if (!session) {
     return null;
   }
   const query = SQL`
     SELECT query, last_validated, last_update
     FROM sessions
     WHERE id = ${session} AND cookie = ${cookieID}
   `;
   const [result] = await dbQuery(query);
   if (result.length === 0) {
     return null;
   }
   return {
     sessionID,
     lastValidated: result[0].last_validated,
     lastUpdate: result[0].last_update,
     calendarQuery: JSON.parse(result[0].query),
   };
 }
 
 // This function is meant to consume a cookie that has already been processed.
 // That means it doesn't have any logic to handle an invalid cookie, and it
 // doesn't update the cookie's last_used timestamp.
 async function fetchViewerFromCookieData(
   req: $Request,
   sessionParameterInfo: SessionParameterInfo,
 ): Promise<FetchViewerResult> {
   let viewerResult;
   const { user, anonymous } = req.cookies;
   if (user) {
     viewerResult = await fetchUserViewer(
       user,
       cookieSources.HEADER,
       sessionParameterInfo,
     );
   } else if (anonymous) {
     viewerResult = await fetchAnonymousViewer(
       anonymous,
       cookieSources.HEADER,
       sessionParameterInfo,
     );
   } else {
     return {
       type: 'nonexistant',
       cookieName: null,
       cookieSource: null,
       sessionParameterInfo,
     };
   }
 
   // We protect against CSRF attacks by making sure that on web,
   // non-GET requests cannot use a bare cookie for session identification
   if (viewerResult.type === 'valid') {
     const { viewer } = viewerResult;
     invariant(
       req.method === 'GET' ||
         viewer.sessionIdentifierType !== sessionIdentifierTypes.COOKIE_ID ||
-        viewer.platform !== 'web',
+        !isWebPlatform(viewer.platform),
       'non-GET request from web using sessionIdentifierTypes.COOKIE_ID',
     );
   }
 
   return viewerResult;
 }
 
 async function fetchViewerFromRequestBody(
   body: mixed,
   sessionParameterInfo: SessionParameterInfo,
 ): Promise<FetchViewerResult> {
   if (!body || typeof body !== 'object') {
     return {
       type: 'nonexistant',
       cookieName: null,
       cookieSource: null,
       sessionParameterInfo,
     };
   }
   const cookiePair = body.cookie;
   if (cookiePair === null || cookiePair === '') {
     return {
       type: 'nonexistant',
       cookieName: null,
       cookieSource: cookieSources.BODY,
       sessionParameterInfo,
     };
   }
   if (!cookiePair || typeof cookiePair !== 'string') {
     return {
       type: 'nonexistant',
       cookieName: null,
       cookieSource: null,
       sessionParameterInfo,
     };
   }
   const [type, cookie] = cookiePair.split('=');
   if (type === cookieTypes.USER && cookie) {
     return await fetchUserViewer(
       cookie,
       cookieSources.BODY,
       sessionParameterInfo,
     );
   } else if (type === cookieTypes.ANONYMOUS && cookie) {
     return await fetchAnonymousViewer(
       cookie,
       cookieSources.BODY,
       sessionParameterInfo,
     );
   }
   return {
     type: 'nonexistant',
     cookieName: null,
     cookieSource: null,
     sessionParameterInfo,
   };
 }
 
 function getRequestIPAddress(req: $Request) {
   const { proxy } = getAppURLFactsFromRequestURL(req.originalUrl);
   let ipAddress;
   if (proxy === 'none') {
     ipAddress = req.socket.remoteAddress;
   } else if (proxy === 'apache') {
     ipAddress = req.get('X-Forwarded-For');
   }
   invariant(ipAddress, 'could not determine requesting IP address');
   return ipAddress;
 }
 
 function getSessionParameterInfoFromRequestBody(
   req: $Request,
 ): SessionParameterInfo {
   const body = (req.body: any);
   let sessionID =
     body.sessionID !== undefined || req.method !== 'GET'
       ? body.sessionID
       : null;
   if (sessionID === '') {
     sessionID = null;
   }
   const sessionIdentifierType =
     req.method === 'GET' || sessionID !== undefined
       ? sessionIdentifierTypes.BODY_SESSION_ID
       : sessionIdentifierTypes.COOKIE_ID;
   return {
     isSocket: false,
     sessionID,
     sessionIdentifierType,
     ipAddress: getRequestIPAddress(req),
     userAgent: req.get('User-Agent'),
   };
 }
 
 async function fetchViewerForJSONRequest(req: $Request): Promise<Viewer> {
   assertSecureRequest(req);
   const sessionParameterInfo = getSessionParameterInfoFromRequestBody(req);
   let result = await fetchViewerFromRequestBody(req.body, sessionParameterInfo);
   if (
     result.type === 'nonexistant' &&
     (result.cookieSource === null || result.cookieSource === undefined)
   ) {
     result = await fetchViewerFromCookieData(req, sessionParameterInfo);
   }
   return await handleFetchViewerResult(result);
 }
 
 const webPlatformDetails = { platform: 'web' };
 async function fetchViewerForHomeRequest(req: $Request): Promise<Viewer> {
   assertSecureRequest(req);
   const sessionParameterInfo = getSessionParameterInfoFromRequestBody(req);
   const result = await fetchViewerFromCookieData(req, sessionParameterInfo);
   return await handleFetchViewerResult(result, webPlatformDetails);
 }
 
 async function fetchViewerForSocket(
   req: $Request,
   clientMessage: InitialClientSocketMessage,
 ): Promise<?Viewer> {
   assertSecureRequest(req);
   const { sessionIdentification } = clientMessage.payload;
   const { sessionID } = sessionIdentification;
   const sessionParameterInfo = {
     isSocket: true,
     sessionID,
     sessionIdentifierType:
       sessionID !== undefined
         ? sessionIdentifierTypes.BODY_SESSION_ID
         : sessionIdentifierTypes.COOKIE_ID,
     ipAddress: getRequestIPAddress(req),
     userAgent: req.get('User-Agent'),
   };
 
   let result = await fetchViewerFromRequestBody(
     clientMessage.payload.sessionIdentification,
     sessionParameterInfo,
   );
   if (
     result.type === 'nonexistant' &&
     (result.cookieSource === null || result.cookieSource === undefined)
   ) {
     result = await fetchViewerFromCookieData(req, sessionParameterInfo);
   }
   if (result.type === 'valid') {
     return result.viewer;
   }
 
   const promises = {};
   if (result.cookieSource === cookieSources.BODY) {
     // We initialize a socket's Viewer after the WebSocket handshake, since to
     // properly initialize the Viewer we need a bunch of data, but that data
     // can't be sent until after the handshake. Consequently, by the time we
     // know that a cookie may be invalid, we are no longer communicating via
     // HTTP, and have no way to set a new cookie for HEADER (web) clients.
     const platformDetails =
       result.type === 'invalidated' ? result.platformDetails : null;
     const deviceToken =
       result.type === 'invalidated' ? result.deviceToken : null;
     promises.anonymousViewerData = createNewAnonymousCookie({
       platformDetails,
       deviceToken,
     });
   }
   if (result.type === 'invalidated') {
     promises.deleteCookie = deleteCookie(result.cookieID);
   }
   const { anonymousViewerData } = await promiseAll(promises);
 
   if (!anonymousViewerData) {
     return null;
   }
 
   return createViewerForInvalidFetchViewerResult(result, anonymousViewerData);
 }
 
 async function handleFetchViewerResult(
   result: FetchViewerResult,
   inputPlatformDetails?: PlatformDetails,
 ) {
   if (result.type === 'valid') {
     return result.viewer;
   }
 
   let platformDetails = inputPlatformDetails;
   if (!platformDetails && result.type === 'invalidated') {
     platformDetails = result.platformDetails;
   }
   const deviceToken = result.type === 'invalidated' ? result.deviceToken : null;
 
   const [anonymousViewerData] = await Promise.all([
     createNewAnonymousCookie({ platformDetails, deviceToken }),
     result.type === 'invalidated' ? deleteCookie(result.cookieID) : null,
   ]);
 
   return createViewerForInvalidFetchViewerResult(result, anonymousViewerData);
 }
 
 function createViewerForInvalidFetchViewerResult(
   result: InvalidFetchViewerResult,
   anonymousViewerData: AnonymousViewerData,
 ): Viewer {
   // If a null cookie was specified in the request body, result.cookieSource
   // will still be BODY here. The only way it would be null or undefined here
   // is if there was no cookie specified in either the body or the header, in
   // which case we default to returning the new cookie in the response header.
   const cookieSource =
     result.cookieSource !== null && result.cookieSource !== undefined
       ? result.cookieSource
       : cookieSources.HEADER;
   const viewer = new Viewer({
     ...anonymousViewerData,
     cookieSource,
     sessionIdentifierType: result.sessionParameterInfo.sessionIdentifierType,
     isSocket: result.sessionParameterInfo.isSocket,
     ipAddress: result.sessionParameterInfo.ipAddress,
     userAgent: result.sessionParameterInfo.userAgent,
   });
   viewer.sessionChanged = true;
 
   // If cookieName is falsey, that tells us that there was no cookie specified
   // in the request, which means we can't be invalidating anything.
   if (result.cookieName) {
     viewer.cookieInvalidated = true;
     viewer.initialCookieName = result.cookieName;
   }
 
   return viewer;
 }
 
 function addSessionChangeInfoToResult(
   viewer: Viewer,
   res: $Response,
   result: Object,
   appURLFacts: AppURLFacts,
 ) {
   let threadInfos = {},
     userInfos = {};
   if (result.cookieChange) {
     ({ threadInfos, userInfos } = result.cookieChange);
   }
   let sessionChange;
   if (viewer.cookieInvalidated) {
     sessionChange = ({
       cookieInvalidated: true,
       threadInfos,
       userInfos: (values(userInfos).map(a => a): UserInfo[]),
       currentUserInfo: {
         id: viewer.cookieID,
         anonymous: true,
       },
     }: ServerSessionChange);
   } else {
     sessionChange = ({
       cookieInvalidated: false,
       threadInfos,
       userInfos: (values(userInfos).map(a => a): UserInfo[]),
     }: ServerSessionChange);
   }
   if (viewer.cookieSource === cookieSources.BODY) {
     sessionChange.cookie = viewer.cookiePairString;
   } else {
     addActualHTTPCookie(viewer, res, appURLFacts);
   }
   if (viewer.sessionIdentifierType === sessionIdentifierTypes.BODY_SESSION_ID) {
     sessionChange.sessionID = viewer.sessionID ? viewer.sessionID : null;
   }
   result.cookieChange = sessionChange;
 }
 
 type AnonymousCookieCreationParams = Shape<{
   +platformDetails: ?PlatformDetails,
   +deviceToken: ?string,
 }>;
 const defaultPlatformDetails = {};
 
 // The result of this function should not be passed directly to the Viewer
 // constructor. Instead, it should be passed to viewer.setNewCookie. There are
 // several fields on AnonymousViewerData that are not set by this function:
 // sessionIdentifierType, cookieSource, ipAddress, and userAgent. These
 // parameters all depend on the initial request. If the result of this function
 // is passed to the Viewer constructor directly, the resultant Viewer object
 // will throw whenever anybody attempts to access the relevant properties.
 async function createNewAnonymousCookie(
   params: AnonymousCookieCreationParams,
 ): Promise<AnonymousViewerData> {
   const { platformDetails, deviceToken } = params;
   const { platform, ...versions } = platformDetails || defaultPlatformDetails;
   const versionsString =
     Object.keys(versions).length > 0 ? JSON.stringify(versions) : null;
 
   const time = Date.now();
   const cookiePassword = crypto.randomBytes(32).toString('hex');
   const cookieHash = bcrypt.hashSync(cookiePassword);
   const [[id]] = await Promise.all([
     createIDs('cookies', 1),
     deviceToken ? clearDeviceToken(deviceToken) : undefined,
   ]);
 
   const cookieRow = [
     id,
     cookieHash,
     null,
     platform,
     time,
     time,
     deviceToken,
     versionsString,
   ];
   const query = SQL`
     INSERT INTO cookies(id, hash, user, platform, creation_time, last_used,
       device_token, versions)
     VALUES ${[cookieRow]}
   `;
   await dbQuery(query);
   return {
     loggedIn: false,
     id,
     platformDetails,
     deviceToken,
     cookieID: id,
     cookiePassword,
     sessionID: undefined,
     sessionInfo: null,
     cookieInsertedThisRequest: true,
     isScriptViewer: false,
   };
 }
 
 type UserCookieCreationParams = {
   platformDetails: PlatformDetails,
   deviceToken?: ?string,
   socialProof?: ?SIWESocialProof,
   signedIdentityKeysBlob?: ?SignedIdentityKeysBlob,
 };
 
 // The result of this function should never be passed directly to the Viewer
 // constructor. Instead, it should be passed to viewer.setNewCookie. There are
 // several fields on UserViewerData that are not set by this function:
 // sessionID, sessionIdentifierType, cookieSource, and ipAddress. These
 // parameters all depend on the initial request. If the result of this function
 // is passed to the Viewer constructor directly, the resultant Viewer object
 // will throw whenever anybody attempts to access the relevant properties.
 async function createNewUserCookie(
   userID: string,
   params: UserCookieCreationParams,
 ): Promise<UserViewerData> {
   const { platformDetails, deviceToken, socialProof, signedIdentityKeysBlob } =
     params;
   const { platform, ...versions } = platformDetails || defaultPlatformDetails;
   const versionsString =
     Object.keys(versions).length > 0 ? JSON.stringify(versions) : null;
 
   const time = Date.now();
   const cookiePassword = crypto.randomBytes(32).toString('hex');
   const cookieHash = bcrypt.hashSync(cookiePassword);
   const [[cookieID]] = await Promise.all([
     createIDs('cookies', 1),
     deviceToken ? clearDeviceToken(deviceToken) : undefined,
   ]);
 
   const cookieRow = [
     cookieID,
     cookieHash,
     userID,
     platform,
     time,
     time,
     deviceToken,
     versionsString,
     JSON.stringify(socialProof),
     signedIdentityKeysBlob ? JSON.stringify(signedIdentityKeysBlob) : null,
   ];
   const query = SQL`
     INSERT INTO cookies(id, hash, user, platform, creation_time, last_used,
       device_token, versions, social_proof, signed_identity_keys)
     VALUES ${[cookieRow]}
   `;
   await dbQuery(query);
   return {
     loggedIn: true,
     id: userID,
     platformDetails,
     deviceToken,
     userID,
     cookieID,
     sessionID: undefined,
     sessionInfo: null,
     cookiePassword,
     cookieInsertedThisRequest: true,
     isScriptViewer: false,
   };
 }
 
 // This gets called after createNewUserCookie and from websiteResponder. If the
 // Viewer's sessionIdentifierType is COOKIE_ID then the cookieID is used as the
 // session identifier; otherwise, a new ID is created for the session.
 async function setNewSession(
   viewer: Viewer,
   calendarQuery: CalendarQuery,
   initialLastUpdate: number,
 ): Promise<void> {
   if (viewer.sessionIdentifierType !== sessionIdentifierTypes.COOKIE_ID) {
     const [sessionID] = await createIDs('sessions', 1);
     viewer.setSessionID(sessionID);
   }
   await createSession(viewer, calendarQuery, initialLastUpdate);
 }
 
 async function extendCookieLifespan(cookieID: string) {
   const time = Date.now();
   const query = SQL`
     UPDATE cookies SET last_used = ${time} WHERE id = ${cookieID}
   `;
   await dbQuery(query);
 }
 
 function addCookieToJSONResponse(
   viewer: Viewer,
   res: $Response,
   result: Object,
   expectCookieInvalidation: boolean,
   appURLFacts: AppURLFacts,
 ) {
   if (expectCookieInvalidation) {
     viewer.cookieInvalidated = false;
   }
   if (!viewer.getData().cookieInsertedThisRequest) {
     handleAsyncPromise(extendCookieLifespan(viewer.cookieID));
   }
   if (viewer.sessionChanged) {
     addSessionChangeInfoToResult(viewer, res, result, appURLFacts);
   } else if (viewer.cookieSource !== cookieSources.BODY) {
     addActualHTTPCookie(viewer, res, appURLFacts);
   }
 }
 
 function addCookieToHomeResponse(
   viewer: Viewer,
   res: $Response,
   appURLFacts: AppURLFacts,
 ) {
   if (!viewer.getData().cookieInsertedThisRequest) {
     handleAsyncPromise(extendCookieLifespan(viewer.cookieID));
   }
   addActualHTTPCookie(viewer, res, appURLFacts);
 }
 
 function getCookieOptions(appURLFacts: AppURLFacts) {
   const { baseDomain, basePath, https } = appURLFacts;
   const domainAsURL = new url.URL(baseDomain);
   return {
     domain: domainAsURL.hostname,
     path: basePath,
     httpOnly: true,
     secure: https,
     maxAge: cookieLifetime,
     sameSite: 'Strict',
   };
 }
 
 function addActualHTTPCookie(
   viewer: Viewer,
   res: $Response,
   appURLFacts: AppURLFacts,
 ) {
   res.cookie(
     viewer.cookieName,
     viewer.cookieString,
     getCookieOptions(appURLFacts),
   );
   if (viewer.cookieName !== viewer.initialCookieName) {
     res.clearCookie(viewer.initialCookieName, getCookieOptions(appURLFacts));
   }
 }
 
 async function setCookiePlatform(
   viewer: Viewer,
   platform: Platform,
 ): Promise<void> {
   const newPlatformDetails = { ...viewer.platformDetails, platform };
   viewer.setPlatformDetails(newPlatformDetails);
   const query = SQL`
     UPDATE cookies
     SET platform = ${platform}
     WHERE id = ${viewer.cookieID}
   `;
   await dbQuery(query);
 }
 
 async function setCookiePlatformDetails(
   viewer: Viewer,
   platformDetails: PlatformDetails,
 ): Promise<void> {
   if (
     hasMinCodeVersion(platformDetails, 70) &&
     !hasMinCodeVersion(viewer.platformDetails, 70)
   ) {
     await updateThreadMembers(viewer);
   }
 
   viewer.setPlatformDetails(platformDetails);
   const { platform, ...versions } = platformDetails;
   const versionsString =
     Object.keys(versions).length > 0 ? JSON.stringify(versions) : null;
   const query = SQL`
     UPDATE cookies
     SET platform = ${platform}, versions = ${versionsString}
     WHERE id = ${viewer.cookieID}
   `;
   await dbQuery(query);
 }
 
 export {
   fetchViewerForJSONRequest,
   fetchViewerForHomeRequest,
   fetchViewerForSocket,
   createNewAnonymousCookie,
   createNewUserCookie,
   setNewSession,
   extendCookieLifespan,
   addCookieToJSONResponse,
   addCookieToHomeResponse,
   setCookiePlatform,
   setCookiePlatformDetails,
 };
diff --git a/lib/shared/message-utils.js b/lib/shared/message-utils.js
index 20b49cf22..a78dc0357 100644
--- a/lib/shared/message-utils.js
+++ b/lib/shared/message-utils.js
@@ -1,578 +1,578 @@
 // @flow
 
 import invariant from 'invariant';
 import _maxBy from 'lodash/fp/maxBy.js';
 import _orderBy from 'lodash/fp/orderBy.js';
 import * as React from 'react';
 
 import { codeBlockRegex, type ParserRules } from './markdown.js';
 import type { CreationSideEffectsFunc } from './messages/message-spec.js';
 import { messageSpecs } from './messages/message-specs.js';
 import { threadIsGroupChat } from './thread-utils.js';
 import { useStringForUser } from '../hooks/ens-cache.js';
 import { userIDsToRelativeUserInfos } from '../selectors/user-selectors.js';
-import type { PlatformDetails } from '../types/device-types.js';
+import { type PlatformDetails, isWebPlatform } from '../types/device-types.js';
 import type { Media } from '../types/media-types.js';
 import {
   type MessageInfo,
   type RawMessageInfo,
   type RobotextMessageInfo,
   type RawMultimediaMessageInfo,
   type MessageData,
   type MessageTruncationStatus,
   type MultimediaMessageData,
   type MessageStore,
   type ComposableMessageInfo,
   messageTypes,
   messageTruncationStatus,
   type RawComposableMessageInfo,
   type ThreadMessageInfo,
 } from '../types/message-types.js';
 import type { ImagesMessageData } from '../types/messages/images.js';
 import type { MediaMessageData } from '../types/messages/media.js';
 import type {
   RawReactionMessageInfo,
   ReactionMessageInfo,
 } from '../types/messages/reaction.js';
 import { type ThreadInfo } from '../types/thread-types.js';
 import type { UserInfos } from '../types/user-types.js';
 import {
   type EntityText,
   useEntityTextAsString,
 } from '../utils/entity-text.js';
 
 const localIDPrefix = 'local';
 
 // Prefers localID
 function messageKey(messageInfo: MessageInfo | RawMessageInfo): string {
   if (messageInfo.localID) {
     return messageInfo.localID;
   }
   invariant(messageInfo.id, 'localID should exist if ID does not');
   return messageInfo.id;
 }
 
 // Prefers serverID
 function messageID(messageInfo: MessageInfo | RawMessageInfo): string {
   if (messageInfo.id) {
     return messageInfo.id;
   }
   invariant(messageInfo.localID, 'localID should exist if ID does not');
   return messageInfo.localID;
 }
 
 function robotextForMessageInfo(
   messageInfo: RobotextMessageInfo,
   threadInfo: ?ThreadInfo,
 ): EntityText {
   const messageSpec = messageSpecs[messageInfo.type];
   invariant(
     messageSpec.robotext,
     `we're not aware of messageType ${messageInfo.type}`,
   );
   return messageSpec.robotext(messageInfo, { threadInfo });
 }
 
 function createMessageInfo(
   rawMessageInfo: RawMessageInfo,
   viewerID: ?string,
   userInfos: UserInfos,
   threadInfos: { +[id: string]: ThreadInfo },
 ): ?MessageInfo {
   const creatorInfo = userInfos[rawMessageInfo.creatorID];
   const creator = {
     id: rawMessageInfo.creatorID,
     username: creatorInfo ? creatorInfo.username : 'anonymous',
     isViewer: rawMessageInfo.creatorID === viewerID,
   };
 
   const createRelativeUserInfos = (userIDs: $ReadOnlyArray<string>) =>
     userIDsToRelativeUserInfos(userIDs, viewerID, userInfos);
   const createMessageInfoFromRaw = (rawInfo: RawMessageInfo) =>
     createMessageInfo(rawInfo, viewerID, userInfos, threadInfos);
 
   const messageSpec = messageSpecs[rawMessageInfo.type];
 
   return messageSpec.createMessageInfo(rawMessageInfo, creator, {
     threadInfos,
     createMessageInfoFromRaw,
     createRelativeUserInfos,
   });
 }
 
 type LengthResult = {
   +local: number,
   +realized: number,
 };
 function findMessageIDMaxLengths(
   messageIDs: $ReadOnlyArray<?string>,
 ): LengthResult {
   const result = {
     local: 0,
     realized: 0,
   };
   for (const id of messageIDs) {
     if (!id) {
       continue;
     }
     if (id.startsWith(localIDPrefix)) {
       result.local = Math.max(result.local, id.length - localIDPrefix.length);
     } else {
       result.realized = Math.max(result.realized, id.length);
     }
   }
   return result;
 }
 
 function extendMessageID(id: ?string, lengths: LengthResult): ?string {
   if (!id) {
     return id;
   }
   if (id.startsWith(localIDPrefix)) {
     const zeroPaddedID = id
       .substr(localIDPrefix.length)
       .padStart(lengths.local, '0');
     return `${localIDPrefix}${zeroPaddedID}`;
   }
   return id.padStart(lengths.realized, '0');
 }
 
 function sortMessageInfoList<T: MessageInfo | RawMessageInfo>(
   messageInfos: $ReadOnlyArray<T>,
 ): T[] {
   const lengths = findMessageIDMaxLengths(
     messageInfos.map(message => message?.id),
   );
   return _orderBy([
     'time',
     (message: T) => extendMessageID(message?.id, lengths),
   ])(['desc', 'desc'])(messageInfos);
 }
 
 const sortMessageIDs: (messages: { +[id: string]: RawMessageInfo }) => (
   messageIDs: $ReadOnlyArray<string>,
 ) => string[] = messages => messageIDs => {
   const lengths = findMessageIDMaxLengths(messageIDs);
   return _orderBy([
     (id: string) => messages[id].time,
     (id: string) => extendMessageID(id, lengths),
   ])(['desc', 'desc'])(messageIDs);
 };
 
 function rawMessageInfoFromMessageData(
   messageData: MessageData,
   id: ?string,
 ): RawMessageInfo {
   const messageSpec = messageSpecs[messageData.type];
   invariant(
     messageSpec.rawMessageInfoFromMessageData,
     `we're not aware of messageType ${messageData.type}`,
   );
   return messageSpec.rawMessageInfoFromMessageData(messageData, id);
 }
 
 function mostRecentMessageTimestamp(
   messageInfos: $ReadOnlyArray<RawMessageInfo>,
   previousTimestamp: number,
 ): number {
   if (messageInfos.length === 0) {
     return previousTimestamp;
   }
   return _maxBy('time')(messageInfos).time;
 }
 
 function usersInMessageInfos(
   messageInfos: $ReadOnlyArray<MessageInfo | RawMessageInfo>,
 ): string[] {
   const userIDs = new Set();
   for (const messageInfo of messageInfos) {
     if (messageInfo.creatorID) {
       userIDs.add(messageInfo.creatorID);
     } else if (messageInfo.creator) {
       userIDs.add(messageInfo.creator.id);
     }
   }
   return [...userIDs];
 }
 
 function combineTruncationStatuses(
   first: MessageTruncationStatus,
   second: ?MessageTruncationStatus,
 ): MessageTruncationStatus {
   if (
     first === messageTruncationStatus.EXHAUSTIVE ||
     second === messageTruncationStatus.EXHAUSTIVE
   ) {
     return messageTruncationStatus.EXHAUSTIVE;
   } else if (
     first === messageTruncationStatus.UNCHANGED &&
     second !== null &&
     second !== undefined
   ) {
     return second;
   } else {
     return first;
   }
 }
 
 function shimUnsupportedRawMessageInfos(
   rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   platformDetails: ?PlatformDetails,
 ): RawMessageInfo[] {
-  if (platformDetails && platformDetails.platform === 'web') {
+  if (platformDetails && isWebPlatform(platformDetails.platform)) {
     return [...rawMessageInfos];
   }
   return rawMessageInfos.map(rawMessageInfo => {
     const { shimUnsupportedMessageInfo } = messageSpecs[rawMessageInfo.type];
     if (shimUnsupportedMessageInfo) {
       return shimUnsupportedMessageInfo(rawMessageInfo, platformDetails);
     }
     return rawMessageInfo;
   });
 }
 
 type MediaMessageDataCreationInput = {
   +threadID: string,
   +creatorID: string,
   +media: $ReadOnlyArray<Media>,
   +localID?: ?string,
   +time?: ?number,
   +sidebarCreation?: ?boolean,
   ...
 };
 function createMediaMessageData(
   input: MediaMessageDataCreationInput,
 ): MultimediaMessageData {
   let allMediaArePhotos = true;
   const photoMedia = [];
   for (const singleMedia of input.media) {
     if (singleMedia.type === 'video') {
       allMediaArePhotos = false;
       break;
     } else {
       photoMedia.push(singleMedia);
     }
   }
 
   const { localID, threadID, creatorID, sidebarCreation } = input;
   const time = input.time ? input.time : Date.now();
   let messageData;
   if (allMediaArePhotos) {
     messageData = ({
       type: messageTypes.IMAGES,
       threadID,
       creatorID,
       time,
       media: photoMedia,
     }: ImagesMessageData);
     if (localID) {
       messageData = { ...messageData, localID };
     }
     if (sidebarCreation) {
       messageData = { ...messageData, sidebarCreation };
     }
   } else {
     messageData = ({
       type: messageTypes.MULTIMEDIA,
       threadID,
       creatorID,
       time,
       media: input.media,
     }: MediaMessageData);
     if (localID) {
       messageData = { ...messageData, localID };
     }
     if (sidebarCreation) {
       messageData = { ...messageData, sidebarCreation };
     }
   }
   return messageData;
 }
 
 type MediaMessageInfoCreationInput = {
   ...$Exact<MediaMessageDataCreationInput>,
   +id?: ?string,
 };
 function createMediaMessageInfo(
   input: MediaMessageInfoCreationInput,
 ): RawMultimediaMessageInfo {
   const messageData = createMediaMessageData(input);
   const createRawMessageInfo =
     messageSpecs[messageData.type].rawMessageInfoFromMessageData;
   invariant(
     createRawMessageInfo,
     'multimedia message spec should have rawMessageInfoFromMessageData',
   );
   const result = createRawMessageInfo(messageData, input.id);
   invariant(
     result.type === messageTypes.MULTIMEDIA ||
       result.type === messageTypes.IMAGES,
     `media messageSpec returned MessageType ${result.type}`,
   );
   return result;
 }
 
 function stripLocalID(
   rawMessageInfo: RawComposableMessageInfo | RawReactionMessageInfo,
 ) {
   const { localID, ...rest } = rawMessageInfo;
   return rest;
 }
 
 function stripLocalIDs(
   input: $ReadOnlyArray<RawMessageInfo>,
 ): RawMessageInfo[] {
   const output = [];
   for (const rawMessageInfo of input) {
     if (rawMessageInfo.localID) {
       invariant(
         rawMessageInfo.id,
         'serverID should be set if localID is being stripped',
       );
       output.push(stripLocalID(rawMessageInfo));
     } else {
       output.push(rawMessageInfo);
     }
   }
   return output;
 }
 
 // Normally we call trim() to remove whitespace at the beginning and end of each
 // message. However, our Markdown parser supports a "codeBlock" format where the
 // user can indent each line to indicate a code block. If we match the
 // corresponding RegEx, we'll only trim whitespace off the end.
 function trimMessage(message: string): string {
   message = message.replace(/^\n*/, '');
   return codeBlockRegex.exec(message) ? message.trimEnd() : message.trim();
 }
 
 function createMessageQuote(message: string): string {
   // add `>` to each line to include empty lines in the quote
   return message.replace(/^/gm, '> ');
 }
 
 function createMessageReply(message: string): string {
   return createMessageQuote(message) + '\n\n';
 }
 
 function getMostRecentNonLocalMessageID(
   threadID: string,
   messageStore: MessageStore,
 ): ?string {
   const thread = messageStore.threads[threadID];
   return thread?.messageIDs.find(id => !id.startsWith(localIDPrefix));
 }
 
 function getMessageTitle(
   messageInfo:
     | ComposableMessageInfo
     | RobotextMessageInfo
     | ReactionMessageInfo,
   threadInfo: ThreadInfo,
   markdownRules: ParserRules,
 ): EntityText {
   const { messageTitle } = messageSpecs[messageInfo.type];
   if (messageTitle) {
     return messageTitle({ messageInfo, threadInfo, markdownRules });
   }
 
   invariant(
     messageInfo.type !== messageTypes.TEXT &&
       messageInfo.type !== messageTypes.IMAGES &&
       messageInfo.type !== messageTypes.MULTIMEDIA &&
       messageInfo.type !== messageTypes.REACTION,
     'messageTitle can only be auto-generated for RobotextMessageInfo',
   );
   return robotextForMessageInfo(messageInfo, threadInfo);
 }
 
 function mergeThreadMessageInfos(
   first: ThreadMessageInfo,
   second: ThreadMessageInfo,
   messages: { +[id: string]: RawMessageInfo },
 ): ThreadMessageInfo {
   let firstPointer = 0;
   let secondPointer = 0;
   const mergedMessageIDs = [];
   let firstCandidate = first.messageIDs[firstPointer];
   let secondCandidate = second.messageIDs[secondPointer];
   while (firstCandidate !== undefined || secondCandidate !== undefined) {
     if (firstCandidate === undefined) {
       mergedMessageIDs.push(secondCandidate);
       secondPointer++;
     } else if (secondCandidate === undefined) {
       mergedMessageIDs.push(firstCandidate);
       firstPointer++;
     } else if (firstCandidate === secondCandidate) {
       mergedMessageIDs.push(firstCandidate);
       firstPointer++;
       secondPointer++;
     } else {
       const firstMessage = messages[firstCandidate];
       const secondMessage = messages[secondCandidate];
       invariant(
         firstMessage && secondMessage,
         'message in messageIDs not present in MessageStore',
       );
       if (
         (firstMessage.id &&
           secondMessage.id &&
           firstMessage.id === secondMessage.id) ||
         (firstMessage.localID &&
           secondMessage.localID &&
           firstMessage.localID === secondMessage.localID)
       ) {
         mergedMessageIDs.push(firstCandidate);
         firstPointer++;
         secondPointer++;
       } else if (firstMessage.time < secondMessage.time) {
         mergedMessageIDs.push(secondCandidate);
         secondPointer++;
       } else {
         mergedMessageIDs.push(firstCandidate);
         firstPointer++;
       }
     }
     firstCandidate = first.messageIDs[firstPointer];
     secondCandidate = second.messageIDs[secondPointer];
   }
   return {
     messageIDs: mergedMessageIDs,
     startReached: first.startReached && second.startReached,
     lastNavigatedTo: Math.max(first.lastNavigatedTo, second.lastNavigatedTo),
     lastPruned: Math.max(first.lastPruned, second.lastPruned),
   };
 }
 
 type MessagePreviewPart = {
   +text: string,
   // unread has highest contrast, followed by primary, followed by secondary
   +style: 'unread' | 'primary' | 'secondary',
 };
 type MessagePreviewResult = {
   +message: MessagePreviewPart,
   +username: ?MessagePreviewPart,
 };
 function useMessagePreview(
   originalMessageInfo: ?MessageInfo,
   threadInfo: ThreadInfo,
   markdownRules: ParserRules,
 ): ?MessagePreviewResult {
   let messageInfo;
   if (
     originalMessageInfo &&
     originalMessageInfo.type === messageTypes.SIDEBAR_SOURCE
   ) {
     messageInfo = originalMessageInfo.sourceMessage;
   } else {
     messageInfo = originalMessageInfo;
   }
 
   const hasUsername =
     threadIsGroupChat(threadInfo) ||
     threadInfo.name !== '' ||
     messageInfo?.creator.isViewer;
   const shouldDisplayUser =
     messageInfo?.type === messageTypes.TEXT && hasUsername;
 
   const stringForUser = useStringForUser(
     shouldDisplayUser ? messageInfo?.creator : null,
   );
 
   const { unread } = threadInfo.currentUser;
   const username = React.useMemo(() => {
     if (!shouldDisplayUser) {
       return null;
     }
     invariant(
       stringForUser,
       'useStringForUser should only return falsey if pass null or undefined',
     );
     return {
       text: stringForUser,
       style: unread ? 'unread' : 'secondary',
     };
   }, [shouldDisplayUser, stringForUser, unread]);
 
   const messageTitleEntityText = React.useMemo(() => {
     if (!messageInfo) {
       return messageInfo;
     }
     return getMessageTitle(messageInfo, threadInfo, markdownRules);
   }, [messageInfo, threadInfo, markdownRules]);
 
   const threadID = threadInfo.id;
   const entityTextToStringParams = React.useMemo(
     () => ({
       threadID,
     }),
     [threadID],
   );
   const messageTitle = useEntityTextAsString(
     messageTitleEntityText,
     entityTextToStringParams,
   );
 
   const isTextMessage = messageInfo?.type === messageTypes.TEXT;
   const message = React.useMemo(() => {
     if (messageTitle === null || messageTitle === undefined) {
       return messageTitle;
     }
 
     let style;
     if (unread) {
       style = 'unread';
     } else if (isTextMessage) {
       style = 'primary';
     } else {
       style = 'secondary';
     }
 
     return { text: messageTitle, style };
   }, [messageTitle, unread, isTextMessage]);
 
   return React.useMemo(() => {
     if (!message) {
       return message;
     }
     return { message, username };
   }, [message, username]);
 }
 
 function useMessageCreationSideEffectsFunc<Info: RawMessageInfo>(
   messageType: $PropertyType<Info, 'type'>,
 ): CreationSideEffectsFunc<Info> {
   const messageSpec = messageSpecs[messageType];
   invariant(messageSpec, `we're not aware of messageType ${messageType}`);
   invariant(
     messageSpec.useCreationSideEffectsFunc,
     `no useCreationSideEffectsFunc in message spec for ${messageType}`,
   );
   return messageSpec.useCreationSideEffectsFunc();
 }
 
 export {
   localIDPrefix,
   messageKey,
   messageID,
   robotextForMessageInfo,
   createMessageInfo,
   sortMessageInfoList,
   sortMessageIDs,
   rawMessageInfoFromMessageData,
   mostRecentMessageTimestamp,
   usersInMessageInfos,
   combineTruncationStatuses,
   shimUnsupportedRawMessageInfos,
   createMediaMessageData,
   createMediaMessageInfo,
   stripLocalIDs,
   trimMessage,
   createMessageQuote,
   createMessageReply,
   getMostRecentNonLocalMessageID,
   getMessageTitle,
   mergeThreadMessageInfos,
   useMessagePreview,
   useMessageCreationSideEffectsFunc,
 };
diff --git a/lib/shared/version-utils.js b/lib/shared/version-utils.js
index 5b0e346af..0f6b56cd5 100644
--- a/lib/shared/version-utils.js
+++ b/lib/shared/version-utils.js
@@ -1,19 +1,19 @@
 // @flow
 
-import type { PlatformDetails } from '../types/device-types.js';
+import { type PlatformDetails, isWebPlatform } from '../types/device-types.js';
 
 function hasMinCodeVersion(
   platformDetails: ?PlatformDetails,
   minCodeVersion: number,
 ): boolean {
-  if (!platformDetails || platformDetails.platform === 'web') {
+  if (!platformDetails || isWebPlatform(platformDetails.platform)) {
     return true;
   }
   const { codeVersion } = platformDetails;
   if (!codeVersion || codeVersion < minCodeVersion) {
     return false;
   }
   return true;
 }
 
 export { hasMinCodeVersion };
diff --git a/lib/socket/socket.react.js b/lib/socket/socket.react.js
index 4711643e5..a3109c919 100644
--- a/lib/socket/socket.react.js
+++ b/lib/socket/socket.react.js
@@ -1,776 +1,778 @@
 // @flow
 
 import invariant from 'invariant';
 import _throttle from 'lodash/throttle.js';
 import * as React from 'react';
 
 import ActivityHandler from './activity-handler.react.js';
 import APIRequestHandler from './api-request-handler.react.js';
 import CalendarQueryHandler from './calendar-query-handler.react.js';
 import {
   InflightRequests,
   SocketTimeout,
   SocketOffline,
 } from './inflight-requests.js';
 import MessageHandler from './message-handler.react.js';
 import ReportHandler from './report-handler.react.js';
 import RequestResponseHandler from './request-response-handler.react.js';
 import UpdateHandler from './update-handler.react.js';
 import { updateActivityActionTypes } from '../actions/activity-actions.js';
 import { logOutActionTypes } from '../actions/user-actions.js';
 import { unsupervisedBackgroundActionType } from '../reducers/lifecycle-state-reducer.js';
 import {
   pingFrequency,
   serverRequestSocketTimeout,
   clientRequestVisualTimeout,
   clientRequestSocketTimeout,
 } from '../shared/timeouts.js';
 import {
   logInActionSources,
   type LogOutResult,
 } from '../types/account-types.js';
+import { isWebPlatform } from '../types/device-types.js';
 import type { CalendarQuery } from '../types/entry-types.js';
 import { forcePolicyAcknowledgmentActionType } from '../types/policy-types.js';
 import type { Dispatch } from '../types/redux-types.js';
 import {
   serverRequestTypes,
   type ClientClientResponse,
   type ClientServerRequest,
 } from '../types/request-types.js';
 import {
   type SessionState,
   type SessionIdentification,
   type PreRequestUserState,
 } from '../types/session-types.js';
 import {
   clientSocketMessageTypes,
   type ClientClientSocketMessage,
   serverSocketMessageTypes,
   type ClientServerSocketMessage,
   stateSyncPayloadTypes,
   fullStateSyncActionType,
   incrementalStateSyncActionType,
   updateConnectionStatusActionType,
   type ConnectionInfo,
   type ClientInitialClientSocketMessage,
   type ClientResponsesClientSocketMessage,
   type PingClientSocketMessage,
   type AckUpdatesClientSocketMessage,
   type APIRequestClientSocketMessage,
   type ClientSocketMessageWithoutID,
   type SocketListener,
   type ConnectionStatus,
   setLateResponseActionType,
   type CommTransportLayer,
 } from '../types/socket-types.js';
 import { actionLogger } from '../utils/action-logger.js';
 import type { DispatchActionPromise } from '../utils/action-utils.js';
 import {
   setNewSessionActionType,
   fetchNewCookieFromNativeCredentials,
 } from '../utils/action-utils.js';
 import { getConfig } from '../utils/config.js';
 import { ServerError } from '../utils/errors.js';
 import { promiseAll } from '../utils/promises.js';
 import sleep from '../utils/sleep.js';
 
 const remainingTimeAfterVisualTimeout =
   clientRequestSocketTimeout - clientRequestVisualTimeout;
 
 export type BaseSocketProps = {
   +detectUnsupervisedBackgroundRef?: (
     detectUnsupervisedBackground: (alreadyClosed: boolean) => boolean,
   ) => void,
 };
 type Props = {
   ...BaseSocketProps,
   // Redux state
   +active: boolean,
   +openSocket: () => CommTransportLayer,
   +getClientResponses: (
     activeServerRequests: $ReadOnlyArray<ClientServerRequest>,
   ) => $ReadOnlyArray<ClientClientResponse>,
   +activeThread: ?string,
   +sessionStateFunc: () => SessionState,
   +sessionIdentification: SessionIdentification,
   +cookie: ?string,
   +urlPrefix: string,
   +connection: ConnectionInfo,
   +currentCalendarQuery: () => CalendarQuery,
   +canSendReports: boolean,
   +frozen: boolean,
   +preRequestUserState: PreRequestUserState,
   +noDataAfterPolicyAcknowledgment?: boolean,
   // Redux dispatch functions
   +dispatch: Dispatch,
   +dispatchActionPromise: DispatchActionPromise,
   // async functions that hit server APIs
   +logOut: (preRequestUserState: PreRequestUserState) => Promise<LogOutResult>,
   +socketCrashLoopRecovery?: () => Promise<void>,
 };
 type State = {
   +inflightRequests: ?InflightRequests,
 };
 class Socket extends React.PureComponent<Props, State> {
   state: State = {
     inflightRequests: null,
   };
   socket: ?CommTransportLayer;
   nextClientMessageID: number = 0;
   listeners: Set<SocketListener> = new Set();
   pingTimeoutID: ?TimeoutID;
   messageLastReceived: ?number;
-  initialPlatformDetailsSent: boolean =
-    getConfig().platformDetails.platform === 'web';
+  initialPlatformDetailsSent: boolean = isWebPlatform(
+    getConfig().platformDetails.platform,
+  );
   reopenConnectionAfterClosing: boolean = false;
   invalidationRecoveryInProgress: boolean = false;
   initializedWithUserState: ?PreRequestUserState;
   failuresAfterPolicyAcknowledgment: number = 0;
 
   openSocket(newStatus: ConnectionStatus) {
     if (
       this.props.frozen ||
-      (getConfig().platformDetails.platform !== 'web' &&
+      (!isWebPlatform(getConfig().platformDetails.platform) &&
         (!this.props.cookie || !this.props.cookie.startsWith('user=')))
     ) {
       return;
     }
     if (this.socket) {
       const { status } = this.props.connection;
       if (status === 'forcedDisconnecting') {
         this.reopenConnectionAfterClosing = true;
         return;
       } else if (status === 'disconnecting' && this.socket.readyState === 1) {
         this.markSocketInitialized();
         return;
       } else if (
         status === 'connected' ||
         status === 'connecting' ||
         status === 'reconnecting'
       ) {
         return;
       }
       if (this.socket.readyState < 2) {
         this.socket.close();
         console.log(`this.socket seems open, but Redux thinks it's ${status}`);
       }
     }
     this.props.dispatch({
       type: updateConnectionStatusActionType,
       payload: { status: newStatus },
     });
 
     const socket = this.props.openSocket();
     const openObject = {};
     socket.onopen = () => {
       if (this.socket === socket) {
         this.initializeSocket();
         openObject.initializeMessageSent = true;
       }
     };
     socket.onmessage = this.receiveMessage;
     socket.onclose = () => {
       if (this.socket === socket) {
         this.onClose();
       }
     };
     this.socket = socket;
 
     (async () => {
       await sleep(clientRequestVisualTimeout);
       if (this.socket !== socket || openObject.initializeMessageSent) {
         return;
       }
       this.setLateResponse(-1, true);
       await sleep(remainingTimeAfterVisualTimeout);
       if (this.socket !== socket || openObject.initializeMessageSent) {
         return;
       }
       this.finishClosingSocket();
     })();
 
     this.setState({
       inflightRequests: new InflightRequests({
         timeout: () => {
           if (this.socket === socket) {
             this.finishClosingSocket();
           }
         },
         setLateResponse: (messageID: number, isLate: boolean) => {
           if (this.socket === socket) {
             this.setLateResponse(messageID, isLate);
           }
         },
       }),
     });
   }
 
   markSocketInitialized() {
     this.props.dispatch({
       type: updateConnectionStatusActionType,
       payload: { status: 'connected' },
     });
     this.resetPing();
   }
 
   closeSocket(
     // This param is a hack. When closing a socket there is a race between this
     // function and the one to propagate the activity update. We make sure that
     // the activity update wins the race by passing in this param.
     activityUpdatePending: boolean,
   ) {
     const { status } = this.props.connection;
     if (status === 'disconnected') {
       return;
     } else if (status === 'disconnecting' || status === 'forcedDisconnecting') {
       this.reopenConnectionAfterClosing = false;
       return;
     }
     this.stopPing();
     this.props.dispatch({
       type: updateConnectionStatusActionType,
       payload: { status: 'disconnecting' },
     });
     if (!activityUpdatePending) {
       this.finishClosingSocket();
     }
   }
 
   forceCloseSocket() {
     this.stopPing();
     const { status } = this.props.connection;
     if (status !== 'forcedDisconnecting' && status !== 'disconnected') {
       this.props.dispatch({
         type: updateConnectionStatusActionType,
         payload: { status: 'forcedDisconnecting' },
       });
     }
     this.finishClosingSocket();
   }
 
   finishClosingSocket(receivedResponseTo?: ?number) {
     const { inflightRequests } = this.state;
     if (
       inflightRequests &&
       !inflightRequests.allRequestsResolvedExcept(receivedResponseTo)
     ) {
       return;
     }
     if (this.socket && this.socket.readyState < 2) {
       // If it's not closing already, close it
       this.socket.close();
     }
     this.socket = null;
     this.stopPing();
     this.setState({ inflightRequests: null });
     if (this.props.connection.status !== 'disconnected') {
       this.props.dispatch({
         type: updateConnectionStatusActionType,
         payload: { status: 'disconnected' },
       });
     }
     if (this.reopenConnectionAfterClosing) {
       this.reopenConnectionAfterClosing = false;
       if (this.props.active) {
         this.openSocket('connecting');
       }
     }
   }
 
   reconnect: $Call<typeof _throttle, () => void, number> = _throttle(
     () => this.openSocket('reconnecting'),
     2000,
   );
 
   componentDidMount() {
     if (this.props.detectUnsupervisedBackgroundRef) {
       this.props.detectUnsupervisedBackgroundRef(
         this.detectUnsupervisedBackground,
       );
     }
     if (this.props.active) {
       this.openSocket('connecting');
     }
   }
 
   componentWillUnmount() {
     this.closeSocket(false);
     this.reconnect.cancel();
   }
 
   componentDidUpdate(prevProps: Props) {
     if (this.props.active && !prevProps.active) {
       this.openSocket('connecting');
     } else if (!this.props.active && prevProps.active) {
       this.closeSocket(!!prevProps.activeThread);
     } else if (
       this.props.active &&
       prevProps.openSocket !== this.props.openSocket
     ) {
       // This case happens when the baseURL/urlPrefix is changed
       this.reopenConnectionAfterClosing = true;
       this.forceCloseSocket();
     } else if (
       this.props.active &&
       this.props.connection.status === 'disconnected' &&
       prevProps.connection.status !== 'disconnected' &&
       !this.invalidationRecoveryInProgress
     ) {
       this.reconnect();
     }
   }
 
   render(): React.Node {
     // It's important that APIRequestHandler get rendered first here. This is so
     // that it is registered with Redux first, so that its componentDidUpdate
     // processes before the other Handlers. This allows APIRequestHandler to
     // register itself with action-utils before other Handlers call
     // dispatchActionPromise in response to the componentDidUpdate triggered by
     // the same Redux change (state.connection.status).
     return (
       <React.Fragment>
         <APIRequestHandler
           inflightRequests={this.state.inflightRequests}
           sendMessage={this.sendMessageWithoutID}
         />
         <ActivityHandler
           activeThread={this.props.activeThread}
           frozen={this.props.frozen}
         />
         <RequestResponseHandler
           inflightRequests={this.state.inflightRequests}
           sendMessage={this.sendMessageWithoutID}
           addListener={this.addListener}
           removeListener={this.removeListener}
           getClientResponses={this.props.getClientResponses}
           currentCalendarQuery={this.props.currentCalendarQuery}
         />
         <UpdateHandler
           sendMessage={this.sendMessageWithoutID}
           addListener={this.addListener}
           removeListener={this.removeListener}
         />
         <MessageHandler
           addListener={this.addListener}
           removeListener={this.removeListener}
         />
         <CalendarQueryHandler
           currentCalendarQuery={this.props.currentCalendarQuery}
           frozen={this.props.frozen}
         />
         <ReportHandler canSendReports={this.props.canSendReports} />
       </React.Fragment>
     );
   }
 
   sendMessageWithoutID: (message: ClientSocketMessageWithoutID) => number =
     message => {
       const id = this.nextClientMessageID++;
       // These conditions all do the same thing and the runtime checks are only
       // necessary for Flow
       if (message.type === clientSocketMessageTypes.INITIAL) {
         this.sendMessage(
           ({ ...message, id }: ClientInitialClientSocketMessage),
         );
       } else if (message.type === clientSocketMessageTypes.RESPONSES) {
         this.sendMessage(
           ({ ...message, id }: ClientResponsesClientSocketMessage),
         );
       } else if (message.type === clientSocketMessageTypes.PING) {
         this.sendMessage(({ ...message, id }: PingClientSocketMessage));
       } else if (message.type === clientSocketMessageTypes.ACK_UPDATES) {
         this.sendMessage(({ ...message, id }: AckUpdatesClientSocketMessage));
       } else if (message.type === clientSocketMessageTypes.API_REQUEST) {
         this.sendMessage(({ ...message, id }: APIRequestClientSocketMessage));
       }
       return id;
     };
 
   sendMessage(message: ClientClientSocketMessage) {
     const socket = this.socket;
     invariant(socket, 'should be set');
     socket.send(JSON.stringify(message));
   }
 
   static messageFromEvent(event: MessageEvent): ?ClientServerSocketMessage {
     if (typeof event.data !== 'string') {
       console.log('socket received a non-string message');
       return null;
     }
     try {
       return JSON.parse(event.data);
     } catch (e) {
       console.log(e);
       return null;
     }
   }
 
   receiveMessage: (event: MessageEvent) => Promise<void> = async event => {
     const message = Socket.messageFromEvent(event);
     if (!message) {
       return;
     }
     this.failuresAfterPolicyAcknowledgment = 0;
 
     const { inflightRequests } = this.state;
     if (!inflightRequests) {
       // inflightRequests can be falsey here if we receive a message after we've
       // begun shutting down the socket. It's possible for a React Native
       // WebSocket to deliver a message even after close() is called on it. In
       // this case the message is probably a PONG, which we can safely ignore.
       // If it's not a PONG, it has to be something server-initiated (like
       // UPDATES or MESSAGES), since InflightRequests.allRequestsResolvedExcept
       // will wait for all responses to client-initiated requests to be
       // delivered before closing a socket. UPDATES and MESSAGES are both
       // checkpointed on the client, so should be okay to just ignore here and
       // redownload them later, probably in an incremental STATE_SYNC.
       return;
     }
 
     // If we receive any message, that indicates that our connection is healthy,
     // so we can reset the ping timeout.
     this.resetPing();
 
     inflightRequests.resolveRequestsForMessage(message);
     const { status } = this.props.connection;
     if (status === 'disconnecting' || status === 'forcedDisconnecting') {
       this.finishClosingSocket(
         // We do this for Flow
         message.responseTo !== undefined ? message.responseTo : null,
       );
     }
 
     for (const listener of this.listeners) {
       listener(message);
     }
 
     if (message.type === serverSocketMessageTypes.ERROR) {
       const { message: errorMessage, payload } = message;
       if (payload) {
         console.log(`socket sent error ${errorMessage} with payload`, payload);
       } else {
         console.log(`socket sent error ${errorMessage}`);
       }
       if (errorMessage === 'policies_not_accepted') {
         this.props.dispatch({
           type: forcePolicyAcknowledgmentActionType,
           payload,
         });
       }
     } else if (message.type === serverSocketMessageTypes.AUTH_ERROR) {
       const { sessionChange } = message;
       const cookie = sessionChange ? sessionChange.cookie : this.props.cookie;
       this.invalidationRecoveryInProgress = true;
 
       const recoverySessionChange = await fetchNewCookieFromNativeCredentials(
         this.props.dispatch,
         cookie,
         this.props.urlPrefix,
         logInActionSources.socketAuthErrorResolutionAttempt,
       );
 
       if (!recoverySessionChange && sessionChange) {
         // This should only happen in the cookieSources.BODY (native) case when
         // the resolution attempt failed
         const { cookie: newerCookie, currentUserInfo } = sessionChange;
         this.props.dispatch({
           type: setNewSessionActionType,
           payload: {
             sessionChange: {
               cookieInvalidated: true,
               currentUserInfo,
               cookie: newerCookie,
             },
             preRequestUserState: this.initializedWithUserState,
             error: null,
             logInActionSource:
               logInActionSources.socketAuthErrorResolutionAttempt,
           },
         });
       } else if (!recoverySessionChange) {
         this.props.dispatchActionPromise(
           logOutActionTypes,
           this.props.logOut(this.props.preRequestUserState),
         );
       }
       this.invalidationRecoveryInProgress = false;
     }
   };
 
   addListener: (listener: SocketListener) => void = listener => {
     this.listeners.add(listener);
   };
 
   removeListener: (listener: SocketListener) => void = listener => {
     this.listeners.delete(listener);
   };
 
   onClose: () => void = () => {
     const { status } = this.props.connection;
     this.socket = null;
     this.stopPing();
     if (this.state.inflightRequests) {
       this.state.inflightRequests.rejectAll(new Error('socket closed'));
       this.setState({ inflightRequests: null });
     }
     const handled = this.detectUnsupervisedBackground(true);
     if (!handled && status !== 'disconnected') {
       this.props.dispatch({
         type: updateConnectionStatusActionType,
         payload: { status: 'disconnected' },
       });
     }
   };
 
   async sendInitialMessage() {
     const { inflightRequests } = this.state;
     invariant(
       inflightRequests,
       'inflightRequests falsey inside sendInitialMessage',
     );
     const messageID = this.nextClientMessageID++;
     const promises = {};
 
     const clientResponses = [];
     if (!this.initialPlatformDetailsSent) {
       this.initialPlatformDetailsSent = true;
       clientResponses.push({
         type: serverRequestTypes.PLATFORM_DETAILS,
         platformDetails: getConfig().platformDetails,
       });
     }
 
     const { queuedActivityUpdates } = this.props.connection;
     if (queuedActivityUpdates.length > 0) {
       clientResponses.push({
         type: serverRequestTypes.INITIAL_ACTIVITY_UPDATES,
         activityUpdates: queuedActivityUpdates,
       });
       promises.activityUpdateMessage = inflightRequests.fetchResponse(
         messageID,
         serverSocketMessageTypes.ACTIVITY_UPDATE_RESPONSE,
       );
     }
 
     const sessionState = this.props.sessionStateFunc();
     const { sessionIdentification } = this.props;
     const initialMessage = {
       type: clientSocketMessageTypes.INITIAL,
       id: messageID,
       payload: {
         clientResponses,
         sessionState,
         sessionIdentification,
       },
     };
     this.initializedWithUserState = this.props.preRequestUserState;
     this.sendMessage(initialMessage);
 
     promises.stateSyncMessage = inflightRequests.fetchResponse(
       messageID,
       serverSocketMessageTypes.STATE_SYNC,
     );
 
     const { stateSyncMessage, activityUpdateMessage } = await promiseAll(
       promises,
     );
 
     if (activityUpdateMessage) {
       this.props.dispatch({
         type: updateActivityActionTypes.success,
         payload: {
           activityUpdates: queuedActivityUpdates,
           result: activityUpdateMessage.payload,
         },
       });
     }
 
     if (stateSyncMessage.payload.type === stateSyncPayloadTypes.FULL) {
       const { sessionID, type, ...actionPayload } = stateSyncMessage.payload;
       this.props.dispatch({
         type: fullStateSyncActionType,
         payload: {
           ...actionPayload,
           calendarQuery: sessionState.calendarQuery,
         },
       });
       if (sessionID !== null && sessionID !== undefined) {
         invariant(
           this.initializedWithUserState,
           'initializedWithUserState should be set when state sync received',
         );
         this.props.dispatch({
           type: setNewSessionActionType,
           payload: {
             sessionChange: { cookieInvalidated: false, sessionID },
             preRequestUserState: this.initializedWithUserState,
             error: null,
             logInActionSource: undefined,
           },
         });
       }
     } else {
       const { type, ...actionPayload } = stateSyncMessage.payload;
       this.props.dispatch({
         type: incrementalStateSyncActionType,
         payload: {
           ...actionPayload,
           calendarQuery: sessionState.calendarQuery,
         },
       });
     }
 
     const currentAsOf =
       stateSyncMessage.payload.type === stateSyncPayloadTypes.FULL
         ? stateSyncMessage.payload.updatesCurrentAsOf
         : stateSyncMessage.payload.updatesResult.currentAsOf;
     this.sendMessageWithoutID({
       type: clientSocketMessageTypes.ACK_UPDATES,
       payload: { currentAsOf },
     });
 
     this.markSocketInitialized();
   }
 
   initializeSocket: (retriesLeft?: number) => Promise<void> = async (
     retriesLeft = 1,
   ) => {
     try {
       await this.sendInitialMessage();
     } catch (e) {
       if (this.props.noDataAfterPolicyAcknowledgment) {
         this.failuresAfterPolicyAcknowledgment++;
       } else {
         this.failuresAfterPolicyAcknowledgment = 0;
       }
       if (
         this.failuresAfterPolicyAcknowledgment >= 2 &&
         this.props.socketCrashLoopRecovery
       ) {
         this.failuresAfterPolicyAcknowledgment = 0;
         try {
           await this.props.socketCrashLoopRecovery();
         } catch (error) {
           console.log(error);
           this.props.dispatchActionPromise(
             logOutActionTypes,
             this.props.logOut(this.props.preRequestUserState),
           );
         }
         return;
       }
 
       console.log(e);
       const { status } = this.props.connection;
       if (
         e instanceof SocketTimeout ||
         e instanceof SocketOffline ||
         (status !== 'connecting' && status !== 'reconnecting')
       ) {
         // This indicates that the socket will be closed. Do nothing, since the
         // connection status update will trigger a reconnect.
       } else if (
         retriesLeft === 0 ||
         (e instanceof ServerError && e.message !== 'unknown_error')
       ) {
         if (e.message === 'not_logged_in') {
           this.props.dispatchActionPromise(
             logOutActionTypes,
             this.props.logOut(this.props.preRequestUserState),
           );
         } else if (this.socket) {
           this.socket.close();
         }
       } else {
         await this.initializeSocket(retriesLeft - 1);
       }
     }
   };
 
   stopPing() {
     if (this.pingTimeoutID) {
       clearTimeout(this.pingTimeoutID);
       this.pingTimeoutID = null;
     }
   }
 
   resetPing() {
     this.stopPing();
     const socket = this.socket;
     this.messageLastReceived = Date.now();
     this.pingTimeoutID = setTimeout(() => {
       if (this.socket === socket) {
         this.sendPing();
       }
     }, pingFrequency);
   }
 
   async sendPing() {
     if (this.props.connection.status !== 'connected') {
       // This generally shouldn't happen because anything that changes the
       // connection status should call stopPing(), but it's good to make sure
       return;
     }
     const messageID = this.sendMessageWithoutID({
       type: clientSocketMessageTypes.PING,
     });
     try {
       invariant(
         this.state.inflightRequests,
         'inflightRequests falsey inside sendPing',
       );
       await this.state.inflightRequests.fetchResponse(
         messageID,
         serverSocketMessageTypes.PONG,
       );
     } catch (e) {}
   }
 
   setLateResponse: (messageID: number, isLate: boolean) => void = (
     messageID,
     isLate,
   ) => {
     this.props.dispatch({
       type: setLateResponseActionType,
       payload: { messageID, isLate },
     });
   };
 
   cleanUpServerTerminatedSocket() {
     if (this.socket && this.socket.readyState < 2) {
       this.socket.close();
     } else {
       this.onClose();
     }
   }
 
   detectUnsupervisedBackground: (alreadyClosed: boolean) => boolean =
     alreadyClosed => {
       // On native, sometimes the app is backgrounded without the proper
       // callbacks getting triggered. This leaves us in an incorrect state for
       // two reasons:
       // (1) The connection is still considered to be active, causing API
       //     requests to be processed via socket and failing.
       // (2) We rely on flipping foreground state in Redux to detect activity
       //     changes, and thus won't think we need to update activity.
       if (
         this.props.connection.status !== 'connected' ||
         !this.messageLastReceived ||
         this.messageLastReceived + serverRequestSocketTimeout >= Date.now() ||
         (actionLogger.mostRecentActionTime &&
           actionLogger.mostRecentActionTime + 3000 < Date.now())
       ) {
         return false;
       }
       if (!alreadyClosed) {
         this.cleanUpServerTerminatedSocket();
       }
       this.props.dispatch({
         type: unsupervisedBackgroundActionType,
         payload: null,
       });
       return true;
     };
 }
 
 export default Socket;
diff --git a/lib/types/device-types.js b/lib/types/device-types.js
index 12746eced..adc3197f4 100644
--- a/lib/types/device-types.js
+++ b/lib/types/device-types.js
@@ -1,30 +1,34 @@
 // @flow
 
 import invariant from 'invariant';
 
 export type DeviceType = 'ios' | 'android';
 export type Platform = DeviceType | 'web';
 
 export function isDeviceType(platform: ?string): boolean {
   return platform === 'ios' || platform === 'android';
 }
 
 export function assertDeviceType(deviceType: ?string): DeviceType {
   invariant(
     deviceType === 'ios' || deviceType === 'android',
     'string is not DeviceType enum',
   );
   return deviceType;
 }
 
+export function isWebPlatform(platform: ?string): boolean {
+  return platform === 'web';
+}
+
 export type DeviceTokenUpdateRequest = {
   +deviceToken: string,
   +deviceType?: DeviceType,
   +platformDetails?: PlatformDetails,
 };
 
 export type PlatformDetails = {
   +platform: Platform,
   +codeVersion?: number,
   +stateVersion?: number,
 };
diff --git a/lib/types/entry-types.js b/lib/types/entry-types.js
index c5ad488f5..1472e10c9 100644
--- a/lib/types/entry-types.js
+++ b/lib/types/entry-types.js
@@ -1,210 +1,210 @@
 // @flow
 
-import type { Platform } from './device-types.js';
+import { type Platform, isWebPlatform } from './device-types.js';
 import { type CalendarFilter, defaultCalendarFilters } from './filter-types.js';
 import type { RawMessageInfo } from './message-types.js';
 import type {
   ServerCreateUpdatesResponse,
   ClientCreateUpdatesResponse,
 } from './update-types.js';
 import type { UserInfo, AccountUserInfo } from './user-types.js';
 import {
   fifteenDaysEarlier,
   fifteenDaysLater,
   thisMonthDates,
 } from '../utils/date-utils.js';
 
 export type RawEntryInfo = {
   id?: string, // null if local copy without ID yet
   localID?: string, // for optimistic creations
   threadID: string,
   text: string,
   year: number,
   month: number, // 1-indexed
   day: number, // 1-indexed
   creationTime: number, // millisecond timestamp
   creatorID: string,
   deleted: boolean,
 };
 
 export type EntryInfo = {
   id?: string, // null if local copy without ID yet
   localID?: string, // for optimistic creations
   threadID: string,
   text: string,
   year: number,
   month: number, // 1-indexed
   day: number, // 1-indexed
   creationTime: number, // millisecond timestamp
   creator: ?UserInfo,
   deleted: boolean,
 };
 
 export type EntryStore = {
   +entryInfos: { +[id: string]: RawEntryInfo },
   +daysToEntries: { +[day: string]: string[] },
   +lastUserInteractionCalendar: number,
 };
 
 export type CalendarQuery = {
   +startDate: string,
   +endDate: string,
   +filters: $ReadOnlyArray<CalendarFilter>,
 };
 
 export const defaultCalendarQuery = (
   platform: ?Platform,
   timeZone?: ?string,
 ): CalendarQuery => {
-  if (platform === 'web') {
+  if (isWebPlatform(platform)) {
     return {
       ...thisMonthDates(timeZone),
       filters: defaultCalendarFilters,
     };
   } else {
     return {
       startDate: fifteenDaysEarlier(timeZone).valueOf(),
       endDate: fifteenDaysLater(timeZone).valueOf(),
       filters: defaultCalendarFilters,
     };
   }
 };
 
 export type SaveEntryInfo = {
   +entryID: string,
   +text: string,
   +prevText: string,
   +timestamp: number,
   +calendarQuery: CalendarQuery,
 };
 
 export type SaveEntryRequest = {
   +entryID: string,
   +text: string,
   +prevText: string,
   +timestamp: number,
   +calendarQuery?: CalendarQuery,
 };
 
 export type SaveEntryResponse = {
   +entryID: string,
   +newMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +updatesResult: ServerCreateUpdatesResponse,
 };
 
 export type SaveEntryResult = {
   +entryID: string,
   +newMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +updatesResult: ClientCreateUpdatesResponse,
 };
 
 export type SaveEntryPayload = {
   ...SaveEntryResult,
   +threadID: string,
 };
 
 export type CreateEntryInfo = {
   +text: string,
   +timestamp: number,
   +date: string,
   +threadID: string,
   +localID: string,
   +calendarQuery: CalendarQuery,
 };
 
 export type CreateEntryRequest = {
   +text: string,
   +timestamp: number,
   +date: string,
   +threadID: string,
   +localID?: string,
   +calendarQuery?: CalendarQuery,
 };
 
 export type CreateEntryPayload = {
   ...SaveEntryPayload,
   +localID: string,
 };
 
 export type DeleteEntryInfo = {
   +entryID: string,
   +prevText: string,
   +calendarQuery: CalendarQuery,
 };
 
 export type DeleteEntryRequest = {
   +entryID: string,
   +prevText: string,
   +timestamp: number,
   +calendarQuery?: CalendarQuery,
 };
 
 export type RestoreEntryInfo = {
   +entryID: string,
   +calendarQuery: CalendarQuery,
 };
 
 export type RestoreEntryRequest = {
   +entryID: string,
   +timestamp: number,
   +calendarQuery?: CalendarQuery,
 };
 
 export type DeleteEntryResponse = {
   +newMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +threadID: string,
   +updatesResult: ServerCreateUpdatesResponse,
 };
 
 export type DeleteEntryResult = {
   +newMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +threadID: string,
   +updatesResult: ClientCreateUpdatesResponse,
 };
 
 export type RestoreEntryResponse = {
   +newMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +updatesResult: ServerCreateUpdatesResponse,
 };
 export type RestoreEntryResult = {
   +newMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +updatesResult: ClientCreateUpdatesResponse,
 };
 export type RestoreEntryPayload = {
   ...RestoreEntryResult,
   +threadID: string,
 };
 
 export type FetchEntryInfosBase = {
   +rawEntryInfos: $ReadOnlyArray<RawEntryInfo>,
 };
 export type FetchEntryInfosResponse = {
   ...FetchEntryInfosBase,
   +userInfos: { [id: string]: AccountUserInfo },
 };
 export type FetchEntryInfosResult = FetchEntryInfosBase;
 
 export type DeltaEntryInfosResponse = {
   +rawEntryInfos: $ReadOnlyArray<RawEntryInfo>,
   +deletedEntryIDs: $ReadOnlyArray<string>,
 };
 export type DeltaEntryInfosResult = {
   +rawEntryInfos: $ReadOnlyArray<RawEntryInfo>,
   +deletedEntryIDs: $ReadOnlyArray<string>,
   +userInfos: $ReadOnlyArray<AccountUserInfo>,
 };
 
 export type CalendarResult = {
   +rawEntryInfos: $ReadOnlyArray<RawEntryInfo>,
   +calendarQuery: CalendarQuery,
 };
 
 export type CalendarQueryUpdateStartingPayload = {
   +calendarQuery?: CalendarQuery,
 };
 export type CalendarQueryUpdateResult = {
   +rawEntryInfos: $ReadOnlyArray<RawEntryInfo>,
   +deletedEntryIDs: $ReadOnlyArray<string>,
   +calendarQuery: CalendarQuery,
   +calendarQueryAlreadyUpdated: boolean,
 };