diff --git a/res/css/structures/_UserMenu.pcss b/res/css/structures/_UserMenu.pcss
index f25c15e48e6..3d37fa73a66 100644
--- a/res/css/structures/_UserMenu.pcss
+++ b/res/css/structures/_UserMenu.pcss
@@ -200,6 +200,10 @@ limitations under the License.
         mask-image: url("$(res)/img/element-icons/settings.svg");
     }
 
+    .mx_UserMenu_iconInfo::before {
+        mask-image: url("$(res)/img/element-icons/info.svg");
+    }
+
     .mx_UserMenu_iconMessage::before {
         mask-image: url("$(res)/img/element-icons/feedback.svg");
     }
diff --git a/res/css/views/auth/_CompleteSecurityBody.pcss b/res/css/views/auth/_CompleteSecurityBody.pcss
index 53d5988c6dd..9b8ad77b146 100644
--- a/res/css/views/auth/_CompleteSecurityBody.pcss
+++ b/res/css/views/auth/_CompleteSecurityBody.pcss
@@ -16,7 +16,12 @@ limitations under the License.
 */
 
 .mx_CompleteSecurityBody {
+    /* :TCHAP:
     width: 600px;
+    */
+    width: 660px;
+    /* end :TCHAP: */
+
     color: $authpage-primary-color;
     background-color: $background;
     border-radius: 4px;
diff --git a/res/css/views/directory/_NetworkDropdown.pcss b/res/css/views/directory/_NetworkDropdown.pcss
index 8dbd7f020db..0b9172c015f 100644
--- a/res/css/views/directory/_NetworkDropdown.pcss
+++ b/res/css/views/directory/_NetworkDropdown.pcss
@@ -17,6 +17,7 @@ limitations under the License.
 .mx_NetworkDropdown_wrapper .mx_ContextualMenu {
     .mx_GenericDropdownMenu_Option {
         &.mx_GenericDropdownMenu_Option--header {
+            display:none;
             padding-top: $spacing-12;
             padding-bottom: $spacing-4;
             min-width: 160px;
@@ -45,12 +46,14 @@ limitations under the License.
     }
 
     .mx_GenericDropdownMenu_divider {
+        display:none;
         margin-top: $spacing-4;
         margin-bottom: $spacing-4;
     }
 }
 
 .mx_NetworkDropdown_addServer {
+    display:none;
     font-weight: normal;
     font-size: $font-15px;
 }
diff --git a/res/css/views/rooms/_RoomHeader.pcss b/res/css/views/rooms/_RoomHeader.pcss
index bc66cd21417..a5330afe293 100644
--- a/res/css/views/rooms/_RoomHeader.pcss
+++ b/res/css/views/rooms/_RoomHeader.pcss
@@ -116,3 +116,17 @@ limitations under the License.
 .mx_RoomHeader .mx_BaseAvatar {
     flex-shrink: 0;
 }
+
+/* :tchap: largely inspired from ;mx_RoomHeader_topic but I couldn't get this add-on to work with $variable */
+.tc_RoomHeader_external {
+    color: var(--external-color);
+    width: 80px;
+    font-weight: 400;
+    font-size: 0.8125rem;
+    line-height: 0.8125rem;
+    max-height: calc(0.8125rem * 2);
+    overflow: hidden;
+    -webkit-line-clamp: 2;
+    -webkit-box-orient: vertical;
+    display: -webkit-box;
+}
diff --git a/src/IConfigOptions.ts b/src/IConfigOptions.ts
index 501d8a3bd64..19c2f3df5a1 100644
--- a/src/IConfigOptions.ts
+++ b/src/IConfigOptions.ts
@@ -211,3 +211,14 @@ export interface ISsoRedirectOptions {
     immediate?: boolean;
     on_welcome_page?: boolean;
 }
+
+/* :tchap:
+* Add tchap specific options to IConfigOptions. Both interfaces get merged in compilation. https://www.typescriptlang.org/docs/handbook/declaration-merging.html#merging-interfaces
+* IConfigOptions declares which options can get retrieved with SdkConfig, if not declared SdkConfig complains it does not know the parameter.
+*/
+export interface IConfigOptions {
+    tchap_features?: {
+        feature_email_notification?:[string]//activate email notification on a list of home servers, ie : "dev01.tchap.incubateur.net"
+    }
+}
+//end :tchap:
\ No newline at end of file
diff --git a/src/IdentityAuthClient.tsx b/src/IdentityAuthClient.tsx
index 9dc6ebd8439..133b3c2206a 100644
--- a/src/IdentityAuthClient.tsx
+++ b/src/IdentityAuthClient.tsx
@@ -29,6 +29,7 @@ import {
 } from "./utils/IdentityServerUtils";
 import QuestionDialog from "./components/views/dialogs/QuestionDialog";
 import { abbreviateUrl } from "./utils/UrlUtils";
+import TchapUIFeature from "../../../src/tchap/util/TchapUIFeature";
 
 export class AbortedIdentityActionError extends Error {}
 
@@ -135,6 +136,18 @@ export default class IdentityAuthClient {
             throw e;
         }
 
+        // :TCHAP: no need confirmation of Terms and Conditions to set a default identity server as we trust our backend servers 
+        if (TchapUIFeature.autoAcceptTermsAndConditions){
+            if (
+                !this.tempClient &&
+                !doesAccountDataHaveIdentityServer(this.matrixClient) 
+            ) {
+                setToDefaultIdentityServer(this.matrixClient);
+            }
+            return;
+        }
+        // end :TCHAP:
+
         if (
             !this.tempClient &&
             !doesAccountDataHaveIdentityServer(this.matrixClient) &&
diff --git a/src/Terms.ts b/src/Terms.ts
index afa65248280..7f54dbb8be8 100644
--- a/src/Terms.ts
+++ b/src/Terms.ts
@@ -20,6 +20,11 @@ import { logger } from "matrix-js-sdk/src/logger";
 
 import Modal from "./Modal";
 import TermsDialog from "./components/views/dialogs/TermsDialog";
+import {
+    doesAccountDataHaveIdentityServer,
+    setToDefaultIdentityServer,
+} from './utils/IdentityServerUtils';
+import TchapUIFeature from "../../../src/tchap/util/TchapUIFeature";
 
 export class TermsNotSignedError extends Error {}
 
@@ -83,6 +88,15 @@ export async function startTermsFlow(
     services: Service[],
     interactionCallback: TermsInteractionCallback = dialogTermsInteractionCallback,
 ): Promise<void> {
+    // :TCHAP: no need to go through Terms flow as we trust our backend servers
+    if (TchapUIFeature.autoAcceptTermsAndConditions){
+        if (!doesAccountDataHaveIdentityServer(client)) {
+            setToDefaultIdentityServer(client);
+        }
+        return;
+    }
+    // end :TCHAP:
+
     const termsPromises = services.map((s) => client.getTerms(s.serviceType, s.baseUrl));
 
     /*
diff --git a/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx b/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx
index 036fb5038b3..bb1d8cd6ff7 100644
--- a/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx
+++ b/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx
@@ -211,13 +211,38 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
                 backupInfo ? await cli.getCrypto()?.isKeyBackupTrusted(backupInfo) : undefined;
 
             const { forceReset } = this.props;
-            const phase = backupInfo && !forceReset ? Phase.Migrate : Phase.ChooseKeyPassphrase;
+            // :tchap: const phase = backupInfo && !forceReset ? Phase.Migrate : Phase.ChooseKeyPassphrase;
+            const phase = backupInfo && !forceReset ? Phase.Migrate : Phase.ShowKey;//:tchap: goes directly to showke
 
+            /* :TCHAP: remove
             this.setState({
                 phase,
                 backupInfo,
                 backupTrustInfo,
             });
+            end :TCHAP: */
+
+            // add :TCHAP:
+            if (phase === Phase.ShowKey) {
+                this.recoveryKey = await cli.createRecoveryKeyFromPassphrase();
+                this.setState({
+                    phase,
+                    backupInfo,
+                    backupTrustInfo,
+                    passPhraseKeySelected:SecureBackupSetupMethod.Key,
+                    copied: false,
+                    downloaded: false,
+                    setPassphrase: false
+                });
+            } else {
+                //if phase is Phase.Migrate
+                this.setState({
+                    phase,
+                    backupInfo,
+                    backupTrustInfo,
+                });
+            }
+            // end :TCHAP:
 
             return backupTrustInfo;
         } catch (e) {
@@ -744,10 +769,23 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
         if (this.state.phase === Phase.ShowKey) {
             continueButton = (
                 <DialogButtons
+                    /* :TCHAP:
                     primaryButton={_t("action|continue")}
                     disabled={!this.state.downloaded && !this.state.copied && !this.state.setPassphrase}
+                    */
+                    primaryButton={_t("I wrote down my code")}
+                    primaryDisabled={!this.state.downloaded && !this.state.copied && !this.state.setPassphrase}
+                    // end :TCHAP:
+
                     onPrimaryButtonClick={this.onShowKeyContinueClick}
+
+                    /* :TCHAP:
                     hasCancel={false}
+                    */
+                    hasCancel={true}
+                    onCancel={this.onCancel}
+                    cancelButtonClass="mx_AccessibleButton mx_AccessibleButton_hasKind mx_AccessibleButton_kind_danger_outline"
+                    // end :TCHAP:
                 />
             );
         } else {
@@ -760,6 +798,10 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
 
         return (
             <div>
+                {/* tchap: add this <p /> */}
+                <p>{_t("This is your recovery key")}</p>
+                <p><b>{_t("Warning: this is the only time this code will be displayed!")}</b></p>
+                {/* end tchap */}
                 <p>{_t("settings|key_backup|setup_secure_backup|security_key_safety_reminder")}</p>
                 <div className="mx_CreateSecretStorageDialog_primaryContainer mx_CreateSecretStorageDialog_recoveryKeyPrimarycontainer">
                     <div className="mx_CreateSecretStorageDialog_recoveryKeyContainer">
@@ -767,6 +809,7 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
                             <code ref={this.recoveryKeyNode}>{this.recoveryKey?.encodedPrivateKey}</code>
                         </div>
                         <div className="mx_CreateSecretStorageDialog_recoveryKeyButtons">
+                            {/* :TCHAP: remove
                             <AccessibleButton
                                 kind="primary"
                                 className="mx_Dialog_primary"
@@ -781,6 +824,7 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
                                     copyButton: "",
                                 })}
                             </span>
+                            end :TCHAP: */}
                             <AccessibleButton
                                 kind="primary"
                                 className="mx_Dialog_primary mx_CreateSecretStorageDialog_recoveryKeyButtons_copyBtn"
diff --git a/src/components/structures/MatrixChat.tsx b/src/components/structures/MatrixChat.tsx
index b4d609850de..44a2236c23e 100644
--- a/src/components/structures/MatrixChat.tsx
+++ b/src/components/structures/MatrixChat.tsx
@@ -146,6 +146,7 @@ import { checkSessionLockFree, getSessionLock } from "../../utils/SessionLock";
 import { SessionLockStolenView } from "./auth/SessionLockStolenView";
 import { ConfirmSessionLockTheftView } from "./auth/ConfirmSessionLockTheftView";
 import { LoginSplashView } from "./auth/LoginSplashView";
+import TchapUrls from "../../../../../src/tchap/util/TchapUrls"; // :TCHAP:
 
 // legacy export
 export { default as Views } from "../../Views";
@@ -1692,6 +1693,15 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             return;
         }
 
+        //:tchap: add a screen to open user tab security
+        if (screen === TchapUrls.secureBackupFragment) {
+            //open the security tab
+            //there is no anchor to sauvegarde-automatique subection
+            const payload: OpenToTabPayload = { action: Action.ViewUserSettings, initialTabId: UserTab.Security };
+            dis.dispatch(payload);
+        } else
+        //:tchap: end
+
         if (screen === "register") {
             dis.dispatch({
                 action: "start_registration",
diff --git a/src/components/structures/RoomSearchView.tsx b/src/components/structures/RoomSearchView.tsx
index bfa993059bf..245fc75ee3b 100644
--- a/src/components/structures/RoomSearchView.tsx
+++ b/src/components/structures/RoomSearchView.tsx
@@ -36,6 +36,7 @@ import ResizeNotifier from "../../utils/ResizeNotifier";
 import MatrixClientContext from "../../contexts/MatrixClientContext";
 import { RoomPermalinkCreator } from "../../utils/permalinks/Permalinks";
 import RoomContext from "../../contexts/RoomContext";
+import Tchapi18nUtils from "../../../../../src/tchap/i18n/Tchapi18nUtils";
 
 const DEBUG = false;
 let debuglog = function (msg: string): void {};
@@ -136,7 +137,8 @@ export const RoomSearchView = forwardRef<ScrollPanel, Props>(
                             logger.error("Search failed", error);
                             Modal.createDialog(ErrorDialog, {
                                 title: _t("error_dialog|search_failed|title"),
-                                description: error?.message ?? _t("error_dialog|search_failed|server_unavailable"),
+                                // :TCHAP: description: error?.message ?? _t("error_dialog|search_failed|server_unavailable"),
+                                description: error?.message ?? Tchapi18nUtils.getServerDownMessage(),
                             });
                             return false;
                         },
diff --git a/src/components/structures/RoomStatusBar.tsx b/src/components/structures/RoomStatusBar.tsx
index 311f6b89b55..ce2f3f87aed 100644
--- a/src/components/structures/RoomStatusBar.tsx
+++ b/src/components/structures/RoomStatusBar.tsx
@@ -29,6 +29,7 @@ import InlineSpinner from "../views/elements/InlineSpinner";
 import MatrixClientContext from "../../contexts/MatrixClientContext";
 import { RoomStatusBarUnsentMessages } from "./RoomStatusBarUnsentMessages";
 import ExternalLink from "../views/elements/ExternalLink";
+import Tchapi18nUtils from '../../../../../src/tchap/i18n/Tchapi18nUtils'; // :TCHAP:
 
 const STATUS_BAR_HIDDEN = 0;
 const STATUS_BAR_EXPANDED = 1;
@@ -270,7 +271,9 @@ export default class RoomStatusBar extends React.PureComponent<IProps, IState> {
                             <WarningIcon width="24" height="24" />
                             <div>
                                 <div className="mx_RoomStatusBar_connectionLostBar_title">
-                                    {_t("room|status_bar|server_connectivity_lost_title")}
+                                    {/* :TCHAP: _t("room|status_bar|server_connectivity_lost_title") */}
+                                    {Tchapi18nUtils.getServerDownMessage()}
+                                    {/* end :TCHAP: */}
                                 </div>
                                 <div className="mx_RoomStatusBar_connectionLostBar_desc">
                                     {_t("room|status_bar|server_connectivity_lost_description")}
diff --git a/src/components/structures/UserMenu.tsx b/src/components/structures/UserMenu.tsx
index f24fa57d7d8..f8c0bbf1f03 100644
--- a/src/components/structures/UserMenu.tsx
+++ b/src/components/structures/UserMenu.tsx
@@ -246,6 +246,10 @@ export default class UserMenu extends React.Component<IProps, IState> {
         this.setState({ contextMenuPosition: null }); // also close the menu
     };
 
+    private onOpenFAQPage = () => {
+        window.open("https://www.tchap.gouv.fr/faq", '_blank');
+    };
+
     private onProvideFeedback = (ev: ButtonEvent): void => {
         ev.preventDefault();
         ev.stopPropagation();
@@ -382,6 +386,11 @@ export default class UserMenu extends React.Component<IProps, IState> {
                     onClick={(e) => this.onSettingsOpen(e)}
                 />
                 {feedbackButton}
+                <IconizedContextMenuOption
+                    iconClassName="mx_UserMenu_iconInfo"
+                    label={_t("common|help")}
+                    onClick={this.onOpenFAQPage}
+                />
                 <IconizedContextMenuOption
                     className="mx_IconizedContextMenu_option_red"
                     iconClassName="mx_UserMenu_iconSignOut"
diff --git a/src/components/structures/auth/CompleteSecurity.tsx b/src/components/structures/auth/CompleteSecurity.tsx
index 71e47a8bd47..a852a28b222 100644
--- a/src/components/structures/auth/CompleteSecurity.tsx
+++ b/src/components/structures/auth/CompleteSecurity.tsx
@@ -66,7 +66,9 @@ export default class CompleteSecurity extends React.Component<IProps, IState> {
             return null;
         } else if (phase === Phase.Intro) {
             if (lostKeys) {
+                /* :tchap: hide anxious icon of warning
                 icon = <span className="mx_CompleteSecurity_headerIcon mx_E2EIcon_warning" />;
+                end :tchap: */
                 title = _t("encryption|verification|after_new_login|unable_to_verify");
             } else {
                 icon = <span className="mx_CompleteSecurity_headerIcon mx_E2EIcon_warning" />;
@@ -92,9 +94,16 @@ export default class CompleteSecurity extends React.Component<IProps, IState> {
 
         let skipButton;
         if (phase === Phase.Intro || phase === Phase.ConfirmReset) {
+            // :Tchap: Condition to skip Phase.ConfirmSkip and its "Are you sure" modal after login for csss
+            const tchapOnSkipClick = phase === Phase.Intro ? this.props.onFinished : this.onSkipClick;
+            // end :Tchap:
+
             skipButton = (
                 <AccessibleButton
-                    onClick={this.onSkipClick}
+                    // :tchap: remove onClick={this.onSkipClick}
+                    // add instead
+                    onClick={tchapOnSkipClick}
+                    // end :tchap:
                     className="mx_CompleteSecurity_skip"
                     aria-label={_t("encryption|verification|after_new_login|skip_verification")}
                 />
diff --git a/src/components/structures/auth/ForgotPassword.tsx b/src/components/structures/auth/ForgotPassword.tsx
index 9487fc5ebef..f9a0d5e9d2b 100644
--- a/src/components/structures/auth/ForgotPassword.tsx
+++ b/src/components/structures/auth/ForgotPassword.tsx
@@ -42,6 +42,8 @@ import { VerifyEmailModal } from "./forgot-password/VerifyEmailModal";
 import Spinner from "../../views/elements/Spinner";
 import { formatSeconds } from "../../../DateUtils";
 import AutoDiscoveryUtils from "../../../utils/AutoDiscoveryUtils";
+import TchapUtils from "../../../../../../src/tchap/util/TchapUtils"; // :TCHAP:
+import Tchapi18nUtils from "../../../../../../src/tchap/i18n/Tchapi18nUtils";
 
 const emailCheckInterval = 2000;
 
@@ -61,7 +63,7 @@ enum Phase {
 }
 
 interface Props {
-    serverConfig: ValidatedServerConfig;
+    // :TCHAP: we get serverConfig when user enters email, so remove it from props - serverConfig: ValidatedServerConfig;
     onLoginClick: () => void;
     onComplete: () => void;
 }
@@ -104,10 +106,13 @@ export default class ForgotPassword extends React.Component<Props, State> {
             serverDeadError: "",
             logoutDevices: false,
         };
-        this.reset = new PasswordReset(this.props.serverConfig.hsUrl, this.props.serverConfig.isUrl);
+        // :TCHAP: no known server yet, this.reset stays undefined - this.reset = new PasswordReset(this.props.serverConfig.hsUrl, this.props.serverConfig.isUrl);
     }
 
+    // todo remove checkServerCapabilities in componentDidMount -> gone ?
+
     public componentDidUpdate(prevProps: Readonly<Props>): void {
+        /* :TCHAP: we ignore serverConfig passed in props. So no use checking the server here.
         if (
             prevProps.serverConfig.hsUrl !== this.props.serverConfig.hsUrl ||
             prevProps.serverConfig.isUrl !== this.props.serverConfig.isUrl
@@ -115,6 +120,7 @@ export default class ForgotPassword extends React.Component<Props, State> {
             // Do a liveliness check on the new URLs
             this.checkServerLiveliness(this.props.serverConfig);
         }
+        end :TCHAP: */
     }
 
     private async checkServerLiveliness(serverConfig: ValidatedServerConfig): Promise<void> {
@@ -136,9 +142,38 @@ export default class ForgotPassword extends React.Component<Props, State> {
         }
     }
 
+    // :TCHAP:
+    private useNewServerConfig =  async (serverConfig) => {
+        console.log('Using serverConfig corresponding to this email :', serverConfig);
+
+        this.reset = new PasswordReset(serverConfig.hsUrl, serverConfig.isUrl);
+        // Note : this.reset is not a react state variable. It doesn't seem necessary to make it one, it seems to work this way.
+        // Note : we do not shut down or close the previous this.reset object in any way. Existing sessions just stay there. There doesn't
+        // seem to be an API for revoking tokens.
+
+        // If the server is not available, this displays "Server unavailable, overloaded, or something else went wrong."
+        await this.checkServerLiveliness(serverConfig);
+        //await this.checkServerCapabilities(serverConfig); // todo
+    }
+    // end :TCHAP:
+
     private async onPhaseEmailInputSubmit(): Promise<void> {
         this.phase = Phase.SendingEmail;
 
+        // :TCHAP: find the server corresponding to the email.
+        const serverResult = await TchapUtils.fetchHomeserverForEmail(this.state.email);
+        if (!serverResult) {
+            this.setState({
+                serverIsAlive: false,
+                errorText: Tchapi18nUtils.getServerDownMessage(),
+                phase: Phase.EnterEmail, // return to original phase, to remove the loding spinner from the submit button.
+            });
+            return;
+        }
+        const serverConfig = await TchapUtils.makeValidatedServerConfig(serverResult);
+        await this.useNewServerConfig(serverConfig);
+        // end :TCHAP:
+
         if (await this.sendVerificationMail()) {
             this.phase = Phase.EmailSent;
             return;
@@ -300,8 +335,10 @@ export default class ForgotPassword extends React.Component<Props, State> {
             errorText: "",
         });
 
+        /* :TCHAP: at this point we may not know the serverConfig to use yet. So don't check.
         // Refresh the server errors. Just in case the server came back online of went offline.
         await this.checkServerLiveliness(this.props.serverConfig);
+        end :TCHAP: */
 
         // Server error
         if (!this.state.serverIsAlive) return;
@@ -335,7 +372,7 @@ export default class ForgotPassword extends React.Component<Props, State> {
             <EnterEmail
                 email={this.state.email}
                 errorText={this.state.errorText}
-                homeserver={this.props.serverConfig.hsName}
+                homeserver={ null /* :TCHAP: - no known homeserver yet - this.props.serverConfig.hsName */}
                 loading={this.state.phase === Phase.SendingEmail}
                 onInputChanged={this.onInputChanged}
                 onLoginClick={this.props.onLoginClick!} // set by default props
diff --git a/src/components/structures/auth/Login.tsx b/src/components/structures/auth/Login.tsx
index 5fadde7cbea..0f81d325950 100644
--- a/src/components/structures/auth/Login.tsx
+++ b/src/components/structures/auth/Login.tsx
@@ -40,6 +40,8 @@ import { ValidatedServerConfig } from "../../../utils/ValidatedServerConfig";
 import { filterBoolean } from "../../../utils/arrays";
 import { Features } from "../../../settings/Settings";
 import { startOidcLogin } from "../../../utils/oidc/authorize";
+import TchapUtils from '../../../../../../src/tchap/util/TchapUtils'; // :TCHAP:
+import Tchapi18nUtils from '../../../../../../src/tchap/i18n/Tchapi18nUtils'; // :TCHAP:
 
 interface IProps {
     serverConfig: ValidatedServerConfig;
@@ -164,12 +166,22 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
 
     public isBusy = (): boolean => !!this.state.busy || !!this.props.busy;
 
+    tchap_setServerInMemory = async (serverConfig) => {
+        const validatedServerConf = await TchapUtils.makeValidatedServerConfig(serverConfig);
+
+        // Simulate the end of the serverPicker component flow.
+        this.props.onServerConfigChange(validatedServerConf);
+
+        await this.initLoginLogic(validatedServerConf);
+    };
+
     public onPasswordLogin: OnPasswordLogin = async (
         username: string | undefined,
         phoneCountry: string | undefined,
         phoneNumber: string | undefined,
         password: string,
     ): Promise<void> => {
+        /* :TCHAP: remove alive check, we don't know which server to call yet.
         if (!this.state.serverIsAlive) {
             this.setState({ busy: true });
             // Do a quick liveliness check on the URLs
@@ -195,6 +207,7 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
                 return;
             }
         }
+        end :TCHAP: */
 
         this.setState({
             busy: true,
@@ -203,6 +216,23 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
             loginIncorrect: false,
         });
 
+        /* :TCHAP: fetch homeserver corresponding to email */
+        const serverResult = await TchapUtils.fetchHomeserverForEmail(username);
+
+        if (!serverResult) {
+            this.setState({
+                busy: false,
+                busyLoggingIn: false,
+                //errorText: _t('Server unavailable, overloaded, or something else went wrong.'), // reuse existing string
+                errorText: Tchapi18nUtils.getServerDownMessage("(err-03)"),
+                loginIncorrect: false,
+            });
+            return;
+        }
+
+        await this.tchap_setServerInMemory(serverResult);
+        /** end :TCHAP: */
+
         this.loginLogic.loginViaPassword(username, phoneCountry, phoneNumber, password).then(
             (data) => {
                 this.setState({ serverIsAlive: true }); // it must be, we logged in.
@@ -555,10 +585,12 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
                     </h1>
                     {errorTextSection}
                     {serverDeadSection}
+                    { /* :TCHAP: remove server picker, we don't allow user to chose, server is assigned to each email.
                     <ServerPicker
                         serverConfig={this.props.serverConfig}
                         onServerConfigChange={this.props.onServerConfigChange}
                     />
+                    end :TCHAP :*/}
                     {this.renderLoginComponentForFlows()}
                     {footer}
                 </AuthBody>
diff --git a/src/components/structures/auth/Registration.tsx b/src/components/structures/auth/Registration.tsx
index 4da7282660e..751b266752b 100644
--- a/src/components/structures/auth/Registration.tsx
+++ b/src/components/structures/auth/Registration.tsx
@@ -50,11 +50,15 @@ import InteractiveAuth, { InteractiveAuthCallback } from "../InteractiveAuth";
 import Spinner from "../../views/elements/Spinner";
 import { AuthHeaderDisplay } from "./header/AuthHeaderDisplay";
 import { AuthHeaderProvider } from "./header/AuthHeaderProvider";
+import { AuthHeaderModifier } from './header/AuthHeaderModifier'; // :TCHAP:
 import SettingsStore from "../../../settings/SettingsStore";
 import { ValidatedServerConfig } from "../../../utils/ValidatedServerConfig";
 import { Features } from "../../../settings/Settings";
 import { startOidcLogin } from "../../../utils/oidc/authorize";
 
+import TchapUtils from '../../../../../../src/tchap/util/TchapUtils'; // :TCHAP:
+import TchapUrls from "../../../../../../src/tchap/util/TchapUrls";
+
 const debuglog = (...args: any[]): void => {
     if (SettingsStore.getValue("debug_registration")) {
         logger.log.call(console, "Registration debuglog:", ...args);
@@ -308,11 +312,24 @@ export default class Registration extends React.Component<IProps, IState> {
     }
 
     private onFormSubmit = async (formVals: Record<string, string>): Promise<void> => {
+        // :TCHAP: find the server corresponding to the entered email
+        const server = await TchapUtils.fetchHomeserverForEmail(formVals.email);
+        const validatedServerConfig = await TchapUtils.makeValidatedServerConfig(server);
+        // Note : onServerConfigChange triggers a state change at the matrixChat level. All the children are rerendered.
+        this.props.onServerConfigChange(validatedServerConfig);
+        // end :TCHAP:
+
         this.setState({
             errorText: "",
             busy: true,
             formVals,
             doingUIAuth: true,
+            // :TCHAP: pass a new temporary client so that InteractiveAuth is set up with the right serverconfig.
+            matrixClient: createClient({
+                baseUrl: validatedServerConfig.hsUrl,
+                idBaseUrl: validatedServerConfig.isUrl,
+            }),
+            // end :TCHAP:
         });
     };
 
@@ -360,6 +377,10 @@ export default class Registration extends React.Component<IProps, IState> {
                 errorText = _t("auth|username_in_use");
             } else if (response instanceof MatrixError && response.errcode === "M_THREEPID_IN_USE") {
                 errorText = _t("auth|3pid_in_use");
+            // :TCHAP: add error message for common case
+            } else if (response instanceof MatrixError && response.errcode === "M_THREEPID_DENIED") {
+                errorText = _t("That email is not allowed on Tchap", {}, {a: (sub)=><a href={TchapUrls.requestDomainUrl}>{sub}</a>});
+            // end :TCHAP:
             }
 
             this.setState({
@@ -491,6 +512,11 @@ export default class Registration extends React.Component<IProps, IState> {
             inhibit_login: undefined,
         };
         if (auth) registerParams.auth = auth;
+        //:tchap: do not send username as tchap workflow does not use username
+        // https://github.com/tchapgouv/tchap-web-v4/issues/281
+        registerParams.username = undefined;
+        //:tchap end
+
         debuglog("Registration: sending registration request:", auth);
         return this.state.matrixClient.registerRequest(registerParams);
     };
@@ -740,6 +766,12 @@ export default class Registration extends React.Component<IProps, IState> {
                             {errorText}
                             {serverDeadSection}
                         </AuthHeaderDisplay>
+                        { /* :TCHAP: remove the serverpicker, using AuthHeaderModifier. Inspired by InteractiveAuthEntryComponents. */}
+                        <AuthHeaderModifier
+                            title={_t("auth|register_action") /* we actually don't want to set this. */}
+                            hideServerPicker={true}
+                        />
+                        { /* end :TCHAP: */}
                         {this.renderRegisterComponent()}
                     </div>
                     <div className="mx_Register_footerActions">
diff --git a/src/components/structures/auth/SetupEncryptionBody.tsx b/src/components/structures/auth/SetupEncryptionBody.tsx
index 3ad4638306d..4558f5d6148 100644
--- a/src/components/structures/auth/SetupEncryptionBody.tsx
+++ b/src/components/structures/auth/SetupEncryptionBody.tsx
@@ -28,6 +28,10 @@ import { SetupEncryptionStore, Phase } from "../../../stores/SetupEncryptionStor
 import EncryptionPanel from "../../views/right_panel/EncryptionPanel";
 import AccessibleButton, { ButtonEvent } from "../../views/elements/AccessibleButton";
 import Spinner from "../../views/elements/Spinner";
+import defaultDispatcher from "../../../dispatcher/dispatcher";
+import { Action } from "matrix-react-sdk/src/dispatcher/actions";
+import { UserTab } from "matrix-react-sdk/src/components/views/dialogs/UserTab";
+import { OpenToTabPayload } from "matrix-react-sdk/src/dispatcher/payloads/OpenToTabPayload";
 
 function keyHasPassphrase(keyInfo: ISecretStorageKeyInfo): boolean {
     return Boolean(keyInfo.passphrase && keyInfo.passphrase.salt && keyInfo.passphrase.iterations);
@@ -159,11 +163,22 @@ export default class SetupEncryptionBody extends React.Component<IProps, IState>
             if (lostKeys) {
                 return (
                     <div>
-                        <p>{_t("encryption|verification|no_key_or_device")}</p>
+                        { /*:TCHAP: change <p>{_t("encryption|verification|no_key_or_device")}</p> */ }
+                        <p>
+                            {_t(
+                                "<p>The Tchap team is working on the deployment of a new feature to "+
+                                "prevent encryption key loss.</p>"+
+                                "<p> You can access it in the section :</p><p>Security and privacy > Secure Backup</p>",
+                                 {}, { 'p': (sub) => <p>{sub}</p>}
+                            )}
+                        </p>
+                        {/* end :TCHAP: */}
 
                         <div className="mx_CompleteSecurity_actionRow">
                             <AccessibleButton kind="primary" onClick={this.onResetConfirmClick}>
-                                {_t("encryption|verification|reset_proceed_prompt")}
+                                {/* :TCHAP: _t("encryption|verification|reset_proceed_prompt") */}
+                                {_t("Set up")}
+                                {/* end :TCHAP: */}
                             </AccessibleButton>
                         </div>
                     </div>
diff --git a/src/components/structures/auth/forgot-password/EnterEmail.tsx b/src/components/structures/auth/forgot-password/EnterEmail.tsx
index 11e44e65626..94bbedd7d57 100644
--- a/src/components/structures/auth/forgot-password/EnterEmail.tsx
+++ b/src/components/structures/auth/forgot-password/EnterEmail.tsx
@@ -64,9 +64,11 @@ export const EnterEmail: React.FC<EnterEmailProps> = ({
         <>
             <EmailIcon className="mx_AuthBody_icon" />
             <h1>{_t("auth|enter_email_heading")}</h1>
+            { /* :TCHAP: we don't display homeservers to users
             <p className="mx_AuthBody_text">
                 {_t("auth|enter_email_explainer", { homeserver }, { b: (t) => <b>{t}</b> })}
             </p>
+            end :TCHAP: */ }
             <form onSubmit={onSubmit}>
                 <fieldset disabled={loading}>
                     <div className="mx_AuthBody_fieldRow">
diff --git a/src/components/views/auth/PassphraseField.tsx b/src/components/views/auth/PassphraseField.tsx
index a9048d74154..87230166694 100644
--- a/src/components/views/auth/PassphraseField.tsx
+++ b/src/components/views/auth/PassphraseField.tsx
@@ -23,6 +23,7 @@ import withValidation, { IFieldState, IValidationResult } from "../elements/Vali
 import { _t, _td, TranslationKey } from "../../../languageHandler";
 import Field, { IInputProps } from "../elements/Field";
 import { MatrixClientPeg } from "../../../MatrixClientPeg";
+import TchapStrongPassword from "../../../../../../src/tchap/util/TchapStrongPassword";
 
 interface IProps extends Omit<IInputProps, "onValidate" | "element"> {
     autoFocus?: boolean;
@@ -99,7 +100,10 @@ class PassphraseField extends PureComponent<IProps> {
     });
 
     public onValidate = async (fieldState: IFieldState): Promise<IValidationResult> => {
-        const result = await this.validate(fieldState);
+        // :TCHAP: use home-made validation
+        // const result = await this.validate(fieldState);
+        const result = await TchapStrongPassword.validate(fieldState);
+        // end :TCHAP:
         if (this.props.onValidate) {
             this.props.onValidate(result);
         }
diff --git a/src/components/views/auth/PasswordLogin.tsx b/src/components/views/auth/PasswordLogin.tsx
index 951262d2a29..a4f2f41ba2c 100644
--- a/src/components/views/auth/PasswordLogin.tsx
+++ b/src/components/views/auth/PasswordLogin.tsx
@@ -50,6 +50,7 @@ interface IProps {
 }
 
 interface IState {
+    displayPassword: boolean;
     fieldValid: Partial<Record<LoginField, boolean>>;
     loginType: LoginField.Email | LoginField.MatrixId | LoginField.Phone;
     password: string;
@@ -84,13 +85,21 @@ export default class PasswordLogin extends React.PureComponent<IProps, IState> {
     public constructor(props: IProps) {
         super(props);
         this.state = {
+            displayPassword: false,
             // Field error codes by field ID
             fieldValid: {},
-            loginType: LoginField.MatrixId,
+            // :TCHAP: force email login
+            // loginType: LoginField.MatrixId,
+            loginType: LoginField.Email,
+            //
             password: "",
         };
     }
 
+    private setDisplayPassword = (value: boolean): void => {
+        this.setState({ displayPassword: value });
+    };
+
     private onForgotPasswordClick = (ev: ButtonEvent): void => {
         ev.preventDefault();
         ev.stopPropagation();
@@ -421,13 +430,17 @@ export default class PasswordLogin extends React.PureComponent<IProps, IState> {
         return (
             <div>
                 <form onSubmit={this.onSubmitForm}>
-                    {loginType}
+                    {
+                        /* :TCHAP: remove loginType selector, we only want Email loginType
+                        loginType
+                        */
+                    }
                     {loginField}
                     <Field
                         id="mx_LoginForm_password"
                         className={pwFieldClass}
                         autoComplete="current-password"
-                        type="password"
+                        type={this.state.displayPassword ? "text": "password"}
                         name="password"
                         label={_t("common|password")}
                         value={this.state.password}
@@ -436,6 +449,20 @@ export default class PasswordLogin extends React.PureComponent<IProps, IState> {
                         autoFocus={autoFocusPassword}
                         onValidate={this.onPasswordValidate}
                         ref={(field) => (this[LoginField.Password] = field)}
+                        postfixComponent={(
+                            <div
+                                className="tc_textInput_postfixComponent"
+                                onMouseDown={() => this.setDisplayPassword(true)}
+                                onMouseUp={() => this.setDisplayPassword(false)}
+                            >
+                                <img
+                                    src={require("../../../../../../res/img/grey-eye.svg").default}
+                                    width="24"
+                                    height="24"
+                                    alt={_t("Eye")}
+                                />
+                            </div>
+                        )}
                     />
                     {forgotPasswordJsx}
                     {!this.props.busy && (
diff --git a/src/components/views/auth/RegistrationForm.tsx b/src/components/views/auth/RegistrationForm.tsx
index 6709b07885e..fe697e1ec80 100644
--- a/src/components/views/auth/RegistrationForm.tsx
+++ b/src/components/views/auth/RegistrationForm.tsx
@@ -267,7 +267,7 @@ export default class RegistrationForm extends React.PureComponent<IProps, IState
     };
 
     private validateEmailRules = withValidation({
-        description: () => _t("auth|reset_password_email_field_description"),
+        // :TCHAP: this is confusing because email=username in the Tchap case. //description: () => _t("auth|reset_password_email_field_description"),
         hideDescriptionIfValid: true,
         rules: [
             {
@@ -275,7 +275,10 @@ export default class RegistrationForm extends React.PureComponent<IProps, IState
                 test(this: RegistrationForm, { value, allowEmpty }) {
                     return allowEmpty || !this.authStepIsRequired("m.login.email.identity") || !!value;
                 },
-                invalid: () => _t("auth|reset_password_email_field_required_invalid"),
+                // :TCHAP: don't mention homeserver, Tchap hides the concept from users.
+                //invalid: () => _t("auth|reset_password_email_field_required_invalid"),
+                invalid: () => _t("auth|email_field_label_required"),
+                // end :TCHAP:
             },
             {
                 key: "email",
@@ -568,16 +571,23 @@ export default class RegistrationForm extends React.PureComponent<IProps, IState
         return (
             <div>
                 <form onSubmit={this.onSubmit}>
-                    <div className="mx_AuthBody_fieldRow">{this.renderUsername()}</div>
+                    { /* :TCHAP: remove username field, the server will generate it from email.
                     <div className="mx_AuthBody_fieldRow">
-                        {this.renderPassword()}
-                        {this.renderPasswordConfirm()}
+                        { this.renderUsername() }
+                    </div>
+                    end :TCHAP: */}
+
+                    { /** :TCHAP: switch fields : email first, password under */}
+                    <div className="mx_AuthBody_fieldRow">
+                        { this.renderEmail() }
+                        { this.renderPhoneNumber() }
                     </div>
                     <div className="mx_AuthBody_fieldRow">
-                        {this.renderEmail()}
-                        {this.renderPhoneNumber()}
+                        { this.renderPassword() }
+                        { this.renderPasswordConfirm() }
                     </div>
-                    {emailHelperText}
+                    { /* end :TCHAP: */}
+                    { /** :TCHAP: remove helper text, adds confusion since email=username in tchap. // emailHelperText */ }
                     {registerButton}
                 </form>
             </div>
diff --git a/src/components/views/avatars/DecoratedRoomAvatar.tsx b/src/components/views/avatars/DecoratedRoomAvatar.tsx
index ed8afe7b61a..a35de5653b6 100644
--- a/src/components/views/avatars/DecoratedRoomAvatar.tsx
+++ b/src/components/views/avatars/DecoratedRoomAvatar.tsx
@@ -31,6 +31,10 @@ import DMRoomMap from "../../../utils/DMRoomMap";
 import { IOOBData } from "../../../stores/ThreepidInviteStore";
 import { getJoinedNonFunctionalMembers } from "../../../utils/room/getJoinedNonFunctionalMembers";
 
+import TchapRoomUtils from "../../../../../../src/tchap/util/TchapRoomUtils";
+import "../../../../../../res/css/views/avatars/_TchapDecoratedRoomAvatar.pcss";
+import { TchapRoomType } from "../../../../../../src/tchap/@types/tchap";
+
 interface IProps {
     room: Room;
     size: string;
@@ -54,6 +58,11 @@ enum Icon {
     // Note: the names here are used in CSS class names
     None = "NONE", // ... except this one
     Globe = "GLOBE",
+    // :TCHAP: add icons for custom room types
+    Forum = "FORUM",
+    Private = "PRIVATE",
+    External = "EXTERNAL",
+    // end :TCHAP:
     PresenceOnline = "ONLINE",
     PresenceAway = "AWAY",
     PresenceOffline = "OFFLINE",
@@ -64,6 +73,14 @@ function tooltipText(variant: Icon): string | undefined {
     switch (variant) {
         case Icon.Globe:
             return _t("room|header|room_is_public");
+        // :TCHAP: add icons for custom room types
+        case Icon.Forum:
+            return _t("This room is a public forum");
+        case Icon.Private:
+            return _t("This room is private");
+        case Icon.External:
+            return _t("This room is private and open to external users");
+        // end :TCHAP:
         case Icon.PresenceOnline:
             return _t("presence|online");
         case Icon.PresenceAway:
@@ -167,7 +184,23 @@ export default class DecoratedRoomAvatar extends React.PureComponent<IProps, ISt
             }
         } else {
             // Track publicity
-            icon = this.isPublicRoom ? Icon.Globe : Icon.None;
+            //icon = this.isPublicRoom ? Icon.Globe : Icon.None;
+            //:tchap: use custom icons for tchap room types
+            const roomType: TchapRoomType = TchapRoomUtils.getTchapRoomType(this.props.room);
+            switch(roomType) {
+                case TchapRoomType.Forum:
+                    icon = Icon.Forum;
+                    break;
+                case TchapRoomType.Private:
+                    icon = Icon.Private;
+                    break;
+                case TchapRoomType.External:
+                    icon = Icon.External;
+                    break;
+                default:
+                    icon = Icon.None;
+            }
+            //end :tchap:
             if (!this.isWatchingTimeline) {
                 this.props.room.on(RoomEvent.Timeline, this.onRoomTimeline);
                 this.isWatchingTimeline = true;
@@ -206,7 +239,11 @@ export default class DecoratedRoomAvatar extends React.PureComponent<IProps, ISt
         });
 
         return (
-            <div className={classes} {...props}>
+            <div className={classes} {...props }>
+                { /*:TCHAP: extra div to fix positioning.
+                https://github.com/tchapgouv/tchap-web-v4/issues/890
+                Issue should be opened in element-web. */ }
+                <div className="mx_DecoratedRoomAvatar_positionedParent">
                 <RoomAvatar
                     room={this.props.room}
                     size={this.props.size}
@@ -219,6 +256,7 @@ export default class DecoratedRoomAvatar extends React.PureComponent<IProps, ISt
                     </Tooltip>
                 )}
                 {badge}
+                </div> { /*:TCHAP: close div */ }
             </div>
         );
     }
diff --git a/src/components/views/context_menus/MessageContextMenu.tsx b/src/components/views/context_menus/MessageContextMenu.tsx
index e0fca0a4c0b..c836aeab66a 100644
--- a/src/components/views/context_menus/MessageContextMenu.tsx
+++ b/src/components/views/context_menus/MessageContextMenu.tsx
@@ -60,6 +60,8 @@ import { getForwardableEvent } from "../../../events/forward/getForwardableEvent
 import { getShareableLocationEvent } from "../../../events/location/getShareableLocationEvent";
 import { ShowThreadPayload } from "../../../dispatcher/payloads/ShowThreadPayload";
 import { CardContext } from "../right_panel/context";
+//:tchap: add feature flags
+import TchapUIFeature from "../../../../../../src/tchap/util/TchapUIFeature";
 
 interface IReplyInThreadButton {
     mxEvent: MatrixEvent;
@@ -676,7 +678,10 @@ export default class MessageContextMenu extends React.Component<IProps, IState>
                 <IconizedContextMenuOptionList>
                     {reactButton}
                     {replyButton}
-                    {replyInThreadButton}
+                    {/* :TCHAP: activate Thread based on homeserver feature flag
+                    {replyInThreadButton} */}
+                    {TchapUIFeature.isFeatureActiveForHomeserver("feature_thread") ? replyInThreadButton : null}
+                    {/*:TCHAP: end */}
                     {editButton}
                 </IconizedContextMenuOptionList>
             );
diff --git a/src/components/views/dialogs/BugReportDialog.tsx b/src/components/views/dialogs/BugReportDialog.tsx
index 5d826f283e3..51baf281569 100644
--- a/src/components/views/dialogs/BugReportDialog.tsx
+++ b/src/components/views/dialogs/BugReportDialog.tsx
@@ -32,6 +32,8 @@ import DialogButtons from "../elements/DialogButtons";
 import { sendSentryReport } from "../../../sentry";
 import defaultDispatcher from "../../../dispatcher/dispatcher";
 import { Action } from "../../../dispatcher/actions";
+import { MatrixClientPeg } from '../../../MatrixClientPeg';  // :TCHAP:
+import TchapUtils from "../../../../../../src/tchap/util/TchapUtils"; // :TCHAP:
 
 interface IProps {
     onFinished: (success: boolean) => void;
@@ -96,12 +98,21 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
     };
 
     private onSubmit = (): void => {
+        /* :TCHAP: do not ask for a github issue
         if ((!this.state.text || !this.state.text.trim()) && (!this.state.issueUrl || !this.state.issueUrl.trim())) {
             this.setState({
                 err: _t("bug_reporting|error_empty"),
             });
             return;
         }
+        */
+        if ((!this.state.text || !this.state.text.trim())) {
+            this.setState({
+                err: _t("Please tell us what went wrong in the \"Notes\" field."),
+            });
+            return;
+        }
+        // end :TCHAP:
 
         const userText =
             (this.state.text.length > 0 ? this.state.text + "\n\n" : "") +
@@ -111,11 +122,34 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
         this.setState({ busy: true, progress: null, err: null });
         this.sendProgressCallback(_t("bug_reporting|preparing_logs"));
 
-        sendBugReport(SdkConfig.get().bug_report_endpoint_url, {
-            userText,
-            sendLogs: true,
-            progressCallback: this.sendProgressCallback,
-            labels: this.props.label ? [this.props.label] : [],
+        // :TCHAP: customise report : add email, prefix with "tchap-web"
+        const client = MatrixClientPeg.get();
+        const customFields = {};
+        client.getThreePids().then(result => {
+            result.threepids.forEach(threepid => {
+                return customFields[threepid.medium] = threepid.address;
+            });
+            return customFields;
+        }).then(customFields => {
+            // is this a voip report ? Add it in "context" field
+            if (this.props.label === "voip-feedback") {
+                customFields.context = "voip";
+            }
+
+            return TchapUtils.isCurrentlyUsingBluetooth().then(isCurrentlyUsingBluetooth => {
+                customFields.audio_input = isCurrentlyUsingBluetooth ? "headset_bluetooth" : "device";
+                return customFields;
+            })
+        }).then(customFields => {
+            return sendBugReport(SdkConfig.get().bug_report_endpoint_url, {
+                userText,
+                sendLogs: true,
+                progressCallback: this.sendProgressCallback,
+                labels: this.props.label ? [this.props.label] : [],
+                customApp: 'tchap-web', // :TCHAP:
+                customFields: customFields, // :TCHAP:
+            });
+            // end :TCHAP:
         }).then(
             () => {
                 if (!this.unmounted) {
@@ -150,6 +184,7 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
                 sendLogs: true,
                 progressCallback: this.downloadProgressCallback,
                 labels: this.props.label ? [this.props.label] : [],
+                customApp: 'tchap-web', // :TCHAP: we don't add email here. You know your own email already.
             });
 
             this.setState({
@@ -214,6 +249,53 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
             );
         }
 
+        { /** :TCHAP: replace with our own dialog */}
+        return (
+            <BaseDialog
+            className="mx_BugReportDialog"
+            onFinished={this.onCancel}
+            title={_t('Submit debug logs to Tchap support team')}
+            contentId="mx_Dialog_content"
+        >
+            <div className="mx_Dialog_content" id="mx_Dialog_content">
+                {warning}
+                <p>{_t("bug_reporting|description")}</p>
+                <Field
+                    className="mx_BugReportDialog_field_input"
+                    element="textarea"
+                    label={_t("bug_reporting|textarea_label")}
+                    rows={5}
+                    onChange={this.onTextChange}
+                    value={this.state.text}
+                    placeholder={_t("bug_reporting|additional_context")}
+                />
+                {progress}
+                {error}
+                <DialogButtons
+                    primaryButton={_t("bug_reporting|send_logs")}
+                    onPrimaryButtonClick={this.onSubmit}
+                    focus={true}
+                    hasCancel={false}
+                    disabled={this.state.busy}
+                />
+
+                <div className="mx_BugReportDialog_download">
+                    <p>
+                        { _t("Just want to get your own logs, without sharing them with the Tchap team?") }
+                    </p>
+                    <DialogButtons
+                        primaryButton={_t("bug_reporting|download_logs")}
+                        onPrimaryButtonClick={this.onDownload}
+                        focus={true}
+                        hasCancel={false}
+                        disabled={this.state.downloadBusy}
+                    />
+                    {this.state.downloadProgress && <span>{this.state.downloadProgress} ...</span>}
+                </div>
+            </div>
+        </BaseDialog>
+        );
+        {/*
         return (
             <BaseDialog
                 className="mx_BugReportDialog"
@@ -281,5 +363,6 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
                 />
             </BaseDialog>
         );
+        end :TCHAP: */}
     }
 }
diff --git a/src/components/views/dialogs/IncomingSasDialog.tsx b/src/components/views/dialogs/IncomingSasDialog.tsx
index a562760b6a1..2d136064e5c 100644
--- a/src/components/views/dialogs/IncomingSasDialog.tsx
+++ b/src/components/views/dialogs/IncomingSasDialog.tsx
@@ -175,6 +175,7 @@ export default class IncomingSasDialog extends React.Component<IProps, IState> {
             profile = <Spinner />;
         }
 
+        /* :TCHAP: remove code
         const userDetailText = [
             <p key="p1">{_t("encryption|verification|incoming_sas_user_dialog_text_1")}</p>,
             <p key="p2">
@@ -190,11 +191,23 @@ export default class IncomingSasDialog extends React.Component<IProps, IState> {
             <p key="p1">{_t("encryption|verification|incoming_sas_device_dialog_text_1")}</p>,
             <p key="p2">{_t("encryption|verification|incoming_sas_device_dialog_text_2")}</p>,
         ];
+        end :TCHAP: */
 
         return (
             <div>
+                {/* :TCHAP: remove code
                 {profile}
                 {isSelf ? selfDetailText : userDetailText}
+                end :TCHAP: */}
+
+                {/* :TCHAP: simplify modal message */}
+                <p>{ _t(
+                    "One of your devices <b>wants to check your Tchap Keys</b> to unlock your messages.",
+                    {},
+                    { b: sub => <b>{ sub }</b> },
+                ) }</p>
+                {/* end :TCHAP: */}
+
                 <DialogButtons
                     primaryButton={_t("action|continue")}
                     hasCancel={true}
diff --git a/src/components/views/dialogs/SpacePreferencesDialog.tsx b/src/components/views/dialogs/SpacePreferencesDialog.tsx
index 8e8e4ce398d..bd2b4d37139 100644
--- a/src/components/views/dialogs/SpacePreferencesDialog.tsx
+++ b/src/components/views/dialogs/SpacePreferencesDialog.tsx
@@ -55,7 +55,7 @@ const SpacePreferencesAppearanceTab: React.FC<Pick<IProps, "space">> = ({ space
                             );
                         }}
                     >
-                        {_t("common|people")}
+                        {_t("Direct Messages") /* TCHAP: change label _t("common|people") */}
                     </StyledCheckbox>
                     <SettingsSubsectionText>
                         {_t("space|preferences|show_people_in_space", {
diff --git a/src/components/views/dialogs/VerificationRequestDialog.tsx b/src/components/views/dialogs/VerificationRequestDialog.tsx
index c6a86ae3e10..0c3f80ab355 100644
--- a/src/components/views/dialogs/VerificationRequestDialog.tsx
+++ b/src/components/views/dialogs/VerificationRequestDialog.tsx
@@ -49,9 +49,12 @@ export default class VerificationRequestDialog extends React.Component<IProps, I
         const request = this.state.verificationRequest;
         const otherUserId = request?.otherUserId;
         const member = this.props.member || (otherUserId ? MatrixClientPeg.safeGet().getUser(otherUserId) : null);
+        /* :TCHAP: remove code
         const title = request?.isSelfVerification
             ? _t("encryption|verification|verification_dialog_title_device")
             : _t("encryption|verification|verification_dialog_title_user");
+        end :TCHAP: */
+        const title = _t("Incoming Verification Request"); // :TCHAP:
 
         if (!member) return null;
 
diff --git a/src/components/views/dialogs/security/AccessSecretStorageDialog.tsx b/src/components/views/dialogs/security/AccessSecretStorageDialog.tsx
index 3d114abc30e..be819702cb1 100644
--- a/src/components/views/dialogs/security/AccessSecretStorageDialog.tsx
+++ b/src/components/views/dialogs/security/AccessSecretStorageDialog.tsx
@@ -48,6 +48,7 @@ interface IProps {
 }
 
 interface IState {
+    displayPassword: boolean;
     recoveryKey: string;
     recoveryKeyValid: boolean | null;
     recoveryKeyCorrect: boolean | null;
@@ -69,6 +70,7 @@ export default class AccessSecretStorageDialog extends React.PureComponent<IProp
         super(props);
 
         this.state = {
+            displayPassword: false,
             recoveryKey: "",
             recoveryKeyValid: null,
             recoveryKeyCorrect: null,
@@ -80,6 +82,16 @@ export default class AccessSecretStorageDialog extends React.PureComponent<IProp
         };
     }
 
+    // :TCHAP: add functionality that displays the Recovery Code for 2mn when clicking on the input eye icon 
+    private setDisplayPassword = (): void => {
+        this.setState({ displayPassword: true });
+    
+        setTimeout(() => {
+          this.setState({ displayPassword: false });
+        }, 120 * 1000);
+    };
+    // end :TCHAP:
+
     private onCancel = (): void => {
         if (this.state.resetting) {
             this.setState({ resetting: false });
@@ -395,7 +407,7 @@ export default class AccessSecretStorageDialog extends React.PureComponent<IProp
                         <div className="mx_AccessSecretStorageDialog_recoveryKeyEntry">
                             <div className="mx_AccessSecretStorageDialog_recoveryKeyEntry_textInput">
                                 <Field
-                                    type="password"
+                                    type={this.state.displayPassword ? "text": "password"}
                                     id="mx_securityKey"
                                     label={_t("encryption|access_secret_storage_dialog|security_key_title")}
                                     value={this.state.recoveryKey}
@@ -403,15 +415,30 @@ export default class AccessSecretStorageDialog extends React.PureComponent<IProp
                                     autoFocus={true}
                                     forceValidity={this.state.recoveryKeyCorrect ?? undefined}
                                     autoComplete="off"
+                                    postfixComponent={(
+                                        <div
+                                            className="tc_textInput_postfixComponent"
+                                            onClick={() => this.setDisplayPassword()}
+                                        >
+                                            <img
+                                                src={require("../../../../../../../res/img/grey-eye.svg").default}
+                                                width="24"
+                                                height="24"
+                                                alt={_t("Eye")}
+                                            />
+                                        </div>
+                                    )}
                                 />
                             </div>
+                            {/*
+                             :TCHAP: hide for csss feature
                             <span className="mx_AccessSecretStorageDialog_recoveryKeyEntry_entryControlSeparatorText">
                                 {_t("encryption|access_secret_storage_dialog|separator", {
                                     recoveryFile: "",
                                     securityKey: "",
                                 })}
                             </span>
-                            <div>
+                             <div>
                                 <input
                                     type="file"
                                     className="mx_AccessSecretStorageDialog_recoveryKeyEntry_fileInput"
@@ -422,7 +449,8 @@ export default class AccessSecretStorageDialog extends React.PureComponent<IProp
                                 <AccessibleButton kind="primary" onClick={this.onRecoveryKeyFileUploadClick}>
                                     {_t("action|upload")}
                                 </AccessibleButton>
-                            </div>
+                            :end TCHAP
+                            </div> */}
                         </div>
                         {recoveryKeyFeedback}
                         <DialogButtons
diff --git a/src/components/views/directory/NetworkDropdown.tsx b/src/components/views/directory/NetworkDropdown.tsx
index e9885f428d8..c708933c0b3 100644
--- a/src/components/views/directory/NetworkDropdown.tsx
+++ b/src/components/views/directory/NetworkDropdown.tsx
@@ -30,6 +30,7 @@ import { GenericDropdownMenu, GenericDropdownMenuItem } from "../../structures/G
 import TextInputDialog from "../dialogs/TextInputDialog";
 import AccessibleButton from "../elements/AccessibleButton";
 import withValidation from "../elements/Validation";
+import TchapUtils from "../../../../../../src/tchap/util/TchapUtils";
 
 const SETTING_NAME = "room_directory_servers";
 
@@ -156,7 +157,8 @@ export const NetworkDropdown: React.FC<IProps> = ({ protocols, config, setConfig
         options: [
             {
                 key: { roomServer, instanceId: undefined },
-                label: _t("common|matrix"),
+                // :TCHAP: remove > label: _t("common|matrix"),
+                label: TchapUtils.toFriendlyServerName(roomServer)
             },
             ...(roomServer === homeServer && protocols
                 ? Object.values(protocols)
@@ -237,7 +239,11 @@ export const NetworkDropdown: React.FC<IProps> = ({ protocols, config, setConfig
             selectedLabel={(option) =>
                 option?.key
                     ? _t("spotlight|public_rooms|network_dropdown_selected_label_instance", {
-                          server: option.key.roomServer,
+                        /* :TCHAP:
+                        server: option.key.roomServer,
+                        */
+                        server: TchapUtils.toFriendlyServerName(option.key.roomServer),
+                        // end :TCHAP:
                           instance: option.key.instanceId ? option.label : "Matrix",
                       })
                     : _t("spotlight|public_rooms|network_dropdown_selected_label")
diff --git a/src/components/views/elements/AccessibleButton.tsx b/src/components/views/elements/AccessibleButton.tsx
index 1eb03792b8d..90955dd33f0 100644
--- a/src/components/views/elements/AccessibleButton.tsx
+++ b/src/components/views/elements/AccessibleButton.tsx
@@ -85,7 +85,7 @@ type Props<T extends keyof JSX.IntrinsicElements> = DynamicHtmlElementProps<T> &
     /**
      * Event handler for button activation. Should be implemented exactly like a normal `onClick` handler.
      */
-    onClick: ((e: ButtonEvent) => void | Promise<void>) | null;
+    onClick?: ((e: ButtonEvent) => void | Promise<void>) | null;
 };
 
 /**
diff --git a/src/components/views/messages/DecryptionFailureBody.tsx b/src/components/views/messages/DecryptionFailureBody.tsx
index 1a68e58b334..a32b4ea683a 100644
--- a/src/components/views/messages/DecryptionFailureBody.tsx
+++ b/src/components/views/messages/DecryptionFailureBody.tsx
@@ -19,11 +19,25 @@ import { MatrixEvent } from "matrix-js-sdk/src/matrix";
 
 import { _t } from "../../../languageHandler";
 import { IBodyProps } from "./IBodyProps";
+import TchapUrls from "../../../../../../src/tchap/util/TchapUrls"; // :TCHAP:
+import ExternalLink from "../elements/ExternalLink"; // :TCHAP:
 
 function getErrorMessage(mxEvent?: MatrixEvent): string {
     return mxEvent?.isEncryptedDisabledForUnverifiedDevices
         ? _t("timeline|decryption_failure_blocked")
-        : _t("threads|unable_to_decrypt");
+        // :TCHAP: : _t("threads|unable_to_decrypt");
+        : _t(
+            "threads|unable_to_decrypt_with_info_message",
+            {},
+            {
+                a: (sub) => (
+                    <ExternalLink href={TchapUrls.lockedMessagesPage}>
+                        {sub}
+                    </ExternalLink>
+                ),
+            },
+        );
+    // end :TCHAP:
 }
 
 // A placeholder element for messages that could not be decrypted
diff --git a/src/components/views/messages/LegacyCallEvent.tsx b/src/components/views/messages/LegacyCallEvent.tsx
index 3c8241d4ea1..cdd9a836380 100644
--- a/src/components/views/messages/LegacyCallEvent.tsx
+++ b/src/components/views/messages/LegacyCallEvent.tsx
@@ -28,6 +28,10 @@ import AccessibleTooltipButton from "../elements/AccessibleTooltipButton";
 import { formatPreciseDuration } from "../../../DateUtils";
 import Clock from "../audio_messages/Clock";
 
+import Modal from "matrix-react-sdk/src/Modal"; // :TCHAP:
+import BugReportDialog from "matrix-react-sdk/src/components/views/dialogs/BugReportDialog"; // :TCHAP:
+import "../../../../../../res/css/views/messages/TchapLegacyCallEvent.pcss"; // :TCHAP:
+
 const MAX_NON_NARROW_WIDTH = (450 / 70) * 100;
 
 interface IProps {
@@ -192,6 +196,7 @@ export default class LegacyCallEvent extends React.PureComponent<IProps, IState>
                 return (
                     <div className="mx_LegacyCallEvent_content">
                         {text}
+                        {this.renderBugReportButton()}
                         {this.props.timestamp}
                     </div>
                 );
@@ -264,6 +269,25 @@ export default class LegacyCallEvent extends React.PureComponent<IProps, IState>
         );
     }
 
+    private onReportBugClick = (): void => {
+        Modal.createDialog(BugReportDialog, {
+            initialText: _t("tchap_voip_bug_report_prefill"),
+            label: "voip-feedback",
+        });
+    };
+
+    private renderBugReportButton(): JSX.Element {
+        return (
+            <AccessibleButton
+                className="mx_LegacyCallEvent_content_button mx_LegacyCallEvent_content_button_reportBug"
+                onClick={this.onReportBugClick}
+                kind="primary"
+            >
+                <span> {_t("Report a problem")} </span>
+            </AccessibleButton>
+        );
+    }
+
     public render(): React.ReactNode {
         const event = this.props.mxEvent;
         const sender = event.sender ? event.sender.name : event.getSender();
diff --git a/src/components/views/messages/MAudioBody.tsx b/src/components/views/messages/MAudioBody.tsx
index 52cd2334afd..106dd15f651 100644
--- a/src/components/views/messages/MAudioBody.tsx
+++ b/src/components/views/messages/MAudioBody.tsx
@@ -23,7 +23,7 @@ import InlineSpinner from "../elements/InlineSpinner";
 import { _t } from "../../../languageHandler";
 import AudioPlayer from "../audio_messages/AudioPlayer";
 import { IMediaEventContent } from "../../../customisations/models/IMediaEventContent";
-import MFileBody from "./MFileBody";
+import MFileBody from "../../../../../../src/tchap/components/views/messages/OriginalFileBody";
 import { IBodyProps } from "./IBodyProps";
 import { PlaybackManager } from "../../../audio/PlaybackManager";
 import { isVoiceMessage } from "../../../utils/EventUtils";
diff --git a/src/components/views/messages/MImageBody.tsx b/src/components/views/messages/MImageBody.tsx
index ff4d573e059..8003410bfc6 100644
--- a/src/components/views/messages/MImageBody.tsx
+++ b/src/components/views/messages/MImageBody.tsx
@@ -23,7 +23,7 @@ import { logger } from "matrix-js-sdk/src/logger";
 import { ClientEvent, ClientEventHandlerMap } from "matrix-js-sdk/src/matrix";
 import { Tooltip } from "@vector-im/compound-web";
 
-import MFileBody from "./MFileBody";
+import MFileBody from "../../../../../../src/tchap/components/views/messages/OriginalFileBody";
 import Modal from "../../../Modal";
 import { _t } from "../../../languageHandler";
 import SettingsStore from "../../../settings/SettingsStore";
diff --git a/src/components/views/messages/MImageReplyBody.tsx b/src/components/views/messages/MImageReplyBody.tsx
index c6d61a7ba5b..0d16a14597b 100644
--- a/src/components/views/messages/MImageReplyBody.tsx
+++ b/src/components/views/messages/MImageReplyBody.tsx
@@ -16,7 +16,7 @@ limitations under the License.
 
 import React from "react";
 
-import MImageBody from "./MImageBody";
+import MImageBody from "../../../../../../src/tchap/components/views/messages/OriginalImageBody";
 import { ImageContent } from "../../../customisations/models/IMediaEventContent";
 
 const FORCED_IMAGE_HEIGHT = 44;
diff --git a/src/components/views/messages/MStickerBody.tsx b/src/components/views/messages/MStickerBody.tsx
index 26c33e89fca..e0fdf7030c7 100644
--- a/src/components/views/messages/MStickerBody.tsx
+++ b/src/components/views/messages/MStickerBody.tsx
@@ -17,7 +17,7 @@ limitations under the License.
 import React, { ComponentProps, ReactNode } from "react";
 import { Tooltip } from "@vector-im/compound-web";
 
-import MImageBody from "./MImageBody";
+import MImageBody from "../../../../../../src/tchap/components/views/messages/OriginalImageBody";
 import { BLURHASH_FIELD } from "../../../utils/image-media";
 import { IMediaEventContent } from "../../../customisations/models/IMediaEventContent";
 
diff --git a/src/components/views/messages/MVideoBody.tsx b/src/components/views/messages/MVideoBody.tsx
index df3ab6abbf9..d057dc0300c 100644
--- a/src/components/views/messages/MVideoBody.tsx
+++ b/src/components/views/messages/MVideoBody.tsx
@@ -25,7 +25,7 @@ import { mediaFromContent } from "../../../customisations/Media";
 import { BLURHASH_FIELD } from "../../../utils/image-media";
 import { IMediaEventContent } from "../../../customisations/models/IMediaEventContent";
 import { IBodyProps } from "./IBodyProps";
-import MFileBody from "./MFileBody";
+import MFileBody from "../../../../../../src/tchap/components/views/messages/OriginalFileBody";
 import { ImageSize, suggestedSize as suggestedVideoSize } from "../../../settings/enums/ImageSize";
 import RoomContext, { TimelineRenderingType } from "../../../contexts/RoomContext";
 import MediaProcessingError from "./shared/MediaProcessingError";
diff --git a/src/components/views/messages/MVoiceMessageBody.tsx b/src/components/views/messages/MVoiceMessageBody.tsx
index 096824e4b23..fe73df6a58a 100644
--- a/src/components/views/messages/MVoiceMessageBody.tsx
+++ b/src/components/views/messages/MVoiceMessageBody.tsx
@@ -19,8 +19,8 @@ import React from "react";
 import InlineSpinner from "../elements/InlineSpinner";
 import { _t } from "../../../languageHandler";
 import RecordingPlayback from "../audio_messages/RecordingPlayback";
-import MAudioBody from "./MAudioBody";
-import MFileBody from "./MFileBody";
+import MAudioBody from "../../../../../../src/tchap/components/views/messages/OriginalAudioBody";
+import MFileBody from "../../../../../../src/tchap/components/views/messages/OriginalFileBody";
 import MediaProcessingError from "./shared/MediaProcessingError";
 
 export default class MVoiceMessageBody extends MAudioBody {
diff --git a/src/components/views/messages/MessageActionBar.tsx b/src/components/views/messages/MessageActionBar.tsx
index 9cf35922089..066deae5021 100644
--- a/src/components/views/messages/MessageActionBar.tsx
+++ b/src/components/views/messages/MessageActionBar.tsx
@@ -61,6 +61,7 @@ import { ShowThreadPayload } from "../../../dispatcher/payloads/ShowThreadPayloa
 import { GetRelationsForEvent, IEventTileType } from "../rooms/EventTile";
 import { VoiceBroadcastInfoEventType } from "../../../voice-broadcast/types";
 import { ButtonEvent } from "../elements/AccessibleButton";
+import TchapUIFeature from "../../../../../../src/tchap/util/TchapUIFeature";
 
 interface IOptionsButtonProps {
     mxEvent: MatrixEvent;
@@ -345,7 +346,10 @@ export default class MessageActionBar extends React.PureComponent<IMessageAction
             !M_BEACON_INFO.matches(this.props.mxEvent.getType()) &&
             !(this.props.mxEvent.getType() === VoiceBroadcastInfoEventType);
 
-        return inNotThreadTimeline && isAllowedMessageType;
+        //:TCHAP: activate Thread based on homeserver feature flag
+        //return inNotThreadTimeline && isAllowedMessageType;
+        return TchapUIFeature.isFeatureActiveForHomeserver("feature_thread") && inNotThreadTimeline && isAllowedMessageType;
+        //:TCHAP: end
     }
 
     /**
diff --git a/src/components/views/right_panel/LegacyRoomHeaderButtons.tsx b/src/components/views/right_panel/LegacyRoomHeaderButtons.tsx
index 672a2886564..285ec1986cb 100644
--- a/src/components/views/right_panel/LegacyRoomHeaderButtons.tsx
+++ b/src/components/views/right_panel/LegacyRoomHeaderButtons.tsx
@@ -40,6 +40,7 @@ import { SummarizedNotificationState } from "../../../stores/notifications/Summa
 import PosthogTrackers from "../../../PosthogTrackers";
 import { ButtonEvent } from "../elements/AccessibleButton";
 import { doesRoomOrThreadHaveUnreadMessages } from "../../../Unread";
+import TchapUIFeature from "../../../../../../src/tchap/util/TchapUIFeature";
 
 const ROOM_INFO_PHASES = [
     RightPanelPhases.RoomSummary,
@@ -273,6 +274,8 @@ export default class LegacyRoomHeaderButtons extends HeaderButtons<IProps> {
                 onClick={this.onTimelineCardClicked}
             />,
         );
+        //:tchap: activate Thread based on homeserver feature flag
+        if(TchapUIFeature.isFeatureActiveForHomeserver("feature_thread")){
         rightPanelPhaseButtons.set(
             RightPanelPhases.ThreadPanel,
             <HeaderButton
@@ -287,6 +290,8 @@ export default class LegacyRoomHeaderButtons extends HeaderButtons<IProps> {
                 <UnreadIndicator color={this.state.threadNotificationLevel} />
             </HeaderButton>,
         );
+        } //close bracket :tchap: end
+
         if (this.state.notificationsEnabled) {
             rightPanelPhaseButtons.set(
                 RightPanelPhases.NotificationPanel,
diff --git a/src/components/views/right_panel/RoomSummaryCard.tsx b/src/components/views/right_panel/RoomSummaryCard.tsx
index d6182e5e2e1..0de098f328a 100644
--- a/src/components/views/right_panel/RoomSummaryCard.tsx
+++ b/src/components/views/right_panel/RoomSummaryCard.tsx
@@ -76,6 +76,9 @@ import { inviteToRoom } from "../../../utils/room/inviteToRoom";
 import { useAccountData } from "../../../hooks/useAccountData";
 import { useRoomState } from "../../../hooks/useRoomState";
 
+import DecoratedRoomAvatar from "../avatars/DecoratedRoomAvatar"; // :TCHAP:
+
+
 interface IProps {
     room: Room;
     permalinkCreator: RoomPermalinkCreator;
@@ -331,7 +334,11 @@ const RoomSummaryCard: React.FC<IProps> = ({ room, permalinkCreator, onClose, on
     const alias = room.getCanonicalAlias() || room.getAltAliases()[0] || "";
     const header = (
         <header className="mx_RoomSummaryCard_container">
+            {/** :TCHAP: decorate the avatar with the tchap lock icons
             <RoomAvatar room={room} size="80px" viewAvatarOnClick />
+            */}
+            <DecoratedRoomAvatar room={room} size="80px" viewAvatarOnClick />
+            {/* end :TCHAP: */}
             <RoomName room={room}>
                 {(name) => (
                     <Heading
@@ -355,6 +362,7 @@ const RoomSummaryCard: React.FC<IProps> = ({ room, permalinkCreator, onClose, on
                 {alias}
             </Text>
 
+            {/* :TCHAP: remove badges
             <Flex as="section" justify="center" gap="var(--cpd-space-2x)" className="mx_RoomSummaryCard_badges">
                 {!isDirectMessage && roomState.getJoinRule() === JoinRule.Public && (
                     <Badge kind="default">
@@ -384,6 +392,7 @@ const RoomSummaryCard: React.FC<IProps> = ({ room, permalinkCreator, onClose, on
                     </Badge>
                 )}
             </Flex>
+            */}
         </header>
     );
 
diff --git a/src/components/views/right_panel/VerificationPanel.tsx b/src/components/views/right_panel/VerificationPanel.tsx
index c0872192ec9..e626a42fd98 100644
--- a/src/components/views/right_panel/VerificationPanel.tsx
+++ b/src/components/views/right_panel/VerificationPanel.tsx
@@ -295,10 +295,13 @@ export default class VerificationPanel extends React.PureComponent<IProps, IStat
                 logger.warn("Verified device we don't know about: " + this.props.request.otherDeviceId);
                 description = _t("encryption|verification|successful_own_device");
             } else {
+                description = _t("The sharing of your Tchap Keys has succeeded. Your messages will be unlocked."); // :TCHAP:
+                /* :TCHAP:
                 description = _t("encryption|verification|successful_device", {
                     deviceName: device.displayName,
                     deviceId: device.deviceId,
                 });
+                end :TCHAP: */
             }
         } else {
             description = _t("encryption|verification|successful_user", {
diff --git a/src/components/views/rooms/MemberList.tsx b/src/components/views/rooms/MemberList.tsx
index 639e1493b26..e6e4317f5c6 100644
--- a/src/components/views/rooms/MemberList.tsx
+++ b/src/components/views/rooms/MemberList.tsx
@@ -55,6 +55,7 @@ import { canInviteTo } from "../../../utils/room/canInviteTo";
 import { inviteToRoom } from "../../../utils/room/inviteToRoom";
 import { Action } from "../../../dispatcher/actions";
 import { SpaceScopeHeader } from "./SpaceScopeHeader";
+import TchapExportMembersButton from "../../../../../../src/tchap/components/views/rooms/TchapExportMembersButton"; // TCHAP
 
 const INITIAL_LOAD_NUM_MEMBERS = 30;
 const INITIAL_LOAD_NUM_INVITED = 5;
@@ -420,6 +421,12 @@ export default class MemberList extends React.Component<IProps, IState> {
                 onClose={this.props.onClose}
             >
                 {inviteButton}
+                {/** TCHAP */}
+                <TchapExportMembersButton
+                    room={room}
+                    roomMembersIds={this.state.filteredJoinedMembers.map(roomMember => roomMember.userId)}>
+                </TchapExportMembersButton>
+                {/** end TCHAP */}
                 <div className="mx_MemberList_wrapper">
                     <TruncatedList
                         className="mx_MemberList_section mx_MemberList_joined"
diff --git a/src/components/views/rooms/RoomHeader.tsx b/src/components/views/rooms/RoomHeader.tsx
index 6d1ea9f8eb6..596e5fa8063 100644
--- a/src/components/views/rooms/RoomHeader.tsx
+++ b/src/components/views/rooms/RoomHeader.tsx
@@ -55,6 +55,10 @@ import { RoomKnocksBar } from "./RoomKnocksBar";
 import { isVideoRoom } from "../../../utils/video-rooms";
 import { notificationLevelToIndicator } from "../../../utils/notifications";
 
+import TchapUIFeature from "../../../../../../src/tchap/util/TchapUIFeature";
+import TchapExternalRoomHeader from "../../../../../../src/tchap/components/views/rooms/TchapExternalRoomHeader";
+import DecoratedRoomAvatar from "../avatars/DecoratedRoomAvatar"; // :TCHAP:
+
 export default function RoomHeader({
     room,
     additionalButtons,
@@ -234,7 +238,14 @@ export default function RoomHeader({
                     }}
                     className="mx_RoomHeader_infoWrapper"
                 >
+                    {/* :TCHAP: RoomAvatar -> DecoratedRoomAvatar
                     <RoomAvatar room={room} size="40px" />
+                    */}
+                    <DecoratedRoomAvatar room={room} size="40px" />
+                    {/* end :TCHAP: */}
+                    {/* :tchap: Add external caption when room is open to external */}
+                    <TchapExternalRoomHeader room={room}></TchapExternalRoomHeader>
+                    {/* :tchap: end */}
                     <Box flex="1" className="mx_RoomHeader_info">
                         <BodyText
                             as="div"
@@ -247,6 +258,7 @@ export default function RoomHeader({
                         >
                             <span className="mx_RoomHeader_truncated mx_lineClamp">{roomName}</span>
 
+                            {/* :tchap: remove public forum icon
                             {!isDirectMessage && roomState.getJoinRule() === JoinRule.Public && (
                                 <Tooltip label={_t("common|public_room")} side="right">
                                     <PublicIcon
@@ -257,7 +269,9 @@ export default function RoomHeader({
                                     />
                                 </Tooltip>
                             )}
+                            */}
 
+                            {/* :tchap: do not show e2eStatus
                             {isDirectMessage && e2eStatus === E2EStatus.Verified && (
                                 <Tooltip label={_t("common|verified")} side="right">
                                     <VerifiedIcon
@@ -268,7 +282,9 @@ export default function RoomHeader({
                                     />
                                 </Tooltip>
                             )}
+                            */}
 
+                            {/* :tchap: do not show E2EStatus.Warning
                             {isDirectMessage && e2eStatus === E2EStatus.Warning && (
                                 <Tooltip label={_t("room|header_untrusted_label")} side="right">
                                     <ErrorIcon
@@ -279,6 +295,7 @@ export default function RoomHeader({
                                     />
                                 </Tooltip>
                             )}
+                            */}
                         </BodyText>
                         {roomTopic && (
                             <BodyText
@@ -316,8 +333,19 @@ export default function RoomHeader({
                         joinCallButton
                     ) : (
                         <>
+                            { /* :TCHAP: activate video call only if directmessage and if feature is activated on homeserver }
                             {!isVideoRoom(room) && videoCallButton}
+                            */ }
+                            {isDirectMessage && TchapUIFeature.isFeatureActiveForHomeserver("feature_video_call") &&
+                              !isVideoRoom(room) && videoCallButton}
+                            {/* end :TCHAP: */}
+
+                            { /* :TCHAP: activate audio call only if directmessage and if feature is activated on homeserver
                             {!useElementCallExclusively && !isVideoRoom(room) && voiceCallButton}
+                            */ }
+                            {isDirectMessage && TchapUIFeature.isFeatureActiveForHomeserver("feature_audio_call") &&
+                              !useElementCallExclusively && !isVideoRoom(room) && voiceCallButton}
+                            {/* end :TCHAP: */}
                         </>
                     )}
 
diff --git a/src/components/views/rooms/RoomList.tsx b/src/components/views/rooms/RoomList.tsx
index 28154c40d65..09f40ca385b 100644
--- a/src/components/views/rooms/RoomList.tsx
+++ b/src/components/views/rooms/RoomList.tsx
@@ -382,7 +382,7 @@ const TAG_AESTHETICS: TagAestheticsMap = {
         defaultHidden: false,
     },
     [DefaultTagID.DM]: {
-        sectionLabel: _td("common|people"),
+        sectionLabel: _td("Direct Messages"), /* TCHAP: change label _td("common|people"), */
         isInvite: false,
         defaultHidden: false,
         AuxButtonComponent: DmAuxButton,
diff --git a/src/components/views/rooms/ThreadSummary.tsx b/src/components/views/rooms/ThreadSummary.tsx
index 1e30dcba9d4..31722e7384a 100644
--- a/src/components/views/rooms/ThreadSummary.tsx
+++ b/src/components/views/rooms/ThreadSummary.tsx
@@ -34,6 +34,8 @@ import { ShowThreadPayload } from "../../../dispatcher/payloads/ShowThreadPayloa
 import defaultDispatcher from "../../../dispatcher/dispatcher";
 import { useUnreadNotifications } from "../../../hooks/useUnreadNotifications";
 import { notificationLevelToIndicator } from "../../../utils/notifications";
+import ExternalLink from "../elements/ExternalLink"; // :TCHAP:
+import TchapUrls from "../../../../../../src/tchap/util/TchapUrls"; // :TCHAP:
 
 interface IProps {
     mxEvent: MatrixEvent;
@@ -105,6 +107,20 @@ export const ThreadMessagePreview: React.FC<IPreviewProps> = ({ thread, showDisp
         return null;
     }
 
+    // :TCHAP:
+    const undecryptedText = _t(
+        "threads|unable_to_decrypt_with_info_message",
+        {},
+        {
+            a: (sub) => (
+                <ExternalLink href={TchapUrls.lockedMessagesPage}>
+                    {sub}
+                </ExternalLink>
+            ),
+        },
+    );
+    // end :TCHAP:
+
     return (
         <>
             <MemberAvatar
@@ -122,7 +138,20 @@ export const ThreadMessagePreview: React.FC<IPreviewProps> = ({ thread, showDisp
                     className="mx_ThreadSummary_content mx_DecryptionFailureBody"
                     title={_t("threads|unable_to_decrypt")}
                 >
-                    <span className="mx_ThreadSummary_message-preview">{_t("threads|unable_to_decrypt")}</span>
+                    { /* :TCHAP: <span className="mx_ThreadSummary_message-preview">{_t("threads|unable_to_decrypt")}</span>*/}
+                    <span className="mx_ThreadSummary_message-preview">
+                        {_t("threads|unable_to_decrypt_with_info_message", {},
+                            {
+                                a: (sub) => (
+                                    <ExternalLink href={TchapUrls.lockedMessagesPage}>
+                                        {sub}
+                                    </ExternalLink>
+                                ),
+                            },
+                        )}
+                    </span>
+                    {/** end :TCHAP: */}
+
                 </div>
             ) : (
                 <div className="mx_ThreadSummary_content" title={preview}>
diff --git a/src/components/views/settings/CrossSigningPanel.tsx b/src/components/views/settings/CrossSigningPanel.tsx
index 869bb716f8d..aff5fd68761 100644
--- a/src/components/views/settings/CrossSigningPanel.tsx
+++ b/src/components/views/settings/CrossSigningPanel.tsx
@@ -227,23 +227,32 @@ export default class CrossSigningPanel extends React.PureComponent<{}, IState> {
             userSigningPrivateKeyCached;
 
         const actions: JSX.Element[] = [];
+        // :TCHAP move Reset button to advanced section
+        const advancedActions: JSX.Element[] = [];
+        // end :TCHAP:
 
         // TODO: determine how better to expose this to users in addition to prompts at login/toast
         if (!keysExistEverywhere && homeserverSupportsCrossSigning) {
-            let buttonCaption = _t("encryption|set_up_toast_title");
+            // :TCHAP: let buttonCaption = _t("encryption|set_up_toast_title");
+            let buttonCaption = _t("Activate on this device");
+            // end :TCHAP:
             if (crossSigningPrivateKeysInStorage) {
                 buttonCaption = _t("encryption|verify_toast_title");
             }
-            actions.push(
-                <AccessibleButton key="setup" kind="primary_outline" onClick={this.onBootstrapClick}>
+            // :TCHAP: actions.push(
+            advancedActions.push(
+            // end :TCHAP:
+                <AccessibleButton key="setup" kind="primary" onClick={this.onBootstrapClick}>
                     {buttonCaption}
                 </AccessibleButton>,
             );
         }
 
         if (keysExistAnywhere) {
-            actions.push(
-                <AccessibleButton key="reset" kind="danger_outline" onClick={this.onResetCrossSigningClick}>
+            // :TCHAP actions.push(
+            advancedActions.push(
+            // end :TCHAP:
+                <AccessibleButton key="reset" kind="danger" onClick={this.onResetCrossSigningClick}>
                     {_t("action|reset")}
                 </AccessibleButton>,
             );
@@ -254,6 +263,13 @@ export default class CrossSigningPanel extends React.PureComponent<{}, IState> {
             actionRow = <div className="mx_CrossSigningPanel_buttonRow">{actions}</div>;
         }
 
+        // :TCHAP add
+        let advancedActionRow;
+        if (advancedActions.length) {
+            advancedActionRow = <div className="mx_CrossSigningPanel_buttonRow">{advancedActions}</div>;
+        }
+        // end :TCHAP:
+
         return (
             <>
                 {summarisedStatus}
@@ -311,6 +327,7 @@ export default class CrossSigningPanel extends React.PureComponent<{}, IState> {
                             </tr>
                         </tbody>
                     </table>
+                    {advancedActionRow}
                 </details>
                 {errorSection}
                 {actionRow}
diff --git a/src/components/views/settings/CryptographyPanel.tsx b/src/components/views/settings/CryptographyPanel.tsx
index 15ead0dec73..42116a68350 100644
--- a/src/components/views/settings/CryptographyPanel.tsx
+++ b/src/components/views/settings/CryptographyPanel.tsx
@@ -72,6 +72,7 @@ export default class CryptographyPanel extends React.Component<IProps, IState> {
             );
         }
 
+        /* :TCHAP: redesign the returned component
         return (
             <SettingsSubsection heading={_t("settings|security|cryptography_section")}>
                 <SettingsSubsectionText>
@@ -96,7 +97,44 @@ export default class CryptographyPanel extends React.Component<IProps, IState> {
                 {noSendUnverifiedSetting}
             </SettingsSubsection>
         );
+        */
+        return (
+            <SettingsSubsection heading={_t("settings|security|cryptography_section")}> {/* :TCHAP: name changed in translations */}
+            <div className="mx_SettingsTab_subsectionText">
+                <div>
+                    {_t("These keys only apply to the current session.")}
+                </div>
+                <div>
+                    <b>{_t("Please note this is not your recovery code for your automatic backup.")}</b>
+                </div>
+            </div>
+            <details>
+                <summary>{_t("common|advanced")}</summary>
+                <SettingsSubsectionText>
+                    <table className="mx_CryptographyPanel_sessionInfo">
+                        <tr>
+                            <th scope="row">{_t("settings|security|session_id")}</th>
+                            <td>
+                                <code>{deviceId}</code>
+                            </td>
+                        </tr>
+                        <tr>
+                            <th scope="row">{_t("settings|security|session_key")}</th>
+                            <td>
+                                <code>
+                                    <b>{identityKey}</b>
+                                </code>
+                            </td>
+                        </tr>
+                    </table>
+                </SettingsSubsectionText>
+            </details>
+            {importExportButtons}
+            {noSendUnverifiedSetting}
+            </SettingsSubsection>
+        );
     }
+    // end :TCHAP:
 
     private onExportE2eKeysClicked = (): void => {
         Modal.createDialogAsync(
diff --git a/src/components/views/settings/Notifications.tsx b/src/components/views/settings/Notifications.tsx
index ec47cff7144..aa70cf84ffd 100644
--- a/src/components/views/settings/Notifications.tsx
+++ b/src/components/views/settings/Notifications.tsx
@@ -59,6 +59,8 @@ import { SettingsSubsectionHeading } from "./shared/SettingsSubsectionHeading";
 import SettingsSubsection from "./shared/SettingsSubsection";
 import { doesRoomHaveUnreadMessages } from "../../../Unread";
 
+import TchapUIFeature from "../../../../../../src/tchap/util/TchapUIFeature";
+
 // TODO: this "view" component still has far too much application logic in it,
 // which should be factored out to other files.
 
@@ -725,7 +727,11 @@ export default class Notifications extends React.PureComponent<IProps, IState> {
                     </>
                 )}
 
+                {/* :TCHAP: show button only if feature is active on homeserver
                 {emailSwitches}
+                */}
+                { TchapUIFeature.isFeatureActiveForHomeserver("feature_email_notification") ? emailSwitches : null}
+                {/* :TCHAP: end */}
             </SettingsSubsection>
         );
     }
diff --git a/src/components/views/settings/SecureBackupPanel.tsx b/src/components/views/settings/SecureBackupPanel.tsx
index 520379cc7b0..790b85be583 100644
--- a/src/components/views/settings/SecureBackupPanel.tsx
+++ b/src/components/views/settings/SecureBackupPanel.tsx
@@ -266,12 +266,23 @@ export default class SecureBackupPanel extends React.PureComponent<{}, IState> {
             } else {
                 statusDescription = (
                     <>
+                        {/* TCHAP add Tchap text */}
+                        <SettingsSubsectionText>
+                                {_t(
+                                    "settings|security|key_backup_inactive_warning",
+                                    {},
+                                    { b: (sub) => <b>{sub}</b> },
+                                )}
+                        </SettingsSubsectionText>
+                        {/* end TCHAP */}
+                        {/* :TCHAP remove element text
                         <SettingsSubsectionText>
                             {_t("settings|security|key_backup_inactive", {}, { b: (sub) => <b>{sub}</b> })}
                         </SettingsSubsectionText>
                         <SettingsSubsectionText>
                             {_t("settings|security|key_backup_connect_prompt")}
                         </SettingsSubsectionText>
+                        end :TCHAP: */}
                     </>
                 );
                 restoreButtonCaption = _t("settings|security|key_backup_connect");
@@ -333,6 +344,7 @@ export default class SecureBackupPanel extends React.PureComponent<{}, IState> {
                 </AccessibleButton>,
             );
 
+            /* :TCHAP: hide
             if (!isSecureBackupRequired(MatrixClientPeg.safeGet())) {
                 actions.push(
                     <AccessibleButton key="delete" kind="danger_outline" onClick={this.deleteBackup}>
@@ -340,13 +352,16 @@ export default class SecureBackupPanel extends React.PureComponent<{}, IState> {
                     </AccessibleButton>,
                 );
             }
+            end :TCHAP: */
         } else {
             statusDescription = (
                 <>
                     <SettingsSubsectionText>
                         {_t("settings|security|key_backup_inactive_warning", {}, { b: (sub) => <b>{sub}</b> })}
                     </SettingsSubsectionText>
+                    {/* :TCHAP: remove
                     <SettingsSubsectionText>{_t("encryption|setup_secure_backup|explainer")}</SettingsSubsectionText>
+                    end :TCHAP: */}
                 </>
             );
             actions.push(
@@ -359,7 +374,9 @@ export default class SecureBackupPanel extends React.PureComponent<{}, IState> {
         if (secretStorageKeyInAccount) {
             actions.push(
                 <AccessibleButton key="reset" kind="danger_outline" onClick={this.resetSecretStorage}>
-                    {_t("action|reset")}
+                    {/* :TCHAP: _t("action|reset") */}
+                    {_t("Generate a new code")}
+                    {/* end :TCHAP: */}
                 </AccessibleButton>,
             );
         }
diff --git a/src/components/views/settings/tabs/room/GeneralRoomSettingsTab.tsx b/src/components/views/settings/tabs/room/GeneralRoomSettingsTab.tsx
index 8e990d7d33c..4a6cf17036f 100644
--- a/src/components/views/settings/tabs/room/GeneralRoomSettingsTab.tsx
+++ b/src/components/views/settings/tabs/room/GeneralRoomSettingsTab.tsx
@@ -89,6 +89,7 @@ export default class GeneralRoomSettingsTab extends React.Component<IProps, ISta
                     <RoomProfileSettings roomId={room.roomId} />
                 </SettingsSection>
 
+                {/* :TCHAP: no aliases for rooms
                 <SettingsSection heading={_t("room_settings|general|aliases_section")}>
                     <AliasSettings
                         roomId={room.roomId}
@@ -97,6 +98,7 @@ export default class GeneralRoomSettingsTab extends React.Component<IProps, ISta
                         canonicalAliasEvent={canonicalAliasEv}
                     />
                 </SettingsSection>
+                end :TCHAP: */}
 
                 <SettingsSection heading={_t("room_settings|general|other_section")}>
                     {urlPreviewSettings}
diff --git a/src/components/views/settings/tabs/room/SecurityRoomSettingsTab.tsx b/src/components/views/settings/tabs/room/SecurityRoomSettingsTab.tsx
index 6ac686e0639..69ded776071 100644
--- a/src/components/views/settings/tabs/room/SecurityRoomSettingsTab.tsx
+++ b/src/components/views/settings/tabs/room/SecurityRoomSettingsTab.tsx
@@ -255,6 +255,7 @@ export default class SecurityRoomSettingsTab extends React.Component<IProps, ISt
         const room = this.props.room;
 
         let aliasWarning: JSX.Element | undefined;
+        /* :TCHAP: remove
         if (room.getJoinRule() === JoinRule.Public && !this.state.hasAliases) {
             aliasWarning = (
                 <div className="mx_SecurityRoomSettingsTab_warning">
@@ -263,12 +264,13 @@ export default class SecurityRoomSettingsTab extends React.Component<IProps, ISt
                 </div>
             );
         }
+        end :TCHAP: */
         const description = _t("room_settings|security|join_rule_description", {
             roomName: room.name,
         });
 
         let advanced: JSX.Element | undefined;
-        if (room.getJoinRule() === JoinRule.Public) {
+        if (false) { // :TCHAP: no guest access - if(room.getJoinRule() === JoinRule.Public) {
             advanced = (
                 <div>
                     <AccessibleButton
@@ -422,9 +424,14 @@ export default class SecurityRoomSettingsTab extends React.Component<IProps, ISt
         const client = this.context;
         const room = this.props.room;
         const isEncrypted = this.state.encrypted;
+        /* :TCHAP: does not allow changing encryption
         const hasEncryptionPermission = room.currentState.mayClientSendStateEvent(EventType.RoomEncryption, client);
         const isEncryptionForceDisabled = shouldForceDisableEncryption(client);
         const canEnableEncryption = !isEncrypted && !isEncryptionForceDisabled && hasEncryptionPermission;
+        */
+        const isEncryptionForceDisabled = false;
+        const canEnableEncryption = false;
+        // end :TCHAP:
 
         let encryptionSettings: JSX.Element | undefined;
         if (
diff --git a/src/components/views/settings/tabs/user/GeneralUserSettingsTab.tsx b/src/components/views/settings/tabs/user/GeneralUserSettingsTab.tsx
index 3009c81a17f..9c626406a18 100644
--- a/src/components/views/settings/tabs/user/GeneralUserSettingsTab.tsx
+++ b/src/components/views/settings/tabs/user/GeneralUserSettingsTab.tsx
@@ -58,6 +58,7 @@ import Heading from "../../../typography/Heading";
 import InlineSpinner from "../../../elements/InlineSpinner";
 import { ThirdPartyIdentifier } from "../../../../../AddThreepid";
 import { SDKContext } from "../../../../../contexts/SDKContext";
+import TchapUIFeature from '../../../../../../../../src/tchap/util/TchapUIFeature'; // :TCHAP:
 
 interface IProps {
     closeSettingsFn: () => void;
@@ -326,7 +327,9 @@ export default class GeneralUserSettingsTab extends React.Component<IProps, ISta
     private renderAccountSection(): JSX.Element {
         let threepidSection: ReactNode = null;
 
-        if (SettingsStore.getValue(UIFeature.ThirdPartyID)) {
+        // :TCHAP: no need for users to view/edit their email or phone (TchapUIFeature.showEmailPhoneDiscoverySettings)
+        if (TchapUIFeature.showEmailPhoneDiscoverySettings &&
+            SettingsStore.getValue(UIFeature.ThirdPartyID)) {
             const emails = this.state.loading3pids ? (
                 <InlineSpinner />
             ) : (
@@ -534,7 +537,8 @@ export default class GeneralUserSettingsTab extends React.Component<IProps, ISta
         }
 
         let discoverySection;
-        if (SettingsStore.getValue(UIFeature.IdentityServer)) {
+        // :TCHAP: no need for users to edit the discovery section (TchapUIFeature.showEmailPhoneDiscoverySettings)
+        if (TchapUIFeature.showEmailPhoneDiscoverySettings && SettingsStore.getValue(UIFeature.IdentityServer)) {
             const discoWarning = this.state.requiredPolicyInfo.hasTerms ? (
                 <WarningIcon
                     className="mx_GeneralUserSettingsTab_warningIcon"
diff --git a/src/components/views/settings/tabs/user/SecurityUserSettingsTab.tsx b/src/components/views/settings/tabs/user/SecurityUserSettingsTab.tsx
index 6d32f683b7a..94785a86085 100644
--- a/src/components/views/settings/tabs/user/SecurityUserSettingsTab.tsx
+++ b/src/components/views/settings/tabs/user/SecurityUserSettingsTab.tsx
@@ -275,11 +275,20 @@ export default class SecurityUserSettingsTab extends React.Component<IProps, ISt
     }
 
     public render(): React.ReactNode {
+        // :TCHAP: we're moving this subsection out, so it's now a section
+        const secureBackup = (
+            <SettingsSection heading={_t("common|secure_backup")}>
+                <SecureBackupPanel />
+            </SettingsSection>
+        );
+        /*
         const secureBackup = (
             <SettingsSubsection heading={_t("common|secure_backup")}>
                 <SecureBackupPanel />
             </SettingsSubsection>
         );
+        */
+        // end :TCHAP:
 
         const eventIndex = (
             <SettingsSubsection heading={_t("settings|security|message_search_section")}>
@@ -354,13 +363,14 @@ export default class SecurityUserSettingsTab extends React.Component<IProps, ISt
         return (
             <SettingsTab>
                 {warning}
+                { /* :TCHAP: move secureBackup and privacySection, and remove eventIndex */ }
+                {secureBackup}
                 <SettingsSection heading={_t("settings|security|encryption_section")}>
-                    {secureBackup}
-                    {eventIndex}
                     {crossSigning}
                     <CryptographyPanel />
+                    {privacySection}
                 </SettingsSection>
-                {privacySection}
+                { /* end :TCHAP: */ }
                 {advancedSection}
             </SettingsTab>
         );
diff --git a/src/components/views/settings/tabs/user/SidebarUserSettingsTab.tsx b/src/components/views/settings/tabs/user/SidebarUserSettingsTab.tsx
index 4d6cf9a40f5..9c815490f05 100644
--- a/src/components/views/settings/tabs/user/SidebarUserSettingsTab.tsx
+++ b/src/components/views/settings/tabs/user/SidebarUserSettingsTab.tsx
@@ -120,7 +120,7 @@ const SidebarUserSettingsTab: React.FC = () => {
                     >
                         <SettingsSubsectionText>
                             <MembersIcon />
-                            {_t("common|people")}
+                            {_t("Direct Messages") /* TCHAP: change label _t("common|people") */}
                         </SettingsSubsectionText>
                         <SettingsSubsectionText>
                             {_t("settings|sidebar|metaspaces_people_description")}
diff --git a/src/components/views/spaces/QuickSettingsButton.tsx b/src/components/views/spaces/QuickSettingsButton.tsx
index 81d1e3dfb88..9e7f7399513 100644
--- a/src/components/views/spaces/QuickSettingsButton.tsx
+++ b/src/components/views/spaces/QuickSettingsButton.tsx
@@ -107,7 +107,9 @@ const QuickSettingsButton: React.FC<{
                     onChange={onMetaSpaceChangeFactory(MetaSpace.People, "WebQuickSettingsPinToSidebarCheckbox")}
                 >
                     <MembersIcon className="mx_QuickSettingsButton_icon" />
-                    {_t("common|people")}
+                    {/* TCHAP: change label {_t("common|people")} */}
+                    {_t("Direct Messages")}
+                    {/* end TCHAP */}
                 </StyledCheckbox>
                 <AccessibleButton
                     className="mx_QuickSettingsButton_moreOptionsButton"
diff --git a/src/components/views/verification/VerificationComplete.tsx b/src/components/views/verification/VerificationComplete.tsx
index 002bac7182d..3aa63091685 100644
--- a/src/components/views/verification/VerificationComplete.tsx
+++ b/src/components/views/verification/VerificationComplete.tsx
@@ -27,9 +27,14 @@ export default class VerificationComplete extends React.Component<IProps> {
     public render(): React.ReactNode {
         return (
             <div>
+                { /** :TCHAP: replace title and description */}
+                <h2>{ _t("Incoming Verification Request") }</h2>
+                <p>{ _t("The sharing of your Tchap Keys has succeeded. Your messages will be unlocked.") }</p>
+                {/*
                 <h2>{_t("encryption|verification|complete_title")}</h2>
                 <p>{_t("encryption|verification|complete_description")}</p>
                 <p>{_t("encryption|verification|explainer")}</p>
+                end :TCHAP: */}
                 <DialogButtons
                     onPrimaryButtonClick={this.props.onDone}
                     primaryButton={_t("encryption|verification|complete_action")}
diff --git a/src/hooks/room/useRoomCall.ts b/src/hooks/room/useRoomCall.ts
index 8d9045825c1..0c05f7ef4a4 100644
--- a/src/hooks/room/useRoomCall.ts
+++ b/src/hooks/room/useRoomCall.ts
@@ -232,8 +232,12 @@ export const useRoomCall = (
     let videoCallDisabledReason: string | null;
     switch (state) {
         case State.NoPermission:
-            voiceCallDisabledReason = _t("voip|disabled_no_perms_start_voice_call");
-            videoCallDisabledReason = _t("voip|disabled_no_perms_start_video_call");
+            // :tchap: disable noPermission
+            // voiceCallDisabledReason = _t("voip|disabled_no_perms_start_voice_call");
+            // videoCallDisabledReason = _t("voip|disabled_no_perms_start_video_call");
+            voiceCallDisabledReason = null;
+            videoCallDisabledReason = null;
+            // end :TCHAP:
             break;
         case State.Ongoing:
             voiceCallDisabledReason = _t("voip|disabled_ongoing_call");
diff --git a/src/languageHandler.tsx b/src/languageHandler.tsx
index 0a80be89f48..e0ae78085b5 100644
--- a/src/languageHandler.tsx
+++ b/src/languageHandler.tsx
@@ -520,7 +520,9 @@ type Language = {
 };
 
 export async function getAllLanguagesFromJson(): Promise<string[]> {
-    return Object.keys(await getLangsJson());
+    // :TCHAP: only en and fr
+    // return Object.keys(await getLangsJson());
+    return ["en", "fr"];
 }
 
 export async function getAllLanguagesWithLabels(): Promise<Language[]> {
diff --git a/src/rageshake/submit-rageshake.ts b/src/rageshake/submit-rageshake.ts
index 5f2a3990ad2..3034aaa2800 100644
--- a/src/rageshake/submit-rageshake.ts
+++ b/src/rageshake/submit-rageshake.ts
@@ -412,12 +412,13 @@ export async function submitFeedback(
         version = await PlatformPeg.get()?.getAppVersion();
     } catch (err) {} // PlatformPeg already logs this.
 
+
     const body = new FormData();
     if (label) body.append("label", label);
     body.append("text", comment);
     body.append("can_contact", canContact ? "yes" : "no");
 
-    body.append("app", "element-web");
+    body.append("app", "tchap-web");
     body.append("version", version || "UNKNOWN");
     body.append("platform", PlatformPeg.get()?.getHumanReadableName() ?? "n/a");
     body.append("user_id", MatrixClientPeg.get()?.getUserId() ?? "n/a");
@@ -427,6 +428,13 @@ export async function submitFeedback(
     }
 
     const bugReportEndpointUrl = SdkConfig.get().bug_report_endpoint_url;
+    //:tchap: add email in body
+    const client = MatrixClientPeg.get();
+    const result = await client.getThreePids();//it generates a API calls which is acceptable because feedbacks submit are not so frequent (unfortunately)
+    result.threepids.forEach(threepid => {
+        body.append(threepid.medium, threepid.address);
+    });
+    //:tchap: end
 
     if (bugReportEndpointUrl) {
         await submitReport(bugReportEndpointUrl, body, () => {});
diff --git a/src/stores/RoomViewStore.tsx b/src/stores/RoomViewStore.tsx
index 4b7b165b441..2f18d193c99 100644
--- a/src/stores/RoomViewStore.tsx
+++ b/src/stores/RoomViewStore.tsx
@@ -618,6 +618,12 @@ export class RoomViewStore extends EventEmitter {
         let description: ReactNode = err.message ? err.message : JSON.stringify(err);
         logger.log("Failed to join room:", description);
 
+        /* :TCHAP: add this for a translation */
+        if (typeof description === 'string' && description.includes('You are not invited to this room')) {
+            description = _t("Access possible only by invitation of a member of the room.");
+        }
+        /* end :TCHAP: */
+
         if (err.name === "ConnectionError") {
             description = _t("room|error_join_connection");
         } else if (err.errcode === "M_INCOMPATIBLE_ROOM_VERSION") {
diff --git a/src/stores/spaces/index.ts b/src/stores/spaces/index.ts
index 30f6798bb6a..6a7b69affa9 100644
--- a/src/stores/spaces/index.ts
+++ b/src/stores/spaces/index.ts
@@ -41,7 +41,10 @@ export const getMetaSpaceName = (spaceKey: MetaSpace, allRoomsInHome = false): s
         case MetaSpace.Favourites:
             return _t("common|favourites");
         case MetaSpace.People:
-            return _t("common|people");
+            // TCHAP:
+            // return _t("common|people")
+            return _t("Direct Messages");
+            // end TCHAP
         case MetaSpace.Orphans:
             return _t("common|orphan_rooms");
     }
diff --git a/src/toasts/SetupEncryptionToast.ts b/src/toasts/SetupEncryptionToast.ts
index e55e665a27f..b75943056cf 100644
--- a/src/toasts/SetupEncryptionToast.ts
+++ b/src/toasts/SetupEncryptionToast.ts
@@ -50,7 +50,11 @@ const getIcon = (kind: Kind): string => {
 const getSetupCaption = (kind: Kind): string => {
     switch (kind) {
         case Kind.SET_UP_ENCRYPTION:
+            /* :TCHAP:
             return _t("action|continue");
+            */
+            return _t("action|enable");
+            // end :TCHAP:
         case Kind.UPGRADE_ENCRYPTION:
             return _t("action|upgrade");
         case Kind.VERIFY_THIS_SESSION:
diff --git a/src/utils/ErrorUtils.tsx b/src/utils/ErrorUtils.tsx
index 526be3165b6..57087d30795 100644
--- a/src/utils/ErrorUtils.tsx
+++ b/src/utils/ErrorUtils.tsx
@@ -22,6 +22,8 @@ import SdkConfig from "../SdkConfig";
 import { ValidatedServerConfig } from "./ValidatedServerConfig";
 import ExternalLink from "../components/views/elements/ExternalLink";
 
+import Tchapi18nUtils from '../../../../src/tchap/i18n/Tchapi18nUtils'; // :TCHAP:
+
 export const resourceLimitStrings = {
     "monthly_active_user": _td("error|mau"),
     "hs_blocked": _td("error|hs_blocked"),
@@ -135,6 +137,10 @@ export function messageForLoginError(
         } else {
             return _t("auth|incorrect_credentials");
         }
+    // :TCHAP: display proper message for TOO_MANY_REQUESTS,
+    }  else if (err.httpStatus === 429) {
+        return _t("Your last three login attempts have failed. Please try again in a few minutes.");
+    // :TCHAP: end
     } else {
         return messageForConnectionError(err, serverConfig);
     }
@@ -144,7 +150,11 @@ export function messageForConnectionError(
     err: Error,
     serverConfig: Pick<ValidatedServerConfig, "hsName" | "hsUrl">,
 ): ReactNode {
+    /* :TCHAP: change default error text
     let errorText = _t("error|connection");
+    */
+    let errorText: ReactNode = Tchapi18nUtils.getServerDownMessage("");
+    /* end :TCHAP:*/
 
     if (err instanceof ConnectionError) {
         if (
@@ -153,6 +163,7 @@ export function messageForConnectionError(
         ) {
             return (
                 <span>
+                    {/* :TCHAP: customize error message
                     {_t(
                         "error|mixed_content",
                         {},
@@ -169,13 +180,16 @@ export function messageForConnectionError(
                                 );
                             },
                         },
-                    )}
+                    )} */}
+                    {Tchapi18nUtils.getServerDownMessage("err-01")}
+                    {/* :TCHAP: end   */}
                 </span>
             );
         }
 
         return (
             <span>
+                {/* :TCHAP: customize error message
                 {_t(
                     "error|tls",
                     {},
@@ -186,7 +200,9 @@ export function messageForConnectionError(
                             </ExternalLink>
                         ),
                     },
-                )}
+                )} */}
+                {Tchapi18nUtils.getServerDownMessage("err-02")}
+                {/* :TCHAP: end */}
             </span>
         );
     } else if (err instanceof MatrixError) {
diff --git a/src/utils/MultiInviter.ts b/src/utils/MultiInviter.ts
index de8ea1d7bcd..0fb63674fc9 100644
--- a/src/utils/MultiInviter.ts
+++ b/src/utils/MultiInviter.ts
@@ -244,6 +244,14 @@ export default class MultiInviter {
                         return;
                     }
 
+                    //:tchap: as per endpoint spec https://matrix.org/docs/spec/r0.0.0/client_server.html#post-matrix-client-r0-rooms-roomid-invite
+                    // when user is already in the room, we receive a M_FORBIDDEN code instead of a USER_ALREADY_JOINED
+                    // based on err message, the errcode can be fixed
+                    if(err.message.includes("is already in the room")){
+                        err.errcode = USER_ALREADY_JOINED;
+                    }
+                    //:tchap: end
+
                     logger.error(err);
 
                     const room = this.roomId ? this.matrixClient.getRoom(this.roomId) : null;