diff --git a/packages/core/src/browser/authentication-service.ts b/packages/core/src/browser/authentication-service.ts
index c47af042a4ae0..2572a4d0a1e61 100644
--- a/packages/core/src/browser/authentication-service.ts
+++ b/packages/core/src/browser/authentication-service.ts
@@ -47,9 +47,9 @@ export interface AuthenticationProviderInformation {
 
 /** Should match the definition from the theia/vscode types */
 export interface AuthenticationProviderAuthenticationSessionsChangeEvent {
-    readonly added: ReadonlyArray<AuthenticationSession | string | undefined>;
-    readonly removed: ReadonlyArray<AuthenticationSession | string | undefined>;
-    readonly changed: ReadonlyArray<AuthenticationSession | string | undefined>;
+    readonly added: readonly AuthenticationSession[] | undefined;
+    readonly removed: readonly AuthenticationSession[] | undefined;
+    readonly changed: readonly AuthenticationSession[] | undefined;
 }
 
 export interface SessionRequest {
@@ -61,24 +61,35 @@ export interface SessionRequestInfo {
     [scopes: string]: SessionRequest;
 }
 
-/** Should match the definition from the theia/vscode types */
+/**
+ * Our authentication provider should at least contain the following information:
+ * - The signuature of authentication providers from vscode
+ * - Registration information about the provider (id, label)
+ * - Provider options (supportsMultipleAccounts)
+ *
+ * Additionally, we provide the possibility to sign out of a specific account name.
+ */
 export interface AuthenticationProvider {
     id: string;
 
-    supportsMultipleAccounts: boolean;
-
     label: string;
 
+    supportsMultipleAccounts: boolean;
+
     hasSessions(): boolean;
 
     signOut(accountName: string): Promise<void>;
 
-    getSessions(scopes?: string[]): Promise<ReadonlyArray<AuthenticationSession>>;
-
     updateSessionItems(event: AuthenticationProviderAuthenticationSessionsChangeEvent): Promise<void>;
 
+    /**
+     * @deprecated use `createSession` instead.
+     */
     login(scopes: string[]): Promise<AuthenticationSession>;
 
+    /**
+     * @deprecated use `removeSession` instead.
+     */
     logout(sessionId: string): Promise<void>;
 
     /**
@@ -169,7 +180,7 @@ export class AuthenticationServiceImpl implements AuthenticationService {
     }
 
     protected async handleSessionChange(changeEvent: SessionChangeEvent): Promise<void> {
-        if (changeEvent.event.added.length > 0) {
+        if (changeEvent.event.added && changeEvent.event.added.length > 0) {
             const sessions = await this.getSessions(changeEvent.providerId);
             sessions.forEach(session => {
                 if (!this.sessionMap.get(session.id)) {
@@ -177,7 +188,7 @@ export class AuthenticationServiceImpl implements AuthenticationService {
                 }
             });
         }
-        for (const removed of changeEvent.event.removed) {
+        for (const removed of changeEvent.event.removed || []) {
             const sessionId = typeof removed === 'string' ? removed : removed?.id;
             if (sessionId) {
                 this.sessionMap.get(sessionId)?.dispose();
@@ -400,7 +411,7 @@ export class AuthenticationServiceImpl implements AuthenticationService {
     async login(id: string, scopes: string[]): Promise<AuthenticationSession> {
         const authProvider = this.authenticationProviders.get(id);
         if (authProvider) {
-            return authProvider.login(scopes);
+            return authProvider.createSession(scopes);
         } else {
             throw new Error(`No authentication provider '${id}' is currently registered.`);
         }
@@ -409,7 +420,7 @@ export class AuthenticationServiceImpl implements AuthenticationService {
     async logout(id: string, sessionId: string): Promise<void> {
         const authProvider = this.authenticationProviders.get(id);
         if (authProvider) {
-            return authProvider.logout(sessionId);
+            return authProvider.removeSession(sessionId);
         } else {
             throw new Error(`No authentication provider '${id}' is currently registered.`);
         }
diff --git a/packages/plugin-ext/src/common/plugin-api-rpc.ts b/packages/plugin-ext/src/common/plugin-api-rpc.ts
index f46c2c0a31f3f..83c59b66091d7 100644
--- a/packages/plugin-ext/src/common/plugin-api-rpc.ts
+++ b/packages/plugin-ext/src/common/plugin-api-rpc.ts
@@ -1943,20 +1943,15 @@ export interface AuthenticationExt {
     $getSessions(id: string, scopes?: string[]): Promise<ReadonlyArray<theia.AuthenticationSession>>;
     $createSession(id: string, scopes: string[]): Promise<theia.AuthenticationSession>;
     $removeSession(id: string, sessionId: string): Promise<void>;
-    $onDidChangeAuthenticationSessions(id: string, label: string): Promise<void>;
-    $onDidChangeAuthenticationProviders(added: theia.AuthenticationProviderInformation[], removed: theia.AuthenticationProviderInformation[]): Promise<void>;
-    $setProviders(providers: theia.AuthenticationProviderInformation[]): Promise<void>;
+    $onDidChangeAuthenticationSessions(provider: theia.AuthenticationProviderInformation): Promise<void>;
 }
 
 export interface AuthenticationMain {
     $registerAuthenticationProvider(id: string, label: string, supportsMultipleAccounts: boolean): void;
     $unregisterAuthenticationProvider(id: string): void;
-    $getProviderIds(): Promise<string[]>;
-    $ensureProvider(id: string): Promise<void>;
-    $sendDidChangeSessions(providerId: string, event: AuthenticationProviderAuthenticationSessionsChangeEvent): void;
+    $onDidChangeSessions(providerId: string, event: AuthenticationProviderAuthenticationSessionsChangeEvent): void;
     $getSession(providerId: string, scopes: readonly string[], extensionId: string, extensionName: string,
         options: theia.AuthenticationGetSessionOptions): Promise<theia.AuthenticationSession | undefined>;
-    $removeSession(providerId: string, sessionId: string): Promise<void>;
 }
 
 export interface RawColorInfo {
diff --git a/packages/plugin-ext/src/main/browser/authentication-main.ts b/packages/plugin-ext/src/main/browser/authentication-main.ts
index 171d7238cc535..1dee9c1f062ef 100644
--- a/packages/plugin-ext/src/main/browser/authentication-main.ts
+++ b/packages/plugin-ext/src/main/browser/authentication-main.ts
@@ -21,7 +21,7 @@
 // code copied and modified from https://github.com/microsoft/vscode/blob/1.47.3/src/vs/workbench/api/browser/mainThreadAuthentication.ts
 
 import { interfaces } from '@theia/core/shared/inversify';
-import { AuthenticationExt, AuthenticationMain, PluginManagerExt, MAIN_RPC_CONTEXT } from '../../common/plugin-api-rpc';
+import { AuthenticationExt, AuthenticationMain, MAIN_RPC_CONTEXT } from '../../common/plugin-api-rpc';
 import { RPCProtocol } from '../../common/rpc-protocol';
 import { MessageService } from '@theia/core/lib/common/message-service';
 import { Dialog, StorageService } from '@theia/core/lib/browser';
@@ -43,28 +43,17 @@ export class AuthenticationMainImpl implements AuthenticationMain {
     private readonly storageService: StorageService;
     private readonly authenticationService: AuthenticationService;
     private readonly quickPickService: QuickPickService;
-    private readonly extensionService: PluginManagerExt;
     constructor(rpc: RPCProtocol, container: interfaces.Container) {
         this.proxy = rpc.getProxy(MAIN_RPC_CONTEXT.AUTHENTICATION_EXT);
         this.messageService = container.get(MessageService);
         this.storageService = container.get(StorageService);
         this.authenticationService = container.get(AuthenticationService);
         this.quickPickService = container.get(QuickPickService);
-        this.extensionService = rpc.getProxy(MAIN_RPC_CONTEXT.HOSTED_PLUGIN_MANAGER_EXT);
 
         this.authenticationService.onDidChangeSessions(e => {
-            this.proxy.$onDidChangeAuthenticationSessions(e.providerId, e.label);
-        });
-        this.authenticationService.onDidRegisterAuthenticationProvider(info => {
-            this.proxy.$onDidChangeAuthenticationProviders([info], []);
-        });
-        this.authenticationService.onDidUnregisterAuthenticationProvider(providerId => {
-            this.proxy.$onDidChangeAuthenticationProviders([], [providerId]);
+            this.proxy.$onDidChangeAuthenticationSessions({ id: e.providerId, label: e.label });
         });
     }
-    $getProviderIds(): Promise<string[]> {
-        return Promise.resolve(this.authenticationService.getProviderIds());
-    }
 
     async $registerAuthenticationProvider(id: string, label: string, supportsMultipleAccounts: boolean): Promise<void> {
         const provider = new AuthenticationProviderImpl(this.proxy, id, label, supportsMultipleAccounts, this.storageService, this.messageService);
@@ -230,15 +219,7 @@ export class AuthenticationMainImpl implements AuthenticationMain {
         this.storageService.setData(`authentication-session-${extensionName}-${providerId}`, sessionId);
     }
 
-    $ensureProvider(id: string): Promise<void> {
-        return this.extensionService.$activateByEvent(getAuthenticationProviderActivationEvent(id));
-    }
-
-    $removeSession(providerId: string, sessionId: string): Promise<void> {
-        return this.authenticationService.logout(providerId, sessionId);
-    }
-
-    $sendDidChangeSessions(providerId: string, event: theia.AuthenticationProviderAuthenticationSessionsChangeEvent): void {
+    $onDidChangeSessions(providerId: string, event: theia.AuthenticationProviderAuthenticationSessionsChangeEvent): void {
         this.authenticationService.updateSessions(providerId, event);
     }
 }
@@ -272,8 +253,10 @@ interface AccountUsage {
 }
 
 export class AuthenticationProviderImpl implements AuthenticationProvider {
-    private accounts = new Map<string, string[]>(); // Map account name to session ids
-    private sessions = new Map<string, string>(); // Map account id to name
+    /** map from account name to session ids */
+    private accounts = new Map<string, string[]>();
+    /** map from session id to account name */
+    private sessions = new Map<string, string>();
 
     readonly onDidChangeSessions: theia.Event<theia.AuthenticationProviderAuthenticationSessionsChangeEvent>;
 
@@ -313,7 +296,7 @@ export class AuthenticationProviderImpl implements AuthenticationProvider {
             Dialog.CANCEL);
 
         if (result && result === nls.localizeByDefault('Sign Out') && sessionsForAccount) {
-            sessionsForAccount.forEach(sessionId => this.logout(sessionId));
+            sessionsForAccount.forEach(sessionId => this.removeSession(sessionId));
             removeAccountUsage(this.storageService, this.id, accountName);
         }
     }
@@ -325,10 +308,10 @@ export class AuthenticationProviderImpl implements AuthenticationProvider {
     async updateSessionItems(event: theia.AuthenticationProviderAuthenticationSessionsChangeEvent): Promise<void> {
         const { added, removed } = event;
         const session = await this.proxy.$getSessions(this.id);
-        const addedSessions = session.filter(s => added.some(addedSession => this.getSessionId(addedSession) === s.id));
+        const addedSessions = added ? session.filter(s => added.some(addedSession => addedSession.id === s.id)) : [];
 
-        removed.forEach(removedSession => {
-            const sessionId = this.getSessionId(removedSession);
+        removed?.forEach(removedSession => {
+            const sessionId = removedSession.id;
             if (sessionId) {
                 const accountName = this.sessions.get(sessionId);
                 if (accountName) {
@@ -347,29 +330,21 @@ export class AuthenticationProviderImpl implements AuthenticationProvider {
         addedSessions.forEach(s => this.registerSession(s));
     }
 
-    login(scopes: string[]): Promise<theia.AuthenticationSession> {
-        return this.proxy.$createSession(this.id, scopes);
+    async login(scopes: string[]): Promise<theia.AuthenticationSession> {
+        return this.createSession(scopes);
     }
 
     async logout(sessionId: string): Promise<void> {
-        await this.proxy.$removeSession(this.id, sessionId);
-        this.messageService.info('Successfully signed out.');
+        return this.removeSession(sessionId);
     }
 
     createSession(scopes: string[]): Thenable<theia.AuthenticationSession> {
-        return this.login(scopes);
+        return this.proxy.$createSession(this.id, scopes);
     }
 
     removeSession(sessionId: string): Thenable<void> {
-        return this.logout(sessionId);
-    }
-
-    // utility method to be backwards compatible with the old AuthenticationProviderAuthenticationSessionsChangeEvent containing only the session id string
-    private getSessionId(obj: string | theia.AuthenticationSession | undefined): string | undefined {
-        if (!obj || typeof obj === 'string') {
-            return obj;
-        }
-        return obj.id;
+        return this.proxy.$removeSession(this.id, sessionId)
+            .then(() => { this.messageService.info('Successfully signed out.'); });
     }
 }
 
diff --git a/packages/plugin-ext/src/plugin/authentication-ext.ts b/packages/plugin-ext/src/plugin/authentication-ext.ts
index 64e403172f9bb..63e34c214808d 100644
--- a/packages/plugin-ext/src/plugin/authentication-ext.ts
+++ b/packages/plugin-ext/src/plugin/authentication-ext.ts
@@ -34,13 +34,6 @@ export class AuthenticationExtImpl implements AuthenticationExt {
     private proxy: AuthenticationMain;
     private authenticationProviders: Map<string, theia.AuthenticationProvider> = new Map<string, theia.AuthenticationProvider>();
 
-    private _providerIds: string[] = [];
-
-    private _providers: theia.AuthenticationProviderInformation[] = [];
-
-    private onDidChangeAuthenticationProvidersEmitter = new Emitter<theia.AuthenticationProvidersChangeEvent>();
-    readonly onDidChangeAuthenticationProviders: Event<theia.AuthenticationProvidersChangeEvent> = this.onDidChangeAuthenticationProvidersEmitter.event;
-
     private onDidChangeSessionsEmitter = new Emitter<theia.AuthenticationSessionsChangeEvent>();
     readonly onDidChangeSessions: Event<theia.AuthenticationSessionsChangeEvent> = this.onDidChangeSessionsEmitter.event;
 
@@ -48,18 +41,6 @@ export class AuthenticationExtImpl implements AuthenticationExt {
         this.proxy = rpc.getProxy(PLUGIN_RPC_CONTEXT.AUTHENTICATION_MAIN);
     }
 
-    getProviderIds(): Promise<ReadonlyArray<string>> {
-        return this.proxy.$getProviderIds();
-    }
-
-    get providerIds(): string[] {
-        return this._providerIds;
-    }
-
-    get providers(): ReadonlyArray<theia.AuthenticationProviderInformation> {
-        return Object.freeze(this._providers.slice());
-    }
-
     async getSession(requestingExtension: InternalPlugin, providerId: string, scopes: readonly string[],
         options: theia.AuthenticationGetSessionOptions & ({ createIfNone: true } | { forceNewSession: true } | { forceNewSession: { detail: string } })):
         Promise<theia.AuthenticationSession>;
@@ -76,29 +57,14 @@ export class AuthenticationExtImpl implements AuthenticationExt {
         return this.proxy.$getSession(providerId, scopes, extensionId, extensionName, options);
     }
 
-    async logout(providerId: string, sessionId: string): Promise<void> {
-        return this.proxy.$removeSession(providerId, sessionId);
-    }
-
     registerAuthenticationProvider(id: string, label: string, provider: theia.AuthenticationProvider, options?: theia.AuthenticationProviderOptions): theia.Disposable {
         if (this.authenticationProviders.get(id)) {
             throw new Error(`An authentication provider with id '${id}' is already registered.`);
         }
 
         this.authenticationProviders.set(id, provider);
-        if (this._providerIds.indexOf(id) === -1) {
-            this._providerIds.push(id);
-        }
-
-        if (!this._providers.find(p => p.id === id)) {
-            this._providers.push({
-                id,
-                label
-            });
-        }
-
         const listener = provider.onDidChangeSessions(e => {
-            this.proxy.$sendDidChangeSessions(id, e);
+            this.proxy.$onDidChangeSessions(id, e);
         });
 
         this.proxy.$registerAuthenticationProvider(id, label, !!options?.supportsMultipleAccounts);
@@ -106,16 +72,6 @@ export class AuthenticationExtImpl implements AuthenticationExt {
         return new Disposable(() => {
             listener.dispose();
             this.authenticationProviders.delete(id);
-            const index = this._providerIds.findIndex(pid => id === pid);
-            if (index > -1) {
-                this._providerIds.splice(index);
-            }
-
-            const i = this._providers.findIndex(p => p.id === id);
-            if (i > -1) {
-                this._providers.splice(i);
-            }
-
             this.proxy.$unregisterAuthenticationProvider(id);
         });
     }
@@ -163,30 +119,7 @@ export class AuthenticationExtImpl implements AuthenticationExt {
         throw new Error(`Unable to find authentication provider with handle: ${providerId}`);
     }
 
-    $onDidChangeAuthenticationSessions(id: string, label: string): Promise<void> {
-        this.onDidChangeSessionsEmitter.fire({ provider: { id, label } });
-        return Promise.resolve();
-    }
-
-    async $onDidChangeAuthenticationProviders(added: theia.AuthenticationProviderInformation[], removed: theia.AuthenticationProviderInformation[]): Promise<void> {
-        added.forEach(id => {
-            if (this._providers.indexOf(id) === -1) {
-                this._providers.push(id);
-            }
-        });
-
-        removed.forEach(p => {
-            const index = this._providers.findIndex(provider => provider.id === p.id);
-            if (index > -1) {
-                this._providers.splice(index);
-            }
-        });
-
-        this.onDidChangeAuthenticationProvidersEmitter.fire({ added, removed });
-    }
-
-    $setProviders(providers: theia.AuthenticationProviderInformation[]): Promise<void> {
-        this._providers.push(...providers);
-        return Promise.resolve(undefined);
+    async $onDidChangeAuthenticationSessions(provider: theia.AuthenticationProviderInformation): Promise<void> {
+        this.onDidChangeSessionsEmitter.fire({ provider });
     }
 }
diff --git a/packages/plugin-ext/src/plugin/plugin-context.ts b/packages/plugin-ext/src/plugin/plugin-context.ts
index 00fddb1f7c806..88566167e1bd5 100644
--- a/packages/plugin-ext/src/plugin/plugin-context.ts
+++ b/packages/plugin-ext/src/plugin/plugin-context.ts
@@ -224,50 +224,14 @@ export function createAPIFactory(
 
     return function (plugin: InternalPlugin): typeof theia {
         const authentication: typeof theia.authentication = {
-            // support older (< 1.53.0) and newer version of authentication provider registration
-            registerAuthenticationProvider(
-                id: string | theia.AuthenticationProvider, label?: string, provider?: theia.AuthenticationProvider, options?: theia.AuthenticationProviderOptions):
-                theia.Disposable {
-                // collect registration data based on registration type: new (all parameters given) vs old (data stored in provider)
-                const isNewRegistration = typeof id === 'string';
-                const regProvider = isNewRegistration ? provider! : id;
-                const regId = isNewRegistration ? id : regProvider.id;
-                const regLabel = isNewRegistration ? label! : regProvider.label;
-                const regOptions = isNewRegistration ? options : { supportsMultipleAccounts: regProvider.supportsMultipleAccounts };
-
-                // ensure that all methods of the new AuthenticationProvider are available or delegate otherwise
-                if (!regProvider['createSession']) {
-                    regProvider['createSession'] = (scopes: string[]) => regProvider.login(scopes);
-                }
-                if (!regProvider['removeSession']) {
-                    regProvider['removeSession'] = (sessionId: string) => regProvider.logout(sessionId);
-                }
-                return authenticationExt.registerAuthenticationProvider(regId, regLabel, regProvider, regOptions);
-            },
-            get onDidChangeAuthenticationProviders(): theia.Event<theia.AuthenticationProvidersChangeEvent> {
-                return authenticationExt.onDidChangeAuthenticationProviders;
-            },
-            getProviderIds(): Thenable<ReadonlyArray<string>> {
-                return Promise.resolve(authenticationExt.providerIds);
-            },
-            get providerIds(): string[] {
-                return authenticationExt.providerIds;
-            },
-            get providers(): ReadonlyArray<theia.AuthenticationProviderInformation> {
-                return authenticationExt.providers;
+            registerAuthenticationProvider(id: string, label: string, provider: theia.AuthenticationProvider, options?: theia.AuthenticationProviderOptions): theia.Disposable {
+                return authenticationExt.registerAuthenticationProvider(id, label, provider, options);
             },
             getSession(providerId: string, scopes: string[], options: theia.AuthenticationGetSessionOptions) {
                 return authenticationExt.getSession(plugin, providerId, scopes, options as any);
             },
-            logout(providerId: string, sessionId: string): Thenable<void> {
-                return authenticationExt.logout(providerId, sessionId);
-            },
             get onDidChangeSessions(): theia.Event<theia.AuthenticationSessionsChangeEvent> {
                 return authenticationExt.onDidChangeSessions;
-            },
-            async hasSession(providerId: string, scopes: readonly string[]): Promise<boolean> {
-                const session = await authenticationExt.getSession(plugin, providerId, scopes, { silent: true });
-                return !!session;
             }
         };
         const commands: typeof theia.commands = {
diff --git a/packages/plugin/src/theia-proposed.d.ts b/packages/plugin/src/theia-proposed.d.ts
index 367c0079ec1f8..509e548003203 100644
--- a/packages/plugin/src/theia-proposed.d.ts
+++ b/packages/plugin/src/theia-proposed.d.ts
@@ -21,130 +21,6 @@
  * These API are NOT stable and subject to change. Use it on own risk.
  */
 export module '@theia/plugin' {
-    // #region auth provider
-
-    /**
-     * An [event](#Event) which fires when an [AuthenticationProvider](#AuthenticationProvider) is added or removed.
-     */
-    export interface AuthenticationProvidersChangeEvent {
-        /**
-         * The ids of the [authenticationProvider](#AuthenticationProvider)s that have been added.
-         */
-        readonly added: ReadonlyArray<AuthenticationProviderInformation>;
-
-        /**
-         * The ids of the [authenticationProvider](#AuthenticationProvider)s that have been removed.
-         */
-        readonly removed: ReadonlyArray<AuthenticationProviderInformation>;
-    }
-
-    /**
-     * An [event](#Event) which fires when an [AuthenticationSession](#AuthenticationSession) is added, removed, or changed.
-     */
-    export interface AuthenticationProviderAuthenticationSessionsChangeEvent {
-        /**
-         * The ids of the [AuthenticationSession](#AuthenticationSession)s that have been added.
-         */
-        readonly added: ReadonlyArray<string>;
-
-        /**
-         * The ids of the [AuthenticationSession](#AuthenticationSession)s that have been removed.
-         */
-        readonly removed: ReadonlyArray<string>;
-
-        /**
-         * The ids of the [AuthenticationSession](#AuthenticationSession)s that have been changed.
-         */
-        readonly changed: ReadonlyArray<string>;
-    }
-
-    /**
-     * **WARNING** When writing an AuthenticationProvider, `id` should be treated as part of your extension's
-     * API, changing it is a breaking change for all extensions relying on the provider. The id is
-     * treated case-sensitively.
-     */
-    export interface AuthenticationProvider {
-        /**
-         * Used as an identifier for extensions trying to work with a particular
-         * provider: 'microsoft', 'github', etc. id must be unique, registering
-         * another provider with the same id will fail.
-         */
-        readonly id: string;
-
-        /**
-         * The human-readable name of the provider.
-         */
-        readonly label: string;
-
-        /**
-         * Whether it is possible to be signed into multiple accounts at once with this provider
-         */
-        readonly supportsMultipleAccounts: boolean;
-
-        /**
-         * Returns an array of current sessions.
-         */
-        getSessions(): Thenable<ReadonlyArray<AuthenticationSession>>;
-
-        /**
-         * Prompts a user to login.
-         */
-        login(scopes: string[]): Thenable<AuthenticationSession>;
-
-        /**
-         * Removes the session corresponding to session id.
-         * @param sessionId The session id to log out of
-         */
-        logout(sessionId: string): Thenable<void>;
-    }
-
-    export namespace authentication {
-        /**
-         * Register an authentication provider.
-         *
-         * There can only be one provider per id and an error is being thrown when an id
-         * has already been used by another provider.
-         *
-         * @param provider The authentication provider provider.
-         * @return A [disposable](#Disposable) that unregisters this provider when being disposed.
-         */
-        export function registerAuthenticationProvider(provider: AuthenticationProvider): Disposable;
-
-        /**
-         * Fires with the provider id that was registered or unregistered.
-         */
-        export const onDidChangeAuthenticationProviders: Event<AuthenticationProvidersChangeEvent>;
-
-        /**
-         * @deprecated
-         * The ids of the currently registered authentication providers.
-         * @returns An array of the ids of authentication providers that are currently registered.
-         */
-        export function getProviderIds(): Thenable<ReadonlyArray<string>>;
-
-        /**
-         * @deprecated
-         * An array of the ids of authentication providers that are currently registered.
-         */
-        export const providerIds: ReadonlyArray<string>;
-
-        /**
-         * An array of the information of authentication providers that are currently registered.
-         */
-        export const providers: ReadonlyArray<AuthenticationProviderInformation>;
-
-        /**
-         * @deprecated
-         * Logout of a specific session.
-         * @param providerId The id of the provider to use
-         * @param sessionId The session id to remove
-         * provider
-         */
-        export function logout(providerId: string, sessionId: string): Thenable<void>;
-    }
-
-    // #endregion
-
     /**
      * The contiguous set of modified lines in a diff.
      */
diff --git a/packages/plugin/src/theia.d.ts b/packages/plugin/src/theia.d.ts
index 825a44b33a0fc..f80aca2ac1b6a 100644
--- a/packages/plugin/src/theia.d.ts
+++ b/packages/plugin/src/theia.d.ts
@@ -11815,7 +11815,7 @@ export module '@theia/plugin' {
          * The permissions granted by the session's access token. Available scopes
          * are defined by the [AuthenticationProvider](#AuthenticationProvider).
          */
-        readonly scopes: ReadonlyArray<string>;
+        readonly scopes: readonly string[];
     }
 
     /**
@@ -12050,12 +12050,6 @@ export module '@theia/plugin' {
          * @return A {@link Disposable} that unregisters this provider when being disposed.
          */
         export function registerAuthenticationProvider(id: string, label: string, provider: AuthenticationProvider, options?: AuthenticationProviderOptions): Disposable;
-
-        /**
-         * @deprecated Use {@link getSession()} {@link AuthenticationGetSessionOptions.silent} instead.
-         */
-        export function hasSession(providerId: string, scopes: readonly string[]): Thenable<boolean>;
-
     }
 }