diff --git a/src/api/admin/AdminService.ts b/src/api/admin/AdminService.ts
index 5ab018b..0a4004f 100644
--- a/src/api/admin/AdminService.ts
+++ b/src/api/admin/AdminService.ts
@@ -1,10 +1,12 @@
-import { GET, Path, QueryParam } from "typescript-rest";
+import { GET, Path, POST, QueryParam } from "typescript-rest";
 import { ScalarService } from "../scalar/ScalarService";
 import config from "../../config";
 import { ApiError } from "../ApiError";
 import { MatrixLiteClient } from "../../matrix/MatrixLiteClient";
 import { CURRENT_VERSION } from "../../version";
 import { getFederationConnInfo } from "../../matrix/helpers";
+import UserScalarToken from "../../db/models/UserScalarToken";
+import { Cache, CACHE_SCALAR_ACCOUNTS } from "../../MemoryCache";
 
 interface DimensionVersionResponse {
     version: string;
@@ -20,6 +22,9 @@ interface DimensionConfigResponse {
         federationHostname: string;
         clientServerUrl: string;
     };
+    sessionInfo: {
+        numTokens: number;
+    };
 }
 
 /**
@@ -82,6 +87,9 @@ export class AdminService {
                 federationHostname: fedInfo.hostname,
                 clientServerUrl: config.homeserver.clientServerUrl,
             },
+            sessionInfo: {
+                numTokens: await UserScalarToken.count(),
+            },
         };
     }
 
@@ -95,4 +103,23 @@ export class AdminService {
             resolvedServer: await getFederationConnInfo(serverName),
         };
     }
+
+    @POST
+    @Path("sessions/logout/all")
+    public async logoutAll(@QueryParam("scalar_token") scalarToken: string): Promise<any> {
+        await AdminService.validateAndGetAdminTokenOwner(scalarToken);
+
+        // Clear the cache first to hopefully invalidate a bunch of them
+        Cache.for(CACHE_SCALAR_ACCOUNTS).clear();
+
+        const tokens = await UserScalarToken.all();
+        for (const token of tokens) {
+            await token.destroy();
+        }
+
+        // Clear it again because the delete loop can be slow
+        Cache.for(CACHE_SCALAR_ACCOUNTS).clear();
+
+        return {};
+    }
 }
\ No newline at end of file
diff --git a/src/api/scalar/ScalarService.ts b/src/api/scalar/ScalarService.ts
index b7c9b1d..afabeb5 100644
--- a/src/api/scalar/ScalarService.ts
+++ b/src/api/scalar/ScalarService.ts
@@ -49,7 +49,11 @@ export class ScalarService {
 
     @POST
     @Path("register")
-    public async register(request: RegisterRequest): Promise<ScalarRegisterResponse> {
+    public async register(request: RegisterRequest, @QueryParam("v") apiVersion: string): Promise<ScalarRegisterResponse> {
+        if (apiVersion !== "1.1") {
+            throw new ApiError(401, "Invalid API version.");
+        }
+
         const mxClient = new MatrixOpenIdClient(<OpenId>request);
         const mxUserId = await mxClient.getUserId();
 
@@ -95,7 +99,11 @@ export class ScalarService {
 
     @GET
     @Path("account")
-    public async getAccount(@QueryParam("scalar_token") scalarToken: string): Promise<ScalarAccountResponse> {
+    public async getAccount(@QueryParam("scalar_token") scalarToken: string, @QueryParam("v") apiVersion: string): Promise<ScalarAccountResponse> {
+        if (apiVersion !== "1.1") {
+            throw new ApiError(401, "Invalid API version.");
+        }
+
         const userId = await ScalarService.getTokenOwner(scalarToken);
         return {user_id: userId};
     }
diff --git a/src/scalar/ScalarClient.ts b/src/scalar/ScalarClient.ts
index c042a8c..47ed0b2 100644
--- a/src/scalar/ScalarClient.ts
+++ b/src/scalar/ScalarClient.ts
@@ -3,6 +3,7 @@ import { ScalarRegisterResponse } from "../models/ScalarResponses";
 import * as request from "request";
 import { LogService } from "matrix-js-snippets";
 import Upstream from "../db/models/Upstream";
+import { SCALAR_API_VERSION } from "../utils/common-constants";
 
 export class ScalarClient {
     constructor(private upstream: Upstream) {
@@ -14,6 +15,7 @@ export class ScalarClient {
             request({
                 method: "POST",
                 url: this.upstream.scalarUrl + "/register",
+                qs: {v: SCALAR_API_VERSION},
                 json: openId,
             }, (err, res, _body) => {
                 if (err) {
diff --git a/src/utils/common-constants.ts b/src/utils/common-constants.ts
new file mode 100644
index 0000000..fe62678
--- /dev/null
+++ b/src/utils/common-constants.ts
@@ -0,0 +1 @@
+export const SCALAR_API_VERSION = "1.1";
\ No newline at end of file
diff --git a/web/app/admin/home/home.component.html b/web/app/admin/home/home.component.html
index e943a6d..a34d9ee 100644
--- a/web/app/admin/home/home.component.html
+++ b/web/app/admin/home/home.component.html
@@ -28,6 +28,16 @@
                     Utility User ID: {{ config.homeserver.userId }}
                 </div>
             </div>
+
+            <div class="row">
+                <div class="col-md-4">
+                    <strong>Sessions</strong><br />
+                    Tokens registered: {{ config.sessionInfo.numTokens }}<br />
+                    <button class="btn btn-danger btn-sm" type="button" (click)="logoutAll()">
+                        Logout Everyone
+                    </button>
+                </div>
+            </div>
         </div>
     </my-ibox>
 </div>
\ No newline at end of file
diff --git a/web/app/admin/home/home.component.ts b/web/app/admin/home/home.component.ts
index 4e3d3aa..e47bb15 100644
--- a/web/app/admin/home/home.component.ts
+++ b/web/app/admin/home/home.component.ts
@@ -1,6 +1,12 @@
 import { Component } from "@angular/core";
 import { AdminApiService } from "../../shared/services/admin/admin-api.service";
 import { FE_DimensionConfig } from "../../shared/models/admin-responses";
+import { ToasterService } from "angular2-toaster";
+import { Modal, overlayConfigFactory } from "ngx-modialog";
+import {
+    AdminLogoutConfirmationDialogComponent,
+    LogoutConfirmationDialogContext
+} from "./logout-confirmation/logout-confirmation.component";
 
 @Component({
     templateUrl: "./home.component.html",
@@ -11,10 +17,26 @@ export class AdminHomeComponent {
     public isLoading = true;
     public config: FE_DimensionConfig;
 
-    constructor(adminApi: AdminApiService) {
+    constructor(private adminApi: AdminApiService,
+                private toaster: ToasterService,
+                private modal: Modal) {
         adminApi.getConfig().then(config => {
             this.config = config;
             this.isLoading = false;
         });
     }
+
+    public logoutAll(): void {
+        this.modal.open(AdminLogoutConfirmationDialogComponent, overlayConfigFactory({
+            isBlocking: true,
+        }, LogoutConfirmationDialogContext)).result.then(() => {
+            this.adminApi.logoutAll().then(() => {
+                this.toaster.pop("success", "Everyone has been logged out");
+                this.config.sessionInfo.numTokens = 0;
+            }).catch(err => {
+                console.error(err);
+                this.toaster.pop("error", "Error logging everyone out");
+            });
+        });
+    }
 }
diff --git a/web/app/admin/home/logout-confirmation/logout-confirmation.component.html b/web/app/admin/home/logout-confirmation/logout-confirmation.component.html
new file mode 100644
index 0000000..c11da9f
--- /dev/null
+++ b/web/app/admin/home/logout-confirmation/logout-confirmation.component.html
@@ -0,0 +1,20 @@
+<div class="dialog">
+    <div class="dialog-header">
+        <h4>Logout confirmation</h4>
+    </div>
+    <div class="dialog-content">
+        <p>
+            Logging everyone out will disable all known login tokens for Dimension and upstream integration managers.
+            Most clients will automatically re-register for a login token behind the scenes, similar to how a login token
+            was first acquired.
+        </p>
+    </div>
+    <div class="dialog-footer">
+        <button type="button" (click)="dialog.dismiss()" title="close" class="btn btn-secondary btn-sm">
+            <i class="far fa-times-circle"></i> Cancel
+        </button>
+        <button type="button" (click)="dialog.close()" title="logout everyone" class="btn btn-danger btn-sm">
+            <i class="far fa-times-circle"></i> Logout Everyone
+        </button>
+    </div>
+</div>
\ No newline at end of file
diff --git a/web/app/admin/home/logout-confirmation/logout-confirmation.component.scss b/web/app/admin/home/logout-confirmation/logout-confirmation.component.scss
new file mode 100644
index 0000000..e69de29
diff --git a/web/app/admin/home/logout-confirmation/logout-confirmation.component.ts b/web/app/admin/home/logout-confirmation/logout-confirmation.component.ts
new file mode 100644
index 0000000..ce71df1
--- /dev/null
+++ b/web/app/admin/home/logout-confirmation/logout-confirmation.component.ts
@@ -0,0 +1,15 @@
+import { Component } from "@angular/core";
+import { DialogRef, ModalComponent } from "ngx-modialog";
+import { BSModalContext } from "ngx-modialog/plugins/bootstrap";
+
+export class LogoutConfirmationDialogContext extends BSModalContext {
+}
+
+@Component({
+    templateUrl: "./logout-confirmation.component.html",
+    styleUrls: ["./logout-confirmation.component.scss"],
+})
+export class AdminLogoutConfirmationDialogComponent implements ModalComponent<LogoutConfirmationDialogContext> {
+
+    constructor(public dialog: DialogRef<LogoutConfirmationDialogContext>) {}
+}
diff --git a/web/app/app.module.ts b/web/app/app.module.ts
index ef6a4a4..e2a23a0 100644
--- a/web/app/app.module.ts
+++ b/web/app/app.module.ts
@@ -109,6 +109,7 @@ import { SlackBridgeConfigComponent } from "./configs/bridge/slack/slack.bridge.
 import { AdminSlackBridgeManageSelfhostedComponent } from "./admin/bridges/slack/manage-selfhosted/manage-selfhosted.component";
 import { AdminSlackBridgeComponent } from "./admin/bridges/slack/slack.component";
 import { AdminSlackApiService } from "./shared/services/admin/admin-slack-api.service";
+import { AdminLogoutConfirmationDialogComponent } from "./admin/home/logout-confirmation/logout-confirmation.component";
 import { ReauthExampleWidgetWrapperComponent } from "./widget-wrappers/reauth-example/reauth-example.component";
 import { ManagerTestWidgetWrapperComponent } from "./widget-wrappers/manager-test/manager-test.component";
 
@@ -200,6 +201,7 @@ import { ManagerTestWidgetWrapperComponent } from "./widget-wrappers/manager-tes
         SlackBridgeConfigComponent,
         AdminSlackBridgeManageSelfhostedComponent,
         AdminSlackBridgeComponent,
+        AdminLogoutConfirmationDialogComponent,
         ReauthExampleWidgetWrapperComponent,
         ManagerTestWidgetWrapperComponent,
 
@@ -254,6 +256,7 @@ import { ManagerTestWidgetWrapperComponent } from "./widget-wrappers/manager-tes
         AdminGitterBridgeManageSelfhostedComponent,
         AdminAddCustomBotComponent,
         AdminSlackBridgeManageSelfhostedComponent,
+        AdminLogoutConfirmationDialogComponent,
     ]
 })
 export class AppModule {
diff --git a/web/app/shared/models/admin-responses.ts b/web/app/shared/models/admin-responses.ts
index 9d007b9..647f934 100644
--- a/web/app/shared/models/admin-responses.ts
+++ b/web/app/shared/models/admin-responses.ts
@@ -10,6 +10,9 @@ export interface FE_DimensionConfig {
         federationHostname: string;
         clientServerUrl: string;
     };
+    sessionInfo: {
+        numTokens: number;
+    };
 }
 
 export interface FE_DimensionVersion {
diff --git a/web/app/shared/services/admin/admin-api.service.ts b/web/app/shared/services/admin/admin-api.service.ts
index a0f4b0b..1609ce6 100644
--- a/web/app/shared/services/admin/admin-api.service.ts
+++ b/web/app/shared/services/admin/admin-api.service.ts
@@ -20,4 +20,8 @@ export class AdminApiService extends AuthedApi {
     public getVersion(): Promise<FE_DimensionVersion> {
         return this.authedGet("/api/v1/dimension/admin/version").map(r => r.json()).toPromise();
     }
+
+    public logoutAll(): Promise<any> {
+        return this.authedPost("/api/v1/dimension/admin/sessions/logout/all").map(r => r.json()).toPromise();
+    }
 }
diff --git a/web/app/shared/services/scalar/scalar-server-api.service.ts b/web/app/shared/services/scalar/scalar-server-api.service.ts
index 69dbac9..7663b6e 100644
--- a/web/app/shared/services/scalar/scalar-server-api.service.ts
+++ b/web/app/shared/services/scalar/scalar-server-api.service.ts
@@ -6,6 +6,7 @@ import {
     FE_ScalarRegisterResponse
 } from "../../models/scalar-server-responses";
 import { AuthedApi } from "../authed-api";
+import { SCALAR_API_VERSION } from "../../../../../src/utils/common-constants";
 
 @Injectable()
 export class ScalarServerApiService extends AuthedApi {
@@ -18,10 +19,12 @@ export class ScalarServerApiService extends AuthedApi {
     }
 
     public getAccount(): Promise<FE_ScalarAccountResponse> {
-        return this.authedGet("/api/v1/scalar/account").map(res => res.json()).toPromise();
+        return this.authedGet("/api/v1/scalar/account", {v: SCALAR_API_VERSION}).map(res => res.json()).toPromise();
     }
 
     public register(openId: FE_ScalarOpenIdRequestBody): Promise<FE_ScalarRegisterResponse> {
-        return this.http.post("/api/v1/scalar/register", openId).map(res => res.json()).toPromise();
+        return this.http.post("/api/v1/scalar/register", openId, {
+            params: {v: SCALAR_API_VERSION},
+        }).map(res => res.json()).toPromise();
     }
 }