diff --git a/.changeset/mean-poets-bow.md b/.changeset/mean-poets-bow.md
new file mode 100644
index 0000000000..1c4c7d93e1
--- /dev/null
+++ b/.changeset/mean-poets-bow.md
@@ -0,0 +1,6 @@
+---
+'@clerk/clerk-js': patch
+'@clerk/clerk-react': patch
+---
+
+Sync IsomorphicClerk with the clerk singleton and the LoadedClerk interface. IsomorphicClerk now extends from LoadedClerk.
diff --git a/packages/clerk-js/src/core/clerk.ts b/packages/clerk-js/src/core/clerk.ts
index 68f4cb3eba..43a403bf7f 100644
--- a/packages/clerk-js/src/core/clerk.ts
+++ b/packages/clerk-js/src/core/clerk.ts
@@ -146,10 +146,10 @@ export class Clerk implements ClerkInterface {
     version: __PKG_VERSION__,
   };
 
-  public client?: ClientResource;
-  public session?: ActiveSessionResource | null;
-  public organization?: OrganizationResource | null;
-  public user?: UserResource | null;
+  public client: ClientResource | undefined;
+  public session: ActiveSessionResource | null | undefined;
+  public organization: OrganizationResource | null | undefined;
+  public user: UserResource | null | undefined;
   public __internal_country?: string | null;
   public telemetry?: TelemetryCollector;
 
@@ -180,6 +180,10 @@ export class Clerk implements ClerkInterface {
     return Clerk.version;
   }
 
+  get sdkMetadata(): SDKMetadata {
+    return Clerk.sdkMetadata;
+  }
+
   get loaded(): boolean {
     return this.#isReady;
   }
diff --git a/packages/react/src/errors.ts b/packages/react/src/errors.ts
index 9ab1690fe6..498e47d280 100644
--- a/packages/react/src/errors.ts
+++ b/packages/react/src/errors.ts
@@ -23,7 +23,7 @@ export const invalidStateError =
   'Invalid state. Feel free to submit a bug or reach out to support here: https://clerk.com/support';
 
 export const unsupportedNonBrowserDomainOrProxyUrlFunction =
-  'Unsupported usage of domain or proxyUrl. The usage of domain or proxyUrl as function is not supported in non-browser environments.';
+  'Unsupported usage of isSatellite, domain or proxyUrl. The usage of isSatellite, domain or proxyUrl as function is not supported in non-browser environments.';
 
 export const userProfilePageRenderedError =
   '<UserProfile.Page /> component needs to be a direct child of `<UserProfile />` or `<UserButton />`.';
diff --git a/packages/react/src/isomorphicClerk.ts b/packages/react/src/isomorphicClerk.ts
index 6ce2d3f79c..c86e580bbe 100644
--- a/packages/react/src/isomorphicClerk.ts
+++ b/packages/react/src/isomorphicClerk.ts
@@ -4,6 +4,7 @@ import type { TelemetryCollector } from '@clerk/shared/telemetry';
 import type {
   ActiveSessionResource,
   AuthenticateWithMetamaskParams,
+  BuildUrlWithAuthParams,
   Clerk,
   ClientResource,
   CreateOrganizationParams,
@@ -11,11 +12,15 @@ import type {
   DomainOrProxyUrl,
   HandleEmailLinkVerificationParams,
   HandleOAuthCallbackParams,
+  InstanceType,
   ListenerCallback,
+  LoadedClerk,
   OrganizationListProps,
   OrganizationProfileProps,
   OrganizationResource,
   OrganizationSwitcherProps,
+  RedirectOptions,
+  SDKMetadata,
   SetActiveParams,
   SignInProps,
   SignInRedirectOptions,
@@ -28,6 +33,7 @@ import type {
   UserButtonProps,
   UserProfileProps,
   UserResource,
+  Without,
 } from '@clerk/types';
 
 import { unsupportedNonBrowserDomainOrProxyUrlFunction } from './errors';
@@ -57,7 +63,80 @@ type MethodName<T> = {
 
 type MethodCallback = () => Promise<unknown> | unknown;
 
-export class IsomorphicClerk {
+type IsomorphicLoadedClerk = Without<
+  LoadedClerk,
+  /**
+   * Override ClerkJS methods in order to support premountMethodCalls
+   */
+  | 'buildSignInUrl'
+  | 'buildSignUpUrl'
+  | 'buildUserProfileUrl'
+  | 'buildCreateOrganizationUrl'
+  | 'buildOrganizationProfileUrl'
+  | 'buildHomeUrl'
+  | 'buildUrlWithAuth'
+  | 'redirectWithAuth'
+  | 'redirectToSignIn'
+  | 'redirectToSignUp'
+  | 'handleRedirectCallback'
+  | 'handleUnauthenticated'
+  | 'authenticateWithMetamask'
+  | 'createOrganization'
+  | 'getOrganization'
+  | 'mountUserButton'
+  | 'mountOrganizationList'
+  | 'mountOrganizationSwitcher'
+  | 'mountOrganizationProfile'
+  | 'mountCreateOrganization'
+  | 'mountSignUp'
+  | 'mountSignIn'
+  | 'mountUserProfile'
+  | 'client'
+> & {
+  // TODO: Align return type
+  redirectWithAuth: (...args: Parameters<Clerk['redirectWithAuth']>) => void;
+  // TODO: Align return type
+  redirectToSignIn: (options: SignInRedirectOptions) => void;
+  // TODO: Align return type
+  redirectToSignUp: (options: SignUpRedirectOptions) => void;
+  // TODO: Align return type and parms
+  handleRedirectCallback: (params: HandleOAuthCallbackParams) => void;
+  handleUnauthenticated: () => void;
+  // TODO: Align Promise unknown
+  authenticateWithMetamask: (params: AuthenticateWithMetamaskParams) => Promise<void>;
+  // TODO: Align return type (maybe not possible or correct)
+  createOrganization: (params: CreateOrganizationParams) => Promise<OrganizationResource | void>;
+  // TODO: Align return type (maybe not possible or correct)
+  getOrganization: (organizationId: string) => Promise<OrganizationResource | void>;
+
+  // TODO: Align return type
+  buildSignInUrl: (opts?: RedirectOptions) => string | void;
+  // TODO: Align return type
+  buildSignUpUrl: (opts?: RedirectOptions) => string | void;
+  // TODO: Align return type
+  buildUserProfileUrl: () => string | void;
+  // TODO: Align return type
+  buildCreateOrganizationUrl: () => string | void;
+  // TODO: Align return type
+  buildOrganizationProfileUrl: () => string | void;
+  // TODO: Align return type
+  buildHomeUrl: () => string | void;
+  // TODO: Align return type
+  buildUrlWithAuth: (to: string, opts?: BuildUrlWithAuthParams | undefined) => string | void;
+
+  // TODO: Align optional props
+  mountUserButton: (node: HTMLDivElement, props: UserButtonProps) => void;
+  mountOrganizationList: (node: HTMLDivElement, props: OrganizationListProps) => void;
+  mountOrganizationSwitcher: (node: HTMLDivElement, props: OrganizationSwitcherProps) => void;
+  mountOrganizationProfile: (node: HTMLDivElement, props: OrganizationProfileProps) => void;
+  mountCreateOrganization: (node: HTMLDivElement, props: CreateOrganizationProps) => void;
+  mountSignUp: (node: HTMLDivElement, props: SignUpProps) => void;
+  mountSignIn: (node: HTMLDivElement, props: SignInProps) => void;
+  mountUserProfile: (node: HTMLDivElement, props: UserProfileProps) => void;
+  client: ClientResource | undefined;
+};
+
+export class IsomorphicClerk implements IsomorphicLoadedClerk {
   private readonly mode: 'browser' | 'server';
   private readonly options: IsomorphicClerkOptions;
   private readonly Clerk: ClerkProp;
@@ -144,6 +223,108 @@ export class IsomorphicClerk {
     void this.loadClerkJS();
   }
 
+  get sdkMetadata(): SDKMetadata | undefined {
+    return this.clerkjs?.sdkMetadata || this.options.sdkMetadata || undefined;
+  }
+
+  get instanceType(): InstanceType | undefined {
+    return this.clerkjs?.instanceType;
+  }
+
+  get frontendApi(): string {
+    return this.clerkjs?.frontendApi || '';
+  }
+
+  get isStandardBrowser(): boolean {
+    return this.clerkjs?.isStandardBrowser || this.options.standardBrowser || false;
+  }
+
+  get isSatellite(): boolean {
+    // This getter can run in environments where window is not available.
+    // In those cases we should expect and use domain as a string
+    if (typeof window !== 'undefined' && window.location) {
+      return handleValueOrFn(this.options.isSatellite, new URL(window.location.href), false);
+    }
+    if (typeof this.options.isSatellite === 'function') {
+      return errorThrower.throw(unsupportedNonBrowserDomainOrProxyUrlFunction);
+    }
+    return false;
+  }
+
+  isReady = (): boolean => Boolean(this.clerkjs?.isReady());
+
+  buildSignInUrl = (opts?: RedirectOptions): string | void => {
+    const callback = () => this.clerkjs?.buildSignInUrl(opts) || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildSignInUrl', callback);
+    }
+  };
+
+  buildSignUpUrl = (opts?: RedirectOptions): string | void => {
+    const callback = () => this.clerkjs?.buildSignUpUrl(opts) || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildSignUpUrl', callback);
+    }
+  };
+
+  buildUserProfileUrl = (): string | void => {
+    const callback = () => this.clerkjs?.buildUserProfileUrl() || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildUserProfileUrl', callback);
+    }
+  };
+
+  buildCreateOrganizationUrl = (): string | void => {
+    const callback = () => this.clerkjs?.buildCreateOrganizationUrl() || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildCreateOrganizationUrl', callback);
+    }
+  };
+
+  buildOrganizationProfileUrl = (): string | void => {
+    const callback = () => this.clerkjs?.buildOrganizationProfileUrl() || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildOrganizationProfileUrl', callback);
+    }
+  };
+
+  buildHomeUrl = (): string | void => {
+    const callback = () => this.clerkjs?.buildHomeUrl() || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildHomeUrl', callback);
+    }
+  };
+
+  buildUrlWithAuth = (to: string, opts?: BuildUrlWithAuthParams | undefined): string | void => {
+    const callback = () => this.clerkjs?.buildUrlWithAuth(to, opts) || '';
+    if (this.clerkjs && this.#loaded) {
+      return callback();
+    } else {
+      this.premountMethodCalls.set('buildUrlWithAuth', callback);
+    }
+  };
+
+  handleUnauthenticated = (): void => {
+    const callback = () => this.clerkjs?.handleUnauthenticated();
+    if (this.clerkjs && this.#loaded) {
+      void callback();
+    } else {
+      this.premountMethodCalls.set('handleUnauthenticated', callback);
+    }
+  };
+
   async loadClerkJS(): Promise<HeadlessBrowserClerk | BrowserClerk | undefined> {
     if (this.mode !== 'browser' || this.#loaded) {
       return;
diff --git a/packages/types/src/clerk.ts b/packages/types/src/clerk.ts
index c38968c9d0..49ccab2843 100644
--- a/packages/types/src/clerk.ts
+++ b/packages/types/src/clerk.ts
@@ -59,14 +59,17 @@ export interface Clerk {
   /**
    * Clerk SDK version number.
    */
-  version?: string;
+  version: string | undefined;
 
   /**
    * If present, contains information about the SDK that the host application is using.
    * For example, if Clerk is loaded through `@clerk/nextjs`, this would be `{ name: '@clerk/nextjs', version: '1.0.0' }`
    */
-  sdkMetadata?: SDKMetadata;
+  sdkMetadata: SDKMetadata | undefined;
 
+  /**
+   * If true the bootstrapping of Clerk.load() has completed successfully.
+   */
   loaded: boolean;
 
   frontendApi: string;
@@ -75,7 +78,7 @@ export interface Clerk {
   publishableKey: string;
 
   /** Clerk Proxy url string. */
-  proxyUrl?: string;
+  proxyUrl: string | undefined;
 
   /** Clerk Satellite Frontend API string. */
   domain: string;
@@ -84,22 +87,22 @@ export interface Clerk {
   isSatellite: boolean;
 
   /** Clerk Instance type is defined from the Publishable key */
-  instanceType?: InstanceType;
+  instanceType: InstanceType | undefined;
 
   /** Clerk flag for loading Clerk in a standard browser setup */
-  isStandardBrowser?: boolean;
+  isStandardBrowser: boolean | undefined;
 
   /** Client handling most Clerk operations. */
-  client?: ClientResource;
+  client: ClientResource | undefined;
 
   /** Active Session. */
-  session?: ActiveSessionResource | null;
+  session: ActiveSessionResource | null | undefined;
 
   /** Active Organization */
-  organization?: OrganizationResource | null;
+  organization: OrganizationResource | null | undefined;
 
   /** Current User. */
-  user?: UserResource | null;
+  user: UserResource | null | undefined;
 
   /**
    * Signs out the current user on single-session instances, or all users on multi-session instances
@@ -760,8 +763,8 @@ export type UserButtonProps = UserButtonProfileMode & {
    */
   showName?: boolean;
   /**
-     Controls the default state of the UserButton
-     */
+   * Controls the default state of the UserButton
+   */
   defaultOpen?: boolean;
   /**
    * Full URL or path to navigate after sign out is complete
@@ -813,7 +816,7 @@ type CreateOrganizationMode =
 export type OrganizationSwitcherProps = CreateOrganizationMode &
   OrganizationProfileMode & {
     /**
-     Controls the default state of the OrganizationSwitcher
+     * Controls the default state of the OrganizationSwitcher
      */
     defaultOpen?: boolean;
     /**