Address @claude review: format core/, typed output-validation error, document progress heuristic

- Run Prettier on the 60 core/ files this PR touched — the deterministic
  import rewrite had collapsed multi-line imports and left throws unwrapped;
  core/ is in no format gate so it slipped past CI. Now Prettier-clean.
- Default-path output-schema violation now throws
  ProtocolError(ProtocolErrorCode.InvalidParams, …) instead of a bare Error,
  matching the prior v1 contract (SDK threw a typed McpError with a code) so
  downstream `instanceof`/`.code` branching keeps working.
- Document the "assumes serial construction" invariant on pollTaskToolCall's
  progress-subscription revival (the `_progressHandlers` new-key heuristic).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

core/auth/cimd.ts

@@ -1,4 +1,7 @@
-import { discoverAuthorizationServerMetadata, discoverOAuthProtectedResourceMetadata } from "@modelcontextprotocol/client";
+import {
+  discoverAuthorizationServerMetadata,
+  discoverOAuthProtectedResourceMetadata,
+} from "@modelcontextprotocol/client";
 import type { OAuthClientInformation } from "@modelcontextprotocol/client";
 import { getAuthorizationServerUrl } from "./discovery.js";
 import type { BaseOAuthClientProvider } from "./providers.js";

core/auth/connection-state.ts

@@ -1,10 +1,18 @@
-import type { OAuthClientInformation, OAuthTokens } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthTokens,
+} from "@modelcontextprotocol/client";
 import type { EnterpriseManagedAuthIdpConfig } from "../client/types.js";
 import { getEmaIdpLoginState, normalizeIdpIssuer } from "./ema/idpSession.js";
 import { idpOAuthStorageKey } from "./ema/storage.js";
 import { isJwtExpired } from "./ema/jwt.js";
 import type { OAuthStorage } from "./storage.js";
-import type { AuthProtocol, OAuthClientRegistrationKind, OAuthConnectionState, OAuthFlowState } from "./types.js";
+import type {
+  AuthProtocol,
+  OAuthClientRegistrationKind,
+  OAuthConnectionState,
+  OAuthFlowState,
+} from "./types.js";
 import { authProtocolFromEnterpriseManaged } from "./types.js";
 
 export interface BuildOAuthConnectionStateParams {
@@ -17,9 +25,7 @@ export interface BuildOAuthConnectionStateParams {
 }
 
 /** True when persisted tokens include a non-expired access token (JWT exp when parseable). */
-export function isAccessTokenUsable(
-  tokens: OAuthTokens | undefined,
-): boolean {
+export function isAccessTokenUsable(tokens: OAuthTokens | undefined): boolean {
   if (!tokens?.access_token) return false;
   return !isJwtExpired(tokens.access_token);
 }
@@ -27,10 +33,9 @@ export function isAccessTokenUsable(
 function resolveClient(
   preregistered: OAuthClientInformation | undefined,
   dynamic: OAuthClientInformation | undefined,
-  dynamicRegistrationKind: Extract<
-    OAuthClientRegistrationKind,
-    "dcr" | "cimd"
-  > | undefined,
+  dynamicRegistrationKind:
+    | Extract<OAuthClientRegistrationKind, "dcr" | "cimd">
+    | undefined,
 ): OAuthConnectionState["client"] | undefined {
   if (preregistered?.client_id) {
     return {
@@ -81,7 +86,7 @@ export async function buildOAuthConnectionState(
       ? flowTokens
       : storedTokens && isAccessTokenUsable(storedTokens)
         ? storedTokens
-        : flowTokens ?? storedTokens;
+        : (flowTokens ?? storedTokens);
 
   const preregistered = await storage.getClientInformation(serverUrl, true);
   const dynamic = await storage.getClientInformation(serverUrl);
@@ -120,7 +125,9 @@ export async function buildOAuthConnectionState(
     const idp = params.enterpriseManagedAuth.idp;
     const issuer = normalizeIdpIssuer(idp.issuer);
     const idpSession = await getEmaIdpLoginState(storage, issuer);
-    const idpMetadata = await storage.getServerMetadata(idpOAuthStorageKey(issuer));
+    const idpMetadata = await storage.getServerMetadata(
+      idpOAuthStorageKey(issuer),
+    );
     state.ema = {
       idpIssuer: issuer,
       idpClientId: idp.clientId,

core/auth/ema/idpOidc.ts

@@ -1,5 +1,12 @@
-import { discoverAuthorizationServerMetadata, exchangeAuthorization, startAuthorization } from "@modelcontextprotocol/client";
-import type { OAuthClientInformation, OAuthMetadata } from "@modelcontextprotocol/client";
+import {
+  discoverAuthorizationServerMetadata,
+  exchangeAuthorization,
+  startAuthorization,
+} from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthMetadata,
+} from "@modelcontextprotocol/client";
 import { OAuthMetadataSchema } from "@modelcontextprotocol/core";
 import type { OAuthStorage } from "../storage.js";
 import type { EnterpriseManagedAuthIdpConfig } from "../../client/types.js";
@@ -44,7 +51,9 @@ export async function discoverIdpMetadata(
     fetchFn,
   });
   if (!metadata) {
-    throw new Error(`Failed to discover OIDC metadata for IdP issuer ${issuer}`);
+    throw new Error(
+      `Failed to discover OIDC metadata for IdP issuer ${issuer}`,
+    );
   }
   return OAuthMetadataSchema.parse(metadata);
 }
@@ -56,7 +65,11 @@ export async function startIdpOidcAuthorization(params: {
   fetchFn?: typeof fetch;
 }): Promise<{ authorizationUrl: URL }> {
   const issuer = normalizeIdpIssuer(params.idp.issuer);
-  const metadata = await resolveIdpMetadata(issuer, params.storage, params.fetchFn);
+  const metadata = await resolveIdpMetadata(
+    issuer,
+    params.storage,
+    params.fetchFn,
+  );
   const clientInformation = idpClientInformation(params.idp);
   const storageKey = idpOAuthStorageKey(issuer);
   const state = generateOAuthState();

core/auth/ema/resourceContext.ts

@@ -1,4 +1,8 @@
-import { discoverAuthorizationServerMetadata, discoverOAuthProtectedResourceMetadata, selectResourceURL } from "@modelcontextprotocol/client";
+import {
+  discoverAuthorizationServerMetadata,
+  discoverOAuthProtectedResourceMetadata,
+  selectResourceURL,
+} from "@modelcontextprotocol/client";
 import type { OAuthClientProvider } from "@modelcontextprotocol/client";
 import type { OAuthProtectedResourceMetadata } from "@modelcontextprotocol/client";
 import { getAuthorizationServerUrl } from "../discovery.js";

core/auth/ema/tokenEndpoint.ts

@@ -1,5 +1,8 @@
 import { selectClientAuthMethod } from "@modelcontextprotocol/client";
-import type { OAuthClientInformation, OAuthMetadata } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthMetadata,
+} from "@modelcontextprotocol/client";
 
 export async function parseOAuthTokenErrorResponse(
   response: Response,

core/auth/ema/transportProvider.ts

@@ -1,5 +1,9 @@
 import type { OAuthClientProvider } from "@modelcontextprotocol/client";
-import type { OAuthClientInformationMixed, OAuthClientMetadata, OAuthTokens } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformationMixed,
+  OAuthClientMetadata,
+  OAuthTokens,
+} from "@modelcontextprotocol/client";
 import type { BaseOAuthClientProvider } from "../providers.js";
 import {
   refreshEmaResourceTokens,
@@ -8,10 +12,7 @@ import {
 } from "./emaFlow.js";
 import { isJwtExpired } from "./jwt.js";
 
-function isAccessTokenUsable(
-  tokens: OAuthTokens,
-  skewMs = 60_000,
-): boolean {
+function isAccessTokenUsable(tokens: OAuthTokens, skewMs = 60_000): boolean {
   if (!tokens.access_token) return false;
   return !isJwtExpired(tokens.access_token, skewMs);
 }
@@ -28,10 +29,7 @@ export class EmaTransportOAuthProvider implements OAuthClientProvider {
   private readonly inner: BaseOAuthClientProvider;
   private readonly emaConfig: EmaFlowConfig;
 
-  constructor(
-    inner: BaseOAuthClientProvider,
-    emaConfig: EmaFlowConfig,
-  ) {
+  constructor(inner: BaseOAuthClientProvider, emaConfig: EmaFlowConfig) {
     this.inner = inner;
     this.emaConfig = emaConfig;
   }

core/auth/ema/wire.ts

@@ -1,5 +1,8 @@
 import { discoverAuthorizationServerMetadata } from "@modelcontextprotocol/client";
-import type { OAuthClientInformation, OAuthTokens } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthTokens,
+} from "@modelcontextprotocol/client";
 import { OAuthTokensSchema } from "@modelcontextprotocol/core";
 import type { EnterpriseManagedAuthIdpConfig } from "../../client/types.js";
 import {

core/auth/mcpAuth.ts

@@ -10,7 +10,14 @@
  * (the same path v2 `auth()` takes when refresh cannot widen scope).
  */
 
-import { auth as sdkAuth, discoverOAuthServerInfo, isHttpsUrl, registerClient, selectResourceURL, startAuthorization } from "@modelcontextprotocol/client";
+import {
+  auth as sdkAuth,
+  discoverOAuthServerInfo,
+  isHttpsUrl,
+  registerClient,
+  selectResourceURL,
+  startAuthorization,
+} from "@modelcontextprotocol/client";
 import type { OAuthClientProvider } from "@modelcontextprotocol/client";
 import type { FetchLike } from "@modelcontextprotocol/client";
 /**

core/auth/oauth-storage.ts

@@ -1,5 +1,12 @@
-import type { OAuthClientInformation, OAuthTokens, OAuthMetadata } from "@modelcontextprotocol/client";
-import { OAuthClientInformationSchema, OAuthTokensSchema } from "@modelcontextprotocol/core";
+import type {
+  OAuthClientInformation,
+  OAuthTokens,
+  OAuthMetadata,
+} from "@modelcontextprotocol/client";
+import {
+  OAuthClientInformationSchema,
+  OAuthTokensSchema,
+} from "@modelcontextprotocol/core";
 import type { OAuthStorage } from "./storage.js";
 import { type OAuthMemoryStore, type ServerOAuthState } from "./store.js";
 import type { OAuthPersistBackend } from "./oauth-persist.js";
@@ -173,7 +180,9 @@ export class OAuthStorageBase implements OAuthStorage {
 
   async clearCodeVerifier(serverUrl: string): Promise<void> {
     await this.ensureLoaded();
-    this.memory.getState().setServerState(serverUrl, { codeVerifier: undefined });
+    this.memory
+      .getState()
+      .setServerState(serverUrl, { codeVerifier: undefined });
     await this.persist();
   }
 
@@ -206,7 +215,9 @@ export class OAuthStorageBase implements OAuthStorage {
     metadata: OAuthMetadata,
   ): Promise<void> {
     await this.ensureLoaded();
-    this.memory.getState().setServerState(serverUrl, { serverMetadata: metadata });
+    this.memory
+      .getState()
+      .setServerState(serverUrl, { serverMetadata: metadata });
     await this.persist();
   }
 

core/auth/providers.ts

@@ -2,7 +2,12 @@ import type {
   OAuthClientProvider,
   OAuthClientInformationContext,
 } from "@modelcontextprotocol/client";
-import type { OAuthClientInformation, OAuthClientMetadata, OAuthTokens, OAuthMetadata } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthClientMetadata,
+  OAuthTokens,
+  OAuthMetadata,
+} from "@modelcontextprotocol/client";
 import type { OAuthStorage, SaveClientInformationOptions } from "./storage.js";
 import { generateOAuthState } from "./utils.js";
 
@@ -210,9 +215,13 @@ export class BaseOAuthClientProvider implements OAuthClientProvider {
       options && "registrationKind" in options
         ? options.registrationKind
         : "dcr";
-    await this.storage.saveClientInformation(this.serverUrl, clientInformation, {
-      registrationKind,
-    });
+    await this.storage.saveClientInformation(
+      this.serverUrl,
+      clientInformation,
+      {
+        registrationKind,
+      },
+    );
   }
 
   async saveScope(scope: string | undefined): Promise<void> {

core/auth/storage.ts

@@ -1,4 +1,8 @@
-import type { OAuthClientInformation, OAuthTokens, OAuthMetadata } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthTokens,
+  OAuthMetadata,
+} from "@modelcontextprotocol/client";
 import type { OAuthClientRegistrationKind } from "./types.js";
 
 /**

core/auth/store.ts

@@ -3,7 +3,11 @@
  * Persisted via `OAuthStorageBase` + `OAuthPersistBackend` backends.
  */
 
-import type { OAuthClientInformation, OAuthTokens, OAuthMetadata } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthTokens,
+  OAuthMetadata,
+} from "@modelcontextprotocol/client";
 import type {
   IdpSessionState,
   OAuthClientRegistrationKind,

core/auth/types.ts

@@ -1,4 +1,10 @@
-import type { OAuthMetadata, OAuthClientInformation, OAuthClientInformationFull, OAuthTokens, OAuthProtectedResourceMetadata } from "@modelcontextprotocol/client";
+import type {
+  OAuthMetadata,
+  OAuthClientInformation,
+  OAuthClientInformationFull,
+  OAuthTokens,
+  OAuthProtectedResourceMetadata,
+} from "@modelcontextprotocol/client";
 
 // OAuth flow steps
 export type OAuthStep =

core/mcp/__tests__/fakeInspectorClient.ts

@@ -6,7 +6,17 @@
  */
 
 import { vi } from "vitest";
-import type { ClientCapabilities, Implementation, LoggingLevel, Prompt, Resource, ResourceTemplateType as ResourceTemplate, ServerCapabilities, Task, Tool } from "@modelcontextprotocol/client";
+import type {
+  ClientCapabilities,
+  Implementation,
+  LoggingLevel,
+  Prompt,
+  Resource,
+  ResourceTemplateType as ResourceTemplate,
+  ServerCapabilities,
+  Task,
+  Tool,
+} from "@modelcontextprotocol/client";
 import { InspectorClientEventTarget } from "../inspectorClientEventTarget.js";
 import type {
   AppRendererClient,

core/mcp/inspectorClient.ts

@@ -46,7 +46,38 @@ import {
   MessageTrackingTransport,
   type MessageTrackingCallbacks,
 } from "./messageTrackingTransport.js";
-import type { CallToolRequest, JSONRPCRequest, JSONRPCNotification, JSONRPCResultResponse, JSONRPCErrorResponse, ServerCapabilities, ClientCapabilities, Implementation, LoggingLevel, Tool, Resource, ResourceTemplateType as ResourceTemplate, Prompt, Root, CreateMessageRequest, CreateMessageResult, ElicitRequest, ElicitResult, ElicitRequestURLParams, CallToolResult, Task, Progress, ProgressToken, ListToolsRequest, ListResourcesRequest, ListResourceTemplatesRequest, ListPromptsRequest, ReadResourceRequest, GetPromptRequest, CompleteRequest } from "@modelcontextprotocol/client";
+import type {
+  CallToolRequest,
+  JSONRPCRequest,
+  JSONRPCNotification,
+  JSONRPCResultResponse,
+  JSONRPCErrorResponse,
+  ServerCapabilities,
+  ClientCapabilities,
+  Implementation,
+  LoggingLevel,
+  Tool,
+  Resource,
+  ResourceTemplateType as ResourceTemplate,
+  Prompt,
+  Root,
+  CreateMessageRequest,
+  CreateMessageResult,
+  ElicitRequest,
+  ElicitResult,
+  ElicitRequestURLParams,
+  CallToolResult,
+  Task,
+  Progress,
+  ProgressToken,
+  ListToolsRequest,
+  ListResourcesRequest,
+  ListResourceTemplatesRequest,
+  ListPromptsRequest,
+  ReadResourceRequest,
+  GetPromptRequest,
+  CompleteRequest,
+} from "@modelcontextprotocol/client";
 import type { Transport } from "@modelcontextprotocol/client";
 import type {
   RequestOptions,
@@ -633,9 +664,7 @@ export class InspectorClient extends InspectorClientEventTarget {
     internal._requestHandlers.set(method, (request, ctx) => {
       const task = (request as { params?: { task?: unknown } })?.params?.task;
       if (this.receiverTasks && task != null) {
-        return rawHandler(
-          request as CreateMessageRequest & ElicitRequest,
-        );
+        return rawHandler(request as CreateMessageRequest & ElicitRequest);
       }
       return validating(request, ctx);
     });
@@ -723,7 +752,10 @@ export class InspectorClient extends InspectorClientEventTarget {
   private async getReceiverTaskPayload(taskId: string): Promise<ClientResult> {
     const record = this.receiverTaskRecords.get(taskId);
     if (!record) {
-      throw new ProtocolError(ProtocolErrorCode.InvalidParams, `Unknown taskId: ${taskId}`);
+      throw new ProtocolError(
+        ProtocolErrorCode.InvalidParams,
+        `Unknown taskId: ${taskId}`,
+      );
     }
     return record.payloadPromise;
   }
@@ -731,7 +763,10 @@ export class InspectorClient extends InspectorClientEventTarget {
   private cancelReceiverTask(taskId: string): Task {
     const record = this.receiverTaskRecords.get(taskId);
     if (!record) {
-      throw new ProtocolError(ProtocolErrorCode.InvalidParams, `Unknown taskId: ${taskId}`);
+      throw new ProtocolError(
+        ProtocolErrorCode.InvalidParams,
+        `Unknown taskId: ${taskId}`,
+      );
     }
     if (InspectorClient.isTerminalTaskStatus(record.task.status)) {
       return record.task;
@@ -1012,7 +1047,10 @@ export class InspectorClient extends InspectorClientEventTarget {
             this.addPendingSample(samplingRequest);
           });
         };
-        this.client.setRequestHandler("sampling/createMessage", samplingHandler);
+        this.client.setRequestHandler(
+          "sampling/createMessage",
+          samplingHandler,
+        );
         if (this.receiverTasks) {
           this.installReceiverTaskResponseBypass(
             "sampling/createMessage",
@@ -2001,7 +2039,14 @@ export class InspectorClient extends InspectorClientEventTarget {
       result as CallToolResult,
     );
     if (outputValidationError && !options?.skipOutputValidation) {
-      throw new Error(outputValidationError);
+      // Match the prior contract: on v1 a strict output-schema violation
+      // surfaced as the SDK's typed `McpError`/`ProtocolError` (code
+      // InvalidParams), not a bare Error — so downstream code that branches on
+      // `instanceof ProtocolError` / `error.code` keeps working.
+      throw new ProtocolError(
+        ProtocolErrorCode.InvalidParams,
+        outputValidationError,
+      );
     }
 
     const invocation: ToolCallInvocation = {
@@ -2161,6 +2206,14 @@ export class InspectorClient extends InspectorClientEventTarget {
     );
     // The SDK registers the progress handler synchronously while constructing
     // the request promise (before this await), so the new key is present now.
+    // ASSUMES SERIAL CONSTRUCTION: `find` takes the first key not present in the
+    // pre-request snapshot, which is unambiguous only because no OTHER request
+    // registers a progress handler between the snapshot and this request's
+    // synchronous registration. Tool calls are user-driven and serial, so that
+    // holds today; if concurrent task-augmented calls are ever constructed in
+    // the same microtask window, two subscription ids could cross-wire and this
+    // must move to an SDK-supported correlation (see the delete-when-native note
+    // on `installReceiverTaskResponseBypass`).
     const progressSubscriptionId = requestOptions.onprogress
       ? [...progressHandlers.keys()].find((k) => !keysBeforeRequest.has(k))
       : undefined;

core/mcp/inspectorClientEventTarget.ts

@@ -24,7 +24,17 @@ import type {
   ResourceReadInvocation,
   ResourceTemplateReadInvocation,
 } from "./types.js";
-import type { Tool, ServerCapabilities, Implementation, Root, Progress, ProgressToken, Task, CallToolResult, ProtocolError } from "@modelcontextprotocol/client";
+import type {
+  Tool,
+  ServerCapabilities,
+  Implementation,
+  Root,
+  Progress,
+  ProgressToken,
+  Task,
+  CallToolResult,
+  ProtocolError,
+} from "@modelcontextprotocol/client";
 import type { SamplingCreateMessage } from "./samplingCreateMessage.js";
 import type { ElicitationCreateMessage } from "./elicitationCreateMessage.js";
 import type { JsonValue } from "../json/jsonUtils.js";

core/mcp/inspectorClientProtocol.ts

@@ -20,7 +20,17 @@ import type {
   PromptGetInvocation,
   ToolCallInvocation,
 } from "./types.js";
-import type { ClientCapabilities, Implementation, LoggingLevel, Prompt, Resource, ResourceTemplateType as ResourceTemplate, ServerCapabilities, Task, Tool } from "@modelcontextprotocol/client";
+import type {
+  ClientCapabilities,
+  Implementation,
+  LoggingLevel,
+  Prompt,
+  Resource,
+  ResourceTemplateType as ResourceTemplate,
+  ServerCapabilities,
+  Task,
+  Tool,
+} from "@modelcontextprotocol/client";
 import type { JsonValue } from "../json/jsonUtils.js";
 import type { InspectorClientEventTarget } from "./inspectorClientEventTarget.js";
 import type { SamplingCreateMessage } from "./samplingCreateMessage.js";

core/mcp/messageTrackingTransport.ts

@@ -1,6 +1,17 @@
-import type { Transport, TransportSendOptions } from "@modelcontextprotocol/client";
-import type { JSONRPCMessage, MessageExtraInfo } from "@modelcontextprotocol/client";
-import type { JSONRPCRequest, JSONRPCNotification, JSONRPCResultResponse, JSONRPCErrorResponse } from "@modelcontextprotocol/client";
+import type {
+  Transport,
+  TransportSendOptions,
+} from "@modelcontextprotocol/client";
+import type {
+  JSONRPCMessage,
+  MessageExtraInfo,
+} from "@modelcontextprotocol/client";
+import type {
+  JSONRPCRequest,
+  JSONRPCNotification,
+  JSONRPCResultResponse,
+  JSONRPCErrorResponse,
+} from "@modelcontextprotocol/client";
 import type { MessageOrigin } from "./types.js";
 
 export interface MessageTrackingCallbacks {
@@ -21,10 +32,7 @@ export class MessageTrackingTransport implements Transport {
   private callbacks: MessageTrackingCallbacks;
   private negotiatedProtocolVersion?: string;
 
-  constructor(
-    baseTransport: Transport,
-    callbacks: MessageTrackingCallbacks,
-  ) {
+  constructor(baseTransport: Transport, callbacks: MessageTrackingCallbacks) {
     this.baseTransport = baseTransport;
     this.callbacks = callbacks;
   }

core/mcp/oauthManager.ts

@@ -286,8 +286,7 @@ export class OAuthManager {
     try {
       if (this.isEnterpriseManaged()) {
         const emaConfig = await this.getEmaFlowConfig();
-        const scopeForMint =
-          this.pendingAuthorizationScope ?? emaConfig.scope;
+        const scopeForMint = this.pendingAuthorizationScope ?? emaConfig.scope;
         const config = scopeForMint
           ? { ...emaConfig, scope: scopeForMint }
           : emaConfig;
@@ -449,7 +448,9 @@ export class OAuthManager {
    */
   async refreshEnterpriseManagedTokens(): Promise<boolean> {
     if (!this.isEnterpriseManaged()) return false;
-    const tokens = await refreshEmaResourceTokens(await this.getEmaFlowConfig());
+    const tokens = await refreshEmaResourceTokens(
+      await this.getEmaFlowConfig(),
+    );
     return tokens !== undefined;
   }
 

core/mcp/remote/node/tokenAuthProvider.ts

@@ -1,5 +1,9 @@
 import type { OAuthClientProvider } from "@modelcontextprotocol/client";
-import type { OAuthClientInformation, OAuthClientMetadata, OAuthTokens } from "@modelcontextprotocol/client";
+import type {
+  OAuthClientInformation,
+  OAuthClientMetadata,
+  OAuthTokens,
+} from "@modelcontextprotocol/client";
 import type { RemoteAuthState } from "../types.js";
 
 const REMOTE_OAUTH_STUB_METADATA: OAuthClientMetadata = {