mcp: add request trace-level logging (microsoft#250898)

* mcp: add request trace-level logging

Refs microsoft#250537

* fix

* update headers for layers

Author: connor4312

src/vs/workbench/api/common/extHostMcp.ts

@@ -10,7 +10,7 @@ import { Disposable, DisposableMap, DisposableStore, IDisposable, toDisposable }
 import { SSEParser } from '../../../base/common/sseParser.js';
 import { ExtensionIdentifier, IExtensionDescription } from '../../../platform/extensions/common/extensions.js';
 import { createDecorator } from '../../../platform/instantiation/common/instantiation.js';
-import { LogLevel } from '../../../platform/log/common/log.js';
+import { canLog, ILogService, LogLevel } from '../../../platform/log/common/log.js';
 import { StorageScope } from '../../../platform/storage/common/storage.js';
 import { extensionPrefixedIdentifier, McpCollectionDefinition, McpConnectionState, McpServerDefinition, McpServerLaunch, McpServerTransportHTTP, McpServerTransportType } from '../../contrib/mcp/common/mcpTypes.js';
 import { ExtHostMcpShape, MainContext, MainThreadMcpShape } from './extHost.protocol.js';
@@ -40,6 +40,7 @@ export class ExtHostMcpService extends Disposable implements IExtHostMpcService
 
 	constructor(
 		@IExtHostRpcService extHostRpc: IExtHostRpcService,
+		@ILogService private readonly _logService: ILogService,
 		@IExtHostInitDataService private readonly _extHostInitData: IExtHostInitDataService
 	) {
 		super();
@@ -52,7 +53,7 @@ export class ExtHostMcpService extends Disposable implements IExtHostMpcService
 
 	protected _startMcp(id: number, launch: McpServerLaunch): void {
 		if (launch.type === McpServerTransportType.HTTP) {
-			this._sseEventSources.set(id, new McpHTTPHandle(id, launch, this._proxy));
+			this._sseEventSources.set(id, new McpHTTPHandle(id, launch, this._proxy, this._logService));
 			return;
 		}
 
@@ -197,7 +198,8 @@ class McpHTTPHandle extends Disposable {
 	constructor(
 		private readonly _id: number,
 		private readonly _launch: McpServerTransportHTTP,
-		private readonly _proxy: MainThreadMcpShape
+		private readonly _proxy: MainThreadMcpShape,
+		private readonly _logService: ILogService,
 	) {
 		super();
 
@@ -246,7 +248,6 @@ class McpHTTPHandle extends Disposable {
 			this._launch.uri.toString(true),
 			{
 				method: 'POST',
-				signal: this._abortCtrl.signal,
 				headers,
 				body: asBytes,
 			},
@@ -280,7 +281,7 @@ class McpHTTPHandle extends Disposable {
 
 			this._proxy.$onDidChangeState(this._id, {
 				state: McpConnectionState.Kind.Error,
-				message: `${res.status} status sending message to ${this._launch.uri}: ${await this._getErrText(res)}` + retryWithSessionId ? `; will retry with new session ID` : '',
+				message: `${res.status} status sending message to ${this._launch.uri}: ${await this._getErrText(res)}` + (retryWithSessionId ? `; will retry with new session ID` : ''),
 				shouldRetry: retryWithSessionId,
 			});
 			return;
@@ -374,9 +375,8 @@ class McpHTTPHandle extends Disposable {
 				...Object.fromEntries(this._launch.headers)
 			};
 		}
-		const resourceMetadataResponse = await fetch(resourceMetadata, {
+		const resourceMetadataResponse = await this._fetch(resourceMetadata, {
 			method: 'GET',
-			signal: this._abortCtrl.signal,
 			headers: {
 				...additionalHeaders,
 				'Accept': 'application/json',
@@ -401,9 +401,8 @@ class McpHTTPHandle extends Disposable {
 		const authorizationServerUrl = new URL(authorizationServer);
 		const extraPath = authorizationServerUrl.pathname === '/' ? '' : authorizationServerUrl.pathname;
 		const pathToFetch = new URL(AUTH_SERVER_METADATA_DISCOVERY_PATH, authorizationServer).toString() + extraPath;
-		let authServerMetadataResponse = await fetch(pathToFetch, {
+		let authServerMetadataResponse = await this._fetch(pathToFetch, {
 			method: 'GET',
-			signal: this._abortCtrl.signal,
 			headers: {
 				...addtionalHeaders,
 				'Accept': 'application/json',
@@ -414,11 +413,10 @@ class McpHTTPHandle extends Disposable {
 			// Try fetching the other discovery URL. For the openid metadata discovery
 			// path, we _ADD_ the well known path after the existing path.
 			// https://datatracker.ietf.org/doc/html/rfc8414#section-3
-			authServerMetadataResponse = await fetch(
+			authServerMetadataResponse = await this._fetch(
 				URI.joinPath(URI.parse(authorizationServer), '.well-known', 'openid-configuration').toString(true),
 				{
 					method: 'GET',
-					signal: this._abortCtrl.signal,
 					headers: {
 						...addtionalHeaders,
 						'Accept': 'application/json',
@@ -505,7 +503,6 @@ class McpHTTPHandle extends Disposable {
 					this._launch.uri.toString(true),
 					{
 						method: 'GET',
-						signal: this._abortCtrl.signal,
 						headers,
 					},
 					headers
@@ -557,7 +554,6 @@ class McpHTTPHandle extends Disposable {
 				this._launch.uri.toString(true),
 				{
 					method: 'GET',
-					signal: this._abortCtrl.signal,
 					headers,
 				},
 				headers
@@ -599,9 +595,8 @@ class McpHTTPHandle extends Disposable {
 			'Content-Length': String(asBytes.length),
 		};
 		await this._addAuthHeader(headers);
-		const res = await fetch(url, {
+		const res = await this._fetch(url, {
 			method: 'POST',
-			signal: this._abortCtrl.signal,
 			headers,
 			body: asBytes,
 		});
@@ -670,8 +665,8 @@ class McpHTTPHandle extends Disposable {
 	 * If the initial request returns 401 and we don't have auth metadata,
 	 * it will populate the auth metadata and retry once.
 	 */
-	private async _fetchWithAuthRetry(url: string, init: RequestInit, headers: Record<string, string>): Promise<Response> {
-		const doFetch = () => fetch(url, init);
+	private async _fetchWithAuthRetry(url: string, init: MinimalRequestInit, headers: Record<string, string>): Promise<Response> {
+		const doFetch = () => this._fetch(url, init);
 
 		let res = await doFetch();
 		if (res.status === 401) {
@@ -687,6 +682,40 @@ class McpHTTPHandle extends Disposable {
 		}
 		return res;
 	}
+
+	private async _fetch(url: string, init: MinimalRequestInit): Promise<Response> {
+		if (canLog(this._logService.getLevel(), LogLevel.Trace)) {
+			const traceObj: any = { ...init, headers: { ...init.headers } };
+			if (traceObj.body) {
+				traceObj.body = new TextDecoder().decode(traceObj.body);
+			}
+			if (traceObj.headers?.Authorization) {
+				traceObj.headers.Authorization = '***'; // don't log the auth header
+			}
+			this._log(LogLevel.Trace, `Fetching ${url} with options: ${JSON.stringify(traceObj)}`);
+		}
+		const res = await fetch(url, {
+			...init,
+			signal: this._abortCtrl.signal,
+		});
+
+		if (canLog(this._logService.getLevel(), LogLevel.Trace)) {
+			const headers: Record<string, string> = {};
+			res.headers.forEach((value, key) => { headers[key] = value; });
+			this._log(LogLevel.Trace, `Fetched ${url}: ${JSON.stringify({
+				status: res.status,
+				headers: headers,
+			})}`);
+		}
+
+		return res;
+	}
+}
+
+interface MinimalRequestInit {
+	method: string;
+	headers: Record<string, string>;
+	body?: Uint8Array<ArrayBuffer>;
 }
 
 function isJSON(str: string): boolean {

src/vs/workbench/api/node/extHostMcpNode.ts

@@ -10,7 +10,7 @@ import { parseEnvFile } from '../../../base/common/envfile.js';
 import { untildify } from '../../../base/common/labels.js';
 import { StreamSplitter } from '../../../base/node/nodeStreams.js';
 import { findExecutable } from '../../../base/node/processes.js';
-import { LogLevel } from '../../../platform/log/common/log.js';
+import { ILogService, LogLevel } from '../../../platform/log/common/log.js';
 import { McpConnectionState, McpServerLaunch, McpServerTransportStdio, McpServerTransportType } from '../../contrib/mcp/common/mcpTypes.js';
 import { ExtHostMcpService } from '../common/extHostMcp.js';
 import { IExtHostRpcService } from '../common/extHostRpcService.js';
@@ -21,8 +21,9 @@ export class NodeExtHostMpcService extends ExtHostMcpService {
 	constructor(
 		@IExtHostRpcService extHostRpc: IExtHostRpcService,
 		@IExtHostInitDataService initDataService: IExtHostInitDataService,
+		@ILogService logService: ILogService,
 	) {
-		super(extHostRpc, initDataService);
+		super(extHostRpc, logService, initDataService);
 	}
 
 	private nodeServers = new Map<number, {