chat: add support for agent plugin sources (#299081)

* chat: add support for agent plugin sources - Adds support for agent plugins to reference sources as specified in PLUGIN_SOURCES.md, enabling installation from GitHub, npm, pip, and other package registries - Integrates source parsing and validation into the plugin installation service and repository service - Adds comprehensive test coverage for plugin source handling and installation from various sources - Creates PLUGIN_SOURCES.md documentation describing how to specify plugin source configurations (Commit message generated by Copilot) * comments * windows fixes and fault handling * fix tests
2026-04-17 07:13:45 +01:00 · 2026-03-04 07:20:21 -08:00
parent 8a03516dd4
commit a4e35e0d69
16 changed files with 1571 additions and 45 deletions
--- a/extensions/git/src/commands.ts
+++ b/extensions/git/src/commands.ts
@@ -1040,19 +1040,29 @@ export class CommandCenter {
 	}

 	@command('_git.cloneRepository')
-	async cloneRepository(url: string, parentPath: string): Promise<void> {
+	async cloneRepository(url: string, localPath: string, ref?: string): Promise<void> {
 		const opts = {
 			location: ProgressLocation.Notification,
 			title: l10n.t('Cloning git repository "{0}"...', url),
 			cancellable: true
 		};

+		const parentPath = path.dirname(localPath);
+		const targetName = path.basename(localPath);
+
 		await window.withProgress(
 			opts,
-			(progress, token) => this.model.git.clone(url, { parentPath, progress }, token)
+			(progress, token) => this.model.git.clone(url, { parentPath, targetName, progress, ref }, token)
 		);
 	}

+	@command('_git.checkout')
+	async checkoutRepository(repositoryPath: string, treeish: string, detached?: boolean): Promise<void> {
+		const dotGit = await this.git.getRepositoryDotGit(repositoryPath);
+		const repo = new GitRepository(this.git, repositoryPath, undefined, dotGit, this.logger);
+		await repo.checkout(treeish, [], detached ? { detached: true } : {});
+	}
+
 	@command('_git.pull')
 	async pullRepository(repositoryPath: string): Promise<void> {
 		const dotGit = await this.git.getRepositoryDotGit(repositoryPath);
--- a/extensions/git/src/git.ts
+++ b/extensions/git/src/git.ts
@@ -378,6 +378,7 @@ const STASH_FORMAT = '%H%n%P%n%gd%n%gs%n%at%n%ct';

 export interface ICloneOptions {
 	readonly parentPath: string;
+	readonly targetName?: string;
 	readonly progress: Progress<{ increment: number }>;
 	readonly recursive?: boolean;
 	readonly ref?: string;
@@ -433,14 +434,16 @@ export class Git {
 	}

 	async clone(url: string, options: ICloneOptions, cancellationToken?: CancellationToken): Promise<string> {
-		const baseFolderName = decodeURI(url).replace(/[\/]+$/, '').replace(/^.*[\/\\]/, '').replace(/\.git$/, '') || 'repository';
+		const baseFolderName = options.targetName || decodeURI(url).replace(/[\/]+$/, '').replace(/^.*[\/\\]/, '').replace(/\.git$/, '') || 'repository';
 		let folderName = baseFolderName;
 		let folderPath = path.join(options.parentPath, folderName);
 		let count = 1;

-		while (count < 20 && await new Promise(c => exists(folderPath, c))) {
-			folderName = `${baseFolderName}-${count++}`;
-			folderPath = path.join(options.parentPath, folderName);
+		if (!options.targetName) {
+			while (count < 20 && await new Promise(c => exists(folderPath, c))) {
+				folderName = `${baseFolderName}-${count++}`;
+				folderPath = path.join(options.parentPath, folderName);
+			}
 		}

 		await mkdirp(options.parentPath);
--- a/src/vs/workbench/contrib/chat/browser/agentPluginEditor/agentPluginEditor.ts
+++ b/src/vs/workbench/contrib/chat/browser/agentPluginEditor/agentPluginEditor.ts
@@ -12,7 +12,7 @@ import { CancellationToken, CancellationTokenSource } from '../../../../../base/
 import { DisposableStore, toDisposable } from '../../../../../base/common/lifecycle.js';
 import { Schemas, matchesScheme } from '../../../../../base/common/network.js';
 import { autorun } from '../../../../../base/common/observable.js';
-import { basename, dirname, joinPath } from '../../../../../base/common/resources.js';
+import { dirname, joinPath } from '../../../../../base/common/resources.js';
 import { URI } from '../../../../../base/common/uri.js';
 import { generateUuid } from '../../../../../base/common/uuid.js';
 import { TokenizationRegistry } from '../../../../../editor/common/languages.js';
@@ -202,6 +202,7 @@ export class AgentPluginEditor extends EditorPane {
 					description: item.description,
 					version: '',
 					source: item.source,
+					sourceDescriptor: item.sourceDescriptor,
 					marketplace: item.marketplace,
 					marketplaceReference: item.marketplaceReference,
 					marketplaceType: item.marketplaceType,
@@ -222,6 +223,7 @@ export class AgentPluginEditor extends EditorPane {
 							name: item.name,
 							description: mp.description,
 							source: mp.source,
+							sourceDescriptor: mp.sourceDescriptor,
 							marketplace: mp.marketplace,
 							marketplaceReference: mp.marketplaceReference,
 							marketplaceType: mp.marketplaceType,
@@ -267,7 +269,7 @@ export class AgentPluginEditor extends EditorPane {
 	}

 	private installedPluginToItem(plugin: IAgentPlugin): IInstalledPluginItem {
-		const name = basename(plugin.uri);
+		const name = plugin.label;
 		const description = plugin.fromMarketplace?.description ?? this.labelService.getUriLabel(dirname(plugin.uri), { relative: true });
 		const marketplace = plugin.fromMarketplace?.marketplace;
 		return { kind: AgentPluginItemKind.Installed, name, description, marketplace, plugin };
@@ -517,6 +519,7 @@ class InstallPluginEditorAction extends Action {
 			description: this.item.description,
 			version: '',
 			source: this.item.source,
+			sourceDescriptor: this.item.sourceDescriptor,
 			marketplace: this.item.marketplace,
 			marketplaceReference: this.item.marketplaceReference,
 			marketplaceType: this.item.marketplaceType,
--- a/src/vs/workbench/contrib/chat/browser/agentPluginEditor/agentPluginItems.ts
+++ b/src/vs/workbench/contrib/chat/browser/agentPluginEditor/agentPluginItems.ts
@@ -5,7 +5,7 @@

 import { URI } from '../../../../../base/common/uri.js';
 import type { IAgentPlugin } from '../../common/plugins/agentPluginService.js';
-import type { IMarketplaceReference, MarketplaceType } from '../../common/plugins/pluginMarketplaceService.js';
+import type { IMarketplaceReference, IPluginSourceDescriptor, MarketplaceType } from '../../common/plugins/pluginMarketplaceService.js';

 export const enum AgentPluginItemKind {
 	Installed = 'installed',
@@ -25,6 +25,7 @@ export interface IMarketplacePluginItem {
 	readonly name: string;
 	readonly description: string;
 	readonly source: string;
+	readonly sourceDescriptor: IPluginSourceDescriptor;
 	readonly marketplace: string;
 	readonly marketplaceReference: IMarketplaceReference;
 	readonly marketplaceType: MarketplaceType;
--- a/src/vs/workbench/contrib/chat/browser/agentPluginRepositoryService.ts
+++ b/src/vs/workbench/contrib/chat/browser/agentPluginRepositoryService.ts
@@ -18,7 +18,7 @@ import { IProgressService, ProgressLocation } from '../../../../platform/progres
 import { IStorageService, StorageScope, StorageTarget } from '../../../../platform/storage/common/storage.js';
 import type { Dto } from '../../../services/extensions/common/proxyIdentifier.js';
 import { IAgentPluginRepositoryService, IEnsureRepositoryOptions, IPullRepositoryOptions } from '../common/plugins/agentPluginRepositoryService.js';
-import { IMarketplacePlugin, IMarketplaceReference, MarketplaceReferenceKind, MarketplaceType } from '../common/plugins/pluginMarketplaceService.js';
+import { IMarketplacePlugin, IMarketplaceReference, IPluginSourceDescriptor, MarketplaceReferenceKind, MarketplaceType, PluginSourceKind } from '../common/plugins/pluginMarketplaceService.js';

 const MARKETPLACE_INDEX_STORAGE_KEY = 'chat.plugins.marketplaces.index.v1';

@@ -176,7 +176,7 @@ export class AgentPluginRepositoryService implements IAgentPluginRepositoryServi
 		this._storageService.store(MARKETPLACE_INDEX_STORAGE_KEY, JSON.stringify(serialized), StorageScope.APPLICATION, StorageTarget.MACHINE);
 	}

-	private async _cloneRepository(repoDir: URI, cloneUrl: string, progressTitle: string, failureLabel: string): Promise<void> {
+	private async _cloneRepository(repoDir: URI, cloneUrl: string, progressTitle: string, failureLabel: string, ref?: string): Promise<void> {
 		try {
 			await this._progressService.withProgress(
 				{
@@ -186,7 +186,7 @@ export class AgentPluginRepositoryService implements IAgentPluginRepositoryServi
 				},
 				async () => {
 					await this._fileService.createFolder(dirname(repoDir));
-					await this._commandService.executeCommand('_git.cloneRepository', cloneUrl, dirname(repoDir).fsPath);
+					await this._commandService.executeCommand('_git.cloneRepository', cloneUrl, repoDir.fsPath, ref);
 				}
 			);
 		} catch (err) {
@@ -212,4 +212,178 @@ export class AgentPluginRepositoryService implements IAgentPluginRepositoryServi
 		}
 		return pluginDir;
 	}
+
+	getPluginSourceInstallUri(sourceDescriptor: IPluginSourceDescriptor): URI {
+		switch (sourceDescriptor.kind) {
+			case PluginSourceKind.RelativePath:
+				throw new Error('Use getPluginInstallUri() for relative-path sources');
+			case PluginSourceKind.GitHub: {
+				const [owner, repo] = sourceDescriptor.repo.split('/');
+				return joinPath(this._cacheRoot, 'github.com', owner, repo, ...this._getSourceRevisionCacheSuffix(sourceDescriptor));
+			}
+			case PluginSourceKind.GitUrl: {
+				const segments = this._gitUrlCacheSegments(sourceDescriptor.url, sourceDescriptor.ref, sourceDescriptor.sha);
+				return joinPath(this._cacheRoot, ...segments);
+			}
+			case PluginSourceKind.Npm:
+				return joinPath(this._cacheRoot, 'npm', sanitizePackageName(sourceDescriptor.package), 'node_modules', sourceDescriptor.package);
+			case PluginSourceKind.Pip:
+				return joinPath(this._cacheRoot, 'pip', sanitizePackageName(sourceDescriptor.package));
+		}
+	}
+
+	async ensurePluginSource(plugin: IMarketplacePlugin, options?: IEnsureRepositoryOptions): Promise<URI> {
+		const descriptor = plugin.sourceDescriptor;
+		switch (descriptor.kind) {
+			case PluginSourceKind.RelativePath:
+				return this.ensureRepository(plugin.marketplaceReference, options);
+			case PluginSourceKind.GitHub: {
+				const cloneUrl = `https://github.com/${descriptor.repo}.git`;
+				const repoDir = this.getPluginSourceInstallUri(descriptor);
+				const repoExists = await this._fileService.exists(repoDir);
+				if (repoExists) {
+					await this._checkoutPluginSourceRevision(repoDir, descriptor, options?.failureLabel ?? descriptor.repo);
+					return repoDir;
+				}
+				const progressTitle = options?.progressTitle ?? localize('cloningPluginSource', "Cloning plugin source '{0}'...", descriptor.repo);
+				const failureLabel = options?.failureLabel ?? descriptor.repo;
+				await this._cloneRepository(repoDir, cloneUrl, progressTitle, failureLabel, descriptor.ref);
+				await this._checkoutPluginSourceRevision(repoDir, descriptor, failureLabel);
+				return repoDir;
+			}
+			case PluginSourceKind.GitUrl: {
+				const repoDir = this.getPluginSourceInstallUri(descriptor);
+				const repoExists = await this._fileService.exists(repoDir);
+				if (repoExists) {
+					await this._checkoutPluginSourceRevision(repoDir, descriptor, options?.failureLabel ?? descriptor.url);
+					return repoDir;
+				}
+				const progressTitle = options?.progressTitle ?? localize('cloningPluginSourceUrl', "Cloning plugin source '{0}'...", descriptor.url);
+				const failureLabel = options?.failureLabel ?? descriptor.url;
+				await this._cloneRepository(repoDir, descriptor.url, progressTitle, failureLabel, descriptor.ref);
+				await this._checkoutPluginSourceRevision(repoDir, descriptor, failureLabel);
+				return repoDir;
+			}
+			case PluginSourceKind.Npm: {
+				// npm/pip install directories are managed by the install service.
+				// Return the expected install URI without performing installation.
+				return joinPath(this._cacheRoot, 'npm', sanitizePackageName(descriptor.package));
+			}
+			case PluginSourceKind.Pip: {
+				return joinPath(this._cacheRoot, 'pip', sanitizePackageName(descriptor.package));
+			}
+		}
+	}
+
+	async updatePluginSource(plugin: IMarketplacePlugin, options?: IPullRepositoryOptions): Promise<void> {
+		const descriptor = plugin.sourceDescriptor;
+		if (descriptor.kind !== PluginSourceKind.GitHub && descriptor.kind !== PluginSourceKind.GitUrl) {
+			return;
+		}
+
+		const repoDir = this.getPluginSourceInstallUri(descriptor);
+		const repoExists = await this._fileService.exists(repoDir);
+		if (!repoExists) {
+			this._logService.warn(`[AgentPluginRepositoryService] Cannot update plugin '${options?.pluginName ?? plugin.name}': source repository not cloned`);
+			return;
+		}
+
+		const updateLabel = options?.pluginName ?? plugin.name;
+		const failureLabel = options?.failureLabel ?? updateLabel;
+
+		try {
+			await this._progressService.withProgress(
+				{
+					location: ProgressLocation.Notification,
+					title: localize('updatingPluginSource', "Updating plugin '{0}'...", updateLabel),
+					cancellable: false,
+				},
+				async () => {
+					await this._commandService.executeCommand('git.openRepository', repoDir.fsPath);
+					if (descriptor.sha) {
+						await this._commandService.executeCommand('git.fetch', repoDir.fsPath);
+					} else {
+						await this._commandService.executeCommand('_git.pull', repoDir.fsPath);
+					}
+					await this._checkoutPluginSourceRevision(repoDir, descriptor, failureLabel);
+				}
+			);
+		} catch (err) {
+			this._logService.error(`[AgentPluginRepositoryService] Failed to update plugin source ${updateLabel}:`, err);
+			this._notificationService.notify({
+				severity: Severity.Error,
+				message: localize('pullPluginSourceFailed', "Failed to update plugin '{0}': {1}", failureLabel, err?.message ?? String(err)),
+				actions: {
+					primary: [new Action('showGitOutput', localize('showGitOutput', "Show Git Output"), undefined, true, () => {
+						this._commandService.executeCommand('git.showOutput');
+					})],
+				},
+			});
+		}
+	}
+
+	private _gitUrlCacheSegments(url: string, ref?: string, sha?: string): string[] {
+		try {
+			const parsed = URI.parse(url);
+			const authority = (parsed.authority || 'unknown').replace(/[\\/:*?"<>|]/g, '_').toLowerCase();
+			const pathPart = parsed.path.replace(/^\/+/, '').replace(/\.git$/i, '').replace(/\/+$/g, '');
+			const segments = pathPart.split('/').map(s => s.replace(/[\\/:*?"<>|]/g, '_'));
+			return [authority, ...segments, ...this._getSourceRevisionCacheSuffix(ref, sha)];
+		} catch {
+			return ['git', url.replace(/[\\/:*?"<>|]/g, '_'), ...this._getSourceRevisionCacheSuffix(ref, sha)];
+		}
+	}
+
+	private _getSourceRevisionCacheSuffix(descriptorOrRef: IPluginSourceDescriptor | string | undefined, sha?: string): string[] {
+		if (typeof descriptorOrRef === 'object' && descriptorOrRef) {
+			if (descriptorOrRef.kind === PluginSourceKind.GitHub || descriptorOrRef.kind === PluginSourceKind.GitUrl) {
+				return this._getSourceRevisionCacheSuffix(descriptorOrRef.ref, descriptorOrRef.sha);
+			}
+			return [];
+		}
+
+		const ref = descriptorOrRef;
+		if (sha) {
+			return [`sha_${sanitizePackageName(sha)}`];
+		}
+		if (ref) {
+			return [`ref_${sanitizePackageName(ref)}`];
+		}
+		return [];
+	}
+
+	private async _checkoutPluginSourceRevision(repoDir: URI, descriptor: IPluginSourceDescriptor, failureLabel: string): Promise<void> {
+		if (descriptor.kind !== PluginSourceKind.GitHub && descriptor.kind !== PluginSourceKind.GitUrl) {
+			return;
+		}
+
+		if (!descriptor.sha && !descriptor.ref) {
+			return;
+		}
+
+		try {
+			if (descriptor.sha) {
+				await this._commandService.executeCommand('_git.checkout', repoDir.fsPath, descriptor.sha, true);
+				return;
+			}
+
+			await this._commandService.executeCommand('_git.checkout', repoDir.fsPath, descriptor.ref);
+		} catch (err) {
+			this._logService.error(`[AgentPluginRepositoryService] Failed to checkout plugin source revision for ${failureLabel}:`, err);
+			this._notificationService.notify({
+				severity: Severity.Error,
+				message: localize('checkoutPluginSourceFailed', "Failed to checkout plugin '{0}' to requested revision: {1}", failureLabel, err?.message ?? String(err)),
+				actions: {
+					primary: [new Action('showGitOutput', localize('showGitOutput', "Show Git Output"), undefined, true, () => {
+						this._commandService.executeCommand('git.showOutput');
+					})],
+				},
+			});
+			throw err;
+		}
+	}
+}
+
+function sanitizePackageName(name: string): string {
+	return name.replace(/[\\/:*?"<>|]/g, '_');
 }
--- a/src/vs/workbench/contrib/chat/browser/agentPluginsView.ts
+++ b/src/vs/workbench/contrib/chat/browser/agentPluginsView.ts
@@ -17,7 +17,7 @@ import { Disposable, DisposableStore, disposeIfDisposable, IDisposable, isDispos
 import { ThemeIcon } from '../../../../base/common/themables.js';
 import { autorun } from '../../../../base/common/observable.js';
 import { IPagedModel, PagedModel } from '../../../../base/common/paging.js';
-import { basename, dirname, joinPath } from '../../../../base/common/resources.js';
+import { dirname, joinPath } from '../../../../base/common/resources.js';
 import { URI } from '../../../../base/common/uri.js';
 import { localize, localize2 } from '../../../../nls.js';
 import { Action2, MenuId, registerAction2 } from '../../../../platform/actions/common/actions.js';
@@ -56,7 +56,7 @@ export const InstalledAgentPluginsViewId = 'workbench.views.agentPlugins.install
 //#region Item model

 function installedPluginToItem(plugin: IAgentPlugin, labelService: ILabelService): IInstalledPluginItem {
-	const name = basename(plugin.uri);
+	const name = plugin.label;
 	const description = plugin.fromMarketplace?.description ?? labelService.getUriLabel(dirname(plugin.uri), { relative: true });
 	const marketplace = plugin.fromMarketplace?.marketplace;
 	return { kind: AgentPluginItemKind.Installed, name, description, marketplace, plugin };
@@ -68,6 +68,7 @@ function marketplacePluginToItem(plugin: IMarketplacePlugin): IMarketplacePlugin
 		name: plugin.name,
 		description: plugin.description,
 		source: plugin.source,
+		sourceDescriptor: plugin.sourceDescriptor,
 		marketplace: plugin.marketplace,
 		marketplaceReference: plugin.marketplaceReference,
 		marketplaceType: plugin.marketplaceType,
@@ -95,6 +96,7 @@ class InstallPluginAction extends Action {
 			description: this.item.description,
 			version: '',
 			source: this.item.source,
+			sourceDescriptor: this.item.sourceDescriptor,
 			marketplace: this.item.marketplace,
 			marketplaceReference: this.item.marketplaceReference,
 			marketplaceType: this.item.marketplaceType,
@@ -518,6 +520,7 @@ export class AgentPluginsListView extends AbstractExtensionsListView<IAgentPlugi
 					description: m.description,
 					version: '',
 					source: m.source,
+					sourceDescriptor: m.sourceDescriptor,
 					marketplace: m.marketplace,
 					marketplaceReference: m.marketplaceReference,
 					marketplaceType: m.marketplaceType,
--- a/src/vs/workbench/contrib/chat/browser/pluginInstallService.ts
+++ b/src/vs/workbench/contrib/chat/browser/pluginInstallService.ts
@@ -3,13 +3,21 @@
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

+import { CancelablePromise, timeout } from '../../../../base/common/async.js';
+import { DisposableStore, toDisposable } from '../../../../base/common/lifecycle.js';
+import { isWindows } from '../../../../base/common/platform.js';
 import { URI } from '../../../../base/common/uri.js';
 import { localize } from '../../../../nls.js';
+import { IDialogService } from '../../../../platform/dialogs/common/dialogs.js';
 import { IFileService } from '../../../../platform/files/common/files.js';
+import { ILogService } from '../../../../platform/log/common/log.js';
 import { INotificationService, Severity } from '../../../../platform/notification/common/notification.js';
+import { IProgressService, ProgressLocation } from '../../../../platform/progress/common/progress.js';
+import { TerminalCapability, type ITerminalCommand } from '../../../../platform/terminal/common/capabilities/capabilities.js';
+import { ITerminalInstance, ITerminalService } from '../../terminal/browser/terminal.js';
 import { IAgentPluginRepositoryService } from '../common/plugins/agentPluginRepositoryService.js';
 import { IPluginInstallService } from '../common/plugins/pluginInstallService.js';
-import { IMarketplacePlugin, IPluginMarketplaceService } from '../common/plugins/pluginMarketplaceService.js';
+import { getPluginSourceLabel, IMarketplacePlugin, INpmPluginSource, IPipPluginSource, IPluginMarketplaceService, PluginSourceKind } from '../common/plugins/pluginMarketplaceService.js';

 export class PluginInstallService implements IPluginInstallService {
 	declare readonly _serviceBrand: undefined;
@@ -19,9 +27,58 @@ export class PluginInstallService implements IPluginInstallService {
 		@IPluginMarketplaceService private readonly _pluginMarketplaceService: IPluginMarketplaceService,
 		@IFileService private readonly _fileService: IFileService,
 		@INotificationService private readonly _notificationService: INotificationService,
+		@IDialogService private readonly _dialogService: IDialogService,
+		@ITerminalService private readonly _terminalService: ITerminalService,
+		@IProgressService private readonly _progressService: IProgressService,
+		@ILogService private readonly _logService: ILogService,
 	) { }

 	async installPlugin(plugin: IMarketplacePlugin): Promise<void> {
+		switch (plugin.sourceDescriptor.kind) {
+			case PluginSourceKind.RelativePath:
+				return this._installRelativePathPlugin(plugin);
+			case PluginSourceKind.GitHub:
+			case PluginSourceKind.GitUrl:
+				return this._installGitPlugin(plugin);
+			case PluginSourceKind.Npm:
+				return this._installNpmPlugin(plugin, plugin.sourceDescriptor);
+			case PluginSourceKind.Pip:
+				return this._installPipPlugin(plugin, plugin.sourceDescriptor);
+		}
+	}
+
+	async updatePlugin(plugin: IMarketplacePlugin): Promise<void> {
+		switch (plugin.sourceDescriptor.kind) {
+			case PluginSourceKind.RelativePath:
+				return this._pluginRepositoryService.pullRepository(plugin.marketplaceReference, {
+					pluginName: plugin.name,
+					failureLabel: plugin.name,
+					marketplaceType: plugin.marketplaceType,
+				});
+			case PluginSourceKind.GitHub:
+			case PluginSourceKind.GitUrl:
+				return this._pluginRepositoryService.updatePluginSource(plugin, {
+					pluginName: plugin.name,
+					failureLabel: plugin.name,
+					marketplaceType: plugin.marketplaceType,
+				});
+			case PluginSourceKind.Npm:
+				return this._installNpmPlugin(plugin, plugin.sourceDescriptor);
+			case PluginSourceKind.Pip:
+				return this._installPipPlugin(plugin, plugin.sourceDescriptor);
+		}
+	}
+
+	getPluginInstallUri(plugin: IMarketplacePlugin): URI {
+		if (plugin.sourceDescriptor.kind === PluginSourceKind.RelativePath) {
+			return this._pluginRepositoryService.getPluginInstallUri(plugin);
+		}
+		return this._pluginRepositoryService.getPluginSourceInstallUri(plugin.sourceDescriptor);
+	}
+
+	// --- Relative-path source (existing git-based flow) -----------------------
+
+	private async _installRelativePathPlugin(plugin: IMarketplacePlugin): Promise<void> {
 		try {
 			await this._pluginRepositoryService.ensureRepository(plugin.marketplaceReference, {
 				progressTitle: localize('installingPlugin', "Installing plugin '{0}'...", plugin.name),
@@ -55,15 +112,212 @@ export class PluginInstallService implements IPluginInstallService {
 		this._pluginMarketplaceService.addInstalledPlugin(pluginDir, plugin);
 	}

-	async updatePlugin(plugin: IMarketplacePlugin): Promise<void> {
-		return this._pluginRepositoryService.pullRepository(plugin.marketplaceReference, {
-			pluginName: plugin.name,
-			failureLabel: plugin.name,
-			marketplaceType: plugin.marketplaceType,
+	// --- GitHub / Git URL source (independent clone) --------------------------
+
+	private async _installGitPlugin(plugin: IMarketplacePlugin): Promise<void> {
+		let pluginDir: URI;
+		try {
+			pluginDir = await this._pluginRepositoryService.ensurePluginSource(plugin, {
+				progressTitle: localize('installingPlugin', "Installing plugin '{0}'...", plugin.name),
+				failureLabel: plugin.name,
+				marketplaceType: plugin.marketplaceType,
+			});
+		} catch {
+			return;
+		}
+
+		const pluginExists = await this._fileService.exists(pluginDir);
+		if (!pluginExists) {
+			this._notificationService.notify({
+				severity: Severity.Error,
+				message: localize('pluginSourceNotFound', "Plugin source '{0}' not found after cloning.", getPluginSourceLabel(plugin.sourceDescriptor)),
+			});
+			return;
+		}
+
+		this._pluginMarketplaceService.addInstalledPlugin(pluginDir, plugin);
+	}
+
+	// --- npm source -----------------------------------------------------------
+
+	private async _installNpmPlugin(plugin: IMarketplacePlugin, source: INpmPluginSource): Promise<void> {
+		const packageSpec = source.version ? `${source.package}@${source.version}` : source.package;
+		const installDir = await this._pluginRepositoryService.ensurePluginSource(plugin);
+		const args = ['npm', 'install', '--prefix', installDir.fsPath, packageSpec];
+		if (source.registry) {
+			args.push('--registry', source.registry);
+		}
+		const command = this._formatShellCommand(args);
+
+		const confirmed = await this._confirmTerminalCommand(plugin.name, command);
+		if (!confirmed) {
+			return;
+		}
+
+		const { success, terminal } = await this._runTerminalCommand(
+			command,
+			localize('installingNpmPlugin', "Installing npm plugin '{0}'...", plugin.name),
+		);
+		if (!success) {
+			return;
+		}
+
+		const pluginDir = this._pluginRepositoryService.getPluginSourceInstallUri(source);
+		const pluginExists = await this._fileService.exists(pluginDir);
+		if (!pluginExists) {
+			this._notificationService.notify({
+				severity: Severity.Error,
+				message: localize('npmPluginNotFound', "npm package '{0}' was not found after installation.", source.package),
+			});
+			return;
+		}
+
+		terminal?.dispose();
+		this._pluginMarketplaceService.addInstalledPlugin(pluginDir, plugin);
+	}
+
+	// --- pip source -----------------------------------------------------------
+
+	private async _installPipPlugin(plugin: IMarketplacePlugin, source: IPipPluginSource): Promise<void> {
+		const packageSpec = source.version ? `${source.package}==${source.version}` : source.package;
+		const installDir = await this._pluginRepositoryService.ensurePluginSource(plugin);
+		const args = ['pip', 'install', '--target', installDir.fsPath, packageSpec];
+		if (source.registry) {
+			args.push('--index-url', source.registry);
+		}
+		const command = this._formatShellCommand(args);
+
+		const confirmed = await this._confirmTerminalCommand(plugin.name, command);
+		if (!confirmed) {
+			return;
+		}
+
+		const { success, terminal } = await this._runTerminalCommand(
+			command,
+			localize('installingPipPlugin', "Installing pip plugin '{0}'...", plugin.name),
+		);
+		if (!success) {
+			return;
+		}
+
+		const pluginDir = this._pluginRepositoryService.getPluginSourceInstallUri(source);
+		const pluginExists = await this._fileService.exists(pluginDir);
+		if (!pluginExists) {
+			this._notificationService.notify({
+				severity: Severity.Error,
+				message: localize('pipPluginNotFound', "pip package '{0}' was not found after installation.", source.package),
+			});
+			return;
+		}
+
+		terminal?.dispose();
+		this._pluginMarketplaceService.addInstalledPlugin(pluginDir, plugin);
+	}
+
+	// --- Helpers --------------------------------------------------------------
+
+	private async _confirmTerminalCommand(pluginName: string, command: string): Promise<boolean> {
+		const { confirmed } = await this._dialogService.confirm({
+			type: 'question',
+			message: localize('confirmPluginInstall', "Install Plugin '{0}'?", pluginName),
+			detail: localize('confirmPluginInstallDetail', "This will run the following command in a terminal:\n\n{0}", command),
+			primaryButton: localize({ key: 'confirmInstall', comment: ['&& denotes a mnemonic'] }, "&&Install"),
+		});
+		return confirmed;
+	}
+
+	private async _runTerminalCommand(command: string, progressTitle: string) {
+		let terminal: ITerminalInstance | undefined;
+		try {
+			await this._progressService.withProgress(
+				{
+					location: ProgressLocation.Notification,
+					title: progressTitle,
+					cancellable: false,
+				},
+				async () => {
+					terminal = await this._terminalService.createTerminal({
+						config: {
+							name: localize('pluginInstallTerminal', "Plugin Install"),
+							forceShellIntegration: true,
+							isTransient: true,
+							isFeatureTerminal: true,
+						},
+					});
+
+					await terminal.processReady;
+					this._terminalService.setActiveInstance(terminal);
+
+					const commandResultPromise = this._waitForTerminalCommandCompletion(terminal);
+					await terminal.runCommand(command, true);
+					const exitCode = await commandResultPromise;
+					if (exitCode !== 0) {
+						throw new Error(localize('terminalCommandExitCode', "Command exited with code {0}", exitCode));
+					}
+				}
+			);
+			return { success: true, terminal };
+		} catch (err) {
+			this._logService.error('[PluginInstallService] Terminal command failed:', err);
+			this._notificationService.notify({
+				severity: Severity.Error,
+				message: localize('terminalCommandFailed', "Plugin installation command failed: {0}", err?.message ?? String(err)),
+			});
+			return { success: false, terminal };
+		}
+	}
+
+	private _waitForTerminalCommandCompletion(terminal: ITerminalInstance): Promise<number | undefined> {
+		return new Promise<number | undefined>(resolve => {
+			const disposables = new DisposableStore();
+			let isResolved = false;
+
+			const resolveAndDispose = (exitCode: number | undefined): void => {
+				if (isResolved) {
+					return;
+				}
+				isResolved = true;
+				disposables.dispose();
+				resolve(exitCode);
+			};
+
+			const attachCommandFinishedListener = (): void => {
+				const commandDetection = terminal.capabilities.get(TerminalCapability.CommandDetection);
+				if (!commandDetection) {
+					return;
+				}
+
+				disposables.add(commandDetection.onCommandFinished((command: ITerminalCommand) => {
+					resolveAndDispose(command.exitCode ?? 0);
+				}));
+			};
+
+			attachCommandFinishedListener();
+			disposables.add(terminal.capabilities.onDidAddCommandDetectionCapability(() => attachCommandFinishedListener()));
+
+			const timeoutHandle: CancelablePromise<void> = timeout(120_000);
+			disposables.add(toDisposable(() => timeoutHandle.cancel()));
+			void timeoutHandle.then(() => {
+				if (isResolved) {
+					return;
+				}
+				this._logService.warn('[PluginInstallService] Terminal command completion timed out');
+				resolveAndDispose(undefined);
+			});
 		});
 	}

-	getPluginInstallUri(plugin: IMarketplacePlugin): URI {
-		return this._pluginRepositoryService.getPluginInstallUri(plugin);
+	private _formatShellCommand(args: readonly string[]): string {
+		const [command, ...rest] = args;
+		return [command, ...rest.map(arg => this._shellEscapeArg(arg))].join(' ');
+	}
+
+	private _shellEscapeArg(value: string): string {
+		if (isWindows) {
+			// PowerShell: use double quotes, escape backticks, dollar signs, and double quotes
+			return `"${value.replace(/[`$"]/g, '`$&')}"`;
+		}
+		// POSIX shells: use single quotes, escape by ending quote, adding escaped quote, reopening
+		return `'${value.replace(/'/g, `'\\''`)}'`;
 	}
 }
--- a/src/vs/workbench/contrib/chat/common/plugins/agentPluginRepositoryService.ts
+++ b/src/vs/workbench/contrib/chat/common/plugins/agentPluginRepositoryService.ts
@@ -5,7 +5,7 @@

 import { URI } from '../../../../../base/common/uri.js';
 import { createDecorator } from '../../../../../platform/instantiation/common/instantiation.js';
-import { IMarketplacePlugin, IMarketplaceReference, MarketplaceType } from './pluginMarketplaceService.js';
+import { IMarketplacePlugin, IMarketplaceReference, IPluginSourceDescriptor, MarketplaceType } from './pluginMarketplaceService.js';

 export const IAgentPluginRepositoryService = createDecorator<IAgentPluginRepositoryService>('agentPluginRepositoryService');

@@ -61,4 +61,26 @@ export interface IAgentPluginRepositoryService {
 	 * Pulls latest changes for a cloned marketplace repository.
 	 */
 	pullRepository(marketplace: IMarketplaceReference, options?: IPullRepositoryOptions): Promise<void>;
+
+	/**
+	 * Returns the local install URI for a plugin based on its
+	 * {@link IPluginSourceDescriptor}. For non-relative-path sources
+	 * (github, url, npm, pip), this computes a cache location independent
+	 * of the marketplace repository.
+	 */
+	getPluginSourceInstallUri(sourceDescriptor: IPluginSourceDescriptor): URI;
+
+	/**
+	 * Ensures the plugin source is available locally. For github/url sources
+	 * this clones the repository into the cache. For npm/pip sources this is
+	 * a no-op (installation via terminal is handled by the install service).
+	 */
+	ensurePluginSource(plugin: IMarketplacePlugin, options?: IEnsureRepositoryOptions): Promise<URI>;
+
+	/**
+	 * Updates a plugin source that is stored outside the marketplace repository.
+	 * For github/url sources this pulls latest changes and reapplies pinned
+	 * ref/sha checkout. For npm/pip sources this is a no-op.
+	 */
+	updatePluginSource(plugin: IMarketplacePlugin, options?: IPullRepositoryOptions): Promise<void>;
 }
--- a/src/vs/workbench/contrib/chat/common/plugins/agentPluginService.ts
+++ b/src/vs/workbench/contrib/chat/common/plugins/agentPluginService.ts
@@ -44,6 +44,8 @@ export interface IAgentPluginMcpServerDefinition {

 export interface IAgentPlugin {
 	readonly uri: URI;
+	/** Human-readable display name for the plugin. */
+	readonly label: string;
 	readonly enabled: IObservable<boolean>;
 	setEnabled(enabled: boolean): void;
 	/** Removes this plugin from its discovery source (config or installed storage). */
--- a/src/vs/workbench/contrib/chat/common/plugins/agentPluginServiceImpl.ts
+++ b/src/vs/workbench/contrib/chat/common/plugins/agentPluginServiceImpl.ts
@@ -416,6 +416,7 @@ export abstract class AbstractAgentPluginDiscovery extends Disposable implements

 		const plugin: PluginEntry = {
 			uri,
+			label: fromMarketplace?.name ?? basename(uri),
 			enabled,
 			setEnabled: setEnabledCallback,
 			remove: removeCallback,
--- a/src/vs/workbench/contrib/chat/common/plugins/pluginMarketplaceService.ts
+++ b/src/vs/workbench/contrib/chat/common/plugins/pluginMarketplaceService.ts
@@ -45,12 +45,64 @@ export interface IMarketplaceReference {
 	readonly localRepositoryUri?: URI;
 }

+export const enum PluginSourceKind {
+	RelativePath = 'relativePath',
+	GitHub = 'github',
+	GitUrl = 'url',
+	Npm = 'npm',
+	Pip = 'pip',
+}
+
+export interface IRelativePathPluginSource {
+	readonly kind: PluginSourceKind.RelativePath;
+	/** Resolved relative path within the marketplace repository. */
+	readonly path: string;
+}
+
+export interface IGitHubPluginSource {
+	readonly kind: PluginSourceKind.GitHub;
+	readonly repo: string;
+	readonly ref?: string;
+	readonly sha?: string;
+}
+
+export interface IGitUrlPluginSource {
+	readonly kind: PluginSourceKind.GitUrl;
+	/** Full git repository URL (must end with .git). */
+	readonly url: string;
+	readonly ref?: string;
+	readonly sha?: string;
+}
+
+export interface INpmPluginSource {
+	readonly kind: PluginSourceKind.Npm;
+	readonly package: string;
+	readonly version?: string;
+	readonly registry?: string;
+}
+
+export interface IPipPluginSource {
+	readonly kind: PluginSourceKind.Pip;
+	readonly package: string;
+	readonly version?: string;
+	readonly registry?: string;
+}
+
+export type IPluginSourceDescriptor =
+	| IRelativePathPluginSource
+	| IGitHubPluginSource
+	| IGitUrlPluginSource
+	| INpmPluginSource
+	| IPipPluginSource;
+
 export interface IMarketplacePlugin {
 	readonly name: string;
 	readonly description: string;
 	readonly version: string;
-	/** Subdirectory within the repository where the plugin lives. */
+	/** Subdirectory within the repository where the plugin lives (for relative-path sources). */
 	readonly source: string;
+	/** Structured source descriptor indicating how the plugin should be fetched/installed. */
+	readonly sourceDescriptor: IPluginSourceDescriptor;
 	/** Marketplace label shown in UI and plugin provenance. */
 	readonly marketplace: string;
 	/** Canonical reference for clone/update/install location resolution. */
@@ -60,6 +112,18 @@ export interface IMarketplacePlugin {
 	readonly readmeUri?: URI;
 }

+/** Raw JSON shape of a remote plugin source object in marketplace.json. */
+interface IJsonPluginSource {
+	readonly source: string;
+	readonly repo?: string;
+	readonly url?: string;
+	readonly package?: string;
+	readonly ref?: string;
+	readonly sha?: string;
+	readonly version?: string;
+	readonly registry?: string;
+}
+
 interface IMarketplaceJson {
 	readonly metadata?: {
 		readonly pluginRoot?: string;
@@ -68,7 +132,7 @@ interface IMarketplaceJson {
 		readonly name?: string;
 		readonly description?: string;
 		readonly version?: string;
-		readonly source?: string;
+		readonly source?: string | IJsonPluginSource;
 	}[];
 }

@@ -118,6 +182,23 @@ interface IStoredInstalledPlugin {
 	readonly enabled: boolean;
 }

+/**
+ * Ensures that an {@link IMarketplacePlugin} loaded from storage has a
+ * {@link IMarketplacePlugin.sourceDescriptor sourceDescriptor}. Plugins
+ * persisted before the sourceDescriptor field was introduced will only
+ * have the legacy `source` string — this function synthesises a
+ * {@link PluginSourceKind.RelativePath} descriptor from it.
+ */
+function ensureSourceDescriptor(plugin: IMarketplacePlugin): IMarketplacePlugin {
+	if (plugin.sourceDescriptor) {
+		return plugin;
+	}
+	return {
+		...plugin,
+		sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: plugin.source },
+	};
+}
+
 const installedPluginsMemento = observableMemento<readonly IStoredInstalledPlugin[]>({
 	defaultValue: [],
 	key: 'chat.plugins.installed.v1',
@@ -151,7 +232,12 @@ export class PluginMarketplaceService extends Disposable implements IPluginMarke
 			installedPluginsMemento(StorageScope.APPLICATION, StorageTarget.MACHINE, _storageService)
 		);

-		this.installedPlugins = this._installedPluginsStore.map(s => revive(s));
+		this.installedPlugins = this._installedPluginsStore.map(s =>
+			(revive(s) as readonly IMarketplaceInstalledPlugin[]).map(e => ({
+				...e,
+				plugin: ensureSourceDescriptor(e.plugin),
+			}))
+		);

 		this.onDidChangeMarketplaces = Event.filter(
 			_configurationService.onDidChangeConfiguration,
@@ -213,21 +299,27 @@ export class PluginMarketplaceService extends Disposable implements IPluginMarke
 					continue;
 				}
 				const plugins = json.plugins
-					.filter((p): p is { name: string; description?: string; version?: string; source?: string } =>
+					.filter((p): p is { name: string; description?: string; version?: string; source?: string | IJsonPluginSource } =>
 						typeof p.name === 'string' && !!p.name
 					)
 					.flatMap(p => {
-						const source = resolvePluginSource(json.metadata?.pluginRoot, p.source ?? '');
-						if (source === undefined) {
-							this._logService.warn(`[PluginMarketplaceService] Skipping plugin '${p.name}' in ${repo}: invalid source path '${p.source ?? ''}' with pluginRoot '${json.metadata?.pluginRoot ?? ''}'`);
+						const sourceDescriptor = parsePluginSource(p.source, json.metadata?.pluginRoot, {
+							pluginName: p.name,
+							logService: this._logService,
+							logPrefix: `[PluginMarketplaceService]`,
+						});
+						if (!sourceDescriptor) {
 							return [];
 						}

+						const source = sourceDescriptor.kind === PluginSourceKind.RelativePath ? sourceDescriptor.path : '';
+
 						return [{
 							name: p.name,
 							description: p.description ?? '',
 							version: p.version ?? '',
 							source,
+							sourceDescriptor,
 							marketplace: reference.displayLabel,
 							marketplaceReference: reference,
 							marketplaceType: def.type,
@@ -293,7 +385,7 @@ export class PluginMarketplaceService extends Disposable implements IPluginMarke
 				continue;
 			}

-			const plugins = entry.plugins.map(plugin => ({
+			const plugins = entry.plugins.map(plugin => ensureSourceDescriptor({
 				...plugin,
 				marketplace: reference.displayLabel,
 				marketplaceReference: reference,
@@ -344,9 +436,11 @@ export class PluginMarketplaceService extends Disposable implements IPluginMarke
 	addInstalledPlugin(pluginUri: URI, plugin: IMarketplacePlugin): void {
 		const current = this.installedPlugins.get();
 		if (current.some(e => isEqual(e.pluginUri, pluginUri))) {
-			return;
+			// Still update to trigger watchers to re-check, something might have happened that we want to know about
+			this._installedPluginsStore.set([...current], undefined);
+		} else {
+			this._installedPluginsStore.set([...current, { pluginUri, plugin, enabled: true }], undefined);
 		}
-		this._installedPluginsStore.set([...current, { pluginUri, plugin, enabled: true }], undefined);
 	}

 	removeInstalledPlugin(pluginUri: URI): void {
@@ -391,21 +485,27 @@ export class PluginMarketplaceService extends Disposable implements IPluginMarke
 			}

 			return json.plugins
-				.filter((p): p is { name: string; description?: string; version?: string; source?: string } =>
+				.filter((p): p is { name: string; description?: string; version?: string; source?: string | IJsonPluginSource } =>
 					typeof p.name === 'string' && !!p.name
 				)
 				.flatMap(p => {
-					const source = resolvePluginSource(json.metadata?.pluginRoot, p.source ?? '');
-					if (source === undefined) {
-						this._logService.warn(`[PluginMarketplaceService] Skipping plugin '${p.name}' in ${reference.rawValue}: invalid source path '${p.source ?? ''}' with pluginRoot '${json.metadata?.pluginRoot ?? ''}'`);
+					const sourceDescriptor = parsePluginSource(p.source, json.metadata?.pluginRoot, {
+						pluginName: p.name,
+						logService: this._logService,
+						logPrefix: `[PluginMarketplaceService]`,
+					});
+					if (!sourceDescriptor) {
 						return [];
 					}

+					const source = sourceDescriptor.kind === PluginSourceKind.RelativePath ? sourceDescriptor.path : '';
+
 					return [{
 						name: p.name,
 						description: p.description ?? '',
 						version: p.version ?? '',
 						source,
+						sourceDescriptor,
 						marketplace: reference.displayLabel,
 						marketplaceReference: reference,
 						marketplaceType: def.type,
@@ -597,6 +697,158 @@ function resolvePluginSource(pluginRoot: string | undefined, source: string): st
 	return relativePath(repoRoot, resolvedUri) ?? undefined;
 }

+/**
+ * Parse a raw `source` field from marketplace.json into a structured
+ * {@link IPluginSourceDescriptor}. Accepts either a relative-path string
+ * or a JSON object with a `source` discriminant indicating the kind.
+ */
+export function parsePluginSource(
+	rawSource: string | IJsonPluginSource | undefined,
+	pluginRoot: string | undefined,
+	logContext: { pluginName: string; logService: ILogService; logPrefix: string },
+): IPluginSourceDescriptor | undefined {
+	if (rawSource === undefined || rawSource === null) {
+		// Treat missing source the same as empty string → pluginRoot or repo root.
+		const resolved = resolvePluginSource(pluginRoot, '');
+		if (resolved === undefined) {
+			return undefined;
+		}
+		return { kind: PluginSourceKind.RelativePath, path: resolved };
+	}
+
+	// String source → legacy relative-path behaviour.
+	if (typeof rawSource === 'string') {
+		const resolved = resolvePluginSource(pluginRoot, rawSource);
+		if (resolved === undefined) {
+			return undefined;
+		}
+		return { kind: PluginSourceKind.RelativePath, path: resolved };
+	}
+
+	// Object source → discriminated by `rawSource.source`.
+	if (typeof rawSource !== 'object' || typeof rawSource.source !== 'string') {
+		logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': source object is missing a 'source' discriminant`);
+		return undefined;
+	}
+
+	switch (rawSource.source) {
+		case 'github': {
+			if (typeof rawSource.repo !== 'string' || !rawSource.repo) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': github source is missing required 'repo' field`);
+				return undefined;
+			}
+			if (!isValidGitHubRepo(rawSource.repo)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': github source repo must be in 'owner/repo' format`);
+				return undefined;
+			}
+			if (!isOptionalString(rawSource.ref)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': github source 'ref' must be a string when provided`);
+				return undefined;
+			}
+			if (!isOptionalGitSha(rawSource.sha)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': github source 'sha' must be a full 40-character commit hash when provided`);
+				return undefined;
+			}
+			return {
+				kind: PluginSourceKind.GitHub,
+				repo: rawSource.repo,
+				ref: rawSource.ref,
+				sha: rawSource.sha,
+			};
+		}
+		case 'url': {
+			if (typeof rawSource.url !== 'string' || !rawSource.url) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': url source is missing required 'url' field`);
+				return undefined;
+			}
+			if (!rawSource.url.toLowerCase().endsWith('.git')) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': url source must end with '.git'`);
+				return undefined;
+			}
+			if (!isOptionalString(rawSource.ref)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': url source 'ref' must be a string when provided`);
+				return undefined;
+			}
+			if (!isOptionalGitSha(rawSource.sha)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': url source 'sha' must be a full 40-character commit hash when provided`);
+				return undefined;
+			}
+			return {
+				kind: PluginSourceKind.GitUrl,
+				url: rawSource.url,
+				ref: rawSource.ref,
+				sha: rawSource.sha,
+			};
+		}
+		case 'npm': {
+			if (typeof rawSource.package !== 'string' || !rawSource.package) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': npm source is missing required 'package' field`);
+				return undefined;
+			}
+			if (!isOptionalString(rawSource.version) || !isOptionalString(rawSource.registry)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': npm source 'version' and 'registry' must be strings when provided`);
+				return undefined;
+			}
+			return {
+				kind: PluginSourceKind.Npm,
+				package: rawSource.package,
+				version: rawSource.version,
+				registry: rawSource.registry,
+			};
+		}
+		case 'pip': {
+			if (typeof rawSource.package !== 'string' || !rawSource.package) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': pip source is missing required 'package' field`);
+				return undefined;
+			}
+			if (!isOptionalString(rawSource.version) || !isOptionalString(rawSource.registry)) {
+				logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': pip source 'version' and 'registry' must be strings when provided`);
+				return undefined;
+			}
+			return {
+				kind: PluginSourceKind.Pip,
+				package: rawSource.package,
+				version: rawSource.version,
+				registry: rawSource.registry,
+			};
+		}
+		default:
+			logContext.logService.warn(`${logContext.logPrefix} Skipping plugin '${logContext.pluginName}': unknown source kind '${rawSource.source}'`);
+			return undefined;
+	}
+}
+
+function isOptionalString(value: unknown): value is string | undefined {
+	return value === undefined || typeof value === 'string';
+}
+
+function isOptionalGitSha(value: unknown): value is string | undefined {
+	return value === undefined || (typeof value === 'string' && /^[0-9a-fA-F]{40}$/.test(value));
+}
+
+function isValidGitHubRepo(repo: string): boolean {
+	return /^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/.test(repo);
+}
+
+/**
+ * Returns a human-readable label for a plugin source descriptor,
+ * suitable for error messages and UI display.
+ */
+export function getPluginSourceLabel(descriptor: IPluginSourceDescriptor): string {
+	switch (descriptor.kind) {
+		case PluginSourceKind.RelativePath:
+			return descriptor.path || '.';
+		case PluginSourceKind.GitHub:
+			return descriptor.repo;
+		case PluginSourceKind.GitUrl:
+			return descriptor.url;
+		case PluginSourceKind.Npm:
+			return descriptor.version ? `${descriptor.package}@${descriptor.version}` : descriptor.package;
+		case PluginSourceKind.Pip:
+			return descriptor.version ? `${descriptor.package}==${descriptor.version}` : descriptor.package;
+	}
+}
+
 function getMarketplaceReadmeUri(repo: string, source: string): URI {
 	const normalizedSource = source.trim().replace(/^\.?\/+|\/+$/g, '');
 	const readmePath = normalizedSource ? `${normalizedSource}/README.md` : 'README.md';
--- a/src/vs/workbench/contrib/chat/test/browser/plugins/agentPluginRepositoryService.test.ts
+++ b/src/vs/workbench/contrib/chat/test/browser/plugins/agentPluginRepositoryService.test.ts
@@ -15,7 +15,7 @@ import { INotificationService } from '../../../../../../platform/notification/co
 import { IProgressService } from '../../../../../../platform/progress/common/progress.js';
 import { IStorageService, InMemoryStorageService, StorageScope, StorageTarget } from '../../../../../../platform/storage/common/storage.js';
 import { AgentPluginRepositoryService } from '../../../browser/agentPluginRepositoryService.js';
-import { IMarketplacePlugin, MarketplaceType, parseMarketplaceReference } from '../../../common/plugins/pluginMarketplaceService.js';
+import { IMarketplacePlugin, MarketplaceType, parseMarketplaceReference, PluginSourceKind } from '../../../common/plugins/pluginMarketplaceService.js';

 suite('AgentPluginRepositoryService', () => {
 	const store = ensureNoDisposablesAreLeakedInTestSuite();
@@ -32,6 +32,7 @@ suite('AgentPluginRepositoryService', () => {
 			description: '',
 			version: '',
 			source,
+			sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: source },
 			marketplace: marketplaceReference.displayLabel,
 			marketplaceReference,
 			marketplaceType: MarketplaceType.Copilot,
@@ -40,7 +41,7 @@ suite('AgentPluginRepositoryService', () => {

 	function createService(
 		onExists?: (resource: URI) => Promise<boolean>,
-		onExecuteCommand?: (id: string) => void,
+		onExecuteCommand?: (id: string, ...args: unknown[]) => void,
 	): AgentPluginRepositoryService {
 		const instantiationService = store.add(new TestInstantiationService());

@@ -53,8 +54,8 @@ suite('AgentPluginRepositoryService', () => {
 		} as unknown as IProgressService;

 		instantiationService.stub(ICommandService, {
-			executeCommand: async (id: string) => {
-				onExecuteCommand?.(id);
+			executeCommand: async (id: string, ...args: unknown[]) => {
+				onExecuteCommand?.(id, ...args);
 				return undefined;
 			},
 		} as unknown as ICommandService);
@@ -170,4 +171,43 @@ suite('AgentPluginRepositoryService', () => {
 		assert.strictEqual(uri.path, '/tmp/marketplace-repo');
 		assert.strictEqual(commandInvocationCount, 0);
 	});
+
+	test('builds revision-aware install URI for github plugin sources', () => {
+		const service = createService();
+		const uri = service.getPluginSourceInstallUri({
+			kind: PluginSourceKind.GitHub,
+			repo: 'owner/repo',
+			ref: 'release/v1',
+		});
+
+		assert.strictEqual(uri.path, '/cache/agentPlugins/github.com/owner/repo/ref_release_v1');
+	});
+
+	test('updates git plugin source by pulling and checking out requested revision', async () => {
+		const commands: string[] = [];
+		const service = createService(async () => true, (id: string) => {
+			commands.push(id);
+		});
+
+		await service.updatePluginSource({
+			name: 'my-plugin',
+			description: '',
+			version: '',
+			source: '',
+			sourceDescriptor: {
+				kind: PluginSourceKind.GitHub,
+				repo: 'owner/repo',
+				sha: 'a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0',
+			},
+			marketplace: 'owner/repo',
+			marketplaceReference: parseMarketplaceReference('owner/repo')!,
+			marketplaceType: MarketplaceType.Copilot,
+		}, {
+			pluginName: 'my-plugin',
+			failureLabel: 'my-plugin',
+			marketplaceType: MarketplaceType.Copilot,
+		});
+
+		assert.deepStrictEqual(commands, ['git.openRepository', 'git.fetch', '_git.checkout']);
+	});
 });
--- a/src/vs/workbench/contrib/chat/test/browser/plugins/pluginInstallService.test.ts
+++ b/src/vs/workbench/contrib/chat/test/browser/plugins/pluginInstallService.test.ts
@@ -0,0 +1,611 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import assert from 'assert';
+import { URI } from '../../../../../../base/common/uri.js';
+import { ensureNoDisposablesAreLeakedInTestSuite } from '../../../../../../base/test/common/utils.js';
+import { IDialogService } from '../../../../../../platform/dialogs/common/dialogs.js';
+import { IFileService } from '../../../../../../platform/files/common/files.js';
+import { TestInstantiationService } from '../../../../../../platform/instantiation/test/common/instantiationServiceMock.js';
+import { ILogService, NullLogService } from '../../../../../../platform/log/common/log.js';
+import { INotificationService } from '../../../../../../platform/notification/common/notification.js';
+import { IProgressService } from '../../../../../../platform/progress/common/progress.js';
+import { ITerminalService } from '../../../../terminal/browser/terminal.js';
+import { PluginInstallService } from '../../../browser/pluginInstallService.js';
+import { IAgentPluginRepositoryService, IEnsureRepositoryOptions, IPullRepositoryOptions } from '../../../common/plugins/agentPluginRepositoryService.js';
+import { IMarketplacePlugin, IMarketplaceReference, IPluginMarketplaceService, IPluginSourceDescriptor, MarketplaceType, parseMarketplaceReference, PluginSourceKind } from '../../../common/plugins/pluginMarketplaceService.js';
+
+suite('PluginInstallService', () => {
+	const store = ensureNoDisposablesAreLeakedInTestSuite();
+
+	// --- Factory helpers -------------------------------------------------------
+
+	function makeMarketplaceRef(marketplace: string): IMarketplaceReference {
+		const ref = parseMarketplaceReference(marketplace);
+		assert.ok(ref);
+		return ref!;
+	}
+
+	function createPlugin(overrides: Partial<IMarketplacePlugin> & { sourceDescriptor: IPluginSourceDescriptor }): IMarketplacePlugin {
+		return {
+			name: overrides.name ?? 'test-plugin',
+			description: overrides.description ?? '',
+			version: overrides.version ?? '',
+			source: overrides.source ?? '',
+			sourceDescriptor: overrides.sourceDescriptor,
+			marketplace: overrides.marketplace ?? 'microsoft/vscode',
+			marketplaceReference: overrides.marketplaceReference ?? makeMarketplaceRef('microsoft/vscode'),
+			marketplaceType: overrides.marketplaceType ?? MarketplaceType.Copilot,
+			readmeUri: overrides.readmeUri,
+		};
+	}
+
+	// --- Mock tracking types ---------------------------------------------------
+
+	interface MockState {
+		notifications: { severity: number; message: string }[];
+		addedPlugins: { uri: string; plugin: IMarketplacePlugin }[];
+		dialogConfirmResult: boolean;
+		fileExistsResult: boolean | ((uri: URI) => Promise<boolean>);
+		ensureRepositoryResult: URI;
+		ensurePluginSourceResult: URI;
+		/** Plugin source install URI, per kind */
+		pluginSourceInstallUris: Map<string, URI>;
+		/** The commands that were sent to the terminal */
+		terminalCommands: string[];
+		/** Simulated exit code from terminal */
+		terminalExitCode: number;
+		/** Whether the terminal resolves the command completion at all */
+		terminalCompletes: boolean;
+		pullRepositoryCalls: { marketplace: IMarketplaceReference; options?: IPullRepositoryOptions }[];
+		updatePluginSourceCalls: { plugin: IMarketplacePlugin; options?: IPullRepositoryOptions }[];
+	}
+
+	function createDefaults(): MockState {
+		return {
+			notifications: [],
+			addedPlugins: [],
+			dialogConfirmResult: true,
+			fileExistsResult: true,
+			ensureRepositoryResult: URI.file('/cache/agentPlugins/github.com/microsoft/vscode'),
+			ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-package'),
+			pluginSourceInstallUris: new Map(),
+			terminalCommands: [],
+			terminalExitCode: 0,
+			terminalCompletes: true,
+			pullRepositoryCalls: [],
+			updatePluginSourceCalls: [],
+		};
+	}
+
+	function createService(stateOverrides?: Partial<MockState>): { service: PluginInstallService; state: MockState } {
+		const state: MockState = { ...createDefaults(), ...stateOverrides };
+		const instantiationService = store.add(new TestInstantiationService());
+
+		// IFileService
+		instantiationService.stub(IFileService, {
+			exists: async (resource: URI) => {
+				if (typeof state.fileExistsResult === 'function') {
+					return state.fileExistsResult(resource);
+				}
+				return state.fileExistsResult;
+			},
+		} as unknown as IFileService);
+
+		// INotificationService
+		instantiationService.stub(INotificationService, {
+			notify: (notification: { severity: number; message: string }) => {
+				state.notifications.push({ severity: notification.severity, message: notification.message });
+				return undefined;
+			},
+		} as unknown as INotificationService);
+
+		// IDialogService
+		instantiationService.stub(IDialogService, {
+			confirm: async () => ({ confirmed: state.dialogConfirmResult }),
+		} as unknown as IDialogService);
+
+		// ITerminalService — the mock coordinates runCommand and onCommandFinished
+		// so the command ID matches, just like a real terminal would.
+		instantiationService.stub(ITerminalService, {
+			createTerminal: async () => {
+				let finishedCallback: ((cmd: { id: string; exitCode: number }) => void) | undefined;
+				return {
+					processReady: Promise.resolve(),
+					dispose: () => { },
+					runCommand: (command: string, _addNewLine?: boolean) => {
+						state.terminalCommands.push(command);
+						// Simulate command completing after runCommand is called
+						if (finishedCallback) {
+							finishedCallback({ id: 'command', exitCode: state.terminalExitCode });
+						}
+					},
+					capabilities: {
+						get: () => state.terminalCompletes ? {
+							onCommandFinished: (callback: (cmd: { id: string; exitCode: number }) => void) => {
+								finishedCallback = callback;
+								return { dispose() { } };
+							},
+						} : undefined,
+						onDidAddCommandDetectionCapability: () => ({ dispose() { } }),
+					},
+				};
+			},
+			setActiveInstance: () => { },
+		} as unknown as ITerminalService);
+
+		// IProgressService
+		instantiationService.stub(IProgressService, {
+			withProgress: async (_options: unknown, callback: (...args: unknown[]) => Promise<unknown>) => callback(),
+		} as unknown as IProgressService);
+
+		// ILogService
+		instantiationService.stub(ILogService, new NullLogService());
+
+		// IAgentPluginRepositoryService
+		instantiationService.stub(IAgentPluginRepositoryService, {
+			getPluginInstallUri: (plugin: IMarketplacePlugin) => {
+				return URI.joinPath(state.ensureRepositoryResult, plugin.source);
+			},
+			getRepositoryUri: () => state.ensureRepositoryResult,
+			ensureRepository: async (_marketplace: IMarketplaceReference, _options?: IEnsureRepositoryOptions) => {
+				return state.ensureRepositoryResult;
+			},
+			pullRepository: async (marketplace: IMarketplaceReference, options?: IPullRepositoryOptions) => {
+				state.pullRepositoryCalls.push({ marketplace, options });
+			},
+			getPluginSourceInstallUri: (descriptor: IPluginSourceDescriptor) => {
+				const key = descriptor.kind;
+				return state.pluginSourceInstallUris.get(key) ?? URI.file(`/cache/agentPlugins/${key}/default`);
+			},
+			ensurePluginSource: async () => state.ensurePluginSourceResult,
+			updatePluginSource: async (plugin: IMarketplacePlugin, options?: IPullRepositoryOptions) => {
+				state.updatePluginSourceCalls.push({ plugin, options });
+			},
+		} as unknown as IAgentPluginRepositoryService);
+
+		// IPluginMarketplaceService
+		instantiationService.stub(IPluginMarketplaceService, {
+			addInstalledPlugin: (uri: URI, plugin: IMarketplacePlugin) => {
+				state.addedPlugins.push({ uri: uri.toString(), plugin });
+			},
+		} as unknown as IPluginMarketplaceService);
+
+		const service = instantiationService.createInstance(PluginInstallService);
+		return { service, state };
+	}
+
+	// =========================================================================
+	// getPluginInstallUri
+	// =========================================================================
+
+	suite('getPluginInstallUri', () => {
+
+		test('delegates to getPluginInstallUri for relative-path plugins', () => {
+			const { service } = createService();
+			const plugin = createPlugin({
+				source: 'plugins/myPlugin',
+				sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: 'plugins/myPlugin' },
+			});
+			const uri = service.getPluginInstallUri(plugin);
+			assert.strictEqual(uri.path, '/cache/agentPlugins/github.com/microsoft/vscode/plugins/myPlugin');
+		});
+
+		test('delegates to getPluginSourceInstallUri for npm plugins', () => {
+			const npmUri = URI.file('/cache/agentPlugins/npm/my-pkg/node_modules/my-pkg');
+			const { service } = createService({
+				pluginSourceInstallUris: new Map([['npm', npmUri]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg' },
+			});
+			const uri = service.getPluginInstallUri(plugin);
+			assert.strictEqual(uri.path, npmUri.path);
+		});
+
+		test('delegates to getPluginSourceInstallUri for pip plugins', () => {
+			const pipUri = URI.file('/cache/agentPlugins/pip/my-pkg');
+			const { service } = createService({
+				pluginSourceInstallUris: new Map([['pip', pipUri]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg' },
+			});
+			const uri = service.getPluginInstallUri(plugin);
+			assert.strictEqual(uri.path, pipUri.path);
+		});
+
+		test('delegates to getPluginSourceInstallUri for github plugins', () => {
+			const ghUri = URI.file('/cache/agentPlugins/github.com/owner/repo');
+			const { service } = createService({
+				pluginSourceInstallUris: new Map([['github', ghUri]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.GitHub, repo: 'owner/repo' },
+			});
+			const uri = service.getPluginInstallUri(plugin);
+			assert.strictEqual(uri.path, ghUri.path);
+		});
+	});
+
+	// =========================================================================
+	// installPlugin — relative path
+	// =========================================================================
+
+	suite('installPlugin — relative path', () => {
+
+		test('installs a relative-path plugin when directory exists', async () => {
+			const { service, state } = createService();
+			const plugin = createPlugin({
+				source: 'plugins/myPlugin',
+				sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: 'plugins/myPlugin' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 1);
+			assert.ok(state.addedPlugins[0].uri.includes('plugins/myPlugin'));
+			assert.strictEqual(state.notifications.length, 0);
+		});
+
+		test('notifies error when plugin directory does not exist', async () => {
+			const { service, state } = createService({ fileExistsResult: false });
+			const plugin = createPlugin({
+				source: 'plugins/missing',
+				sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: 'plugins/missing' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 0);
+			assert.strictEqual(state.notifications.length, 1);
+			assert.ok(state.notifications[0].message.includes('not found'));
+		});
+
+		test('does not install when ensureRepository throws', async () => {
+			const { state } = createService();
+			// Override ensureRepository to throw
+			const instantiationService = store.add(new TestInstantiationService());
+			const repoService = {
+				ensureRepository: async () => { throw new Error('clone failed'); },
+				getPluginInstallUri: () => URI.file('/x'),
+				getPluginSourceInstallUri: () => URI.file('/x'),
+			};
+			instantiationService.stub(IAgentPluginRepositoryService, repoService as unknown as IAgentPluginRepositoryService);
+			instantiationService.stub(IFileService, { exists: async () => true } as unknown as IFileService);
+			instantiationService.stub(INotificationService, { notify: (n: { severity: number; message: string }) => { state.notifications.push(n); } } as unknown as INotificationService);
+			instantiationService.stub(IDialogService, { confirm: async () => ({ confirmed: true }) } as unknown as IDialogService);
+			instantiationService.stub(ITerminalService, {} as unknown as ITerminalService);
+			instantiationService.stub(IProgressService, { withProgress: async (_o: unknown, cb: () => Promise<unknown>) => cb() } as unknown as IProgressService);
+			instantiationService.stub(ILogService, new NullLogService());
+			instantiationService.stub(IPluginMarketplaceService, { addInstalledPlugin: () => { } } as unknown as IPluginMarketplaceService);
+			const svc = instantiationService.createInstance(PluginInstallService);
+
+			const plugin = createPlugin({
+				source: 'plugins/myPlugin',
+				sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: 'plugins/myPlugin' },
+			});
+			await svc.installPlugin(plugin);
+
+			// Should return without installing or crashing
+			assert.strictEqual(state.addedPlugins.length, 0);
+		});
+	});
+
+	// =========================================================================
+	// installPlugin — GitHub / GitUrl
+	// =========================================================================
+
+	suite('installPlugin — git sources', () => {
+
+		test('installs a GitHub plugin when source exists after clone', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/github.com/owner/repo'),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.GitHub, repo: 'owner/repo' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 1);
+			assert.strictEqual(state.notifications.length, 0);
+		});
+
+		test('installs a GitUrl plugin when source exists after clone', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/example.com/repo'),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.GitUrl, url: 'https://example.com/repo.git' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 1);
+			assert.strictEqual(state.notifications.length, 0);
+		});
+
+		test('notifies error when cloned directory does not exist', async () => {
+			const { service, state } = createService({
+				fileExistsResult: false,
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/github.com/owner/repo'),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.GitHub, repo: 'owner/repo' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 0);
+			assert.strictEqual(state.notifications.length, 1);
+			assert.ok(state.notifications[0].message.includes('not found'));
+		});
+	});
+
+	// =========================================================================
+	// installPlugin — npm
+	// =========================================================================
+
+	suite('installPlugin — npm', () => {
+
+		test('runs npm install and registers plugin on success', async () => {
+			const npmInstallUri = URI.file('/cache/agentPlugins/npm/my-pkg/node_modules/my-pkg');
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-pkg'),
+				pluginSourceInstallUris: new Map([['npm', npmInstallUri]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('npm'));
+			assert.ok(state.terminalCommands[0].includes('install'));
+			assert.ok(state.terminalCommands[0].includes('my-pkg'));
+			assert.strictEqual(state.addedPlugins.length, 1);
+			assert.strictEqual(state.notifications.length, 0);
+		});
+
+		test('includes version in npm install command', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-pkg'),
+				pluginSourceInstallUris: new Map([['npm', URI.file('/cache/agentPlugins/npm/my-pkg/node_modules/my-pkg')]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg', version: '1.2.3' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('my-pkg@1.2.3'));
+		});
+
+		test('includes registry in npm install command', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-pkg'),
+				pluginSourceInstallUris: new Map([['npm', URI.file('/cache/agentPlugins/npm/my-pkg/node_modules/my-pkg')]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg', registry: 'https://custom.registry.com' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('--registry'));
+			assert.ok(state.terminalCommands[0].includes('https://custom.registry.com'));
+		});
+
+		test('does not install when user declines confirmation', async () => {
+			const { service, state } = createService({ dialogConfirmResult: false });
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 0);
+			assert.strictEqual(state.addedPlugins.length, 0);
+		});
+
+		test('notifies error when npm package directory not found after install', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-pkg'),
+				// exists returns true for ensurePluginSource but false for the final check
+				fileExistsResult: false,
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 0);
+			assert.strictEqual(state.notifications.length, 1);
+			assert.ok(state.notifications[0].message.includes('not found'));
+		});
+
+		test('notifies error when terminal command fails with non-zero exit code', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-pkg'),
+				terminalExitCode: 1,
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 0);
+			assert.strictEqual(state.notifications.length, 1);
+			assert.ok(state.notifications[0].message.includes('failed'));
+		});
+	});
+
+	// =========================================================================
+	// installPlugin — pip
+	// =========================================================================
+
+	suite('installPlugin — pip', () => {
+
+		test('runs pip install and registers plugin on success', async () => {
+			const pipInstallUri = URI.file('/cache/agentPlugins/pip/my-pkg');
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/pip/my-pkg'),
+				pluginSourceInstallUris: new Map([['pip', pipInstallUri]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('pip'));
+			assert.ok(state.terminalCommands[0].includes('install'));
+			assert.ok(state.terminalCommands[0].includes('my-pkg'));
+			assert.strictEqual(state.addedPlugins.length, 1);
+			assert.strictEqual(state.notifications.length, 0);
+		});
+
+		test('includes version with == syntax in pip install command', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/pip/my-pkg'),
+				pluginSourceInstallUris: new Map([['pip', URI.file('/cache/agentPlugins/pip/my-pkg')]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg', version: '2.0.0' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('my-pkg==2.0.0'));
+		});
+
+		test('includes registry with --index-url in pip install command', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/pip/my-pkg'),
+				pluginSourceInstallUris: new Map([['pip', URI.file('/cache/agentPlugins/pip/my-pkg')]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg', registry: 'https://pypi.custom.com/simple' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('--index-url'));
+			assert.ok(state.terminalCommands[0].includes('https://pypi.custom.com/simple'));
+		});
+
+		test('does not install when user declines confirmation', async () => {
+			const { service, state } = createService({ dialogConfirmResult: false });
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 0);
+			assert.strictEqual(state.addedPlugins.length, 0);
+		});
+
+		test('notifies error when pip package directory not found after install', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/pip/my-pkg'),
+				fileExistsResult: false,
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg' },
+			});
+
+			await service.installPlugin(plugin);
+
+			assert.strictEqual(state.addedPlugins.length, 0);
+			assert.strictEqual(state.notifications.length, 1);
+			assert.ok(state.notifications[0].message.includes('not found'));
+		});
+	});
+
+	// =========================================================================
+	// updatePlugin
+	// =========================================================================
+
+	suite('updatePlugin', () => {
+
+		test('calls pullRepository for relative-path plugins', async () => {
+			const { service, state } = createService();
+			const plugin = createPlugin({
+				source: 'plugins/myPlugin',
+				sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: 'plugins/myPlugin' },
+			});
+
+			await service.updatePlugin(plugin);
+
+			assert.strictEqual(state.pullRepositoryCalls.length, 1);
+			assert.strictEqual(state.updatePluginSourceCalls.length, 0);
+		});
+
+		test('calls updatePluginSource for GitHub plugins', async () => {
+			const { service, state } = createService();
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.GitHub, repo: 'owner/repo' },
+			});
+
+			await service.updatePlugin(plugin);
+
+			assert.strictEqual(state.updatePluginSourceCalls.length, 1);
+			assert.strictEqual(state.pullRepositoryCalls.length, 0);
+		});
+
+		test('calls updatePluginSource for GitUrl plugins', async () => {
+			const { service, state } = createService();
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.GitUrl, url: 'https://example.com/repo.git' },
+			});
+
+			await service.updatePlugin(plugin);
+
+			assert.strictEqual(state.updatePluginSourceCalls.length, 1);
+			assert.strictEqual(state.pullRepositoryCalls.length, 0);
+		});
+
+		test('re-installs for npm plugin updates', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/npm/my-pkg'),
+				pluginSourceInstallUris: new Map([['npm', URI.file('/cache/agentPlugins/npm/my-pkg/node_modules/my-pkg')]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Npm, package: 'my-pkg' },
+			});
+
+			await service.updatePlugin(plugin);
+
+			// npm update goes through the same install flow
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('npm'));
+		});
+
+		test('re-installs for pip plugin updates', async () => {
+			const { service, state } = createService({
+				ensurePluginSourceResult: URI.file('/cache/agentPlugins/pip/my-pkg'),
+				pluginSourceInstallUris: new Map([['pip', URI.file('/cache/agentPlugins/pip/my-pkg')]]),
+			});
+			const plugin = createPlugin({
+				sourceDescriptor: { kind: PluginSourceKind.Pip, package: 'my-pkg' },
+			});
+
+			await service.updatePlugin(plugin);
+
+			assert.strictEqual(state.terminalCommands.length, 1);
+			assert.ok(state.terminalCommands[0].includes('pip'));
+		});
+	});
+});
--- a/src/vs/workbench/contrib/chat/test/common/plugins/pluginMarketplaceService.test.ts
+++ b/src/vs/workbench/contrib/chat/test/common/plugins/pluginMarketplaceService.test.ts
@@ -15,7 +15,7 @@ import { IStorageService, InMemoryStorageService } from '../../../../../../platf
 import { ensureNoDisposablesAreLeakedInTestSuite } from '../../../../../../base/test/common/utils.js';
 import { IAgentPluginRepositoryService } from '../../../common/plugins/agentPluginRepositoryService.js';
 import { ChatConfiguration } from '../../../common/constants.js';
-import { MarketplaceReferenceKind, MarketplaceType, PluginMarketplaceService, parseMarketplaceReference, parseMarketplaceReferences } from '../../../common/plugins/pluginMarketplaceService.js';
+import { MarketplaceReferenceKind, MarketplaceType, PluginMarketplaceService, PluginSourceKind, getPluginSourceLabel, parseMarketplaceReference, parseMarketplaceReferences, parsePluginSource } from '../../../common/plugins/pluginMarketplaceService.js';

 suite('PluginMarketplaceService', () => {
 	ensureNoDisposablesAreLeakedInTestSuite();
@@ -142,6 +142,7 @@ suite('PluginMarketplaceService - getMarketplacePluginMetadata', () => {
 			description: 'A test plugin',
 			version: '2.0.0',
 			source: 'plugins/my-plugin',
+			sourceDescriptor: { kind: PluginSourceKind.RelativePath, path: 'plugins/my-plugin' } as const,
 			marketplace: marketplaceRef.displayLabel,
 			marketplaceReference: marketplaceRef,
 			marketplaceType: MarketplaceType.Copilot,
@@ -165,3 +166,152 @@ suite('PluginMarketplaceService - getMarketplacePluginMetadata', () => {
 		assert.strictEqual(result, undefined);
 	});
 });
+
+suite('parsePluginSource', () => {
+	ensureNoDisposablesAreLeakedInTestSuite();
+
+	const logContext = {
+		pluginName: 'test',
+		logService: new NullLogService(),
+		logPrefix: '[test]',
+	};
+
+	test('parses string source as RelativePath', () => {
+		const result = parsePluginSource('./my-plugin', undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.RelativePath, path: 'my-plugin' });
+	});
+
+	test('parses string source with pluginRoot', () => {
+		const result = parsePluginSource('sub', 'plugins', logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.RelativePath, path: 'plugins/sub' });
+	});
+
+	test('parses undefined source as RelativePath using pluginRoot', () => {
+		const result = parsePluginSource(undefined, 'root', logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.RelativePath, path: 'root' });
+	});
+
+	test('parses empty string source as RelativePath using pluginRoot', () => {
+		const result = parsePluginSource('', 'base', logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.RelativePath, path: 'base' });
+	});
+
+	test('returns undefined for empty source without pluginRoot', () => {
+		assert.strictEqual(parsePluginSource('', undefined, logContext), undefined);
+	});
+
+	test('parses github object source', () => {
+		const result = parsePluginSource({ source: 'github', repo: 'owner/repo' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.GitHub, repo: 'owner/repo', ref: undefined, sha: undefined });
+	});
+
+	test('parses github object source with ref and sha', () => {
+		const result = parsePluginSource({ source: 'github', repo: 'owner/repo', ref: 'v2.0.0', sha: 'a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.GitHub, repo: 'owner/repo', ref: 'v2.0.0', sha: 'a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0' });
+	});
+
+	test('returns undefined for github source missing repo', () => {
+		assert.strictEqual(parsePluginSource({ source: 'github' }, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for github source with invalid repo format', () => {
+		assert.strictEqual(parsePluginSource({ source: 'github', repo: 'owner' }, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for github source with invalid sha', () => {
+		assert.strictEqual(parsePluginSource({ source: 'github', repo: 'owner/repo', sha: 'abc123' }, undefined, logContext), undefined);
+	});
+
+	test('parses url object source', () => {
+		const result = parsePluginSource({ source: 'url', url: 'https://gitlab.com/team/plugin.git' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.GitUrl, url: 'https://gitlab.com/team/plugin.git', ref: undefined, sha: undefined });
+	});
+
+	test('returns undefined for url source missing url field', () => {
+		assert.strictEqual(parsePluginSource({ source: 'url' }, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for url source not ending in .git', () => {
+		assert.strictEqual(parsePluginSource({ source: 'url', url: 'https://gitlab.com/team/plugin' }, undefined, logContext), undefined);
+	});
+
+	test('parses npm object source', () => {
+		const result = parsePluginSource({ source: 'npm', package: '@acme/claude-plugin' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.Npm, package: '@acme/claude-plugin', version: undefined, registry: undefined });
+	});
+
+	test('parses npm object source with version and registry', () => {
+		const result = parsePluginSource({ source: 'npm', package: '@acme/claude-plugin', version: '2.1.0', registry: 'https://npm.example.com' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.Npm, package: '@acme/claude-plugin', version: '2.1.0', registry: 'https://npm.example.com' });
+	});
+
+	test('returns undefined for npm source missing package', () => {
+		assert.strictEqual(parsePluginSource({ source: 'npm' }, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for npm source with non-string version', () => {
+		assert.strictEqual(parsePluginSource({ source: 'npm', package: '@acme/claude-plugin', version: 123 } as never, undefined, logContext), undefined);
+	});
+
+	test('parses pip object source', () => {
+		const result = parsePluginSource({ source: 'pip', package: 'my-plugin' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.Pip, package: 'my-plugin', version: undefined, registry: undefined });
+	});
+
+	test('parses pip object source with version and registry', () => {
+		const result = parsePluginSource({ source: 'pip', package: 'my-plugin', version: '1.0.0', registry: 'https://pypi.example.com' }, undefined, logContext);
+		assert.deepStrictEqual(result, { kind: PluginSourceKind.Pip, package: 'my-plugin', version: '1.0.0', registry: 'https://pypi.example.com' });
+	});
+
+	test('returns undefined for pip source missing package', () => {
+		assert.strictEqual(parsePluginSource({ source: 'pip' }, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for pip source with non-string registry', () => {
+		assert.strictEqual(parsePluginSource({ source: 'pip', package: 'my-plugin', registry: 42 } as never, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for unknown source kind', () => {
+		assert.strictEqual(parsePluginSource({ source: 'unknown' }, undefined, logContext), undefined);
+	});
+
+	test('returns undefined for object source without source discriminant', () => {
+		assert.strictEqual(parsePluginSource({ package: 'test' } as never, undefined, logContext), undefined);
+	});
+});
+
+suite('getPluginSourceLabel', () => {
+	ensureNoDisposablesAreLeakedInTestSuite();
+
+	test('formats relative path', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.RelativePath, path: 'plugins/foo' }), 'plugins/foo');
+	});
+
+	test('formats empty relative path', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.RelativePath, path: '' }), '.');
+	});
+
+	test('formats github source', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.GitHub, repo: 'owner/repo' }), 'owner/repo');
+	});
+
+	test('formats url source', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.GitUrl, url: 'https://example.com/repo.git' }), 'https://example.com/repo.git');
+	});
+
+	test('formats npm source without version', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.Npm, package: '@acme/plugin' }), '@acme/plugin');
+	});
+
+	test('formats npm source with version', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.Npm, package: '@acme/plugin', version: '1.0.0' }), '@acme/plugin@1.0.0');
+	});
+
+	test('formats pip source without version', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.Pip, package: 'my-plugin' }), 'my-plugin');
+	});
+
+	test('formats pip source with version', () => {
+		assert.strictEqual(getPluginSourceLabel({ kind: PluginSourceKind.Pip, package: 'my-plugin', version: '2.0' }), 'my-plugin==2.0');
+	});
+});
--- a/src/vs/workbench/contrib/chat/test/common/promptSyntax/service/promptsService.test.ts
+++ b/src/vs/workbench/contrib/chat/test/common/promptSyntax/service/promptsService.test.ts
@@ -11,7 +11,7 @@ import { match } from '../../../../../../../base/common/glob.js';
 import { ResourceSet } from '../../../../../../../base/common/map.js';
 import { Schemas } from '../../../../../../../base/common/network.js';
 import { ISettableObservable, observableValue } from '../../../../../../../base/common/observable.js';
-import { relativePath } from '../../../../../../../base/common/resources.js';
+import { basename, relativePath } from '../../../../../../../base/common/resources.js';
 import { URI } from '../../../../../../../base/common/uri.js';
 import { ensureNoDisposablesAreLeakedInTestSuite } from '../../../../../../../base/test/common/utils.js';
 import { Range } from '../../../../../../../editor/common/core/range.js';
@@ -3505,6 +3505,7 @@ suite('PromptsService', () => {
 			return {
 				plugin: {
 					uri: URI.file(path),
+					label: basename(URI.file(path)),
 					enabled,
 					setEnabled: () => { },
 					remove: () => { },
--- a/src/vs/workbench/contrib/mcp/common/discovery/pluginMcpDiscovery.ts
+++ b/src/vs/workbench/contrib/mcp/common/discovery/pluginMcpDiscovery.ts
@@ -8,7 +8,6 @@ import { Disposable, DisposableResourceMap } from '../../../../../base/common/li
 import { ResourceSet } from '../../../../../base/common/map.js';
 import { Schemas } from '../../../../../base/common/network.js';
 import { autorun } from '../../../../../base/common/observable.js';
-import { basename } from '../../../../../base/common/resources.js';
 import { isDefined } from '../../../../../base/common/types.js';
 import { URI } from '../../../../../base/common/uri.js';
 import { ConfigurationTarget } from '../../../../../platform/configuration/common/configuration.js';
@@ -61,7 +60,7 @@ export class PluginMcpDiscovery extends Disposable implements IMcpDiscovery {
 		const collectionId = `plugin.${plugin.uri}`;
 		return this._mcpRegistry.registerCollection({
 			id: collectionId,
-			label: `${basename(plugin.uri)} (Agent Plugin)`,
+			label: `${plugin.label} (Agent Plugin)`,
 			remoteAuthority: plugin.uri.scheme === Schemas.vscodeRemote ? plugin.uri.authority : null,
 			configTarget: ConfigurationTarget.USER,
 			scope: StorageScope.PROFILE,