Reconstruct batch 028/124: 2026-08-26 → 2026-08-30 (chat, agenthost, extensions/copilot, sessions)

.github/instructions/language-model-tool-descriptions.instructions.md

@@ -0,0 +1,21 @@
+---
+description: Use when writing or reviewing model-facing language model tool descriptions.
+applyTo: "src/vs/**/*Tool.ts,src/vs/**/*Tools.ts"
+---
+
+# Language model tool descriptions
+
+Apply these rules only when adding or changing a model-facing tool description, such as `modelDescription`. They do not govern display names, user-facing messages, confirmation text, or routine schema property descriptions.
+
+- Begin with a direct imperative statement of the tool's capability.
+- When tool selection could be ambiguous, state the positive invocation criteria explicitly.
+- Place exclusions for likely near-neighbor requests immediately after the positive criteria.
+- Describe persistent, external, costly, or otherwise consequential side effects.
+- State meaningful defaults, cross-field requirements, and prerequisite tool calls that are not obvious from the input schema.
+- Put approval, cancellation, retry, repeat-call, and polling guidance last.
+- Do not repeat the complete input schema in prose.
+- Keep descriptions concise and scale their detail with the ambiguity and cost of incorrect selection.
+- Preserve terminology and formatting conventions used by related tools.
+- Reserve `MUST`, `ONLY`, `CRITICAL`, and direct "Do not" language for likely, consequential misuse.
+
+When correctness depends on specific model-facing guidance, add a focused test for the required semantic clauses. Prefer checking a small set of meaningful phrases or conditions over snapshotting the entire description. Do not test routine descriptive prose.

.github/instructions/source-code-organization.instructions.md

@@ -64,4 +64,6 @@ class MyComponent {
 }
 ```
 
+Decorated service parameters must use their canonical service interface. Do not invent local subset interfaces or `Pick<...>` aliases in production to simplify tests; keep partial stubs, adapters, and other test-only conveniences in test code.
+
 Services are provided via `registerSingleton(IMyService, MyServiceImpl, InstantiationType.Delayed)`.

.github/skills/policy-and-managed-settings/local-testing.md

@@ -28,6 +28,11 @@ Choose the client setup in the GUI:
   proxy mapping and enable Proxyman's platform proxy toggle (**Tools > macOS
   Proxy** or **Tools > Override Windows Proxy**). VS Code clients must also add
   the displayed `http.proxy` property to `settings.json`.
+- **File-based settings (no proxy):** expand **Deploy as a file** under the
+  Managed Settings response body and run the copied per-platform command to write
+  the current body to `managed-settings.json` on the device. Restart the client to
+  load it. Use it to skip proxying or to test precedence against a server-managed
+  response. See [Deploying file-based settings](https://docs.github.com/en/copilot/how-tos/administer-copilot/manage-for-enterprise/manage-agents/configure-enterprise-managed-settings#deploying-file-based-settings).
 
 Use **Clear SDK Policy Cache**, expand the macOS or Windows section, and run the
 copied command when the runtime's fresh managed-settings cache prevents a network

build/agent-sdk/agents/claude/package.json

@@ -3,6 +3,6 @@
 	"private": true,
 	"comment": "Pinned dependency set for the build/agent-sdk claude tarball. The package-lock.json alongside is the source of truth for transitive deps — produce.ts runs `npm ci` against this directory to get byte-deterministic output across pipeline runs.",
 	"dependencies": {
-		"@anthropic-ai/claude-agent-sdk": "0.3.220"
+		"@anthropic-ai/claude-agent-sdk": "0.3.239"
 	}
 }

build/lib/preLaunch.ts

@@ -66,6 +66,9 @@ async function ensureCompiled() {
 async function main() {
 	await ensureNodeModules();
 	await getElectron();
+	if (process.argv.includes('--only-electron')) {
+		return;
+	}
 	await ensureCompiled();
 
 	// Can't require this until after dependencies are installed

extensions/copilot/package.json

@@ -4024,6 +4024,15 @@
             ],
             "description": "%github.copilot.config.gemini35FlashReducedToolUsePrompt.enabled%"
           },
+          "github.copilot.chat.geminiFlashPromptAdditions.enabled": {
+            "type": "boolean",
+            "default": false,
+            "tags": [
+              "experimental",
+              "onExp"
+            ],
+            "description": "%github.copilot.config.geminiFlashPromptAdditions.enabled%"
+          },
           "github.copilot.chat.anthropic.contextEditing.mode": {
             "type": "string",
             "default": "off",

extensions/copilot/package.nls.json

@@ -163,6 +163,7 @@
 	"github.copilot.config.alternateGptPrompt.enabled": "Enables an experimental alternate prompt for GPT models instead of the default prompt.",
 	"github.copilot.config.alternateGeminiModelFPrompt.enabled": "Enables an experimental alternate prompt for Gemini Model F instead of the default prompt.",
 	"github.copilot.config.gemini35FlashReducedToolUsePrompt.enabled": "Enables an experimental prompt for Gemini 3.5 Flash that instructs the model to minimize tool calls to reduce token usage.",
+	"github.copilot.config.geminiFlashPromptAdditions.enabled": "Enables experimental additional prompt guidance for Gemini Flash 3.6 and 3.7 models.",
 	"github.copilot.config.gpt5CodexAlternatePrompt": "Specifies an experimental alternate prompt to use for the GPT-5-Codex model.",
 	"github.copilot.command.fixTestFailure": "Fix Test Failure",
 	"copilot.description": "Ask or edit in context",

extensions/copilot/src/extension/chatSessions/vscode-node/copilotCloudSessionsProvider.ts

@@ -228,6 +228,25 @@ const OPEN_PULL_REQUEST_COMMAND_ID = 'github.copilot.chat.cloudSessions.openPull
 const CLEAR_CACHES_COMMAND_ID = 'github.copilot.chat.cloudSessions.clearCaches';
 const CREATE_PULL_REQUEST_FOR_TASK_COMMAND_ID = 'github.copilot.chat.cloudSessions.createPullRequestForTask';
 const OPEN_PULL_REQUEST_FOR_TASK_COMMAND_ID = 'github.copilot.chat.cloudSessions.openPullRequestForTask';
+
+export function parseGitHubContextUrl(value: string, kind: 'issue' | 'pullRequest'): { readonly repoId: string; readonly url: string; readonly label: string } | undefined {
+	const match = /^https:\/\/(?:www\.)?github\.com\/(?<owner>[^/?#]+)\/(?<repository>[^/?#]+)\/(?<resource>issues|pull)\/(?<number>[1-9]\d*)\/?(?:[?#].*)?$/i.exec(value.trim());
+	if (!match?.groups) {
+		return undefined;
+	}
+	const resource = match.groups.resource.toLowerCase();
+	if ((resource === 'issues') !== (kind === 'issue')) {
+		return undefined;
+	}
+
+	const repoId = `${match.groups.owner}/${match.groups.repository}`;
+	return {
+		repoId,
+		url: `https://github.com/${repoId}/${resource}/${match.groups.number}`,
+		label: `${repoId}#${match.groups.number}`,
+	};
+}
+
 /** Context key gating the chat-input "Create pull request" toolbar action: true while the viewed cloud task is settled and has no PR yet. */
 const CAN_CREATE_PULL_REQUEST_CONTEXT_KEY = 'github.copilot.chat.cloudTaskCanCreatePullRequest';
 /** Context key gating the chat-input "Open pull request" toolbar action: true once the viewed cloud task has a pull request. */
@@ -706,6 +725,18 @@ export class CopilotCloudSessionsProvider extends Disposable implements vscode.C
 						clearTimeout(searchTimeout);
 					}
 					const query = value.trim();
+					const pastedSelection = parseGitHubContextUrl(query, kind);
+					if (pastedSelection) {
+						searchGeneration++;
+						quickPick.busy = false;
+						quickPick.items = [{
+							label: pastedSelection.label,
+							description: pastedSelection.repoId,
+							alwaysShow: true,
+							selection: pastedSelection,
+						}];
+						return;
+					}
 					if (query.length < 2) {
 						if (query.length === 0) {
 							void search('', ++searchGeneration);

extensions/copilot/src/extension/chatSessions/vscode-node/test/copilotCloudSessionsProvider.spec.ts

@@ -12,7 +12,7 @@ import { mock } from '../../../../util/common/test/simpleMock';
 import { ChatRequestTurn2, ChatResponseMarkdownPart, ChatResponseTurn2, ChatToolInvocationPart } from '../../../../vscodeTypes';
 import { ITaskApiClient, ListTaskEventsOptions, ListTasksOptions } from '../../common/taskApiTypes';
 import { ChatSessionContentBuilder, extractTaskErrorDetail, formatTaskStoppedMessage } from '../copilotCloudSessionContentBuilder';
-import { formatNewSessionContextReference, getCloudSessionItemMetadata, getCloudSessionResources, normalizeInitialSessionOptions, taskStateToChatSessionStatus } from '../copilotCloudSessionsProvider';
+import { formatNewSessionContextReference, getCloudSessionItemMetadata, getCloudSessionResources, normalizeInitialSessionOptions, parseGitHubContextUrl, taskStateToChatSessionStatus } from '../copilotCloudSessionsProvider';
 import { TaskApiBackend, parseRepoFromTaskUrl, isCloudCodingAgentTask } from '../taskApiBackend';
 import { isActiveTaskState, isFailedTaskState } from '../../vscode/copilotCodingAgentUtils';
 import { NullCloudBackendInstrumentation } from '../cloudBackendTelemetry';
@@ -60,6 +60,28 @@ describe('copilotCloudSessionsProvider helpers', () => {
 		]);
 	});
 
+	it('parses pasted GitHub issue and pull request URLs for the matching picker', () => {
+		expect({
+			issue: parseGitHubContextUrl(' https://github.com/microsoft/vscode/ISSUES/333149#issuecomment-1 ', 'issue'),
+			pullRequest: parseGitHubContextUrl('https://www.github.com/microsoft/vscode/pull/333149/', 'pullRequest'),
+			wrongPicker: parseGitHubContextUrl('https://github.com/microsoft/vscode/pull/333149', 'issue'),
+			unrelated: parseGitHubContextUrl('https://example.com/microsoft/vscode/issues/333149', 'issue'),
+		}).toEqual({
+			issue: {
+				repoId: 'microsoft/vscode',
+				url: 'https://github.com/microsoft/vscode/issues/333149',
+				label: 'microsoft/vscode#333149',
+			},
+			pullRequest: {
+				repoId: 'microsoft/vscode',
+				url: 'https://github.com/microsoft/vscode/pull/333149',
+				label: 'microsoft/vscode#333149',
+			},
+			wrongPicker: undefined,
+			unrelated: undefined,
+		});
+	});
+
 	it('coerces object-shaped initialSessionOptions into option entries', () => {
 		const logService = new RecordingLogService();
 		const sessionResource = vscode.Uri.parse('copilot-cloud-agent:/1');

extensions/copilot/src/extension/inlineEdits/vscode-node/inlineEditProviderFeature.ts

@@ -9,6 +9,7 @@ import { ConfigKey, IConfigurationService } from '../../../platform/configuratio
 import { IEnvService } from '../../../platform/env/common/envService';
 import { IVSCodeExtensionContext } from '../../../platform/extContext/common/extensionContext';
 import { InlineEditRequestLogContext } from '../../../platform/inlineEdits/common/inlineEditLogContext';
+import { IInlineEditsModelService } from '../../../platform/inlineEdits/common/inlineEditsModelService';
 import { ObservableGit } from '../../../platform/inlineEdits/common/observableGit';
 import { NesHistoryContextProvider } from '../../../platform/inlineEdits/common/workspaceEditTracker/nesHistoryContextProvider';
 import { ILogService } from '../../../platform/log/common/logService';
@@ -63,6 +64,9 @@ export class InlineEditProviderFeature {
 	private readonly _yieldToCopilot = this._configurationService.getExperimentBasedConfigObservable(ConfigKey.TeamInternal.InlineEditsYieldToCopilot, this._expService);
 	private readonly _excludedProviders = this._configurationService.getExperimentBasedConfigObservable(ConfigKey.TeamInternal.InlineEditsExcludedProviders, this._expService).map(v => v ? v.split(',').map(v => v.trim()).filter(v => v !== '') : []);
 	private readonly _copilotToken = observableFromEvent(this, this._authenticationService.onDidCopilotTokenChange, () => this._authenticationService.copilotToken);
+	// Read reactively: on a fetched `/models` deployment this resolves async, so a brief cold-start
+	// window can emit completions until `onModelListUpdated` fires and re-registers with the excludes.
+	private readonly _supportsUnifiedCompletions = observableFromEvent(this, this._modelService.onModelListUpdated, () => this._modelService.selectedModelConfiguration().supportsUnifiedCompletions ?? false);
 
 	public readonly inlineEditsEnabled = derived(this, (reader) => {
 		const copilotToken = this._copilotToken.read(reader);
@@ -92,6 +96,7 @@ export class InlineEditProviderFeature {
 		@IExperimentationService private readonly _expService: IExperimentationService,
 		@IEnvService private readonly _envService: IEnvService,
 		@IInstantiationService private readonly _instantiationService: IInstantiationService,
+		@IInlineEditsModelService private readonly _modelService: IInlineEditsModelService,
 	) {
 	}
 
@@ -158,8 +163,11 @@ export class InlineEditProviderFeature {
 			const provider = this._instantiationService.createInstance(InlineCompletionProviderImpl, model, logger, logContextRecorder, inlineEditDebugComponent, telemetrySender, expectedEditCaptureController);
 
 			const unificationStateValue = unificationState.read(reader);
+			// Unify when the selected model's strategy bakes in `supportsUnifiedCompletions`, or when the
+			// core deployment/ExP `modelUnification` toggle is set.
+			const modelUnification = this._supportsUnifiedCompletions.read(reader) || (unificationStateValue?.modelUnification ?? false);
 			let excludes = this._excludedProviders.read(reader);
-			if (unificationStateValue?.modelUnification) {
+			if (modelUnification) {
 				excludes = excludes.slice(0);
 				if (!excludes.includes('completions')) {
 					excludes.push('completions');