Activate Python environments in Agent Host shell commands with shell init scripts

src/vs/platform/agentHost/common/agentHostSchema.ts

@@ -11,6 +11,7 @@ import type { IMcpServerConfiguration } from '../../mcp/common/mcpPlatformTypes.
 import { TelemetryConfiguration, TelemetryLevel } from '../../telemetry/common/telemetry.js';
 import { telemetryLevelToAgentHostValue } from './agentHostTelemetry.js';
 import { SessionConfigKey } from './sessionConfigKeys.js';
+import type { IShellInitScript } from './shellInitScript.js';
 import type { SessionConfigPropertySchema, SessionConfigSchema } from './state/protocol/commands.js';
 import { JsonRpcErrorCodes, ProtocolError } from './state/sessionProtocol.js';
 
@@ -299,6 +300,40 @@ const permissionsProperty = schemaProperty<IPermissionsValue>({
 	sessionMutable: true,
 });
 
+/**
+ * Scripts the client generated for this session, sourced before every built-in
+ * shell tool command (see `common/shellInitScript.ts`). Written by the
+ * workbench and consumed by the Copilot provider; `readOnly` because no user
+ * edits it directly, `sessionMutable` because the selected Python environment
+ * can change while a session is live.
+ *
+ * Deliberately has no `default`: an absent value means "nothing to apply",
+ * which must stay distinguishable from an explicit empty array (clear).
+ */
+const shellInitSnippetsProperty = schemaProperty<readonly IShellInitScript[]>({
+	type: 'array',
+	title: localize('agentHost.sessionConfig.shellInitSnippets', "Shell Init Script"),
+	description: localize('agentHost.sessionConfig.shellInitSnippetsDescription', "A script sourced before each built-in shell tool command."),
+	items: {
+		type: 'object',
+		title: localize('agentHost.sessionConfig.shellInitSnippets.item', "Shell Init Script"),
+		properties: {
+			shell: {
+				type: 'string',
+				title: localize('agentHost.sessionConfig.shellInitSnippets.shell', "Shell"),
+				enum: ['bash', 'powershell'],
+			},
+			script: {
+				type: 'string',
+				title: localize('agentHost.sessionConfig.shellInitSnippets.script', "Script"),
+			},
+		},
+		required: ['shell', 'script'],
+	},
+	readOnly: true,
+	sessionMutable: true,
+});
+
 /**
  * Session-config properties owned by the platform itself — i.e. consumed
  * by the agent host rather than by any particular agent.
@@ -345,6 +380,7 @@ export const platformSessionSchema = createSchema({
 		default: 'interactive',
 		sessionMutable: true,
 	}),
+	[SessionConfigKey.ShellInitSnippets]: shellInitSnippetsProperty,
 });
 
 /**

src/vs/platform/agentHost/common/copilotCliConfig.ts

@@ -47,6 +47,9 @@ export const CopilotCliVSCodeAssignmentContextKey = 'copilotCliVSCodeAssignmentC
 
 export const AgentHostCustomTerminalToolEnabledSettingId = 'chat.agentHost.customTerminalTool.enabled';
 
+/** Enable VS Code's generated init script for the SDK built-in shell tool. */
+export const AgentHostShellToolInitScriptEnabledSettingId = 'chat.agentHost.shellTool.initScript.enabled';
+
 export const AgentHostCopilotSdkLogLevelSettingId = 'chat.agentHost.copilotSdk.logLevel';
 
 export const AgentHostOpus48PromptEnabledSettingId = 'chat.agentHost.opus48Prompt.enabled';

src/vs/platform/agentHost/common/sessionConfigKeys.ts

@@ -39,6 +39,8 @@ export const enum SessionConfigKey {
 	AgentMerge = 'agentMerge',
 	/** `'agentMerge.controller'` — host-owned Agent Merge lifecycle state. */
 	AgentMergeController = 'agentMerge.controller',
+	/** `'shellInitSnippets'` — host-generated scripts sourced before built-in shell tool commands. */
+	ShellInitSnippets = 'shellInitSnippets',
 }
 
 /**

src/vs/platform/agentHost/common/shellInitScript.ts

@@ -0,0 +1,120 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+export type ShellInitScriptShell = 'bash' | 'powershell';
+
+/**
+ * One host-generated script sourced before every SDK built-in shell command.
+ * The array-valued session config carries either no script (`[]`) or this one
+ * script, so clearing a previously applied script is explicit.
+ */
+export interface IShellInitScript {
+	readonly shell: ShellInitScriptShell;
+	readonly script: string;
+}
+
+function quoteBash(value: string): string {
+	return `'${value.replaceAll(`'`, `'\\''`)}'`;
+}
+
+function powerShellHereString(value: string): string {
+	if (value.split(/\r?\n/).some(line => line.trimEnd() === `'@`)) {
+		throw new Error(`Cannot embed a PowerShell here-string payload containing a line equal to "'@"`);
+	}
+	return `@'\n${value}\n'@`;
+}
+
+function powerShellBlock(body: readonly string[], failureMessage: string): string[] {
+	return [
+		`$__vscodePreviousErrorActionPreference = $ErrorActionPreference`,
+		`try {`,
+		`\t$ErrorActionPreference = 'Stop'`,
+		...body,
+		`} catch {`,
+		`\tWrite-Output '${failureMessage.replaceAll(`'`, `''`)}'`,
+		`} finally {`,
+		`\t$ErrorActionPreference = $__vscodePreviousErrorActionPreference`,
+		`}`,
+	];
+}
+
+/**
+ * Creates the single script VS Code registers with the SDK shell tool.
+ *
+ * Profile loading comes first because Python activation can depend on shell
+ * functions such as `conda`. Bash then replays conda's managed block when a
+ * stock non-interactive `.bashrc` guard returned before reaching it.
+ *
+ * Every script ends successfully: the runtime reports a nonzero init-script
+ * status before every later command, and discards Bash init-script stderr.
+ */
+export function createShellInitScript(shell: ShellInitScriptShell, pythonActivation: string | undefined): IShellInitScript {
+	return shell === 'powershell'
+		? createPowerShellInitScript(pythonActivation)
+		: createBashInitScript(pythonActivation);
+}
+
+function createBashInitScript(pythonActivation: string | undefined): IShellInitScript {
+	const lines = [
+		`# Generated by VS Code for Agent Host shell commands.`,
+		`if [ -r "$HOME/.bashrc" ]; then`,
+		`\tif ! builtin source "$HOME/.bashrc"; then`,
+		`\t\tprintf '%s\\n' 'copilot shell init: loading ~/.bashrc failed; continuing.'`,
+		`\tfi`,
+		`\tif ! builtin declare -F conda >/dev/null 2>&1; then`,
+		`\t\t__vscode_conda_block="$(sed -n '/^# >>> conda initialize >>>$/,/^# <<< conda initialize <<<$/p' "$HOME/.bashrc" 2>/dev/null)"`,
+		`\t\tif [ -n "$__vscode_conda_block" ] && ! builtin eval "$__vscode_conda_block"; then`,
+		`\t\t\tprintf '%s\\n' 'copilot shell init: conda initialization failed; continuing.'`,
+		`\t\tfi`,
+		`\t\tbuiltin unset __vscode_conda_block`,
+		`\tfi`,
+		`fi`,
+	];
+	if (pythonActivation?.trim()) {
+		lines.push(
+			`if ! builtin eval ${quoteBash(pythonActivation)}; then`,
+			`\tprintf '%s\\n' 'copilot shell init: Python activation failed; continuing without the selected environment.'`,
+			`fi`,
+		);
+	}
+	lines.push(`builtin true`, ``);
+	return { shell: 'bash', script: lines.join('\n') };
+}
+
+function createPowerShellInitScript(pythonActivation: string | undefined): IShellInitScript {
+	const lines = [
+		`# Generated by VS Code for Agent Host shell commands.`,
+		...powerShellBlock([
+			`\tforeach ($__vscodeProfile in @($PROFILE.CurrentUserAllHosts, $PROFILE.CurrentUserCurrentHost)) {`,
+			`\t\tif ($__vscodeProfile -and (Test-Path -LiteralPath $__vscodeProfile)) {`,
+			`\t\t\t. $__vscodeProfile`,
+			`\t\t}`,
+			`\t}`,
+		], 'copilot shell init: loading the PowerShell profile failed; continuing.'),
+	];
+	if (pythonActivation?.trim()) {
+		lines.push(...powerShellBlock(
+			[`\tInvoke-Expression ${powerShellHereString(pythonActivation)}`],
+			'copilot shell init: Python activation failed; continuing without the selected environment.',
+		));
+	}
+	lines.push(`$global:LASTEXITCODE = 0`, ``);
+	return { shell: 'powershell', script: lines.join('\n') };
+}
+
+/** Validates the client-pushed list before the agent host writes it to disk. */
+export function isShellInitScriptList(value: unknown): value is readonly IShellInitScript[] {
+	return Array.isArray(value)
+		&& value.length <= 1
+		&& value.every(entry => {
+			if (!entry || typeof entry !== 'object') {
+				return false;
+			}
+			const script = entry as Partial<IShellInitScript>;
+			return (script.shell === 'bash' || script.shell === 'powershell')
+				&& typeof script.script === 'string'
+				&& script.script.length > 0;
+		});
+}