mcp: support envFile for mcp.json (#244059)

Fixes #243709

Note it needs #244029 to support ${workspaceFolder}

src/vs/base/common/envfile.ts

@@ -0,0 +1,100 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+/**
+ * Parses a standard .env/.envrc file into a map of the environment variables
+ * it defines.
+ *
+ * todo@connor4312: this can go away (if only used in Node.js targets) and be
+ * replaced with `util.parseEnv`. However, currently calling that makes the
+ * extension host crash.
+ */
+export function parseEnvFile(src: string) {
+	const result = new Map<string, string>();
+
+	// Normalize line breaks
+	const normalizedSrc = src.replace(/\r\n?/g, '\n');
+	const lines = normalizedSrc.split('\n');
+
+	for (let line of lines) {
+		// Skip empty lines and comments
+		line = line.trim();
+		if (!line || line.startsWith('#')) {
+			continue;
+		}
+
+		// Parse the line into key and value
+		const [key, value] = parseLine(line);
+		if (key) {
+			result.set(key, value);
+		}
+	}
+
+	return result;
+
+	function parseLine(line: string): [string, string] | [null, null] {
+		// Handle export prefix
+		if (line.startsWith('export ')) {
+			line = line.substring(7).trim();
+		}
+
+		// Find the key-value separator
+		const separatorIndex = findIndexOutsideQuotes(line, c => c === '=' || c === ':');
+		if (separatorIndex === -1) {
+			return [null, null];
+		}
+
+		const key = line.substring(0, separatorIndex).trim();
+		let value = line.substring(separatorIndex + 1).trim();
+
+		// Handle comments and remove them
+		const commentIndex = findIndexOutsideQuotes(value, c => c === '#');
+		if (commentIndex !== -1) {
+			value = value.substring(0, commentIndex).trim();
+		}
+
+		// Process quoted values
+		if (value.length >= 2) {
+			const firstChar = value[0];
+			const lastChar = value[value.length - 1];
+
+			if ((firstChar === '"' && lastChar === '"') ||
+				(firstChar === '\'' && lastChar === '\'') ||
+				(firstChar === '`' && lastChar === '`')) {
+				// Remove surrounding quotes
+				value = value.substring(1, value.length - 1);
+
+				// Handle escaped characters in double quotes
+				if (firstChar === '"') {
+					value = value.replace(/\\n/g, '\n').replace(/\\r/g, '\r');
+				}
+			}
+		}
+
+		return [key, value];
+	}
+
+	function findIndexOutsideQuotes(text: string, predicate: (char: string) => boolean): number {
+		let inQuote = false;
+		let quoteChar = '';
+
+		for (let i = 0; i < text.length; i++) {
+			const char = text[i];
+
+			if (inQuote) {
+				if (char === quoteChar && text[i - 1] !== '\\') {
+					inQuote = false;
+				}
+			} else if (char === '"' || char === '\'' || char === '`') {
+				inQuote = true;
+				quoteChar = char;
+			} else if (predicate(char)) {
+				return i;
+			}
+		}
+
+		return -1;
+	}
+}

src/vs/base/test/common/envfile.test.ts

@@ -0,0 +1,130 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { parseEnvFile } from '../../common/envfile.js';
+import { ensureNoDisposablesAreLeakedInTestSuite } from './utils.js';
+import * as assert from 'assert';
+
+/*
+Test cases from https://github.com/motdotla/dotenv/blob/master/tests/.env
+
+	Copyright (c) 2015, Scott Motte
+	All rights reserved.
+
+	Redistribution and use in source and binary forms, with or without
+	modification, are permitted provided that the following conditions are met:
+
+	* Redistributions of source code must retain the above copyright notice, this
+		list of conditions and the following disclaimer.
+
+	* Redistributions in binary form must reproduce the above copyright notice,
+		this list of conditions and the following disclaimer in the documentation
+		and/or other materials provided with the distribution.
+
+	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+	DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+	FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+	DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+	SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+	CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+	OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+const example = `
+BASIC=basic
+
+# previous line intentionally left blank
+AFTER_LINE=after_line
+EMPTY=
+EMPTY_SINGLE_QUOTES=''
+EMPTY_DOUBLE_QUOTES=""
+EMPTY_BACKTICKS=\`\`
+SINGLE_QUOTES='single_quotes'
+SINGLE_QUOTES_SPACED='    single quotes    '
+DOUBLE_QUOTES="double_quotes"
+DOUBLE_QUOTES_SPACED="    double quotes    "
+DOUBLE_QUOTES_INSIDE_SINGLE='double "quotes" work inside single quotes'
+DOUBLE_QUOTES_WITH_NO_SPACE_BRACKET="{ port: $MONGOLAB_PORT}"
+SINGLE_QUOTES_INSIDE_DOUBLE="single 'quotes' work inside double quotes"
+BACKTICKS_INSIDE_SINGLE='\`backticks\` work inside single quotes'
+BACKTICKS_INSIDE_DOUBLE="\`backticks\` work inside double quotes"
+BACKTICKS=\`backticks\`
+BACKTICKS_SPACED=\`    backticks    \`
+DOUBLE_QUOTES_INSIDE_BACKTICKS=\`double "quotes" work inside backticks\`
+SINGLE_QUOTES_INSIDE_BACKTICKS=\`single 'quotes' work inside backticks\`
+DOUBLE_AND_SINGLE_QUOTES_INSIDE_BACKTICKS=\`double "quotes" and single 'quotes' work inside backticks\`
+EXPAND_NEWLINES="expand\\nnew\\nlines"
+DONT_EXPAND_UNQUOTED=dontexpand\\nnewlines
+DONT_EXPAND_SQUOTED='dontexpand\\nnewlines'
+# COMMENTS=work
+INLINE_COMMENTS=inline comments # work #very #well
+INLINE_COMMENTS_SINGLE_QUOTES='inline comments outside of #singlequotes' # work
+INLINE_COMMENTS_DOUBLE_QUOTES="inline comments outside of #doublequotes" # work
+INLINE_COMMENTS_BACKTICKS=\`inline comments outside of #backticks\` # work
+INLINE_COMMENTS_SPACE=inline comments start with a#number sign. no space required.
+EQUAL_SIGNS=equals==
+RETAIN_INNER_QUOTES={"foo": "bar"}
+RETAIN_INNER_QUOTES_AS_STRING='{"foo": "bar"}'
+RETAIN_INNER_QUOTES_AS_BACKTICKS=\`{"foo": "bar's"}\`
+TRIM_SPACE_FROM_UNQUOTED=    some spaced out string
+USERNAME=therealnerdybeast@example.tld
+		SPACED_KEY = parsed
+`;
+
+suite('parseEnvFile', () => {
+	ensureNoDisposablesAreLeakedInTestSuite();
+
+	test('parses', () => {
+		const parsed = parseEnvFile(example);
+		assert.strictEqual(parsed.get('BASIC'), 'basic');
+		assert.strictEqual(parsed.get('AFTER_LINE'), 'after_line');
+		assert.strictEqual(parsed.get('EMPTY'), '');
+		assert.strictEqual(parsed.get('EMPTY_SINGLE_QUOTES'), '');
+		assert.strictEqual(parsed.get('EMPTY_DOUBLE_QUOTES'), '');
+		assert.strictEqual(parsed.get('EMPTY_BACKTICKS'), '');
+		assert.strictEqual(parsed.get('SINGLE_QUOTES'), 'single_quotes');
+		assert.strictEqual(parsed.get('SINGLE_QUOTES_SPACED'), '    single quotes    ');
+		assert.strictEqual(parsed.get('DOUBLE_QUOTES'), 'double_quotes');
+		assert.strictEqual(parsed.get('DOUBLE_QUOTES_SPACED'), '    double quotes    ');
+		assert.strictEqual(parsed.get('DOUBLE_QUOTES_INSIDE_SINGLE'), 'double "quotes" work inside single quotes');
+		assert.strictEqual(parsed.get('DOUBLE_QUOTES_WITH_NO_SPACE_BRACKET'), '{ port: $MONGOLAB_PORT}');
+		assert.strictEqual(parsed.get('SINGLE_QUOTES_INSIDE_DOUBLE'), "single 'quotes' work inside double quotes");
+		assert.strictEqual(parsed.get('BACKTICKS_INSIDE_SINGLE'), '`backticks` work inside single quotes');
+		assert.strictEqual(parsed.get('BACKTICKS_INSIDE_DOUBLE'), '`backticks` work inside double quotes');
+		assert.strictEqual(parsed.get('BACKTICKS'), 'backticks');
+		assert.strictEqual(parsed.get('BACKTICKS_SPACED'), '    backticks    ');
+		assert.strictEqual(parsed.get('DOUBLE_QUOTES_INSIDE_BACKTICKS'), 'double "quotes" work inside backticks');
+		assert.strictEqual(parsed.get('SINGLE_QUOTES_INSIDE_BACKTICKS'), "single 'quotes' work inside backticks");
+		assert.strictEqual(parsed.get('DOUBLE_AND_SINGLE_QUOTES_INSIDE_BACKTICKS'), "double \"quotes\" and single 'quotes' work inside backticks");
+		assert.strictEqual(parsed.get('EXPAND_NEWLINES'), 'expand\nnew\nlines');
+		assert.strictEqual(parsed.get('DONT_EXPAND_UNQUOTED'), 'dontexpand\\nnewlines');
+		assert.strictEqual(parsed.get('DONT_EXPAND_SQUOTED'), 'dontexpand\\nnewlines');
+		assert.strictEqual(parsed.get('COMMENTS'), undefined);
+		assert.strictEqual(parsed.get('INLINE_COMMENTS'), 'inline comments');
+		assert.strictEqual(parsed.get('INLINE_COMMENTS_SINGLE_QUOTES'), 'inline comments outside of #singlequotes');
+		assert.strictEqual(parsed.get('INLINE_COMMENTS_DOUBLE_QUOTES'), 'inline comments outside of #doublequotes');
+		assert.strictEqual(parsed.get('INLINE_COMMENTS_BACKTICKS'), 'inline comments outside of #backticks');
+		assert.strictEqual(parsed.get('INLINE_COMMENTS_SPACE'), 'inline comments start with a');
+		assert.strictEqual(parsed.get('EQUAL_SIGNS'), 'equals==');
+		assert.strictEqual(parsed.get('RETAIN_INNER_QUOTES'), '{"foo": "bar"}');
+		assert.strictEqual(parsed.get('RETAIN_INNER_QUOTES_AS_STRING'), '{"foo": "bar"}');
+		assert.strictEqual(parsed.get('RETAIN_INNER_QUOTES_AS_BACKTICKS'), '{"foo": "bar\'s"}');
+		assert.strictEqual(parsed.get('TRIM_SPACE_FROM_UNQUOTED'), 'some spaced out string');
+		assert.strictEqual(parsed.get('USERNAME'), 'therealnerdybeast@example.tld');
+		assert.strictEqual(parsed.get('SPACED_KEY'), 'parsed');
+		const payload = parseEnvFile('BUFFER=true');
+		assert.strictEqual(payload.get('BUFFER'), 'true');
+		const expectedPayload = Object.entries({ SERVER: 'localhost', PASSWORD: 'password', DB: 'tests' });
+		const RPayload = parseEnvFile('SERVER=localhost\rPASSWORD=password\rDB=tests\r');
+		assert.deepStrictEqual([...RPayload], expectedPayload);
+		const NPayload = parseEnvFile('SERVER=localhost\nPASSWORD=password\nDB=tests\n');
+		assert.deepStrictEqual([...NPayload], expectedPayload);
+		const RNPayload = parseEnvFile('SERVER=localhost\r\nPASSWORD=password\r\nDB=tests\r\n');
+		assert.deepStrictEqual([...RNPayload], expectedPayload);
+	});
+});

src/vs/platform/mcp/common/mcpPlatformTypes.ts

@@ -17,6 +17,7 @@ export interface IMcpConfigurationStdio {
 	command: string;
 	args?: readonly string[];
 	env?: Record<string, string | number | null>;
+	envFile?: string;
 }
 
 export interface IMcpConfigurationSSE {

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

@@ -108,7 +108,8 @@ export class ExtHostMcpService extends Disposable implements IExtHostMpcService
 							cwd: item.cwd,
 							args: item.args,
 							command: item.command,
-							env: item.env
+							env: item.env,
+							envFile: undefined,
 						}
 				});
 			}

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

@@ -4,14 +4,15 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { ChildProcessWithoutNullStreams, spawn } from 'child_process';
-import { mapValues } from '../../../base/common/objects.js';
+import { readFile } from 'fs/promises';
+import { homedir } from 'os';
+import { PassThrough } from 'stream';
+import { parseEnvFile } from '../../../base/common/envfile.js';
 import { URI } from '../../../base/common/uri.js';
 import { StreamSplitter } from '../../../base/node/nodeStreams.js';
 import { McpConnectionState, McpServerLaunch, McpServerTransportStdio, McpServerTransportType } from '../../contrib/mcp/common/mcpTypes.js';
 import { ExtHostMcpService } from '../common/extHostMcp.js';
 import { IExtHostRpcService } from '../common/extHostRpcService.js';
-import { homedir } from 'os';
-import { PassThrough } from 'stream';
 
 export class NodeExtHostMpcService extends ExtHostMcpService {
 	constructor(
@@ -47,19 +48,35 @@ export class NodeExtHostMpcService extends ExtHostMcpService {
 		const nodeServer = this.nodeServers.get(id);
 		if (nodeServer) {
 			this._proxy.$onDidPublishLog(id, '[Client Says] ' + message.toString());
-
 			nodeServer.child.stdin.write(message + '\n');
 		} else {
 			super.$sendMessage(id, message);
 		}
 	}
 
-	private startNodeMpc(id: number, launch: McpServerTransportStdio): void {
-		const onError = (err: Error) => this._proxy.$onDidChangeState(id, {
+	private async startNodeMpc(id: number, launch: McpServerTransportStdio) {
+		const onError = (err: Error | string) => this._proxy.$onDidChangeState(id, {
 			state: McpConnectionState.Kind.Error,
-			message: err.message,
+			message: typeof err === 'string' ? err : err.message,
 		});
 
+		// MCP servers are run on the same authority where they are defined, so
+		// reading the envfile based on its path off the filesystem here is fine.
+		const env = { ...process.env };
+		if (launch.envFile) {
+			try {
+				for (const [key, value] of parseEnvFile(await readFile(launch.envFile, 'utf-8'))) {
+					env[key] = value;
+				}
+			} catch (e) {
+				onError(`Failed to read envFile '${launch.envFile}': ${e.message}`);
+				return;
+			}
+		}
+		for (const [key, value] of Object.entries(launch.env)) {
+			env[key] = value === null ? undefined : String(value);
+		}
+
 		const abortCtrl = new AbortController();
 		let child: ChildProcessWithoutNullStreams;
 		try {
@@ -67,10 +84,7 @@ export class NodeExtHostMpcService extends ExtHostMcpService {
 				stdio: 'pipe',
 				cwd: launch.cwd ? URI.revive(launch.cwd).fsPath : homedir(),
 				signal: abortCtrl.signal,
-				env: {
-					...process.env,
-					...mapValues(launch.env, v => typeof v === 'number' ? String(v) : (v === null ? undefined : v)),
-				},
+				env,
 			});
 		} catch (e) {
 			onError(e);

src/vs/workbench/contrib/mcp/common/discovery/configMcpDiscovery.ts

@@ -109,6 +109,7 @@ export class ConfigMcpDiscovery extends Disposable implements IMcpDiscovery {
 					args: value.args || [],
 					command: value.command,
 					env: value.env || {},
+					envFile: value.envFile,
 					cwd: undefined,
 				},
 				variableReplacement: {

src/vs/workbench/contrib/mcp/common/discovery/nativeMcpDiscoveryAdapters.ts

@@ -63,6 +63,7 @@ export class ClaudeDesktopMpcDiscoveryAdapter implements NativeMpcDiscoveryAdapt
 					args: server.args || [],
 					command: server.command,
 					env: server.env || {},
+					envFile: undefined,
 					cwd: homedir,
 				}
 			};

src/vs/workbench/contrib/mcp/common/mcpConfigPathsService.ts

@@ -13,6 +13,7 @@ import { createDecorator } from '../../../../platform/instantiation/common/insta
 import { ILabelService } from '../../../../platform/label/common/label.js';
 import { IProductService } from '../../../../platform/product/common/productService.js';
 import { StorageScope } from '../../../../platform/storage/common/storage.js';
+import { IWorkspaceFolder } from '../../../../platform/workspace/common/workspace.js';
 import { IWorkbenchEnvironmentService } from '../../../services/environment/common/environmentService.js';
 import { IPreferencesService } from '../../../services/preferences/common/preferences.js';
 import { IRemoteAgentService } from '../../../services/remote/common/remoteAgentService.js';
@@ -28,6 +29,8 @@ export interface IMcpConfigPath {
 	scope: StorageScope;
 	/** Configuration target that correspond to this file */
 	target: ConfigurationTarget;
+	/** Associated workspace folder, for workspace folder values */
+	folder?: IWorkspaceFolder;
 	/** Order in which the configuration should be displayed */
 	order: number;
 	/** Config's remote authority */

src/vs/workbench/contrib/mcp/common/mcpConfiguration.ts

@@ -54,6 +54,11 @@ export const mcpStdioServerSchema: IJSONSchema = {
 				type: 'string'
 			},
 		},
+		envFile: {
+			type: 'string',
+			description: localize('app.mcp.envFile.command', "Path to a file containing environment variables for the server."),
+			examples: ['${workspaceFolder}/.env'],
+		},
 		env: {
 			description: localize('app.mcp.env.command', "Environment variables passed to the server."),
 			additionalProperties: {

src/vs/workbench/contrib/mcp/common/mcpRegistry.ts

@@ -284,7 +284,6 @@ export class McpRegistry extends Disposable implements IMcpRegistry {
 			}
 		}
 
-
 		// resolve variables requiring user input
 		await this._configurationResolverService.resolveWithInteraction(folder, expr, section, undefined, target);
 

src/vs/workbench/contrib/mcp/common/mcpTypes.ts

@@ -261,6 +261,7 @@ export interface McpServerTransportStdio {
 	readonly command: string;
 	readonly args: readonly string[];
 	readonly env: Record<string, string | number | null>;
+	readonly envFile: string | undefined;
 }
 
 /**
@@ -280,7 +281,7 @@ export type McpServerLaunch =
 export namespace McpServerLaunch {
 	export type Serialized =
 		| { type: McpServerTransportType.SSE; uri: UriComponents; headers: [string, string][] }
-		| { type: McpServerTransportType.Stdio; cwd: UriComponents | undefined; command: string; args: readonly string[]; env: Record<string, string | number | null> };
+		| { type: McpServerTransportType.Stdio; cwd: UriComponents | undefined; command: string; args: readonly string[]; env: Record<string, string | number | null>; envFile: string | undefined };
 
 	export function toSerialized(launch: McpServerLaunch): McpServerLaunch.Serialized {
 		return launch;
@@ -297,6 +298,7 @@ export namespace McpServerLaunch {
 					command: launch.command,
 					args: launch.args,
 					env: launch.env,
+					envFile: launch.envFile,
 				};
 		}
 	}

src/vs/workbench/contrib/mcp/test/common/mcpRegistry.test.ts

@@ -158,6 +158,7 @@ suite('Workbench - MCP - Registry', () => {
 				command: 'test-command',
 				args: [],
 				env: {},
+				envFile: undefined,
 				cwd: URI.parse('file:///test')
 			}
 		};
@@ -196,6 +197,7 @@ suite('Workbench - MCP - Registry', () => {
 				env: {
 					PATH: '${input:testInteractive}'
 				},
+				envFile: undefined,
 				cwd: URI.parse('file:///test')
 			},
 			variableReplacement: {

src/vs/workbench/contrib/mcp/test/common/mcpServerConnection.test.ts

@@ -97,6 +97,7 @@ suite('Workbench - MCP - ServerConnection', () => {
 				command: 'test-command',
 				args: [],
 				env: {},
+				envFile: undefined,
 				cwd: URI.parse('file:///test')
 			}
 		};