Use MCP direct env var mode in Node SDK

Author: SteveSandersonMS

nodejs/src/client.ts

@@ -34,11 +34,11 @@ import type {
     ModelInfo,
     ResumeSessionConfig,
     SessionConfig,
+    SessionContext,
     SessionEvent,
     SessionLifecycleEvent,
     SessionLifecycleEventType,
     SessionLifecycleHandler,
-    SessionContext,
     SessionListFilter,
     SessionMetadata,
     Tool,
@@ -529,6 +529,7 @@ export class CopilotClient {
             workingDirectory: config.workingDirectory,
             streaming: config.streaming,
             mcpServers: config.mcpServers,
+            envValueMode: "direct",
             customAgents: config.customAgents,
             configDir: config.configDir,
             skillDirectories: config.skillDirectories,
@@ -611,6 +612,7 @@ export class CopilotClient {
             configDir: config.configDir,
             streaming: config.streaming,
             mcpServers: config.mcpServers,
+            envValueMode: config.mcpServers ? "direct" : undefined,
             customAgents: config.customAgents,
             skillDirectories: config.skillDirectories,
             disabledSkills: config.disabledSkills,

nodejs/test/e2e/harness/sdkTestContext.ts

@@ -19,7 +19,7 @@ const SNAPSHOTS_DIR = resolve(__dirname, "../../../../test/snapshots");
 
 export async function createSdkTestContext({
     logLevel,
-}: { logLevel?: "error" | "none" | "warning" | "info" | "debug" | "all" } = {}) {
+}: { logLevel?: "error" | "none" | "warning" | "info" | "debug" | "all"; cliPath?: string } = {}) {
     const homeDir = realpathSync(fs.mkdtempSync(join(os.tmpdir(), "copilot-test-config-")));
     const workDir = realpathSync(fs.mkdtempSync(join(os.tmpdir(), "copilot-test-work-")));
 
@@ -40,6 +40,7 @@ export async function createSdkTestContext({
         cwd: workDir,
         env,
         logLevel: logLevel || "error",
+        cliPath: process.env.COPILOT_CLI_PATH,
         // Use fake token in CI to allow cached responses without real auth
         githubToken: process.env.CI === "true" ? "fake-token-for-e2e-tests" : undefined,
     });

nodejs/test/e2e/mcp_and_agents.test.ts

@@ -2,10 +2,16 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *--------------------------------------------------------------------------------------------*/
 
+import { dirname, resolve } from "path";
+import { fileURLToPath } from "url";
 import { describe, expect, it } from "vitest";
 import type { CustomAgentConfig, MCPLocalServerConfig, MCPServerConfig } from "../../src/index.js";
 import { createSdkTestContext } from "./harness/sdkTestContext.js";
 
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const TEST_MCP_SERVER = resolve(__dirname, "../../../test/harness/test-mcp-server.mjs");
+
 describe("MCP Servers and Custom Agents", async () => {
     const { copilotClient: client } = await createSdkTestContext();
 
@@ -88,6 +94,31 @@ describe("MCP Servers and Custom Agents", async () => {
             expect(session.sessionId).toBeDefined();
             await session.destroy();
         });
+
+        it("should pass literal env values to MCP server subprocess", async () => {
+            const mcpServers: Record<string, MCPServerConfig> = {
+                "env-echo": {
+                    type: "local",
+                    command: "node",
+                    args: [TEST_MCP_SERVER],
+                    tools: ["*"],
+                    env: { TEST_SECRET: "hunter2" },
+                } as MCPLocalServerConfig,
+            };
+
+            const session = await client.createSession({
+                mcpServers,
+            });
+
+            expect(session.sessionId).toBeDefined();
+
+            const message = await session.sendAndWait({
+                prompt: "Use the env-echo/get_env tool to read the TEST_SECRET environment variable. Reply with just the value, nothing else.",
+            });
+            expect(message?.data.content).toContain("hunter2");
+
+            await session.destroy();
+        });
     });
 
     describe("Custom Agents", () => {