From df6b41289d90322c1f8717c5e59625e38090dba4 Mon Sep 17 00:00:00 2001
From: Oliver Slapinski <olliefromcanada@gmail.com>
Date: Sun, 23 Aug 2026 23:51:16 -0400
Subject: [PATCH] Node: expose MCP server instruction policy

Signed-off-by: Oliver Slapinski <olliefromcanada@gmail.com>
---
 nodejs/src/client.ts       |  6 +++++
 nodejs/src/types.ts        | 11 +++++++++
 nodejs/test/client.test.ts | 50 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)

diff --git a/nodejs/src/client.ts b/nodejs/src/client.ts
index 1be2cbb94..5c109d1b3 100644
--- a/nodejs/src/client.ts
+++ b/nodejs/src/client.ts
@@ -1604,6 +1604,9 @@ export class CopilotClient {
                     ? { enableGitHubTelemetryForwarding: true }
                     : {}),
                 mcpServers: toWireMcpServers(config.mcpServers),
+                ...(config.allowAllMcpServerInstructions !== undefined
+                    ? { allowAllMcpServerInstructions: config.allowAllMcpServerInstructions }
+                    : {}),
                 mcpOAuthTokenStorage: config.mcpOAuthTokenStorage,
                 envValueMode: "direct",
                 customAgents: toWireCustomAgents(config.customAgents),
@@ -1864,6 +1867,9 @@ export class CopilotClient {
                     ? { enableGitHubTelemetryForwarding: true }
                     : {}),
                 mcpServers: toWireMcpServers(config.mcpServers),
+                ...(config.allowAllMcpServerInstructions !== undefined
+                    ? { allowAllMcpServerInstructions: config.allowAllMcpServerInstructions }
+                    : {}),
                 mcpOAuthTokenStorage: config.mcpOAuthTokenStorage,
                 envValueMode: "direct",
                 customAgents: toWireCustomAgents(config.customAgents),
diff --git a/nodejs/src/types.ts b/nodejs/src/types.ts
index 678cd5863..e943e3acf 100644
--- a/nodejs/src/types.ts
+++ b/nodejs/src/types.ts
@@ -2623,6 +2623,17 @@ export interface SessionConfigBase {
      */
     mcpServers?: Record<string, MCPServerConfig>;
 
+    /**
+     * Include instructions from every MCP server in the system prompt instead
+     * of only allowlisted servers.
+     *
+     * Enabling this broadens the session's instruction trust boundary. Only
+     * enable it when every configured MCP server is trusted.
+     *
+     * @default false
+     */
+    allowAllMcpServerInstructions?: boolean;
+
     /**
      * Custom agent configurations for the session.
      */
diff --git a/nodejs/test/client.test.ts b/nodejs/test/client.test.ts
index e2d630ba0..97ec08905 100644
--- a/nodejs/test/client.test.ts
+++ b/nodejs/test/client.test.ts
@@ -3888,6 +3888,56 @@ describe("CopilotClient", () => {
     });
 });
 
+describe("allowAllMcpServerInstructions serialization", () => {
+    async function startCaptureClient() {
+        const client = new CopilotClient({
+            connection: RuntimeConnection.forUri("localhost:1234"),
+        });
+        const sendRequest = vi.fn(async (method: string, params: any) => {
+            if (method === "session.create") return { sessionId: params.sessionId };
+            if (method === "session.resume") return { sessionId: params.sessionId };
+            throw new Error(`Unexpected method: ${method}`);
+        });
+        vi.spyOn(client as any, "connectToServer").mockImplementation(async () => {
+            (client as any).connection = { sendRequest, dispose: vi.fn() };
+        });
+        vi.spyOn(client as any, "verifyProtocolVersion").mockResolvedValue(undefined);
+        await client.start();
+        onTestFinished(() => client.forceStop());
+        return { client, sendRequest };
+    }
+
+    it.each([true, false])("forwards %s on create and resume", async (value) => {
+        const { client, sendRequest } = await startCaptureClient();
+
+        const session = await client.createSession({
+            onPermissionRequest: approveAll,
+            allowAllMcpServerInstructions: value,
+        });
+        await client.resumeSession(session.sessionId, {
+            onPermissionRequest: approveAll,
+            allowAllMcpServerInstructions: value,
+        });
+
+        const createCall = sendRequest.mock.calls.find(([method]) => method === "session.create");
+        const resumeCall = sendRequest.mock.calls.find(([method]) => method === "session.resume");
+        expect(createCall![1].allowAllMcpServerInstructions).toBe(value);
+        expect(resumeCall![1].allowAllMcpServerInstructions).toBe(value);
+    });
+
+    it("omits the option on create and resume by default", async () => {
+        const { client, sendRequest } = await startCaptureClient();
+
+        const session = await client.createSession({ onPermissionRequest: approveAll });
+        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });
+
+        const createCall = sendRequest.mock.calls.find(([method]) => method === "session.create");
+        const resumeCall = sendRequest.mock.calls.find(([method]) => method === "session.resume");
+        expect(createCall![1]).not.toHaveProperty("allowAllMcpServerInstructions");
+        expect(resumeCall![1]).not.toHaveProperty("allowAllMcpServerInstructions");
+    });
+});
+
 describe("managedSettings serialization", () => {
     async function captureCreateParams(config: Record<string, unknown>): Promise<any> {
         const client = new CopilotClient();