Expose respondToExitPlanMode in the copilot-sdk package - blocking VS plan mode integration

[nicolasdossantos]

Summary

The copilot-sdk package does not expose respondToExitPlanMode, even though the full SDK (sdk/index.d.ts) has it. VS receives ExitPlanModeRequestedEvent with the available actions but has no way to respond. The CLI auto-proceeds with the recommended action, bypassing the user's choice.

Evidence

Full SDK (@github/copilot/sdk/index.d.ts) — HAS it:

// Line 13896 — method on session class
respondToExitPlanMode(requestId: string, response: ExitPlanModeResponse): void;

// Line 17077 — hook on session base
protected onExitPlanMode?: (request: ExitPlanModeRequest) => Promise<ExitPlanModeResponse>;

// Line 10224 — response type
type ExitPlanModeResponse = {
    approved: boolean;
    selectedAction?: ExitPlanModeAction; // "exit_only" | "interactive" | "autopilot" | "autopilot_fleet"
    autoApproveEdits?: boolean;
    feedback?: string;
};

Thin wrapper (copilot-sdk/session.d.ts) — MISSING:

• session-events.d.ts line 2943 references it in a comment: "used to respond via session.respondToExitPlanMode()" — but the method does not exist on the CopilotSession class
• session.d.ts exposes registerPermissionHandler and registerUserInputHandler — no registerExitPlanModeHandler
• extension.js handles permission.requested and tool.call broadcasts — no handler for exit_plan_mode.requested
• types.d.ts SessionConfig has onPermissionRequest and onUserInputRequest — no onExitPlanMode

What VS sees:

• ExitPlanModeRequestedEvent fires correctly with RequestId, Summary, Actions[], RecommendedAction ✅
• No way to call respondToExitPlanMode(requestId, response) ❌
• CLI auto-proceeds after timeout, ignoring the user

What we need

Either of:

1. A method on CopilotSession:

respondToExitPlanMode(requestId: string, response: ExitPlanModeResponse): void;

2. A callback on SessionConfig:

onExitPlanMode?: (request: ExitPlanModeRequest) => Promise<ExitPlanModeResponse>;

Both patterns already exist for permissions (onPermissionRequest / registerPermissionHandler) and user input (onUserInputRequest / registerUserInputHandler). This would follow the same pattern.

Impact

This blocks VS from offering plan approval with mode selection.

Thank you