.NET [Feature]: GitHubCopilotAgent should translate Copilot SDK permission.requested events to AG-UI human-in-the-loop events

[ShrayRastogi]

Description

Issue

When using GitHubCopilotAgent with MapAGUI, the Copilot SDK's permission.requested events (including MCP tool call approvals) are not translated into AG-UI human-in-the-loop events. The user has no opportunity to approve or deny tool calls in the AG-UI client.

Description

The Copilot SDK emits permission.requested events for all tool executions, including MCP tool calls (kind: "mcp"). The GitHubCopilotAgent.RunCoreStreamingAsync() correctly passes OnPermissionRequest through to the SessionConfig and catches unhandled events via the default branch, wrapping them as AIContent with RawRepresentation = sessionEvent.

However, AsAGUIEventStreamAsync() does not recognize permission.requested events from RawRepresentation and does not emit the corresponding AG-UI human-in-the-loop protocol events. This means when using MapAGUI with a Copilot SDK-backed agent, the only option is PermissionHandler.ApproveAll — there is no way to surface permission requests to the AG-UI client (e.g., CopilotKit) for user approval.

Expected Behavior

When OnPermissionRequest is NOT set to ApproveAll, the AG-UI adapter should:

1. Detect permission.requested events in RawRepresentation within the AgentResponseUpdate stream
2. Emit AG-UI TOOL_CALL_START events with approval-required semantics (similar to ServerFunctionApprovalAgent pattern)
3. Pause the SSE stream and wait for the client to send an approve/deny response
4. Forward the user's decision back to session.respondToPermission() via the OnPermissionRequest callback

This would enable AG-UI clients like CopilotKit (useHumanInTheLoop) to show native approve/deny UI for ALL tool calls — including MCP tools — without requiring ServerFunctionApprovalAgent or custom side channels.

Current Workarounds

1. CopilotKit useHumanInTheLoop — intercepts at AG-UI protocol level before reaching backend, but only works with CopilotKit clients
2. ServerFunctionApprovalAgent — unclean and complex, still not tied to core copilot sdk permission handler
3. PermissionHandler.ApproveAll — auto-approves everything, no user oversight

Relevant Source Code

• GitHubCopilotAgent.cs L268-290 — event subscription with default branch catching permission.requested
• GitHubCopilotAgent.cs L328 — CopySessionConfig passes OnPermissionRequest through
• Copilot SDK streaming events — documents permission.requested with MCP kind
• Step04_HumanInLoop sample — unclean and complex.

Package Versions

• Microsoft.Agents.AI.GitHub.Copilot 1.0.0-preview.260311.1
• Microsoft.Agents.AI.Hosting.AGUI.AspNetCore 1.0.0-preview.260311.1
• GitHub.Copilot.SDK 0.1.33-preview.3

.NET Version

10.0

Additional Context

The Copilot SDK's permission.requested event includes a kind discriminator with values: "shell", "write", "read", "mcp", "url", "custom-tool". Each carries tool-specific metadata (e.g., serverName, toolName, args for MCP). This is rich enough data to generate proper AG-UI tool call approval events.

Code Sample

Language/SDK

.NET

[ShrayRastogi]

@markwallace-microsoft - Happy to contribute, kindly review here - #4988