Copilot SDK version mismatch causes error with copilot-cli (v3)

[Jayonics]

Apologies if this issue belongs in windbg-agent instead of your copilot-sdk-cpp repo, but seeing as the issue lies here, I thought this repo's appropriate. Please let me know if it's not and I'll reopen it in windbg-agent.

Description:

I upgraded Github.Copilot (CLI) using winget couple of days ago to version v1.0.2, I'm guessing this updates what copilot-sdk-cpp uses as the server of the copilot provider in windbg-agent.
github copilot CLI now uses API version 3 for the server which causes windbg-agent's copilot-sdk-cpp to throw an error when running.

Error

Error: Failed to create session - SDK protocol version mismatch: SDK expects version 2, but server reports version 3

Environment

windbg-agent

windbg-agent v1.0.4

github copilot

github.copilot gh-repo v1.0.2
github-copilot npm source v1.0.2

Github Copilot CLI winget package info

winget show --id "Github.Copilot" --version "v1.0.2"
Found Copilot CLI [GitHub.Copilot]
Version: v1.0.2
Publisher: GitHub, Inc.
Publisher Url: https://github.com/home/
Publisher Support Url: https://support.github.com/
Moniker: copilot
Description: GitHub Copilot CLI brings AI-powered coding assistance directly to your command line, enabling you to build, debug, and understand code through natural language conversations. Powered by the same agentic harness as GitHub's Copilot coding agent, it provides intelligent assistance while staying deeply integrated with your GitHub workflow.
Homepage: https://github.com/github/copilot-cli
License: Proprietary
License Url: https://github.com/github/copilot-cli/blob/HEAD/LICENSE.md
Privacy Url: https://docs.github.com/site-policy/privacy-policies/github-privacy-statement
Copyright: Copyright (c) GitHub 2025. All rights reserved.
Copyright Url: https://github.com/github/copilot-cli?tab=License-1-ov-file
Release Notes Url: https://github.com/github/copilot-cli/releases/tag/v1.0.2
Documentation:
  Wiki: https://github.com/github/copilot-cli/wiki
Tags:
  cli
  copilot
  github
Installer:
  Installer Type: portable (zip)
  Installer Url: https://github.com/github/copilot-cli/releases/download/v1.0.2/copilot-win32-x64.zip
  Installer SHA256: 14f7e639721861ad49519863aad154925ed442b653dc3306efd68e6383b03ca8
  Release Date: 2026-03-06
  Offline Distribution Supported: true
  Dependencies:
    - Package Dependencies:
        Microsoft.PowerShell [>= 7.0.0]

Workarounds

Use older version of Github Copilot CLI? (Unsure which is the latest V2 server from the npm source)
github copilot cli npm
copilot sdk npm v0.1.30

Possibly useful notes?

• copilot-sdk v0.1.32 Operates in V3 but also added in backwards compatibility for V2 according to the release notes: SDK applications written against the v3 API now also work when connected to a v2 CLI server, with no code changes required.
• copilot-sdk v0.1.31 Bumped the version to V3
• copilot-sdk v0.1.30 was the most recent tagged version to explicitly use V2 in the server API.

Of course, this is a cpp implementation of the sdk so I'm not sure how useful the points about the copilot-sdk releases are but hopefully it helps.