Image: Microsoft / code.visualstudio.com VS Code 1.133 Open-Sources the Agent Host Protocol and Makes GitHub Sign-In Optional
Microsoft's latest release decouples AI agents from the editor, publishes the Agent Host Protocol under MIT, and lets Claude users skip GitHub authentication entirely.
Microsoft shipped VS Code 1.133 on August 12, 2026, and the release carries two decisions that will matter well past this update cycle: the Agent Host Protocol is now open-sourced under MIT, and GitHub authentication is no longer required to open an agent session.
The Agent Host Protocol Goes Open
VS Code 1.132 introduced the Agent Host Protocol as the communication layer between the editor and its AI harnesses. Version 1.133 publishes the full AHP spec under the MIT license.
The practical point is interoperability. AHP now sits alongside the Language Server Protocol and the Debug Adapter Protocol as a documented, open interface that third-party tools can implement. The spec covers how agent harnesses, Copilot, Claude, Codex, and anything else, talk to the editor, handle sessions, and exchange context. Teams building custom tooling or integrating agents into their own IDEs can now build against a stable, published contract instead of reverse-engineering VS Code internals.
Agent sessions also gained the ability to span multiple VS Code windows from a single Agent Host process. Open the same coding session in two windows, on a laptop and an external monitor, and the session state is shared. That works over SSH and dev tunnels too, which means a session running on a remote machine is accessible from any VS Code instance with network access.
Claude Sessions Without GitHub
The biggest quality-of-life change for teams that provision Claude API keys directly: a new experimental setting, chat.agentHost.allowSignedOutWhenUsable, lets you open the Agents window without a GitHub login.
Before this, the Agents window required GitHub authentication even when the actual AI requests were going through an Anthropic API key. The friction was real enough that Microsoft built a workaround into the release notes. With the setting enabled, VS Code detects existing Claude configuration and surfaces a direct path into the session.
This matters for organizations that can’t route traffic through github.com, or that authenticate through a different identity provider. The enterprise agent case in particular, where Copilot seats sit alongside Claude API access, became noticeably cleaner.
Mid-Session Model Switching
Version 1.133 also lets you switch providers inside a running Claude session without tearing down the agent host. The model picker now shows both Anthropic models and Copilot models grouped separately. Select an Anthropic model and requests bill to your API key; select a Copilot model and they consume your subscription quota.
For developers who start a session under Copilot’s included rate and want to shift to a higher-capacity Anthropic model mid-conversation, this removes a step that previously required closing and reconfiguring the session.
Other Changes
Long conversations now support sticky scroll. The current prompt stays anchored at the top as you scroll through history, and navigation controls let you jump between earlier prompts.
The integrated browser now auto-reloads local HTML files on disk changes. Useful for frontend work where an agent is editing files and you want to see the output immediately.
VS Code 1.134, currently in the Insiders channel, adds subtitles and status indicators to the Chats picker in the Agents window. Regular chats, forked chats, and active subagents appear in separate groups.
Sources: VS Code 1.133 Release Notes, InfoWorld, DevOps.com