VS Code 1.129 runs Claude and Codex agents in a separate Agent Host process

VS Code 1.129, released July 15, 2026, moved Copilot, Claude and Codex agents into a dedicated Agent Host process that talks to editor windows over the open AHP protocol. Sessions survive window closure, can be shared across windows and, since 1.138–1.139, run in Dev Containers, over SSH, Tunnel and WSL.

• Agent Host talks to windows over the open MIT-licensed AHP JSON-RPC protocol
• Sessions keep running after the window closes, unlike the extension-host path
• 1.138 added Dev Container support; 1.139 extended it to SSH, Tunnel and WSL
• Session catalog cut first listing of ~645 sessions from 1.3 s to 0.1 s