Choose the harness that runs new Crew sessions. Agent backends are a Preview feature, so you must opt in before the selector appears.
Each backend shows whether it is installed, missing on this machine, or installed but waiting for a gateway restart. Install or restart before selecting an unavailable backend.
The selection applies to new sessions. Existing sessions keep the backend that started them.
Crew keeps the same session controls across the selectable backends. Monitor loops, project changes, follow-up cards, and conversation reset work with Claude Code, Codex, and KAS.
Claude tools pre-approved in Claude's own settings bypass Crew approvals, and Codex requires the sandbox, so review the Crew security guidance before switching backends.
Agent backends (Preview)