A Connector is what actually runs a coding agent's process on your behalf. Claude Code and Codex CLI are both fully built out and verified end to end — runs, tool calls, terminal-session sync, and Frontier's own MCP tools all work through either.
Setting one up is a single step: during a new context's guided setup (and again any time from Settings → General → Connectors), tick the installed CLIs you want wired up, pick which one runs by default, and continue. A CLI that isn't installed on your machine shows greyed out until it is.
You can pick a different connector for the whole app, or override it for a single workspace — see Choosing a connector per workspace — from that workspace's own Settings — no need to touch anything else.
A few other connectors exist as an early starting point, not a finished guarantee — see What "scaffolded" means for the newer connectors before you lean on one for something that matters.