There's nothing consistent with Anthropic on this matter.
Their documentation, cli, SDKs, TOS, their public stance - have major contradictions and are subject to so much interpretation that you can't really figure out what's allowed and what's not.
Opencode allowed? No
Custom agentic harnesses allowed? Yes
Opencode is a custom agentic harness? Yes, but not allowed
Which agentic harness is allowed? Can I use a custom agentic harness I develop - say, tmux that runs claude code? We don't know, but you'll know if we ban you
Their documentation, cli, SDKs, TOS, their public stance - have major contradictions and are subject to so much interpretation that you can't really figure out what's allowed and what's not.
Opencode allowed? No
Custom agentic harnesses allowed? Yes
Opencode is a custom agentic harness? Yes, but not allowed
Which agentic harness is allowed? Can I use a custom agentic harness I develop - say, tmux that runs claude code? We don't know, but you'll know if we ban you