Description

When driving opencode acp from ACP client hydra-acp, sending a session/cancel does nothing — the running turn keeps generating until it finishes on its own. The agent responds to the cancel with an error (UnsupportedOperationError, method session/cancel).

Plugins

No response

OpenCode version

No response

Steps to reproduce

No response

Screenshot and/or share link

1. Start opencode acp.
2. From an ACP client, initialize → session/new.
3. Send a session/prompt that runs for a while (e.g. a long shell command or a big generation).
4. While it's running, send session/cancel for that session.
5. The turn keeps running to completion; the cancel has no effect.

Operating System

No response

Terminal

tmux running hydra-acp