Warp Documentation
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SSH

When you SSH into a remote box, you get all the features of Warp without any configuration on your part. The input editor, auto-completions, and history search work the same, regardless of machine.
Limitations of SSH (as of February 2022):
  • Warp specific features like Blocks are currently supported only for bash or zsh.
  • If you're using a different shell, you'll want to use /usr/bin/ssh directly (see below for more details).
  • For zsh, xxd is required to bootstrap warp.
If you're using zsh on the remote host, we create a temp folder to act as the ZDOTDIR during the bootstrapping process and remove it when the shell is set up.
SSH

Implementation

We create a wrapper (around /usr/bin/ssh) to set up the shell for Warp's feature set. We authenticate normally using /usr/bin/ssh, and bootstrap the remote shell to work with Warp Blocks and the Input Editor. You can opt out of this functionality by invoking /usr/bin/ssh directly.
  • Warp takes over the prompt which enables us to build a modern input editor.
  • Warp configures histcontrol to ignore commands with leading spaces. We do this so our bootstrapping code does not clutter the history.
You can see the SSH wrapper by using which warp_ssh_helper in Zsh, type warp_ssh_helper in Bash.

Troubleshooting

channel 2: open failed: connect failed: open failed

If you're seeing these errors, you may have some config on your server (usually in /etc/ssh/sshd_config) preventing Warp's ControlMaster connection from working. In this state, completions that require information from your remote host won't work and your history also won't work.
You should ensure that MaxSessions is either commented out or is at least 2.
Write access in /etc/ssh/ typically requires sudo access. After any edits, you'd also need to restart the sshd daemon.