Advanced host options

Configure jump hosts, startup commands, forwarding, environment variables, and other OpenSSH settings.

Advanced host options control how OpenSSH starts and carries a connection. Open the host form, choose Advanced, then choose a section. Blank or Default values leave the decision to OpenSSH and your wider SSH config.

Jump and proxy

Option	What it does	Example
Proxy jump	Connects through another SSH host before reaching the destination. Choose a host already known to Bast or enter an SSH alias manually.	`bastion`

This writes OpenSSH's ProxyJump setting. The jump value should be an SSH host alias, not a display label containing spaces.

Session

Option	What it does	Example
Startup command	Runs a command on the server immediately after connecting.	`tmux attach -t main`
Request TTY	Controls whether SSH allocates a terminal. Force yes is useful for interactive startup commands; Disable is useful for non-interactive commands.	`Force yes`

Startup command maps to RemoteCommand. Request TTY maps to RequestTTY force or RequestTTY no.

Forwarding

Option	What it does	Example
Agent forwarding	Lets the remote server use keys from your local ssh-agent. Only enable it for servers you trust.	`Yes`
Local forwards	Makes a service reachable on a local port. Use `local-port destination-host:destination-port`. Separate multiple forwards with semicolons.	`8080 localhost:80`
Remote forwards	Makes a local service reachable from the remote side. Use `remote-port destination-host:destination-port`. Separate multiple forwards with semicolons.	`9000 localhost:3000`
Dynamic forward	Starts a local SOCKS proxy on the given port.	`1080`
Compression	Enables SSH compression. It can help on slow links but usually adds overhead on fast networks.	`Yes`
Keepalive	Sends a server-alive message after this many idle seconds. This can keep connections alive through firewalls and NAT.	`30`

These values map to ForwardAgent, LocalForward, RemoteForward, DynamicForward, Compression, and ServerAliveInterval.

Agent forwarding gives the remote host access to your agent while the session is open. It does not copy private-key files to the server, but a compromised server could use the forwarded agent during that session.

Environment

Environment variables use NAME=value pairs and OpenSSH's SetEnv setting. Separate multiple values with semicolons:

APP_ENV=production; LOG_LEVEL=info

The SSH server can restrict which environment variables it accepts.

Custom flags

Use custom flags for OpenSSH options that do not have a dedicated field. Enter one directive and value per item, separated by semicolons:

TCPKeepAlive yes; ConnectTimeout 10

Bast rejects directives that would redefine the host block or bypass dedicated fields. Avoid duplicating an option already available elsewhere in the form.

CLI equivalents

Every advanced field has a matching option on bast hosts add and bast hosts edit:

TUI option	Set with	Remove or reset with
Proxy jump	`--proxy-jump`	`--clear-proxy-jump`
Agent forwarding	`--forward-agent yes\|no`	`--clear-forward-agent`
Startup command	`--startup-command`	`--clear-startup-command`
Request TTY	`--request-tty force\|no`	`--clear-request-tty`
Environment variable	`--set-env`	`--clear-set-env`
Local forward	`--local-forward`	`--clear-local-forward`
Remote forward	`--remote-forward`	`--clear-remote-forward`
Dynamic forward	`--dynamic-forward`	`--clear-dynamic-forward`
Compression	`--compression yes\|no`	`--clear-compression`
Keepalive	`--keepalive`	`--clear-keepalive`
Custom flag	`--ssh-option`	`--clear-ssh-options`

Repeat --set-env, --local-forward, --remote-forward, or --ssh-option to add more than one value.

bast hosts add "Production web" \
  --hostname prod.example.com \
  --proxy-jump bastion \
  --startup-command "tmux attach -t main" \
  --request-tty force \
  --set-env APP_ENV=production \
  --local-forward "8080 localhost:80" \
  --keepalive 30

Host edits are patches, so omitted options stay unchanged. Use the matching clear option to restore the OpenSSH default or remove existing values, for example:

bast hosts edit Production_web \
  --clear-proxy-jump \
  --clear-startup-command \
  --clear-local-forward

Run bast hosts add --help or bast hosts edit --help for the option list.