Configuration

simstim reads two files from ~/.config/simstim/ (or $XDG_CONFIG_HOME/simstim/). simstim config path prints where they are.

config.toml

Your preferences. Every key is optional; a missing key takes its default.

Key	Type	Default	What it does
`ui.motion`	string	`"auto"`	Turns the launcher’s animation on or off: “auto” (off inside SSH sessions, Emacs and JetBrains terminals, and with NO_COLOR or TERM=dumb), “on” or “off”.
`attach.detach_key`	string	`"ctrl+\"`	Leaves the session and keeps it running. Press it twice to send it to the agent.
`attach.image_paste_key`	string	`"ctrl+v"`	Uploads the image on the clipboard to the host and pastes its path. Without an image, the key goes to the agent.
`attach.scrollback`	string	`"keep"`	Says what happens to the terminal’s scrollback when you attach again: “keep” replays what you missed after what you saw, “clear” starts from a clean screen.
`agents.inline`	boolean	`false`	Starts each agent that has one in its inline mode, where it draws in the terminal’s normal screen, so your terminal keeps its scrollback: Claude Code’s classic renderer, Codex with –no-alt-screen. Off by default, so each agent starts as its own defaults say. `new --inline` does it for one session.
`keymap`	table	—	Rebinds launcher commands by name (“session: delete”). A value is a key, a list of keys, or "" to unbind. `config keymap` lists the names.
`secrets`	table	—	Names environment variables for sessions, each with a command that prints its value on this computer, such as a keychain or password manager read: OPENAI_API_KEY = “op read op://dev/openai/key”. A session gets one only when asked (`new --secret`, or a host’s secrets). The value goes to that session’s environment and is never stored.

hosts.toml

The hosts you added. host add writes it, and you can edit it by hand. Each host is a [[host]] table.

Key	Type	What it does
`name`	string	Names the host in commands, as in `attach <name>/<session>`.
`ssh`	string	Says how to reach the host: a Host alias from your SSH config, or user@host[:port].
`ssh_config`	string	Adds an SSH config file to read as well, for example a repo’s own.
`labels`	table	Tags the host with key-value pairs of your own, for example provider = “gcp”.
`[provider]`	table	Names a script that starts and stops the host. Optional.
`provider.script`	string	Names a program that starts, stops and reports on the host. It gets the action as its argument and a JSON job on stdin (see examples/providers).
`provider.wake_on_attach`	boolean	Starts the host through the script when it does not answer and you attach or start a session.
`[machine]`	table	Records the VM, container or sandbox that `host create` made for this host. Hosts you added yourself have none.
`machine.provider`	string	Names the provider that made the machine: “lima”, “docker” or “e2b”.
`machine.id`	string	Names the machine as the provider knows it: the Lima instance, the Docker container, or the E2B sandbox ID.
`machine.user`	string	Runs the helper and the sessions on docker and e2b hosts. Lima hosts use the user from Lima’s SSH config.
`machine.image`	string	Names the container image a docker host was made from.
`machine.template`	string	Names the E2B template a sandbox was made from. It sets the sandbox’s CPUs and memory.
`machine.idle_stop`	string	Sets how long the host may go with no client connected and no session working before it stops: a duration such as “30m”, or “never”. A Lima VM powers itself off (30m by default; it needs passwordless sudo). An E2B sandbox pauses when its lease runs out (15m by default).
`machine.busy_lease`	string	Sets how long an E2B sandbox keeps running after the last client goes, while a session is working (60m by default).
`machine.token_command`	string	Prints the E2B API key, for example a read from your keychain. It is used when E2B_API_KEY is not set and the E2B CLI is not logged in. The key is never written down.
`machine.stdin`	string	Says how keys reach an E2B sandbox: “send” (one request for each chunk, the default) or “stream” (one long request; not yet proved on E2B’s servers).
`secrets`	array of string	Lists secrets from config.toml that every new session on this host gets, for example [“ANTHROPIC_API_KEY”]. `new --secret` adds more.