Persistence and remote access

Preview docs describe unreleased preview builds. Stable docs remain at /docs/.

Herdr keeps panes running in a background server. Your terminal client can detach and reconnect later.

For the local, SSH, and herdr --remote workflows, see How to work with Herdr.

Detach and reattach

Detach the client with ctrl+b q; panes and agents keep running. Reattach by running herdr again. Stop the session and its panes with herdr server stop.

When Herdr starts again after a full server stop, it restores the saved session shape. For what survives detach, server restart, screen history replay, native agent session restore, and live handoff, see Session state and restore.

Named sessions

Use named sessions when you want independent Herdr servers.

herdr session list
herdr session attach work
herdr session attach side-project
herdr session stop work
herdr session delete side-project

A named session has its own panes, tabs, workspaces, sockets, and runtime state. It still shares the same global config file.

Use --json for scripts:

herdr session list --json
herdr session stop work --json
herdr session delete side-project --json

Remote attach over SSH

There are two remote modes; How to work with Herdr compares them. SSH to the server and run herdr there for the tmux-style path. Or attach through SSH from your local machine:

herdr --remote workbox
herdr --remote ssh://you@server:2222

In this mode your local Herdr is a thin client. It connects over SSH, starts or attaches to the remote Herdr server, and streams the UI back to your local terminal. Because the client runs locally, Herdr can bridge local desktop features such as image clipboard paste into the remote session by copying the image to a remote temp file and pasting that path.

By default, herdr --remote uses your local Herdr keybindings for that attach. This keeps local muscle memory even when the remote server has different config. The local keybindings are a snapshot from attach time; detach and reattach after editing local keybindings. Use --remote-keybindings server when you want the remote server config instead. Local custom command keybindings are not sent, because those commands would run on the remote host.

For repeat targets, use your SSH config:

Host workbox
  HostName server.example.com
  User you
  Port 2222

Then attach with:

herdr --remote workbox

Remote attach supports Linux, macOS, and Windows local clients connecting to Linux or macOS hosts on x86_64 and aarch64. Herdr checks the remote platform, prefers a matching herdr already on the remote PATH, then checks common direct, Homebrew, mise, and Nix profile install paths. If no matching binary exists, interactive runs prompt to install one to ~/.local/bin/herdr; non-interactive runs fail instead of modifying the host. If ~/.local/bin is not on the remote PATH, Herdr warns after install. Windows is not supported as the remote host.

By default, herdr --remote runs remote setup and the bridge through a temporary SSH config that includes your SSH config first, then adds fallback keepalive settings. Existing user keepalive settings win. Linux and macOS clients also use a private per-attach control socket for connection reuse; Windows OpenSSH does not. Set [remote].manage_ssh_config = false to use plain ssh without Herdr’s generated config or control socket.

Remote attach uses your normal OpenSSH authentication. If the target uses a passphrase-protected key in a non-interactive shell, script, CI job, or mobile terminal that cannot show the passphrase prompt, load the key into ssh-agent first:

ssh-add
herdr --remote workbox

For any remote authentication failure, verify plain SSH access first with ssh workbox, then run herdr --remote workbox again.

By default, remote attach uses the normal restart/stop flow if it needs to replace or restart a running remote server. To opt into experimental live handoff for a supported running remote server, pass --handoff:

herdr --remote workbox --handoff

If you SSH into the server first and run herdr there, Herdr runs entirely on the server. That mode is useful and simple, but it cannot access your local desktop clipboard beyond normal terminal text paste.

When your local and remote platforms match, Herdr can copy the current local binary for direct installs. For Homebrew, mise, and Nix installs, or when the platforms differ, it downloads the matching release asset for the current client version from https://herdr.chefgroep.nl/latest.json.

For local builds or custom binaries, set HERDR_REMOTE_BINARY to a local file path before running remote attach.

HERDR_REMOTE_BINARY=target/release/herdr herdr --remote workbox

Mobile access (Moshi)

On iPhone, use a mobile terminal such as Moshi against the same SSH (or mosh) host where Herdr already runs your agents. Herdr stays the server-side multiplexer; Moshi is the phone UI.

Typical flow:

1. Run agents under Herdr on the host (herdr or herdr session attach).
2. Reach the host over SSH or mosh (Tailscale works well for fleet hosts).
3. Attach from Moshi to the shell or session you need.

Load passphrase-protected keys into ssh-agent before connecting from Moshi if the phone cannot show an interactive passphrase prompt.

When many hosts are online, set unique HERDR_HOST_NAME values and use the Fleet ops and gateway docs (/v1/ops/context or the Fleet Ops Bar) to see what runs where before attaching from a phone. Full Moshi setup notes live in Moshi (iPhone) with Herdr.

Remote named sessions

Use --session with --remote to attach to a named session on the remote host:

herdr --remote workbox --session agents

Direct terminal attach

Full Herdr attach opens the whole workspace UI. Direct attach opens one server-owned terminal in your current terminal.

Direct terminal attach is Unix-only in the Windows beta.

Attach by agent target:

herdr agent attach reviewer

Attach by terminal ID:

herdr terminal attach term_abc123

Direct attach streams the current rendered terminal state, then live ANSI frames. Input goes straight to that terminal.

Detach with ctrl+b q. Send a literal ctrl+b with ctrl+b ctrl+b.

Only one writable direct attach client owns input and resize for a terminal. Use --takeover to replace an existing owner:

herdr terminal attach term_abc123 --takeover

For third-party bridges that only need rendered terminal bytes, use a read-only terminal session observer:

herdr terminal session observe w1:p1 --cols 120 --rows 40

It prints newline-delimited JSON terminal.frame records with base64 ANSI bytes, then a terminal.closed record when the server closes the stream. Multiple observers can watch the same terminal without taking input, resize, scroll, or takeover ownership.

For an interactive bridge, use a writable terminal session controller:

herdr terminal session control w1:p1 --takeover --cols 120 --rows 40

Control mode prints the same newline-delimited frame records and reads newline-delimited JSON commands on stdin. terminal.input sends text or base64 bytes, terminal.resize changes the controller viewport, terminal.scroll scrolls the attached viewport, and terminal.release closes the controller. Only one controller owns input and resize at a time.

Single-process escape hatch

Use --no-session to run Herdr without the background server/client split:

herdr --no-session

This is mainly an escape hatch for debugging or compatibility. The default persistent session mode is the normal path.