There are two separate ways to use more than one device with bb:
- A browser device is a control surface for one bb server. It can view projects, send prompts, and manage threads, but it does not execute them.
- An execution machine runs a host daemon. One bb server can dispatch project sources and thread environments across several enrolled machines.
You can use either story independently or combine them.
In both stories one computer runs the bb server. It stores your threads, the
database, and settings, and every browser and execution machine connects to it.
Pick a computer that stays on, such as a desktop, home server, or VM: while the
server machine is asleep or off, nothing can reach bb and running threads may
stop. Settings → Machines badges it server once several machines are
connected, bb machine list shows server in its Role column, and the server
machine cannot be removed.
The simplest managed route is bb connect. Sign the server in to your bb
account from Settings → bb connect (or bb account login, or
bb connect --code ... with a dashboard code), then open its getbb.app URL.
The server owns the tunnel and reconnects after restart.
For a private tailnet route, keep bb on its loopback default and publish it through Tailscale Serve:
tailscale serve --bg --https=443 http://127.0.0.1:38886
npx bb-app config set BB_APP_URL https://<machine>.<tailnet>.ts.netStart bb with npx bb-app and open the HTTPS URL. Tailscale ACLs are the access
boundary for this route; do not expose the server through Funnel or the public
internet. bb connect URLs require the paired account owner's session.
Existing remote host daemons that target a direct tailnet IP or
http://<machine>.<tailnet>.ts.net:38886 must migrate before restarting an
upgraded server. Prefer pairing bb connect and re-adding the machine from
Settings → Machines so its installer records the account-gated route. The
private alternative is to open bb through the Tailscale Serve URL and re-run
the Add machine installer from there.
For compatibility only, npx bb-app --server-bind-host 0.0.0.0 restores direct
IPv4 network access. The public API is unauthenticated and permits command
execution and file reads, so use wildcard binding only behind a trusted network
boundary and never through Funnel or the public internet.
Inside a container, 0.0.0.0 listens on the container's IPv4 interfaces; the
container runtime must still publish that port to the host (for example,
docker run -p 3000:3000 ...). Host firewall and upstream network rules also
remain separate from bb's bind setting.
Local editor integration is optional. It connects the remote bb page to the
loopback-only helper started by the bb desktop app or npx bb-app on the
computer running the browser. The helper discovers installed editors and opens
paths without exposing its API to the network.
If that browser should open work-host files in its local editor, first make
sure bb is running on the browser device. Verify ssh <work-host> succeeds
there, then map the server/work-host to that SSH target:
npx bb-app client ssh-target set <bb-server-origin> <ssh-target> --host-id <work-host-id>Copy the work-host ID from bb machine list. --host-id may be omitted when
the server has exactly one machine. A browser running on an enrolled execution
machine needs no SSH mapping for that same machine: connected daemons report
their helper ports to the server, and the browser discovers the matching local
helper after you enable integration.
Then open Settings → Files in that browser and enable Local editor integration. The browser may ask once for permission to connect to software on the computer. bb does not request that permission during normal remote page loads; it is only needed for discovering and launching local editors.
If Settings reports that it cannot connect to the helper:
- Confirm the bb desktop app or
npx bb-appis running on the browser device. - Confirm the browser allows local network access for the bb page.
- A helper enrolled with this exact server trusts its origin automatically.
For a separate local bb helper serving a custom HTTPS or Tailscale browser,
configure that exact origin with
npx bb-app config set BB_APP_URL <origin>and restart bb. - Return to Settings → Files and choose Retry.
Phones and tablets need no helper; editor-launch actions are simply unavailable.
The bb mobile app is a client for a bb server; it runs nothing itself. Over bb connect it pairs the same way the desktop app does: the phone enrolls as a connect machine with its own credential, which the getbb.app dashboard lists and can revoke.
- Sign the bb server in to your bb account first (Settings → bb account,
bb account login, orbb connect --code …). - Mint a pairing code for the phone: Settings → Mobile → Add mobile device (QR code plus the code as text, with a countdown), or run
bb connect machine-code(--jsonprints{code, serverUrl, apex, expiresAt}). - In the mobile app, add a server over bb connect and scan the QR code or type the code. Codes last 10 minutes and work once.
The phone keeps its credential in the device keychain and mints sessions from
it; it never holds the server's pairing secret. A session lasts seven days and
renews while the phone is in use. To cut a phone off, revoke it in the
getbb.app dashboard machine list; its session stops working within about 20
seconds. Every phone takes one of
the account's machine slots, so a machine-limit error means an unused device
should be revoked first. On a trusted network the app can also use a direct
server URL (Tailscale Serve or --server-bind-host 0.0.0.0) with the same
caveats as a browser. What the phone cannot do is listed in
platform-support.md.
The built-in Push notifications plugin sends each notification's thread title
and a short plain-text preview through Expo, so a self-hosted server must reach
https://exp.host; it needs no Apple or Google key. An Expo push token can only
send notifications to one app installation, but treat it as private. Device
commands are in the push-notifications plugin skill; the relay URL and proxy
settings are in configuration.md.
The desktop app's Server menu lists "This Mac", every bb connect server on the account, and a custom URL. When you select a remote server, the app stops starting a bb server on this Mac. It starts one again only when you select "This Mac".
To reach bb connect without a local server, the app enrolls itself once as a connect machine. That step needs the local server, so the first switch to a remote server still starts it. The app keeps its own credential, encrypted with the OS keychain, and never holds the server's pairing secret. The app appears in the getbb.app dashboard machine list, where you can revoke it. After a revoke, the app drops the credential and asks the local server again.
A remote server has no realtime link for keybindings and theme. The app re-reads them when it starts, when it becomes active, and every five minutes.
Open Settings → Machines and choose Add a machine. Run the generated one-line installer on the computer that should execute work. Choose Windows in the dialog for a PowerShell command; a Windows machine needs Node.js 22.19 or newer and Git for Windows, and its daemon starts when you sign in to Windows. It installs and enrolls a host daemon; when bb connect is paired, the installer also configures the machine credential used to reach the server through the account gate. Without bb connect, open the server through a Tailscale Serve URL before generating the installer; the loopback listener is not directly reachable from another machine. When bb connect is not paired and the server URL is a loopback or unspecified address, the dialog does not show an installer. It asks you to set up machine access first by choosing the address machines should use. Once access is ready, the dialog also names the server machine the new machine will depend on.
The installer always installs the exact host-only bb-app package exposed by
that server at /install/bb-app.tgz: the host daemon, provider/plugin workers,
native host dependencies, and bundled bb CLI, but no web app or server. A
bb-app already on PATH, or the npm registry, is used only when the server
provides no package. The installer verifies the route's SHA-256 digest and
skips reinstalling an identical artifact. Like /install.sh, the package route
is public. npm installs the package into the machine's bb data directory, not
its system-wide global prefix, so enrollment needs neither sudo nor a PATH
change.
Each joined server gets its own daemon instance, data directory
(~/.bb-machines/<server-host>, override with BB_DATA_DIR when running the
installer), local API port, and launchd/systemd service. The installer persists
the selected port in that data directory. Subsequent runs reuse it; pass
--host-daemon-port <port> to the installer to override the selection. One machine can therefore
serve several bb servers at once, and joining never touches a full local bb
install's ~/.bb. Each instance keeps its own bb-app under that data
directory and self-updates against its own server, so servers running different
bb versions on one machine remain isolated.
On Linux, the installer uses the current user's systemd manager (or a system
unit when run as root on a non-container systemd host). If the user bus is
unavailable on a systemd host, installation fails before enrolling or creating
a unit; rerun it from a systemd user session. In containers and on machines without systemd
as init, the installer runs a detached daemon instead. Set
BB_INSTALL_SKIP_SERVICE=1 only when a detached daemon is acceptable: no
service starts it after a reboot. The temporary daemon used
for a first join is not supervised. When the installer starts a previously
joined daemon without a service, its launcher restarts it after crashes and
self-updates while the launcher remains running.
The installed launchd/systemd service enables --auto-update. If session open
reports a newer server protocol, the daemon downloads the server artifact,
verifies its SHA-256 digest, updates its private install, then exits so the
service manager restarts it. Failed attempts fall back to normal reconnect behavior with a persisted
exponential retry backoff from 5 seconds to 5 minutes. Settings → Machines and
bb machine retry-update <id-or-name> can bypass the current backoff. A daemon
never downgrades itself to an older server protocol. To opt out, remove
--auto-update from
~/Library/LaunchAgents/app.getbb.host-daemon.<server>.plist or
~/.config/systemd/user/bb-host-daemon-<server>.service, then reload the
service.
After it connects:
- To create a project from that machine, choose New project, select the machine, and browse to its folder. To map an existing project there instead, add its path or clone source in project settings.
- Select the machine when creating a thread, or use
bb thread spawn --machine <id-or-name> .... - Inspect enrolled machines with
bb machine list.
Machine names are conveniences and may be duplicated; CLI targeting by name requires an unambiguous match. IDs are always accepted. Removing a machine from Settings stops bb from dispatching new work to it; revoke a lost machine's bb connect access from the getbb.app dashboard as well.
Browser access and execution remain independent: opening bb on a laptop does not enroll that laptop, and enrolling it as a machine does not expose the bb UI.