Pty Relay

pty-relay — remote access to pty sessions

Experimental / pre-release. Protocols and on-disk formats can still change.

What it is

pty-relay gives you remote, end-to-end-encrypted access to pty sessions. A daemon on the machine that owns the sessions forwards Noise-encrypted bytes to clients (a browser, a phone, another terminal); the relay in the middle only sees opaque frames. Two modes, one session protocol:

• Self-hosted (pty-relay local start) — one process runs a lightweight relay + daemon on your machine. No accounts, no email; auth is the #pk.secret fragment in the token URL it prints. Great for a laptop reaching a desktop over Tailscale or a LAN.
• Public relay (pty-relay server signin + server start) — your daemon dials outbound to a multi-tenant relay (relay.pty.computer); email + TOTP auth, account-scoped devices, works across any NAT.

When to reach for it

• You need to attach to / read / drive a pty session that lives on a different machine than the one you're typing on.
• You want to expose this machine's sessions to a browser or a phone.
• You're scripting against a remote daemon: the ls / peek / send / tag / events verbs mirror pty's, but each takes a <host> peer first.

For a session on THIS machine, use plain pty. For "start N sessions on host Y and orchestrate them," that's convoy — pty-relay just moves the bytes.

The idiom (happy path)

Serve this machine's sessions (self-hosted):

pty-relay init                          # one-time secret storage
pty-relay local start --tailscale       # prints a token URL (auth = the #pk.secret fragment)
# background it: add -d, then reattach with `pty attach relay-daemon`

Reach a remote daemon (client):

pty-relay connect <token-url>           # attach to a self-hosted token URL
pty-relay ls                            # known peers + their sessions (fans out)
pty-relay peek --wait "<ready text>" --plain <host> <session> -t 30
pty-relay send <host> <session> --seq "<text>" --seq key:return

Public relay instead of a token URL:

# on the daemon machine:
pty-relay server signin --email you@example.com --relay https://relay.pty.computer
pty-relay server start
# on a client device:
pty-relay client signin --email you@example.com --relay https://relay.pty.computer
pty-relay server hosts --merge          # pull the account's daemons into known-hosts
pty-relay client connect <label>

Footguns (the ones that actually bite)

• Remote session verbs take a <host> FIRST. pty peek <session> is local; the relay equivalent is pty-relay peek <host> <session>. The verbs look identical to pty's but are addressed to a remote daemon — a missing peer arg is the #1 "why is this erroring." (kill only works on ssh:// peers today; other peer kinds return "not yet supported.")
• Three resets at three altitudes — mind the blast radius. pty-relay reset wipes ALL saved credentials on this machine. pty-relay local reset wipes only the self-hosted daemon's state (keeps your public-relay enrollment). pty-relay server reset --email <addr> does neither — it requests a locked-out account-key recovery email. Same word, three meanings; read twice before running the bare one.
• send submits nothing on its own. Like pty, pty-relay send <host> <s> "text" sends the text with no newline. To submit, add a key: --seq "text" --seq key:return. If a fast burst lands before the remote readline is ready, tune --with-delay <sec>; use --paste to wrap a multi-line payload in bracketed-paste markers.
• Remote spawn is OFF by default — that's a feature. Clients can only attach to sessions you already started with pty run. Starting new sessions (connect --spawn) needs the daemon running with --allow-new-sessions; running non-PTY commands (exec / rsync) needs --allow-exec. "It won't let me start a shell remotely" almost always means the daemon didn't opt in.
• The token URL is the credential (self-hosted). Anyone holding the full …#pk.secret URL can connect. Never paste it into a log, an issue, or anywhere that gets indexed. When it matters, keep --tailscale and per-client approval (i.e. don't add --auto-approve), so each new client is confirmed once.

The exact surface

pty-relay --help prints the authoritative command + flag + files/env reference (there is no per-verb --help for top-level verbs — the full usage is the list). The namespaced helps drill in: pty-relay local --help, pty-relay server --help, pty-relay client --help. pty-relay --version prints <semver>+<short-sha>; pty-relay doctor prints a shareable, secret-free environment report. See README.md for the full self-hosted and public-relay quickstarts.