Sailbox is a Linux VM on the Sail platform: a full cloud environment
designed for long-horizon agents. Create one, then run commands, transfer
files, expose ports, and checkpoint or pause it. For a guided walkthrough, see
the Sailboxes guide; this page is the API reference. In a language
without a Sail SDK, reach for the HTTP API.
Sync and async
- Python methods are synchronous, and every method that does I/O has an
async twin under
.aio(await sb.exec.aio(...)). Handles returned by async calls are already async:await sb.exec.aio(...)returns a process whose own methods (wait,cancel,resize) are awaited directly, with no.aio. The one exception to the rule isshell, which is sync-only since it drives your local terminal. - TypeScript is async-only: every operation returns a
Promise. - Rust is async-only, on a Tokio runtime. Synchronous code can drive any
call with
sail::block_on.
Naming
The three SDKs expose the same operations with each language’s conventions: Python issnake_case with keyword arguments, TypeScript is camelCase with
options objects and unit-suffixed durations (timeoutSeconds), and Rust pairs
a Sailbox object with explicit argument structs. Parameter tables on this
page use the Python spelling; each section’s TypeScript signature shows the
real names. Every TypeScript static also accepts an explicitly constructed
client in its options object (see
Configuration); the signatures on this page omit it.
Attributes
EverySailbox carries its identity and lifecycle state: sailbox_id,
name, and status (running, paused, sleeping, failed,
terminated). A Sailbox returned by get or
list also carries the monitoring snapshot from that fetch:
owning app, image, configured and observed resource usage, timestamps, and its
egress policy (see snapshot fields).
Treat sailbox_id as the durable handle: store the id, and turn it back into
a usable Sailbox any time with Sailbox.get (which fetches
fresh state), or without a network call via Sailbox.from_id /
Sailbox.fromId / client.sailbox(id). The get result reflects the
Sailbox at the time of the call; call it again for fresh state.
Sailbox.create
size is a resource ceiling, not a billing reservation; ongoing Sailbox
billing uses your actual CPU, memory, and disk consumption. Each size also has
a one-time creation charge. memory_limit_gib and disk_limit_gib optionally tune the
size’s ceilings, in whole GiB within the size’s range; raising a ceiling does
not increase the ongoing rate, and lowering one caps what the Sailbox can use.
See Sailbox pricing.
Volumes are currently in Alpha. To pilot them, reach out in the Sail
Slack.
Sailbox.
Raises a creation error when Sail cannot create the Sailbox, a
permission error on 401/403, and an invalid-argument error for an unknown
size or invalid ingress ports and
volume mounts.
In Python, pin
image=sail.Image.debian_arm64 or debian_amd64 when using
@sail.function; those images match your local Python version so function
bytecode can deserialize in the guest. See Images &
Functions.SSH
For a quick shell, useshell() or sail box shell: it streams a
PTY over the same channel as exec and uses no ingress port. SSH is opt-in,
for when you want a standard SSH endpoint: a devbox, your own client, scp,
or port forwarding.
Enable SSH after create with enable_ssh, which trusts
your org’s SSH certificate authority, starts sshd, and exposes guest port 22
as raw TCP. See the SSH access guide for the
access model, how to connect, and source restrictions.
visibility chooses who may operate the Sailbox, fixed for its life. "org",
the default, lets any credential in your org exec, copy files, SSH into, or run
lifecycle operations on it. "private" restricts all of that to you: only your
credential can operate the Sailbox (your org can still see it in listings, but
not act on it). It requires an API key minted by your user, not a service key. Org admins can override the restriction for exec, file,
setting a wake time, and the pause, sleep, resume, terminate, and upgrade
operations by setting SAIL_OWNER_OVERRIDE_REASON (or the
X-Sail-Owner-Override-Reason header on raw HTTP calls); exposing or removing
listeners, checkpoint, and restore stay creator-only. Every override
requires that reason, and your org’s audit log records it. SSH has no override:
a private Sailbox’s SSH server
accepts only its creator’s certificates. From the CLI, pass
--visibility private to sail box create.
Sailbox.get
Sailbox: run commands,
read and write files, and manage listeners on it directly. get never wakes a
paused or sleeping Sailbox. Operations that run inside it (commands, file
reads and writes, network traffic) wake a sleeping Sailbox on demand; a
paused Sailbox rejects them until you call resume. The returned object
reflects the Sailbox at the time of the call, so call get again for fresh
state. Unknown and wrong-org ids both raise a not-found error, so you cannot
tell an unknown id from one owned by another org.
In Rust, client.sailbox(id) binds the id without a network call; fetch
current state with sb.info().
Sailbox.list
limit of them) is collected; limit caps
the total returned, bounding the fetch for large orgs. (Rust’s
list_sailboxes returns one page with its envelope.) app_id filters by the owning
app id (resolve a name through App.find first).
search filters by name substring. order is "newest_active" (most recently
active first, the default) or "newest_created" (newest-created first). Use
Sailbox.list_page to control paging yourself or to
read the pagination envelope.
Sailbox.list_page
Sailbox.list, but returns a SailboxPage with
the Sailboxes plus the limit/offset/total/has_more pagination envelope.
(In Rust, list_sailboxes always returns the page.)
exec
timeout ends the pauses,
and a stream you are not reading keeps only its most recent 1 MiB. To get every
byte, start reading right after exec returns. output_mode and
output_buffer_bytes (outputMode and outputBufferBytes in TypeScript)
change that; what counts as reading a stream differs by
language. See Exec process.
A string command runs via /bin/sh -lc, so shell syntax (pipes, redirects,
&&) works. Python and TypeScript also accept an argv list, which execs the
program directly with no shell interpretation, and Rust separates the two as
exec_shell (string) and exec (argv).
Python’s exec additionally accepts a @sail.function-decorated Python
callable; it then blocks and returns the function’s return value directly. For
a function, output_mode must stay auto, and the function’s complete encoded
response (its serialized return value, captured stdout and stderr, and any
error details, as encoded on the wire) must fit output_buffer_bytes; a larger
response raises SailboxFunctionSerializationError. A second call with the same idempotency_key while the function runs takes over its output, and the earlier call may then fail to decode its result. See
Images & Functions.
resume.
run
exec followed by wait(). A string command runs
via /bin/sh -lc; a list is exec’d directly. cwd sets the working directory
for string commands only (like exec, an argv command with cwd raises).
user picks the user the command runs as (see exec).
By default a nonzero exit code returns normally on the result; check
exit_code. With check set, a nonzero exit or a timeout raises
CommandFailedError carrying the completed result instead. (Rust reports
everything through the returned ExecResult.) A command that exceeds
timeout is killed and reports timed_out on the result; without check,
a timeout alone does not raise.
idempotency_key makes a retried run wait on the original command instead
of launching it again, so a control-loop retry cannot double-execute. While
the first call is still running, a second call with the same key takes over
its output stream, and the earlier call’s result may come back truncated.
In TypeScript, aborting signal force-cancels the remote command and rejects.
The result’s stdout and stderr hold only the most recent
output_buffer_bytes (outputBufferBytes in TypeScript) of each stream
(1 MiB by default, up to 64 MiB), with
stdout_truncated and stderr_truncated set when older output was dropped;
the command never pauses for unread output. To get every byte, use
exec and read the
stream (see Exec process). The interactive and detached
exec options (open_stdin, pty, background) and the pipe output mode
are not available on run.
shell
command, runs a login shell; pass command to run that
under a pty instead (e.g. a REPL or vim). Keystrokes (including Ctrl-C,
Ctrl-Z, and Ctrl-D) reach the remote process, its output renders locally, and
terminal resizes propagate. Blocks until the remote process exits and returns
its exit code. Requires an interactive local terminal (stdin and stdout must
be TTYs) on a Unix machine, so it suits CLIs and dev tools rather than
server-side harnesses.
This is the equivalent of ssh-ing into the Sailbox, without running an SSH
server. shell overrides the login shell (default $SHELL, else
/bin/bash); it is ignored when command is given. env adds environment
variables to the session, with the same precedence and reserved names as for
exec.
The session runs as the image’s USER when the image sets one, root
otherwise: the same identity exec uses. user runs it as someone
else instead (a user name or numeric uid, optionally with a group after a
colon, like "alice", 1000, "alice:staff"); user="0:0" is always root.
A user other than "0:0" requires a Sailbox whose guest honors requested
users; on older Sailboxes the session fails until upgrade is
called.
While the session is open, browser opens and localhost servers in the Sailbox are
forwarded to your machine. When a program in the Sailbox opens a browser (a login
like claude login or gh auth login), the page opens in your local browser,
and a login that redirects to a localhost callback completes end to end. A
server the Sailbox starts on localhost keeps serving inside the Sailbox the whole
time (code and agents there reach it as usual); while the shell is open it is
also mirrored to the same port on your machine, unless that port is already in
use locally. The mirror lasts only for the session. Files dragged onto the terminal upload
into the Sailbox and paste as their guest paths, and Ctrl+V forwards your
clipboard. On devbox images the clipboard is two-way: a pasted image or text
lands on the Sailbox’s clipboard, and text copied inside the Sailbox comes back to
yours. Other images upload a pasted image as a file and paste its path. Pass
no_forward=True (TS noForward) to turn all of it off, for example for an
untrusted or automated session. Plain
exec forwards nothing; for the same forwarding on sail box exec --tty, see
the CLI reference.
The fs namespace
File and directory operations live under thefs namespace: sb.fs in Python
and TypeScript, sb.fs() in Rust. Reads and writes stream bytes to and from
the guest, and Python paths accept str or PurePosixPath. The directory
helpers mkdir (creates missing parents), remove (deletes recursively),
and exists behave like mkdir -p, rm -rf, and test -e, and
upload_dir and download_dir transfer whole directories.
Writes give what they create to the image’s USER by default, or to root
when the image sets none. That is the same identity exec runs
commands as, so an uploaded file is usable by the code in the Sailbox. Reads
and the directory helpers act as root by default, so they work on any path.
Each operation except the reads and the directory download takes an
optional user in the Docker
USER syntax: a user name or numeric uid, optionally with a group after a
colon ("alice", 1000, "alice:staff"). The other directory helpers
then run as that user, with its permissions enforced. The writes give what
they create that owner (like COPY --chown) while the write itself always
runs as root, so it works even where the owner cannot write. "0:0" is
always root, and the directory upload gives what it creates the same way.
Reads and the download take no user: a user only decides which paths an
operation may touch and who owns what it creates, a read creates nothing in
the Sailbox, and a download reads any path as root the way the reads do.
A user other than "0:0" requires a Sailbox whose guest honors requested
users; on older Sailboxes the operation fails until upgrade
is called.
fs.read
read_stream. Raises a file-not-found error if the path does
not exist.
fs.read_stream
for and async for.
fs.write
path must be absolute. To write
several files in one call, see fs.write_files.
fs.write_files
files maps each absolute guest
path to its contents; every file gets the same create_parents, mode, and
user as fs.write. In Rust, files is any iterator of path and
contents pairs, borrowed or owned: each entry is streamed from the buffer you
pass, not copied first. How a batch runs, what happens on a failure,
and when to stream instead are covered in
Filesystem.
fs.write_stream
write and
confirm with finish. Only finish commits the write; a writer that goes
away without finishing (an explicit abort, an exception, or dropping it)
cancels the transfer instead, and the guest file state is then unspecified.
Use it when your data arrives incrementally (streaming logs, assembling an
archive on the fly) rather than from a source write can consume
whole. The options match write, including user for the written
file’s owner. Python makes the file mode explicit and defaults it to 0o644.
fs.mkdir / fs.remove / fs.exists
mkdir creates a directory and any missing parents (like mkdir -p) and is a
no-op if it already exists. remove deletes a file or a whole directory tree
(like rm -rf) and is a no-op if the path is already absent. exists reports
whether a path exists; it follows symlinks (like test -e), so a dangling
symlink reports false even though fs.ls lists it. A failure (for
example a permission error) raises with the guest’s stderr in the message.
With user, the helper runs as that user with its permissions enforced:
mkdir leaves the created directories owned by it, remove can only delete
what that user may delete, and exists reports what that user can observe (a
path it lacks permission to reach reports false).
fs.ls
DirEntry records. A missing path raises, as does a path that is not
a directory and a listing too large for the exec output cap. An entry whose
name is not valid UTF-8 fails the listing, since the path API cannot address
it. With user, the listing runs as that user, so a directory it cannot read
raises a permission error.
fs.upload_dir
USER (root when the image sets none or its identity cannot be
read). A user (the same syntax the other operations take) gives the
entries to that user instead, like COPY --chown; it must exist in the
Sailbox, and like the other operations’ user it requires a Sailbox whose
guest honors requested users. The Sailbox’s image must provide tar and
gzip, which the transfer uses to ship the directory as one compressed
archive; the default images do.
fs.download_dir
/proc or /sys hold files that cannot
be read as plain data, and downloading them fails. A file that is being
written while the download runs is captured as it is at that moment, the
way copying a live file would; download after writers finish for a
consistent copy. On Windows, a directory that contains symbolic links
cannot be downloaded, since Windows restricts creating them. The Sailbox’s
image must provide tar and gzip, which the transfer uses to ship the
directory as one compressed archive; the default images do.
listener / listeners
ingress_ports, or at runtime with
expose/unexpose (see Networking).
enable_ssh
sshd, and exposes guest port 22 as raw TCP
once the CA-only server owns it. See the
SSH access guide for the access model and
how to connect. By default it blocks until SSH is reachable, up to timeout
seconds, and returns the endpoint to dial; pass wait=False to skip the probe
and return nothing.
allowlist restricts which source addresses or ranges may connect to port
22, replacing any existing restriction. Left empty, a first enable opens the
port to any source, and a re-enable keeps the existing restriction. Disabling
SSH removes the port-22 listener along with its restriction, so enabling again
starts fresh.
checkpoint
name sets a display name for the handle. ttl_seconds (ttl in Rust),
when set, must be > 0 and overrides the server’s default retention window. Set it when you
keep a checkpoint to reuse as a template, so the handle does not expire while
you still need it.
The returned handle carries expires_at, a timestamp (datetime in Python,
Date in TypeScript, OffsetDateTime in Rust) for when the checkpoint expires:
seven days out unless you asked for a different window. Starting a Sailbox from
it after that fails.
from_checkpoint
name, from a durable checkpoint
handle returned by checkpoint. The new Sailbox gets a fresh network identity;
existing TCP connections do not carry over, and ingress ports are not
inherited. It keeps the original’s egress policy. timeout (seconds, > 0
when set) bounds the call, since a
restore can block for many minutes while the new Sailbox queues for
capacity. A call that times out fails, and the restore may still finish
in the background; the new Sailbox then shows up in
Sailbox.list. Omit timeout to wait without a client-side
bound.
The new Sailbox restores the memory saved in the checkpoint as well as the
writable disk, so processes the original was running carry on there. Commands
you started with exec stop in the new Sailbox, though their writes up to the
checkpoint are kept, and one you started with the background option keeps
running there. Start the other commands you need again.
Sometimes the new Sailbox comes up cold instead, with the disk intact and
nothing running. Write code that expects a cold start.
upgrade
UpgradeResult: applied is true when the upgrade happened
immediately (the Sailbox was running) and false when it will apply at the next
wake, and status is the Sailbox’s lifecycle status after the call.
Already-up-to-date Sailboxes report immediate success without rebooting.
pause / sleep / resume / terminate
pausecheckpoints and pauses the Sailbox in memory until you explicitly resume it. Commands and network traffic do not wake a paused Sailbox.sleepcheckpoints the Sailbox to disk; inbound traffic, an operation, or an explicitresumewakes it. An optional wake time schedules a wall-clock wake (see Lifecycle).resumewakes a paused or sleeping Sailbox. Raises a not-found error if the Sailbox is terminated.terminatepermanently ends the Sailbox. Idempotent: terminating an already-terminated Sailbox succeeds.
Volumes
AVolume is an org-scoped shared filesystem (NFS) that can be mounted into
one or more Sailboxes. Resolve one by name, then pass it (or its id) in the
volumes mapping of Sailbox.create, keyed by the
absolute guest path to mount it at:
findlooks up a volume by name;mint_if_missingcreates it when no volume with that name exists.listreturns the org’s active volumes, newest first;max_objectscaps the count.deletedeletes the volume. Withallow_missing, deleting an already-deleted volume succeeds instead of raising a not-found error.
volume_id, name, backend, status, and
created_at / updated_at timestamps.
Egress policy
An egress policy limits which hosts a Sailbox can connect to and can add credentials to the HTTPS requests it sends. It is chosen at creation withegress_policy (TypeScript egressPolicy, Rust
CreateSailboxRequest.egress_policy) and can be replaced at any time:
egress_policy at creation and set_egress_policy take the same values:
- a saved
EgressPolicyfromEgressPolicy.createorEgressPolicy.get, its id string, or a summary row fromEgressPolicy.list()(RustEgressPolicySpec::Named, or(&policy).into()). - a document:
EgressPolicy.allow_only(hosts)(RustEgressPolicyDocument::allow_only) to reach only the listed destinations,EgressPolicy.no_egress()(Rustno_egress) for no outbound connections,EgressPolicy.no_network()(Rustno_network) for no network at all, or the JSON document itself as adict(TypeScript object, RustEgressPolicyDocument). A document that references a secret must be saved first. At creation, an invalid document fails the call withInvalidArgumentErrorbefore a Sailbox is created, and omitting the argument (or passingNone) lets the Sailbox reach any host.
no_network() cannot be combined with ingress_ports at creation, and is
refused with ApiError while the Sailbox exposes ports or SSH. The other
documents can be used alongside exposed ports and SSH. from_checkpoint
copies the source’s policy.
set_egress_policyreplaces the policy and returns the new one.clear_egress_policyremoves all restrictions and rules and returns the new policy, whose document is{}.egress_policyis the policy the Sailbox runs under, as aSailboxEgressPolicy: thedocumentplus thepolicy_idandnameof the saved policy it came from (Nonefor an inline document).get,list,set_egress_policy, andclear_egress_policyfill it; the handlecreatereturns does not carry it.
EgressPolicy and
Secret classes (Client methods in Rust). The
egress policy guide covers the document, and
credential injection walks through the secrets flow
in every language.
Supporting types
Field names below use the Python spelling; TypeScript exposes the same fields in camelCase.DirEntry
One entry in a directory listing fromfs.ls. Reported for the entry
itself, so a symlink’s type is "symlink" regardless of what it points at.
IngressPort
A guest port to expose for ingress. In Python,Sailbox.create
also accepts a bare int as shorthand for IngressPort(port) (an HTTP port).
Address and range entries work for HTTP and TCP listeners. App-name entries
match authenticated traffic from another Sailbox and work on HTTP listeners
only, because raw-TCP connections carry no source app identity (so a
"tcp"
allowlist must contain only addresses and ranges). An entry that reads as an
address or a range is taken as one, so an app name cannot read as either, and
cannot contain a /. An address must not carry an IPv6 zone, such as
fe80::1%eth0, which names an interface on one machine rather than a source.
To send that authenticated traffic, pass headers=sail.ingress_auth_headers()
on the request when calling from inside a Sailbox. From the host, fetch a
specific Sailbox’s headers with sb.ingress_auth_headers() (this needs an
organization-scoped API key).
Reserved ports: guest port 22 cannot be an HTTP port (expose it as tcp
for SSH) and 10000/10001/15001/15002 are reserved for Sail’s
in-guest services. Leaving allowlist empty normally makes the port publicly
reachable, with one exception: for well-known database, cache, and search
ports (e.g. 5432, 6379), a raw-TCP expose with no allowlist is rejected,
so you can’t accidentally publish an unprotected Postgres or Redis to the
whole internet. To make one of these ports public on purpose, say so
explicitly with allowlist=["0.0.0.0/0", "::/0"].
Exec process
A handle to a command running in the Sailbox (ExecProcess in Python,
ExecProcess in TypeScript and Rust). The command runs inside the Sailbox, and
a temporary network interruption does not kill it. Sail may reattach after an
interruption, but reattachment does not guarantee exact output replay. Closing
the handle abandons the live attachment without killing the command.
Live output. stdout and stderr are iterators (for in Python,
for await in TypeScript, next().await in Rust). The Python and TypeScript
iterators yield text, incrementally decoded from the raw stream (a multibyte
character split across chunks arrives whole); the raw byte stream is available
as stdout_bytes / stderr_bytes in Python, .raw() on the stream in
TypeScript, and is what the Rust reader yields directly. Bytes travel exactly
as the command wrote them (escape sequences and binary payloads included).
Output limits. Each stream has a buffer, 1 MiB by default.
output_buffer_bytes (outputBufferBytes in TypeScript) sets its size, from
64 KiB to 64 MiB. The output_mode option (outputMode in TypeScript) sets what happens when
a buffer fills.
This applies to commands started without a pty; a pty command always
behaves like tail.
auto, the default. If you are reading a stream and fall behind, the command pauses when the buffer fills and resumes as you read, like a pipe. If you are not reading a stream, the command never pauses and the stream keeps only its most recent bytes. Reading a stream is how you get every byte, and it slows the command when you cannot keep up.pipe. The command pauses when either buffer fills and stays paused until you read that stream, so nothing is lost while you are late to start reading. Read both streams, or the command stays paused on the one you ignore;2>&1or2>/dev/nullin a shell command is the easy way out. Once you release a reader, its stream goes back to keeping only its most recent bytes.wait()without a reader waits for as long as the command stays paused. Not available with apty.tail. The command never pauses for you. Each stream keeps only its most recent bytes, even while you are reading it, so a slow reader skips output without notice (a RustStreamReadercan checktook_drop).stdout_truncatedandstderr_truncatedsay only that the result holds less than the command wrote, which is also the case after a reader consumed everything.
cancel(), and the exec
timeout, end every pause: from then on each stream keeps only its most recent
bytes, so a reader more than a buffer behind skips ahead. A command that ignores
the cancel signal keeps running that way; cancel with force to stop it. The
command keeps its original timeout. If a handle attaches to a command launched
earlier under the same idempotency_key, that handle’s pause deadline starts
when the attachment succeeds, so it can release the pauses one full timeout
after that; cancel() and close() release them at once. A command that
never pauses for you still runs no faster than your connection carries its
output; when output outruns the connection, the command pauses on the Sailbox
until the backlog drains.
With auto, start reading right after exec() returns to get every byte
(what starts a read differs by language; see below). You can read stdout
without holding stderr, or the reverse. The stream you are not holding keeps
its most recent bytes and never pauses the command when it fills, and a reader
that starts on it late begins with whatever is still held; with pipe, that
is everything. If you hold both readers, read them at the same time, each from
its own thread or task
(asyncio.gather in Python, Promise.all in TypeScript, two tasks in Rust).
The exit code is available from poll() (Python also has exit_code) as soon
as the streams end.
Claiming and releasing a stream. Each stream can be read once; a second
attempt fails (InvalidArgumentError in Python and TypeScript,
SailError::InvalidArgument in Rust), before or after the first reader is
released. After release, Sail again keeps only the stream’s most recent bytes,
in every mode.
- Python. Accessing
proc.stdoutorproc.stdout_bytes(and thestderrtwins) claims the stream and returns a generator; from that access on the command pauses rather than lose output (see Output limits for the exceptions). The stream is released when the generator ends, when you callclose()on it (awaititsaclose()for an async generator), or when nothing references it any more (aforloop overproc.stdoutdrops it when the loop ends, including bybreak). To stop early on purpose, keep the generator in a variable and callclose(). - TypeScript. Accessing
proc.stdoutorproc.stderrclaims nothing. The stream is claimed when iteration starts (for await,.raw(),.text(),.bytes()) or when you call.toReadable(). It is released when the iteration finishes or you leave it (break,return, or a thrown error insidefor await), when.text()or.bytes()reaches the end, or when theReadableis destroyed (released at once, even while a read is waiting for output). - Rust.
reader(OutputStream::Stdout)orreader_async(...)claims the stream. It is held while the reader value exists and released when the reader is dropped.
close() on the handle, or your process exiting, releases
both streams. The command keeps running and never pauses. wait() fails after
close() unless it already resolved a result. If the connection to the
Sailbox is interrupted, the command keeps
running and does not pause while Sail reconnects; output produced in the
meantime can be missing, and stdout_truncated / stderr_truncated report
when that happened. Reattachment is best-effort, not an exact replay.
A pty command never pauses: Sail keeps only its most recent output, up to
the buffer size, so a reader further behind than that misses older output. Use
resync() to
ask the command to repaint its current screen.
stdin. With open_stdin=True, write to the command’s stdin and deliver EOF
by closing it (Python proc.stdin.write/close, TypeScript
writeStdin/closeStdin, Rust write_stdin/close_stdin). Writes block
(like a pipe write) while the command is not reading. Writing to a completed
command, or after the command closed its stdin, raises a broken-pipe error.
wait() waits for the command to finish and returns its
result, holding each stream’s buffer, its most recent
output (see Output limits above). It never pauses the command itself and
can be called while a reader is still open; with pipe, it waits for as long
as an unread stream keeps the command paused. After close() it fails,
unless a result was already resolved; a repeat call returns that result. For
foreground execs it waits
for the command to finish; for background execs it waits only for the detached
launcher. An exec that ended without a real exit code (the
machine hosting the Sailbox was lost before the command finished) raises a
host-lost error instead of returning a result.
In Python and the sail CLI, Ctrl-C during a wait additionally sends
SIGINT to the remote command and resumes waiting, and a second Ctrl-C
escalates to SIGKILL; terminal-facing surfaces forward the interrupt like
a local foreground job. The TypeScript and Rust libraries leave process
signal handling to your application; wire the same behavior with
cancel if you want it.
poll() (Rust: try_wait) returns the exit code once the output stream
has ended, else nothing. It never blocks and never drops output, so it is the
way to get the exit code after reading the streams yourself. If the connection
was lost for good mid-command, the stream ends early with the outcome still
unknown: poll() stays empty and wait() fetches the result Sail recorded.
cancel() signals the guest command: SIGINT by default, SIGKILL with
force. Idempotent on the server. If the Sailbox is sleeping, cancel wakes it
to deliver the signal; if you paused the Sailbox, resume it first (cancel
raises rather than waiting, since the guest cannot receive the signal while
paused).
close() abandons the handle without killing the command. It releases both
streams. The command keeps running and never pauses, and Sail keeps only the
most recent output of each stream. Call cancel() instead if the command
should stop. wait() fails after close() unless it already resolved a
result.
resize(cols, rows) adjusts a pty command’s window.
resync() asks a pty command to repaint its current screen on the output
stream. A command runs at full speed and never waits for a slow reader, so if
you render its output yourself and fall far behind, the oldest output is dropped
and the screen can end up garbled. Call resync() to receive the current screen
instead of a broken, partial one. It does nothing for a command with no pty.
The interactive shell helper calls it for you.
Exec result
The output of a completed exec (ExecResult in Python, ExecResult in
TypeScript and Rust).
Listener
An exposed guest port and how to reach it. Every listener carries its guest port,protocol, route status, and a typed
endpoint: an HttpEndpoint (with url) or a
TcpEndpoint (with host/port), absent until routable. In
TypeScript the endpoint is a union discriminated on kind; in Rust it is the
ListenerEndpoint enum returned by listener.endpoint(). Listeners are
snapshots; re-fetch with sb.listener(guest_port).
HttpEndpoint
The routable HTTPS address of an"http" listener.
TcpEndpoint
The host and port to connect to for a"tcp" listener.
Sailbox snapshot fields
The monitoring snapshot carried by everySailbox returned from
Sailbox.get and Sailbox.list.
Observed-usage fields reflect the latest live sample within roughly the last
two minutes, falling back to zero when no recent sample is available.
SailboxPage
One page ofSailbox.list_page results.