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Unix local sandbox

UnixLocalSandboxClient

Bases: BaseSandboxClient[UnixLocalSandboxClientOptions | None]

Source code in src/agents/sandbox/sandboxes/unix_local.py
class UnixLocalSandboxClient(BaseSandboxClient[UnixLocalSandboxClientOptions | None]):
    backend_id = "unix_local"
    supports_default_options = True
    _instrumentation: Instrumentation

    def __init__(
        self,
        *,
        instrumentation: Instrumentation | None = None,
        dependencies: Dependencies | None = None,
    ) -> None:
        self._instrumentation = instrumentation or Instrumentation()
        self._dependencies = dependencies

    async def create(
        self,
        *,
        snapshot: SnapshotSpec | SnapshotBase | None = None,
        manifest: Manifest | None = None,
        options: UnixLocalSandboxClientOptions | None = None,
    ) -> SandboxSession:
        resolved_options = options or UnixLocalSandboxClientOptions()
        # For local execution, runner-created sessions should always get an isolated temp root
        # unless the caller explicitly chose a custom host path.
        workspace_root_owned = False
        if manifest is None or manifest.root == _DEFAULT_MANIFEST_ROOT:
            workspace_dir = tempfile.mkdtemp(prefix=_DEFAULT_WORKSPACE_PREFIX)
            workspace_root_owned = True
            if manifest is None:
                manifest = Manifest(root=workspace_dir)
            else:
                manifest = manifest.model_copy(update={"root": workspace_dir}, deep=True)

        session_id = uuid.uuid4()
        snapshot_id = str(session_id)
        snapshot_instance = resolve_snapshot(snapshot, snapshot_id)
        state = UnixLocalSandboxSessionState(
            session_id=session_id,
            manifest=manifest,
            snapshot=snapshot_instance,
            workspace_root_owned=workspace_root_owned,
            exposed_ports=resolved_options.exposed_ports,
        )
        inner = UnixLocalSandboxSession.from_state(state)
        return self._wrap_session(inner, instrumentation=self._instrumentation)

    async def delete(self, session: SandboxSession) -> SandboxSession:
        """Best-effort cleanup of the on-disk workspace directory."""
        inner = session._inner
        if not isinstance(inner, UnixLocalSandboxSession):
            raise TypeError("UnixLocalSandboxClient.delete expects a UnixLocalSandboxSession")
        if not inner.state.workspace_root_owned:
            return session
        unmount_failed = False
        for mount_entry, mount_path in inner.state.manifest.ephemeral_mount_targets():
            try:
                await mount_entry.unmount(inner, mount_path, Path("/"))
            except Exception:
                unmount_failed = True
                logger.warning(
                    "Failed to unmount UnixLocal workspace mount before deleting root: %s",
                    mount_path,
                    exc_info=True,
                )
        if unmount_failed:
            return session
        try:
            shutil.rmtree(Path(inner.state.manifest.root), ignore_errors=False)
        except FileNotFoundError:
            pass
        except Exception:
            pass
        return session

    async def resume(
        self,
        state: SandboxSessionState,
    ) -> SandboxSession:
        if not isinstance(state, UnixLocalSandboxSessionState):
            raise TypeError("UnixLocalSandboxClient.resume expects a UnixLocalSandboxSessionState")
        inner = UnixLocalSandboxSession.from_state(state)
        return self._wrap_session(inner, instrumentation=self._instrumentation)

    def deserialize_session_state(self, payload: dict[str, object]) -> SandboxSessionState:
        return UnixLocalSandboxSessionState.model_validate(payload)

delete async

delete(session: SandboxSession) -> SandboxSession

Best-effort cleanup of the on-disk workspace directory.

Source code in src/agents/sandbox/sandboxes/unix_local.py
async def delete(self, session: SandboxSession) -> SandboxSession:
    """Best-effort cleanup of the on-disk workspace directory."""
    inner = session._inner
    if not isinstance(inner, UnixLocalSandboxSession):
        raise TypeError("UnixLocalSandboxClient.delete expects a UnixLocalSandboxSession")
    if not inner.state.workspace_root_owned:
        return session
    unmount_failed = False
    for mount_entry, mount_path in inner.state.manifest.ephemeral_mount_targets():
        try:
            await mount_entry.unmount(inner, mount_path, Path("/"))
        except Exception:
            unmount_failed = True
            logger.warning(
                "Failed to unmount UnixLocal workspace mount before deleting root: %s",
                mount_path,
                exc_info=True,
            )
    if unmount_failed:
        return session
    try:
        shutil.rmtree(Path(inner.state.manifest.root), ignore_errors=False)
    except FileNotFoundError:
        pass
    except Exception:
        pass
    return session

serialize_session_state

serialize_session_state(
    state: SandboxSessionState,
) -> dict[str, object]

Serialize backend-specific sandbox state into a JSON-compatible payload.

Source code in src/agents/sandbox/session/sandbox_client.py
def serialize_session_state(self, state: SandboxSessionState) -> dict[str, object]:
    """Serialize backend-specific sandbox state into a JSON-compatible payload."""
    return state.model_dump(mode="json")

UnixLocalSandboxClientOptions

Bases: BaseSandboxClientOptions

Source code in src/agents/sandbox/sandboxes/unix_local.py
class UnixLocalSandboxClientOptions(BaseSandboxClientOptions):
    type: Literal["unix_local"] = "unix_local"
    exposed_ports: tuple[int, ...] = ()

    def __init__(
        self,
        exposed_ports: tuple[int, ...] = (),
        *,
        type: Literal["unix_local"] = "unix_local",
    ) -> None:
        super().__init__(
            type=type,
            exposed_ports=exposed_ports,
        )

UnixLocalSandboxSession

Bases: BaseSandboxSession

Unix-only session implementation that runs commands on the host and uses the host filesystem as the workspace (rooted at self.state.manifest.root).

Source code in src/agents/sandbox/sandboxes/unix_local.py
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class UnixLocalSandboxSession(BaseSandboxSession):
    """
    Unix-only session implementation that runs commands on the host and uses the host filesystem
    as the workspace (rooted at `self.state.manifest.root`).
    """

    state: UnixLocalSandboxSessionState
    _running: bool
    _pty_lock: asyncio.Lock
    _pty_processes: dict[int, _UnixPtyProcessEntry]
    _reserved_pty_process_ids: set[int]

    def __init__(self, *, state: UnixLocalSandboxSessionState) -> None:
        self.state = state
        self._running = False
        self._pty_lock = asyncio.Lock()
        self._pty_processes = {}
        self._reserved_pty_process_ids = set()

    @classmethod
    def from_state(cls, state: UnixLocalSandboxSessionState) -> "UnixLocalSandboxSession":
        return cls(state=state)

    async def _prepare_backend_workspace(self) -> None:
        workspace = Path(self.state.manifest.root)
        try:
            workspace.mkdir(parents=True, exist_ok=True)
        except OSError as e:
            raise WorkspaceStartError(path=workspace, cause=e) from e

    async def _after_start(self) -> None:
        # Mark the session live only after restore/apply completes. A resumed UnixLocal session may
        # recreate an empty workspace after cleanup deleted the previous root, so reporting
        # "running" too early can incorrectly skip snapshot restoration based on a stale
        # fingerprint cache file.
        self._running = True

    async def _after_start_failed(self) -> None:
        self._running = False

    def _wrap_stop_error(self, error: Exception) -> Exception:
        return WorkspaceStopError(path=Path(self.state.manifest.root), cause=error)

    async def _apply_manifest(
        self,
        *,
        only_ephemeral: bool = False,
        provision_accounts: bool = True,
    ) -> MaterializationResult:
        if self.state.manifest.users or self.state.manifest.groups:
            raise ValueError(
                "UnixLocalSandboxSession does not support manifest users or groups because "
                "provisioning would run on the host machine"
            )
        return await super()._apply_manifest(
            only_ephemeral=only_ephemeral,
            provision_accounts=provision_accounts,
        )

    async def apply_manifest(self, *, only_ephemeral: bool = False) -> MaterializationResult:
        return await self._apply_manifest(
            only_ephemeral=only_ephemeral,
            provision_accounts=not only_ephemeral,
        )

    async def provision_manifest_accounts(self) -> None:
        if self.state.manifest.users or self.state.manifest.groups:
            raise ValueError(
                "UnixLocalSandboxSession does not support manifest users or groups because "
                "provisioning would run on the host machine"
            )

    async def _after_shutdown(self) -> None:
        # Best-effort: mark session not running. We intentionally do not delete the workspace
        # directory here; cleanup is handled by the Client.delete().
        self._running = False

    async def _resolve_exposed_port(self, port: int) -> ExposedPortEndpoint:
        return ExposedPortEndpoint(host="127.0.0.1", port=port, tls=False)

    def supports_pty(self) -> bool:
        return True

    def _prepare_exec_command(
        self,
        *command: str | Path,
        shell: bool | list[str],
        user: str | User | None,
    ) -> list[str]:
        if shell is True:
            shell = ["sh", "-c"]
        return super()._prepare_exec_command(*command, shell=shell, user=user)

    async def _exec_internal(
        self, *command: str | Path, timeout: float | None = None
    ) -> ExecResult:
        env, cwd = await self._resolved_exec_context()
        workspace_root = Path(cwd).resolve()
        command_parts = self._workspace_relative_command_parts(command, workspace_root)
        process_cwd, command_parts = self._shell_workspace_process_context(
            command_parts=command_parts,
            workspace_root=workspace_root,
            cwd=cwd,
        )
        exec_command = self._confined_exec_command(
            command_parts=command_parts,
            workspace_root=workspace_root,
            env=env,
        )

        try:
            proc = await asyncio.create_subprocess_exec(
                *exec_command,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
                cwd=process_cwd,
                env=env,
                start_new_session=True,
            )

            try:
                stdout, stderr = await asyncio.wait_for(proc.communicate(), timeout=timeout)
            except asyncio.TimeoutError as e:
                try:
                    # process tree cleanup
                    os.killpg(proc.pid, signal.SIGKILL)
                except Exception:
                    pass
                raise ExecTimeoutError(command=command, timeout_s=timeout, cause=e) from e
        except ExecTimeoutError:
            raise
        except Exception as e:
            raise ExecTransportError(command=command, cause=e) from e

        return ExecResult(
            stdout=stdout or b"", stderr=stderr or b"", exit_code=proc.returncode or 0
        )

    async def pty_exec_start(
        self,
        *command: str | Path,
        timeout: float | None = None,
        shell: bool | list[str] = True,
        user: str | User | None = None,
        tty: bool = False,
        yield_time_s: float | None = None,
        max_output_tokens: int | None = None,
    ) -> PtyExecUpdate:
        _ = timeout
        env, cwd = await self._resolved_exec_context()
        workspace_root = Path(cwd).resolve()
        sanitized_command = self._prepare_exec_command(*command, shell=shell, user=user)
        command_parts = self._workspace_relative_command_parts(sanitized_command, workspace_root)
        process_cwd, command_parts = self._shell_workspace_process_context(
            command_parts=command_parts,
            workspace_root=workspace_root,
            cwd=cwd,
        )
        exec_command = self._confined_exec_command(
            command_parts=command_parts,
            workspace_root=workspace_root,
            env=env,
        )

        if tty:
            primary_fd, secondary_fd = os.openpty()

            def _preexec() -> None:
                os.setsid()
                fcntl.ioctl(secondary_fd, termios.TIOCSCTTY, 0)

            try:
                process = await asyncio.create_subprocess_exec(
                    *exec_command,
                    stdin=secondary_fd,
                    stdout=secondary_fd,
                    stderr=secondary_fd,
                    cwd=process_cwd,
                    env=env,
                    preexec_fn=_preexec,
                )
            except Exception:
                with suppress(OSError):
                    os.close(primary_fd)
                with suppress(OSError):
                    os.close(secondary_fd)
                raise
            else:
                with suppress(OSError):
                    os.close(secondary_fd)
            entry = _UnixPtyProcessEntry(process=process, tty=True, primary_fd=primary_fd)
            entry.pump_tasks = [asyncio.create_task(self._pump_pty_primary_fd(entry))]
        else:
            process = await asyncio.create_subprocess_exec(
                *exec_command,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
                cwd=process_cwd,
                env=env,
                start_new_session=True,
            )
            entry = _UnixPtyProcessEntry(process=process, tty=False)
            entry.pump_tasks = [
                asyncio.create_task(self._pump_process_stream(entry, process.stdout)),
                asyncio.create_task(self._pump_process_stream(entry, process.stderr)),
            ]

        entry.wait_task = asyncio.create_task(self._watch_process_exit(entry))

        pruned_entry: _UnixPtyProcessEntry | None = None
        async with self._pty_lock:
            process_id = allocate_pty_process_id(self._reserved_pty_process_ids)
            self._reserved_pty_process_ids.add(process_id)
            pruned_entry = self._prune_pty_processes_if_needed()
            self._pty_processes[process_id] = entry
            process_count = len(self._pty_processes)

        if pruned_entry is not None:
            await self._terminate_pty_entry(pruned_entry)

        if process_count >= PTY_PROCESSES_WARNING:
            logger.warning(
                "PTY process count reached warning threshold: %s active sessions",
                process_count,
            )

        yield_time_ms = 10_000 if yield_time_s is None else int(yield_time_s * 1000)
        output, original_token_count = await self._collect_pty_output(
            entry=entry,
            yield_time_ms=clamp_pty_yield_time_ms(yield_time_ms),
            max_output_tokens=max_output_tokens,
        )
        return await self._finalize_pty_update(
            process_id=process_id,
            entry=entry,
            output=output,
            original_token_count=original_token_count,
        )

    async def pty_write_stdin(
        self,
        *,
        session_id: int,
        chars: str,
        yield_time_s: float | None = None,
        max_output_tokens: int | None = None,
    ) -> PtyExecUpdate:
        async with self._pty_lock:
            entry = self._resolve_pty_session_entry(
                pty_processes=self._pty_processes,
                session_id=session_id,
            )

        if chars:
            if not entry.tty or entry.primary_fd is None:
                raise RuntimeError("stdin is not available for this process")
            try:
                os.write(entry.primary_fd, chars.encode("utf-8"))
            except OSError as e:
                if e.errno not in {
                    errno.EIO,
                    errno.EBADF,
                    errno.EPIPE,
                    errno.ECONNRESET,
                }:
                    raise
            await asyncio.sleep(0.1)

        yield_time_ms = 250 if yield_time_s is None else int(yield_time_s * 1000)
        output, original_token_count = await self._collect_pty_output(
            entry=entry,
            yield_time_ms=resolve_pty_write_yield_time_ms(
                yield_time_ms=yield_time_ms, input_empty=chars == ""
            ),
            max_output_tokens=max_output_tokens,
        )
        entry.last_used = time.monotonic()
        return await self._finalize_pty_update(
            process_id=session_id,
            entry=entry,
            output=output,
            original_token_count=original_token_count,
        )

    async def pty_terminate_all(self) -> None:
        async with self._pty_lock:
            entries = list(self._pty_processes.values())
            self._pty_processes.clear()
            self._reserved_pty_process_ids.clear()

        for entry in entries:
            await self._terminate_pty_entry(entry)

    async def _resolved_exec_context(self) -> tuple[dict[str, str], str]:
        env = os.environ.copy()
        env.update(await self.state.manifest.environment.resolve())

        workspace = Path(self.state.manifest.root)
        if not workspace.exists():
            raise WorkspaceRootNotFoundError(path=workspace)

        env["HOME"] = str(workspace)
        return env, str(workspace)

    async def _pump_process_stream(
        self,
        entry: _UnixPtyProcessEntry,
        stream: asyncio.StreamReader | None,
    ) -> None:
        if stream is None:
            return

        while True:
            chunk = await stream.read(_PTY_READ_CHUNK_BYTES)
            if chunk == b"":
                break
            async with entry.output_lock:
                entry.output_chunks.append(chunk)
            entry.output_notify.set()

    async def _watch_process_exit(self, entry: _UnixPtyProcessEntry) -> None:
        await entry.process.wait()
        if entry.pump_tasks:
            await asyncio.gather(*entry.pump_tasks, return_exceptions=True)
        entry.output_closed.set()
        entry.output_notify.set()

    async def _pump_pty_primary_fd(self, entry: _UnixPtyProcessEntry) -> None:
        primary_fd = entry.primary_fd
        if primary_fd is None:
            return

        loop = asyncio.get_running_loop()
        while True:
            try:
                chunk = await loop.run_in_executor(None, os.read, primary_fd, _PTY_READ_CHUNK_BYTES)
            except OSError as e:
                if e.errno in {errno.EIO, errno.EBADF}:
                    break
                raise

            if chunk == b"":
                break
            async with entry.output_lock:
                entry.output_chunks.append(chunk)
            entry.output_notify.set()

    async def _collect_pty_output(
        self,
        *,
        entry: _UnixPtyProcessEntry,
        yield_time_ms: int,
        max_output_tokens: int | None,
    ) -> tuple[bytes, int | None]:
        deadline = time.monotonic() + (yield_time_ms / 1000)
        output = bytearray()

        while True:
            async with entry.output_lock:
                while entry.output_chunks:
                    output.extend(entry.output_chunks.popleft())

            if time.monotonic() >= deadline:
                break

            if entry.output_closed.is_set():
                async with entry.output_lock:
                    while entry.output_chunks:
                        output.extend(entry.output_chunks.popleft())
                break

            remaining_s = deadline - time.monotonic()
            if remaining_s <= 0:
                break

            try:
                await asyncio.wait_for(entry.output_notify.wait(), timeout=remaining_s)
            except asyncio.TimeoutError:
                break
            entry.output_notify.clear()

        text = output.decode("utf-8", errors="replace")
        truncated_text, original_token_count = truncate_text_by_tokens(text, max_output_tokens)
        return truncated_text.encode("utf-8", errors="replace"), original_token_count

    async def _finalize_pty_update(
        self,
        *,
        process_id: int,
        entry: _UnixPtyProcessEntry,
        output: bytes,
        original_token_count: int | None,
    ) -> PtyExecUpdate:
        exit_code: int | None = entry.process.returncode
        live_process_id: int | None = process_id

        if exit_code is not None:
            async with self._pty_lock:
                removed = self._pty_processes.pop(process_id, None)
                self._reserved_pty_process_ids.discard(process_id)
            if removed is not None:
                await self._terminate_pty_entry(removed)
            live_process_id = None

        return PtyExecUpdate(
            process_id=live_process_id,
            output=output,
            exit_code=exit_code,
            original_token_count=original_token_count,
        )

    def _prune_pty_processes_if_needed(self) -> _UnixPtyProcessEntry | None:
        if len(self._pty_processes) < PTY_PROCESSES_MAX:
            return None

        meta = [
            (process_id, entry.last_used, entry.process.returncode is not None)
            for process_id, entry in self._pty_processes.items()
        ]
        process_id = process_id_to_prune_from_meta(meta)
        if process_id is None:
            return None

        self._reserved_pty_process_ids.discard(process_id)
        return self._pty_processes.pop(process_id, None)

    async def _terminate_pty_entry(self, entry: _UnixPtyProcessEntry) -> None:
        process = entry.process
        primary_fd = entry.primary_fd
        entry.primary_fd = None

        if process.returncode is None and process.pid is not None:
            with suppress(ProcessLookupError):
                os.killpg(process.pid, signal.SIGKILL)

        for task in entry.pump_tasks:
            task.cancel()
        if entry.wait_task is not None:
            entry.wait_task.cancel()
        if entry.tty:
            if primary_fd is not None:
                # On macOS we have observed os.close() on the PTY master fd block while a
                # background reader thread is still inside os.read(). Close it off-thread so
                # session teardown remains best-effort and non-blocking.
                asyncio.create_task(asyncio.to_thread(_close_fd_quietly, primary_fd))
            entry.output_closed.set()
            entry.output_notify.set()
            return

        if primary_fd is not None:
            _close_fd_quietly(primary_fd)
        await asyncio.gather(*entry.pump_tasks, return_exceptions=True)
        if entry.wait_task is not None:
            await asyncio.gather(entry.wait_task, return_exceptions=True)

    def _confined_exec_command(
        self,
        *,
        command_parts: list[str],
        workspace_root: Path,
        env: Mapping[str, str],
    ) -> list[str]:
        if sys.platform != "darwin":
            return command_parts

        sandbox_exec = shutil.which("sandbox-exec")
        if not sandbox_exec:
            raise ExecTransportError(
                command=command_parts,
                context={
                    "reason": "unix_local_confinement_unavailable",
                    "platform": sys.platform,
                    "workspace_root": str(workspace_root),
                },
            )

        profile = self._darwin_exec_profile(
            workspace_root,
            extra_read_paths=self._darwin_additional_read_paths(
                command_parts=command_parts,
                env=env,
            ),
        )
        return [sandbox_exec, "-p", profile, *command_parts]

    @staticmethod
    def _workspace_relative_command_parts(
        command: Sequence[str | Path],
        workspace_root: Path,
    ) -> list[str]:
        command_parts = [str(part) for part in command]
        rewritten = [command_parts[0]]
        for part in command_parts[1:]:
            path_part = Path(part)
            if not path_part.is_absolute():
                rewritten.append(part)
                continue
            try:
                relative = path_part.relative_to(workspace_root)
            except ValueError:
                rewritten.append(part)
                continue
            rewritten.append("." if not relative.parts else relative.as_posix())
        return rewritten

    @staticmethod
    def _darwin_allowable_read_roots(path: Path, *, host_home: Path) -> list[Path]:
        candidates: set[Path] = set()
        normalized = path.expanduser()
        try:
            resolved = normalized.resolve(strict=False)
        except OSError:
            resolved = normalized

        if normalized.is_dir():
            candidates.add(normalized)
        else:
            candidates.add(normalized.parent)

        if resolved.is_dir():
            candidates.add(resolved)
        else:
            candidates.add(resolved.parent)

        resolved_text = resolved.as_posix()
        if resolved_text == "/opt/homebrew" or resolved_text.startswith("/opt/homebrew/"):
            candidates.add(Path("/opt/homebrew"))
        if resolved_text == "/usr/local" or resolved_text.startswith("/usr/local/"):
            candidates.add(Path("/usr/local"))
        if resolved_text == "/Library/Frameworks" or resolved_text.startswith(
            "/Library/Frameworks/"
        ):
            candidates.add(Path("/Library/Frameworks"))

        try:
            relative_to_home = resolved.relative_to(host_home)
        except ValueError:
            relative_to_home = None
        if relative_to_home is not None and relative_to_home.parts:
            first_segment = relative_to_home.parts[0]
            if first_segment.startswith("."):
                candidates.add(host_home / first_segment)
            elif len(relative_to_home.parts) >= 2 and relative_to_home.parts[:2] == (
                "Library",
                "Python",
            ):
                candidates.add(host_home / "Library" / "Python")

        return sorted(
            candidates, key=lambda candidate: (len(candidate.parts), candidate.as_posix())
        )

    def _darwin_additional_read_paths(
        self,
        *,
        command_parts: list[str],
        env: Mapping[str, str],
    ) -> list[Path]:
        host_home = Path.home().resolve()
        allowed: list[Path] = []
        seen: set[str] = set()

        def _append(path: str | Path | None) -> None:
            if path is None:
                return
            candidate = Path(path).expanduser()
            if not candidate.is_absolute():
                return
            for root in self._darwin_allowable_read_roots(candidate, host_home=host_home):
                key = root.as_posix()
                if key in seen:
                    continue
                seen.add(key)
                allowed.append(root)

        for path_entry in env.get("PATH", "").split(os.pathsep):
            if path_entry:
                _append(path_entry)

        executable = shutil.which(command_parts[0], path=env.get("PATH"))
        _append(executable)
        return allowed

    def _darwin_exec_profile(
        self,
        workspace_root: Path,
        *,
        extra_read_paths: Sequence[Path] = (),
    ) -> str:
        def _literal(path: Path | str) -> str:
            escaped = str(path).replace("\\", "\\\\").replace('"', '\\"')
            return f'"{escaped}"'

        denied_paths = [
            Path("/Users"),
            Path("/Volumes"),
            Path("/Applications"),
            Path("/Library"),
            Path("/opt"),
            Path("/etc"),
            Path("/private/etc"),
            Path("/tmp"),
            Path("/private/tmp"),
            Path("/private"),
            Path("/var"),
            Path("/usr"),
        ]
        allow_rules = [
            f"(allow file-read-data file-read-metadata (subpath {_literal(workspace_root)}))",
            f"(allow file-write* (subpath {_literal(workspace_root)}))",
            *[
                f"(allow file-read-data file-read-metadata (subpath {_literal(path)}))"
                for path in extra_read_paths
            ],
            '(allow file-read-data file-read-metadata (subpath "/usr/bin"))',
            '(allow file-read-data file-read-metadata (subpath "/usr/lib"))',
            '(allow file-read-data file-read-metadata (subpath "/bin"))',
            '(allow file-read-data file-read-metadata (subpath "/System"))',
            '(allow file-read-data file-read-metadata (literal "/private/var/select/sh"))',
            '(allow file-write* (literal "/dev/null"))',
        ]
        deny_rules = "\n".join(
            f"(deny file-read-data (subpath {_literal(path)}))\n"
            f"(deny file-write* (subpath {_literal(path)}))"
            for path in denied_paths
        )
        return "\n".join(
            [
                "(version 1)",
                "(allow default)",
                deny_rules,
                *allow_rules,
            ]
        )

    @staticmethod
    def _shell_workspace_process_context(
        *,
        command_parts: list[str],
        workspace_root: Path,
        cwd: str,
    ) -> tuple[str, list[str]]:
        if len(command_parts) < 3 or command_parts[0] != "sh" or command_parts[1] != "-c":
            return cwd, command_parts

        workspace_cd = f"cd {shlex.quote(str(workspace_root))} && {command_parts[2]}"
        rewritten = [*command_parts]
        rewritten[2] = workspace_cd
        return "/", rewritten

    def normalize_path(self, path: Path | str) -> Path:
        return self._workspace_path_policy().normalize_path_for_host_io(path)

    async def ls(
        self,
        path: Path | str,
        *,
        user: str | User | None = None,
    ) -> list[FileEntry]:
        if user is not None:
            return await super().ls(path, user=user)

        normalized = self.normalize_path(path)
        command = ("ls", "-la", "--", str(normalized))
        try:
            with os.scandir(normalized) as entries:
                listed: list[FileEntry] = []
                for entry in entries:
                    stat_result = entry.stat(follow_symlinks=False)
                    if entry.is_symlink():
                        kind = EntryKind.SYMLINK
                    elif entry.is_dir(follow_symlinks=False):
                        kind = EntryKind.DIRECTORY
                    elif entry.is_file(follow_symlinks=False):
                        kind = EntryKind.FILE
                    else:
                        kind = EntryKind.OTHER
                    listed.append(
                        FileEntry(
                            path=entry.path,
                            permissions=Permissions.from_mode(stat_result.st_mode),
                            owner=str(stat_result.st_uid),
                            group=str(stat_result.st_gid),
                            size=stat_result.st_size,
                            kind=kind,
                        )
                    )
                return listed
        except OSError as e:
            raise ExecNonZeroError(
                ExecResult(stdout=b"", stderr=str(e).encode("utf-8"), exit_code=1),
                command=command,
                cause=e,
            ) from e

    async def mkdir(
        self,
        path: Path | str,
        *,
        parents: bool = False,
        user: str | User | None = None,
    ) -> None:
        if user is not None:
            normalized = await self._check_mkdir_with_exec(path, parents=parents, user=user)
        else:
            normalized = self.normalize_path(path)
        try:
            normalized.mkdir(parents=parents, exist_ok=True)
        except OSError as e:
            raise WorkspaceArchiveWriteError(path=normalized, cause=e) from e

    async def rm(
        self,
        path: Path | str,
        *,
        recursive: bool = False,
        user: str | User | None = None,
    ) -> None:
        if user is not None:
            normalized = await self._check_rm_with_exec(path, recursive=recursive, user=user)
        else:
            normalized = self.normalize_path(path)
        try:
            if normalized.is_dir() and not normalized.is_symlink():
                if recursive:
                    shutil.rmtree(normalized)
                else:
                    normalized.rmdir()
            else:
                normalized.unlink()
        except FileNotFoundError as e:
            if recursive:
                return
            raise ExecNonZeroError(
                ExecResult(stdout=b"", stderr=str(e).encode("utf-8"), exit_code=1),
                command=("rm", "-rf" if recursive else "--", str(normalized)),
                cause=e,
            ) from e
        except OSError as e:
            raise WorkspaceArchiveWriteError(path=normalized, cause=e) from e

    async def read(self, path: Path, *, user: str | User | None = None) -> io.IOBase:
        if user is not None:
            await self._check_read_with_exec(path, user=user)

        workspace_path = self.normalize_path(path)
        try:
            return workspace_path.open("rb")
        except FileNotFoundError as e:
            raise WorkspaceReadNotFoundError(path=path, cause=e) from e
        except OSError as e:
            raise WorkspaceArchiveReadError(path=path, cause=e) from e

    async def write(
        self,
        path: Path,
        data: io.IOBase,
        *,
        user: str | User | None = None,
    ) -> None:
        payload = coerce_write_payload(path=path, data=data)

        workspace_path = self.normalize_path(path)
        if user is not None:
            await self._write_stream_with_exec(workspace_path, payload.stream, user=user)
            return

        try:
            workspace_path.parent.mkdir(parents=True, exist_ok=True)
            with workspace_path.open("wb") as f:
                shutil.copyfileobj(payload.stream, f)
        except OSError as e:
            raise WorkspaceArchiveWriteError(path=workspace_path, cause=e) from e

    async def _write_stream_with_exec(
        self,
        path: Path,
        stream: io.IOBase,
        *,
        user: str | User,
    ) -> None:
        env, cwd = await self._resolved_exec_context()
        workspace_root = Path(cwd).resolve()
        command_parts = self._prepare_exec_command(
            "sh",
            "-c",
            'mkdir -p "$(dirname "$1")" && cat > "$1"',
            "sh",
            str(path),
            shell=False,
            user=user,
        )
        command_parts = self._workspace_relative_command_parts(command_parts, workspace_root)
        process_cwd, command_parts = self._shell_workspace_process_context(
            command_parts=command_parts,
            workspace_root=workspace_root,
            cwd=cwd,
        )
        exec_command = self._confined_exec_command(
            command_parts=command_parts,
            workspace_root=workspace_root,
            env=env,
        )

        payload = stream.read()
        if isinstance(payload, str):
            payload = payload.encode("utf-8")
        elif not isinstance(payload, bytes):
            payload = bytes(payload)

        try:
            proc = await asyncio.create_subprocess_exec(
                *exec_command,
                stdin=asyncio.subprocess.PIPE,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
                cwd=process_cwd,
                env=env,
                start_new_session=True,
            )
            stdout, stderr = await proc.communicate(payload)
        except OSError as e:
            raise WorkspaceArchiveWriteError(path=path, cause=e) from e

        if proc.returncode:
            raise WorkspaceArchiveWriteError(
                path=path,
                context={
                    "command": command_parts,
                    "stdout": stdout.decode("utf-8", errors="replace"),
                    "stderr": stderr.decode("utf-8", errors="replace"),
                },
            )

    async def running(self) -> bool:
        return self._running

    async def persist_workspace(self) -> io.IOBase:
        root = Path(self.state.manifest.root)
        if not root.exists():
            raise WorkspaceArchiveReadError(
                path=root, context={"reason": "workspace_root_not_found"}
            )

        skip = self._persist_workspace_skip_relpaths()
        buf = io.BytesIO()
        try:
            with tarfile.open(fileobj=buf, mode="w") as tar:
                tar.add(
                    root,
                    arcname=".",
                    filter=lambda ti: (
                        None
                        if should_skip_tar_member(
                            ti.name,
                            skip_rel_paths=skip,
                            root_name=None,
                        )
                        else ti
                    ),
                )
        except (tarfile.TarError, OSError) as e:
            raise WorkspaceArchiveReadError(path=root, cause=e) from e

        buf.seek(0)
        return buf

    async def hydrate_workspace(self, data: io.IOBase) -> None:
        root = Path(self.state.manifest.root)
        try:
            root.mkdir(parents=True, exist_ok=True)
            with tarfile.open(fileobj=data, mode="r:*") as tar:
                safe_extract_tarfile(tar, root=root)
        except UnsafeTarMemberError as e:
            raise WorkspaceArchiveWriteError(
                path=root, context={"reason": e.reason, "member": e.member}, cause=e
            ) from e
        except (tarfile.TarError, OSError) as e:
            raise WorkspaceArchiveWriteError(path=root, cause=e) from e

stop async

stop() -> None

Persist/snapshot the workspace.

Note: stop() is intentionally persistence-only. Sandboxes that need to tear down sandbox resources (Docker containers, remote sessions, etc.) should implement shutdown() instead.

Source code in src/agents/sandbox/session/base_sandbox_session.py
async def stop(self) -> None:
    """
    Persist/snapshot the workspace.

    Note: `stop()` is intentionally persistence-only. Sandboxes that need to tear down
    sandbox resources (Docker containers, remote sessions, etc.) should implement
    `shutdown()` instead.
    """
    try:
        try:
            await self._before_stop()
            await self._persist_snapshot()
        except Exception as e:
            wrapped = self._wrap_stop_error(e)
            if wrapped is e:
                raise
            raise wrapped from e
    finally:
        await self._after_stop()

supports_docker_volume_mounts

supports_docker_volume_mounts() -> bool

Return whether this backend attaches Docker volume mounts before manifest apply.

Source code in src/agents/sandbox/session/base_sandbox_session.py
def supports_docker_volume_mounts(self) -> bool:
    """Return whether this backend attaches Docker volume mounts before manifest apply."""

    return False

shutdown async

shutdown() -> None

Tear down sandbox resources (best-effort).

Default is a no-op. Sandbox-specific sessions (e.g. Docker) should override.

Source code in src/agents/sandbox/session/base_sandbox_session.py
async def shutdown(self) -> None:
    """
    Tear down sandbox resources (best-effort).

    Default is a no-op. Sandbox-specific sessions (e.g. Docker) should override.
    """
    await self._before_shutdown()
    await self._shutdown_backend()
    await self._after_shutdown()

aclose async

aclose() -> None

Run the session cleanup lifecycle outside of async with.

This performs the same session-owned cleanup as __aexit__(): persist/snapshot the workspace via stop(), tear down session resources via shutdown(), and close session-scoped dependencies. If the session came from a sandbox client, call the client's delete() separately for backend-specific deletion such as removing a Docker container or deleting a temporary host workspace.

Source code in src/agents/sandbox/session/base_sandbox_session.py
async def aclose(self) -> None:
    """Run the session cleanup lifecycle outside of ``async with``.

    This performs the same session-owned cleanup as ``__aexit__()``: persist/snapshot the
    workspace via ``stop()``, tear down session resources via ``shutdown()``, and close
    session-scoped dependencies. If the session came from a sandbox client, call the client's
    ``delete()`` separately for backend-specific deletion such as removing a Docker container
    or deleting a temporary host workspace.
    """
    try:
        await self.run_pre_stop_hooks()
        await self.stop()
        await self.shutdown()
    finally:
        await self._aclose_dependencies()

register_pre_stop_hook

register_pre_stop_hook(
    hook: Callable[[], Awaitable[None]],
) -> None

Register an async hook to run once before the session workspace is persisted.

Source code in src/agents/sandbox/session/base_sandbox_session.py
def register_pre_stop_hook(self, hook: Callable[[], Awaitable[None]]) -> None:
    """Register an async hook to run once before the session workspace is persisted."""

    hooks = self._pre_stop_hooks
    if hooks is None:
        hooks = []
        self._pre_stop_hooks = hooks
    hooks.append(hook)
    self._pre_stop_hooks_ran = False

run_pre_stop_hooks async

run_pre_stop_hooks() -> None

Run registered pre-stop hooks once before workspace persistence.

Source code in src/agents/sandbox/session/base_sandbox_session.py
async def run_pre_stop_hooks(self) -> None:
    """Run registered pre-stop hooks once before workspace persistence."""

    hooks = self._pre_stop_hooks
    if hooks is None or self._pre_stop_hooks_ran:
        return
    self._pre_stop_hooks_ran = True
    cleanup_error: BaseException | None = None
    for hook in hooks:
        try:
            await hook()
        except BaseException as exc:
            if cleanup_error is None:
                cleanup_error = exc
    if cleanup_error is not None:
        raise cleanup_error

register_persist_workspace_skip_path

register_persist_workspace_skip_path(
    path: Path | str,
) -> Path

Exclude a runtime-created workspace path from future workspace snapshots.

Use this for session side effects that are not part of durable workspace state, such as generated mount config or ephemeral sink output.

Source code in src/agents/sandbox/session/base_sandbox_session.py
def register_persist_workspace_skip_path(self, path: Path | str) -> Path:
    """Exclude a runtime-created workspace path from future workspace snapshots.

    Use this for session side effects that are not part of durable workspace state, such as
    generated mount config or ephemeral sink output.
    """

    rel_path = Manifest._coerce_rel_path(path)
    Manifest._validate_rel_path(rel_path)
    if rel_path in (Path(""), Path(".")):
        raise ValueError("Persist workspace skip paths must target a concrete relative path.")
    overlapping_mounts = self._overlapping_mount_relpaths(rel_path)
    if overlapping_mounts:
        overlapping_mount = min(overlapping_mounts, key=lambda p: (len(p.parts), p.as_posix()))
        raise MountConfigError(
            message="persist workspace skip path must not overlap mount path",
            context={
                "skip_path": rel_path.as_posix(),
                "mount_path": overlapping_mount.as_posix(),
            },
        )

    if self._runtime_persist_workspace_skip_relpaths is None:
        self._runtime_persist_workspace_skip_relpaths = set()
    self._runtime_persist_workspace_skip_relpaths.add(rel_path)
    return rel_path

exec async

exec(
    *command: str | Path,
    timeout: float | None = None,
    shell: bool | list[str] = True,
    user: str | User | None = None,
) -> ExecResult

Execute a command inside the session.

:param command: Command and args (will be stringified). :param timeout: Optional wall-clock timeout in seconds. :param shell: Whether to run this command in a shell. If True is provided, the command will be run prefixed by sh -lc. A custom shell prefix may be used by providing a list.

:returns: An ExecResult containing stdout/stderr and exit code.

:raises TimeoutError: If the sandbox cannot complete within timeout.

Source code in src/agents/sandbox/session/base_sandbox_session.py
async def exec(
    self,
    *command: str | Path,
    timeout: float | None = None,
    shell: bool | list[str] = True,
    user: str | User | None = None,
) -> ExecResult:
    """Execute a command inside the session.

    :param command: Command and args (will be stringified).
    :param timeout: Optional wall-clock timeout in seconds.
    :param shell: Whether to run this command in a shell. If ``True`` is provided,
        the command will be run prefixed by ``sh -lc``. A custom shell prefix may be used
        by providing a list.

    :returns: An ``ExecResult`` containing stdout/stderr and exit code.

    :raises TimeoutError: If the sandbox cannot complete within `timeout`.
    """

    sanitized_command = self._prepare_exec_command(*command, shell=shell, user=user)
    return await self._exec_internal(*sanitized_command, timeout=timeout)

extract async

extract(
    path: Path | str,
    data: IOBase,
    *,
    compression_scheme: Literal["tar", "zip"] | None = None,
) -> None

Write a compressed archive to a destination on the remote. Optionally extract the archive once written.

:param path: Path on the host machine to extract to :param data: a file-like io stream. :param compression_scheme: either "tar" or "zip". If not provided, it will try to infer from the path.

Source code in src/agents/sandbox/session/base_sandbox_session.py
async def extract(
    self,
    path: Path | str,
    data: io.IOBase,
    *,
    compression_scheme: Literal["tar", "zip"] | None = None,
) -> None:
    """
    Write a compressed archive to a destination on the remote.
    Optionally extract the archive once written.

    :param path: Path on the host machine to extract to
    :param data: a file-like io stream.
    :param compression_scheme: either "tar" or "zip". If not provided,
        it will try to infer from the path.
    """
    if isinstance(path, str):
        path = Path(path)

    if compression_scheme is None:
        suffix = path.suffix.removeprefix(".")
        compression_scheme = cast(Literal["tar", "zip"], suffix) if suffix else None

    if compression_scheme is None or compression_scheme not in ["zip", "tar"]:
        raise InvalidCompressionSchemeError(path=path, scheme=compression_scheme)

    normalized_path = await self._normalize_path_for_io(path)
    destination_root = normalized_path.parent

    # Materialize the archive into a local spool once because both `write()` and the
    # extraction step consume the stream, and zip extraction may require seeking.
    spool = tempfile.SpooledTemporaryFile(max_size=16 * 1024 * 1024, mode="w+b")
    try:
        shutil.copyfileobj(data, spool)
        spool.seek(0)
        await self.write(normalized_path, spool)
        spool.seek(0)

        if compression_scheme == "tar":
            await self._extract_tar_archive(
                archive_path=normalized_path,
                destination_root=destination_root,
                data=spool,
            )
        else:
            await self._extract_zip_archive(
                archive_path=normalized_path,
                destination_root=destination_root,
                data=spool,
            )
    finally:
        spool.close()

should_provision_manifest_accounts_on_resume

should_provision_manifest_accounts_on_resume() -> bool

Return whether resume should reprovision manifest-managed users and groups.

Source code in src/agents/sandbox/session/base_sandbox_session.py
def should_provision_manifest_accounts_on_resume(self) -> bool:
    """Return whether resume should reprovision manifest-managed users and groups."""

    return not self._system_state_preserved_on_start()

UnixLocalSandboxSessionState

Bases: SandboxSessionState

Source code in src/agents/sandbox/sandboxes/unix_local.py
class UnixLocalSandboxSessionState(SandboxSessionState):
    type: Literal["unix_local"] = "unix_local"
    workspace_root_owned: bool = False

__pydantic_init_subclass__ classmethod

__pydantic_init_subclass__(**kwargs: Any) -> None

Auto-register every subclass by its type field default.

Source code in src/agents/sandbox/session/sandbox_session_state.py
@classmethod
def __pydantic_init_subclass__(cls, **kwargs: Any) -> None:
    """Auto-register every subclass by its ``type`` field default."""
    super().__pydantic_init_subclass__(**kwargs)

    type_field = cls.model_fields.get("type")
    if type_field is None:
        return

    annotation = type_field.annotation
    if get_origin(annotation) is not Literal:
        return

    args = get_args(annotation)
    if not args:
        return

    type_default = type_field.default
    if not isinstance(type_default, str) or type_default == "":
        return

    SandboxSessionState._subclass_registry[type_default] = cls

parse classmethod

parse(payload: object) -> SandboxSessionState

Deserialize payload into the correct registered subclass.

Accepts a SandboxSessionState instance (returned as-is if already a subclass, or upgraded via model_dump -> registry lookup if it is a bare base instance) or a plain dict.

Source code in src/agents/sandbox/session/sandbox_session_state.py
@classmethod
def parse(cls, payload: object) -> SandboxSessionState:
    """Deserialize *payload* into the correct registered subclass.

    Accepts a ``SandboxSessionState`` instance (returned as-is if already a
    subclass, or upgraded via ``model_dump`` -> registry lookup if it is a
    bare base instance) or a plain ``dict``.
    """
    if isinstance(payload, SandboxSessionState):
        if type(payload) is not SandboxSessionState:
            return payload
        payload = payload.model_dump()

    if isinstance(payload, dict):
        state_type = payload.get("type")
        if not isinstance(state_type, str):
            raise ValueError("sandbox session state payload must include a string `type`")

        subclass = SandboxSessionState._subclass_registry.get(state_type)
        if subclass is None:
            raise ValueError(f"unknown sandbox session state type `{state_type}`")

        return subclass.model_validate(payload)

    raise TypeError("session state payload must be a SandboxSessionState or dict")