diff --git a/.gitignore b/.gitignore
index c7b87ea..a543049 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,3 +46,18 @@ $RECYCLE.BIN/
 # Copilot Orchestrator temporary files
 .orchestrator/
 .worktrees/
+
+# Python
+__pycache__/
+*.py[cod]
+*.egg-info/
+build/
+dist/
+.venv/
+venv/
+.coverage
+.coverage.*
+htmlcov/
+.pytest_cache/
+.mypy_cache/
+.ruff_cache/
diff --git a/README.md b/README.md
index ca95e2a..cef37af 100644
--- a/README.md
+++ b/README.md
@@ -146,6 +146,40 @@ Variante **Windows Server 2022**: `*WinBuild2022.ps1` + VMX `F:\CI\Templates\Win
 
 ---
 
+## Python orchestrator (Phase A — in progress)
+
+A new Python 3.11+ rewrite of the orchestrator lives under `src/ci_orchestrator/`.
+Phase A (see [implementation-plan-A-B](plans/implementation-plan-A-B.md)) is on
+branch `feature/python-rewrite-phase-a`.
+
+Quick setup on the Windows host:
+
+```powershell
+# Create venv (one-time)
+python -m venv F:\CI\python\venv
+F:\CI\python\venv\Scripts\python.exe -m pip install --upgrade pip
+F:\CI\python\venv\Scripts\python.exe -m pip install -e ".[dev]"
+
+# Sanity checks
+F:\CI\python\venv\Scripts\python.exe -m ci_orchestrator --help
+F:\CI\python\venv\Scripts\python.exe -m pytest tests\python -q
+F:\CI\python\venv\Scripts\python.exe -m ruff check src tests\python
+F:\CI\python\venv\Scripts\python.exe -m mypy --strict src
+```
+
+Configuration: copy `config.example.toml` to `F:\CI\config.toml` (or set
+`$env:CI_CONFIG`). Environment variables (`CI_ROOT`, `CI_TEMPLATES`, …) override
+the file.
+
+In Phase A1 only the `wait-ready` PoC is wired:
+
+```powershell
+F:\CI\python\venv\Scripts\python.exe -m ci_orchestrator wait-ready `
+    --vmx F:\CI\BuildVMs\smoke\smoke.vmx --guest-os windows --timeout 300
+```
+
+---
+
 ## Setup rapido
 
 ### 1a. Template VM Windows
diff --git a/config.example.toml b/config.example.toml
new file mode 100644
index 0000000..51a1f6b
--- /dev/null
+++ b/config.example.toml
@@ -0,0 +1,30 @@
+# ci-orchestrator config example.
+#
+# Copy to $CI_ROOT/config.toml or set $CI_CONFIG to the file path.
+# Environment variables (CI_ROOT, CI_TEMPLATES, CI_BUILD_VMS, CI_ARTIFACTS,
+# CI_KEYS, CI_VMRUN_PATH, CI_SSH_KEY_PATH, CI_GUEST_CRED_TARGET) override
+# anything set here.
+
+# --------------------------------------------------------------- Windows host
+[paths]
+root       = "F:/CI"
+templates  = "F:/CI/Templates"
+build_vms  = "F:/CI/BuildVMs"
+artifacts  = "F:/CI/Artifacts"
+keys       = "F:/CI/keys"
+
+# Phase B (Linux host) — uncomment after migration.
+# [paths]
+# root       = "/var/lib/ci"
+# templates  = "/var/lib/ci/templates"
+# build_vms  = "/var/lib/ci/build-vms"
+# artifacts  = "/var/lib/ci/artifacts"
+# keys       = "/etc/ci/keys"
+
+# Phase C hook: backend selector. Only "workstation" is implemented in Phase A.
+[backend]
+type = "workstation"
+
+vmrun_path        = "C:/Program Files (x86)/VMware/VMware Workstation/vmrun.exe"
+ssh_key_path      = "F:/CI/keys/ci_linux"
+guest_cred_target = "BuildVMGuest"
diff --git a/gitea/workflows/lint.yml b/gitea/workflows/lint.yml
index 204f4fb..ff95bbc 100644
--- a/gitea/workflows/lint.yml
+++ b/gitea/workflows/lint.yml
@@ -5,20 +5,26 @@
 # Failures block the PR. Fix warnings with:
 #   Invoke-ScriptAnalyzer -Path scripts\ -Recurse -Fix
 
-name: Lint (PSScriptAnalyzer)
+name: Lint
 
 on:
   push:
     paths:
       - '**.ps1'
       - '**.psm1'
+      - '**.py'
+      - 'pyproject.toml'
+      - 'gitea/workflows/lint.yml'
   pull_request:
     paths:
       - '**.ps1'
       - '**.psm1'
+      - '**.py'
+      - 'pyproject.toml'
+      - 'gitea/workflows/lint.yml'
 
 jobs:
-  lint:
+  pssa:
     runs-on: windows-build
     timeout-minutes: 10
 
@@ -53,3 +59,55 @@ jobs:
           else {
             Write-Host "PSScriptAnalyzer: no issues found."
           }
+
+  python:
+    runs-on: windows-build
+    timeout-minutes: 15
+
+    env:
+      PYTHONIOENCODING: utf-8
+      VENV_DIR: F:\CI\python\venv
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Setup venv + install package
+        shell: powershell
+        run: |
+          $ErrorActionPreference = 'Stop'
+
+          $py = (Get-Command python -ErrorAction Stop).Source
+          if (-not (Test-Path "$env:VENV_DIR\Scripts\python.exe")) {
+            Write-Host "Creating venv at $env:VENV_DIR"
+            & $py -m venv $env:VENV_DIR
+            if ($LASTEXITCODE -ne 0) { throw "venv creation failed" }
+          }
+          $venvPy = Join-Path $env:VENV_DIR 'Scripts\python.exe'
+          & $venvPy -m pip install --upgrade pip
+          if ($LASTEXITCODE -ne 0) { throw "pip upgrade failed" }
+          & $venvPy -m pip install -e ".[dev]"
+          if ($LASTEXITCODE -ne 0) { throw "pip install failed" }
+
+      - name: ruff
+        shell: powershell
+        run: |
+          $venvPy = Join-Path $env:VENV_DIR 'Scripts\python.exe'
+          & $venvPy -m ruff check src tests/python
+          if ($LASTEXITCODE -ne 0) { throw "ruff failed" }
+
+      - name: mypy --strict
+        shell: powershell
+        run: |
+          $venvPy = Join-Path $env:VENV_DIR 'Scripts\python.exe'
+          & $venvPy -m mypy --strict src
+          if ($LASTEXITCODE -ne 0) { throw "mypy failed" }
+
+      - name: pytest (coverage >= 70%)
+        shell: powershell
+        run: |
+          $venvPy = Join-Path $env:VENV_DIR 'Scripts\python.exe'
+          & $venvPy -m pytest tests/python --cov=ci_orchestrator --cov-fail-under=70
+          if ($LASTEXITCODE -ne 0) { throw "pytest failed" }
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..9ebbd08
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,89 @@
+[build-system]
+requires = ["hatchling>=1.18"]
+build-backend = "hatchling.build"
+
+[project]
+name = "ci-orchestrator"
+version = "0.1.0"
+description = "Local CI/CD orchestrator (Phase A: Python rewrite of PowerShell scripts)"
+readme = "README.md"
+requires-python = ">=3.11"
+license = { text = "Proprietary" }
+authors = [{ name = "Local CI/CD System" }]
+dependencies = [
+    "click>=8.1",
+    "pypsrp>=0.8",
+    "paramiko>=3.4",
+    "keyring>=24.0",
+    "tomli>=2.0; python_version < '3.11'",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0",
+    "pytest-cov>=5.0",
+    "pytest-mock>=3.12",
+    "ruff>=0.5",
+    "mypy>=1.10",
+    "types-paramiko",
+]
+
+[project.scripts]
+ci-orchestrator = "ci_orchestrator.__main__:cli"
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/ci_orchestrator"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py311"
+src = ["src", "tests"]
+
+[tool.ruff.lint]
+select = [
+    "E",   # pycodestyle errors
+    "W",   # pycodestyle warnings
+    "F",   # pyflakes
+    "I",   # isort
+    "B",   # flake8-bugbear
+    "UP",  # pyupgrade
+    "SIM", # flake8-simplify
+    "RUF", # ruff-specific
+]
+ignore = [
+    "E501",  # line length handled by formatter
+]
+
+[tool.ruff.lint.per-file-ignores]
+"tests/**" = ["B011", "SIM117"]
+
+[tool.mypy]
+python_version = "3.11"
+strict = true
+files = ["src"]
+warn_unused_ignores = true
+warn_redundant_casts = true
+
+[[tool.mypy.overrides]]
+module = ["pypsrp.*", "keyring.*"]
+ignore_missing_imports = true
+
+[tool.pytest.ini_options]
+minversion = "8.0"
+addopts = "-q --strict-markers"
+testpaths = ["tests"]
+pythonpath = ["src"]
+markers = [
+    "integration: requires real VM/network (skipped in unit-test runs)",
+]
+
+[tool.coverage.run]
+source = ["ci_orchestrator"]
+branch = true
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "if TYPE_CHECKING:",
+    "raise NotImplementedError",
+]
diff --git a/src/ci_orchestrator/__init__.py b/src/ci_orchestrator/__init__.py
new file mode 100644
index 0000000..84646d9
--- /dev/null
+++ b/src/ci_orchestrator/__init__.py
@@ -0,0 +1,9 @@
+"""Local CI/CD orchestrator package.
+
+Phase A: Python rewrite of the PowerShell-based orchestrator.
+See plans/implementation-plan-A-B.md for the full scope.
+"""
+
+__version__ = "0.1.0"
+
+__all__ = ["__version__"]
diff --git a/src/ci_orchestrator/__main__.py b/src/ci_orchestrator/__main__.py
new file mode 100644
index 0000000..864da0b
--- /dev/null
+++ b/src/ci_orchestrator/__main__.py
@@ -0,0 +1,123 @@
+"""CLI entry point.
+
+Phase A1 ships the ``wait-ready`` PoC sub-command. Subsequent steps add
+``vm``, ``build``, ``artifacts``, ``monitor``, ``report``, and ``job``.
+"""
+
+from __future__ import annotations
+
+import sys
+import time
+
+import click
+
+from ci_orchestrator import __version__
+from ci_orchestrator.backends import load_backend
+from ci_orchestrator.backends.errors import BackendError
+from ci_orchestrator.backends.protocol import VmHandle
+from ci_orchestrator.config import load_config
+from ci_orchestrator.credentials import KeyringCredentialStore
+from ci_orchestrator.transport.errors import TransportError
+from ci_orchestrator.transport.ssh import SshTransport
+from ci_orchestrator.transport.winrm import WinRmTransport
+
+
+@click.group()
+@click.version_option(__version__, prog_name="ci-orchestrator")
+def cli() -> None:
+    """Local CI/CD orchestrator (Phase A)."""
+
+
+@cli.command("wait-ready")
+@click.option("--vmx", required=True, help="Path to the guest VMX.")
+@click.option(
+    "--guest-os",
+    type=click.Choice(["windows", "linux"]),
+    default="windows",
+    show_default=True,
+)
+@click.option("--timeout", type=float, default=300.0, show_default=True)
+@click.option(
+    "--poll-interval", type=float, default=5.0, show_default=True, help="Seconds between probes."
+)
+@click.option(
+    "--credential-target",
+    default=None,
+    help="Override credential target name (defaults to config.guest_cred_target).",
+)
+@click.option("--ssh-user", default="ci_build", show_default=True)
+def wait_ready(
+    vmx: str,
+    guest_os: str,
+    timeout: float,
+    poll_interval: float,
+    credential_target: str | None,
+    ssh_user: str,
+) -> None:
+    """Poll a guest until WinRM (Windows) or SSH (Linux) is responsive."""
+    config = load_config()
+    backend = load_backend(config)
+    handle = VmHandle(identifier=vmx)
+
+    deadline = time.monotonic() + timeout
+
+    # Step 1: wait until backend reports the VM as running.
+    click.echo(f"[wait-ready] waiting for backend to report VM running: {vmx}")
+    while time.monotonic() < deadline:
+        try:
+            if backend.is_running(handle):
+                break
+        except BackendError as exc:
+            click.echo(f"[wait-ready] backend probe error: {exc}", err=True)
+        time.sleep(poll_interval)
+    else:
+        click.echo("[wait-ready] timeout waiting for VM to be running.", err=True)
+        sys.exit(2)
+
+    # Step 2: wait for an IP.
+    ip: str | None = None
+    while time.monotonic() < deadline:
+        try:
+            ip = backend.get_ip(handle)
+        except BackendError:
+            ip = None
+        if ip:
+            break
+        time.sleep(poll_interval)
+    if not ip:
+        click.echo("[wait-ready] timeout waiting for guest IP.", err=True)
+        sys.exit(3)
+    click.echo(f"[wait-ready] guest IP: {ip}")
+
+    # Step 3: probe the transport layer.
+    if guest_os == "windows":
+        store = KeyringCredentialStore()
+        target = credential_target or config.guest_cred_target
+        cred = store.get(target)
+        while time.monotonic() < deadline:
+            try:
+                with WinRmTransport(ip, cred.username, cred.password) as t:
+                    if t.is_ready():
+                        click.echo("[wait-ready] WinRM ready.")
+                        return
+            except TransportError as exc:
+                click.echo(f"[wait-ready] WinRM probe failed: {exc}", err=True)
+            time.sleep(poll_interval)
+    else:
+        key_path = config.ssh_key_path
+        while time.monotonic() < deadline:
+            try:
+                with SshTransport(ip, username=ssh_user, key_path=key_path) as t:
+                    if t.is_ready():
+                        click.echo("[wait-ready] SSH ready.")
+                        return
+            except TransportError as exc:
+                click.echo(f"[wait-ready] SSH probe failed: {exc}", err=True)
+            time.sleep(poll_interval)
+
+    click.echo("[wait-ready] timeout waiting for transport to be ready.", err=True)
+    sys.exit(4)
+
+
+if __name__ == "__main__":  # pragma: no cover
+    cli()
diff --git a/src/ci_orchestrator/backends/__init__.py b/src/ci_orchestrator/backends/__init__.py
new file mode 100644
index 0000000..761a213
--- /dev/null
+++ b/src/ci_orchestrator/backends/__init__.py
@@ -0,0 +1,30 @@
+"""VM backend implementations.
+
+The :class:`~ci_orchestrator.backends.protocol.VmBackend` Protocol defines
+the neutral interface every backend must satisfy. Phase A ships only the
+:class:`~ci_orchestrator.backends.workstation.WorkstationVmrunBackend`;
+Phase C will add an ESXi backend behind the same interface.
+"""
+
+from __future__ import annotations
+
+from ci_orchestrator.backends.protocol import VmBackend, VmHandle, VmState
+from ci_orchestrator.backends.workstation import WorkstationVmrunBackend
+
+__all__ = ["VmBackend", "VmHandle", "VmState", "WorkstationVmrunBackend", "load_backend"]
+
+
+def load_backend(config: object) -> VmBackend:
+    """Factory: pick a backend implementation from ``config.backend.type``.
+
+    Phase C hook: when the ESXi backend lands, this function will dispatch
+    on ``config.backend.type``. For now only ``workstation`` is supported.
+    """
+    backend_type = getattr(getattr(config, "backend", None), "type", "workstation")
+    if backend_type != "workstation":
+        raise NotImplementedError(
+            f"Backend type '{backend_type}' is not implemented. "
+            "Only 'workstation' is available in Phase A."
+        )
+    vmrun_path = getattr(config, "vmrun_path", None)
+    return WorkstationVmrunBackend(vmrun_path=vmrun_path)
diff --git a/src/ci_orchestrator/backends/errors.py b/src/ci_orchestrator/backends/errors.py
new file mode 100644
index 0000000..7b6a161
--- /dev/null
+++ b/src/ci_orchestrator/backends/errors.py
@@ -0,0 +1,24 @@
+"""Backend error hierarchy."""
+
+from __future__ import annotations
+
+
+class BackendError(RuntimeError):
+    """Base error for VM backend failures."""
+
+
+class BackendNotAvailable(BackendError):
+    """Backend tooling (e.g. ``vmrun``) is missing or unusable."""
+
+
+class BackendOperationFailed(BackendError):
+    """A backend operation (clone, start, ...) returned a non-zero status."""
+
+    def __init__(self, operation: str, returncode: int, output: str) -> None:
+        super().__init__(
+            f"Backend operation '{operation}' failed "
+            f"(exit={returncode}): {output.strip() or '<no output>'}"
+        )
+        self.operation = operation
+        self.returncode = returncode
+        self.output = output
diff --git a/src/ci_orchestrator/backends/protocol.py b/src/ci_orchestrator/backends/protocol.py
new file mode 100644
index 0000000..19af3b9
--- /dev/null
+++ b/src/ci_orchestrator/backends/protocol.py
@@ -0,0 +1,81 @@
+"""Neutral VM backend Protocol.
+
+Phase C hook: keep names hypervisor-agnostic. ``clone_linked``, ``start``,
+``stop``, ``delete``, ``get_ip``, ``list_snapshots`` map cleanly onto both
+``vmrun`` and pyVmomi (vSphere). Identifiers are opaque strings (a VMX path
+on Workstation, a managed object reference on ESXi).
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import StrEnum
+from typing import Protocol
+
+
+class VmState(StrEnum):
+    """Coarse VM power state, normalised across backends."""
+
+    POWERED_OFF = "powered_off"
+    POWERED_ON = "powered_on"
+    SUSPENDED = "suspended"
+    UNKNOWN = "unknown"
+
+
+@dataclass(frozen=True)
+class VmHandle:
+    """Opaque reference to a VM managed by a backend.
+
+    ``identifier`` is backend-specific (a VMX path for Workstation, a
+    managed object reference for vSphere). Callers MUST treat it as opaque.
+    """
+
+    identifier: str
+    name: str | None = None
+
+
+class VmBackend(Protocol):
+    """Hypervisor-agnostic VM operations.
+
+    All methods raise :class:`~ci_orchestrator.backends.errors.BackendError`
+    on failure. Implementations are free to add backend-specific kwargs but
+    MUST honour the documented signature for the listed parameters.
+    """
+
+    def clone_linked(
+        self,
+        template: str,
+        snapshot: str,
+        name: str,
+        destination: str | None = None,
+    ) -> VmHandle:
+        """Create a linked clone of ``template`` at snapshot ``snapshot``."""
+        ...
+
+    def start(self, handle: VmHandle, headless: bool = True) -> None:
+        """Power on the VM."""
+        ...
+
+    def stop(self, handle: VmHandle, hard: bool = False) -> None:
+        """Power off the VM. ``hard=True`` requests a forced power-off."""
+        ...
+
+    def delete(self, handle: VmHandle) -> None:
+        """Remove the VM from inventory and delete its files."""
+        ...
+
+    def get_ip(self, handle: VmHandle, timeout: float = 0.0) -> str | None:
+        """Return the guest's primary IP, or ``None`` if not yet known."""
+        ...
+
+    def list_snapshots(self, handle: VmHandle) -> list[str]:
+        """Return snapshot names defined on ``handle``."""
+        ...
+
+    def is_running(self, handle: VmHandle) -> bool:
+        """Return ``True`` if the VM appears in the running-VM list.
+
+        Implementations MUST NOT rely on guest tools (e.g. ``vmrun
+        getGuestIPAddress``) for this check — see ``AGENTS.md`` error #10.
+        """
+        ...
diff --git a/src/ci_orchestrator/backends/workstation.py b/src/ci_orchestrator/backends/workstation.py
new file mode 100644
index 0000000..652a846
--- /dev/null
+++ b/src/ci_orchestrator/backends/workstation.py
@@ -0,0 +1,157 @@
+"""VMware Workstation backend (``vmrun -T ws`` wrapper).
+
+Mirrors the behaviour of ``scripts/_Common.psm1`` :func:`Invoke-Vmrun` plus
+the higher-level helpers used by ``New-BuildVM.ps1`` and
+``Wait-VMReady.ps1``. Only ``subprocess`` is used — no PowerShell.
+
+Cross-platform: ``vmrun`` lives at different paths on Windows vs Linux;
+when ``vmrun_path`` is not provided, :func:`shutil.which` is consulted and
+finally a Windows default is tried.
+"""
+
+from __future__ import annotations
+
+import shutil
+import subprocess
+from pathlib import Path
+
+from ci_orchestrator.backends.errors import BackendNotAvailable, BackendOperationFailed
+from ci_orchestrator.backends.protocol import VmHandle
+
+_DEFAULT_WIN_VMRUN = r"C:\Program Files (x86)\VMware\VMware Workstation\vmrun.exe"
+
+
+def _resolve_vmrun(explicit: str | None) -> str:
+    """Pick a usable ``vmrun`` binary path."""
+    if explicit:
+        if not Path(explicit).is_file():
+            raise BackendNotAvailable(f"vmrun not found at: {explicit}")
+        return explicit
+    found = shutil.which("vmrun")
+    if found:
+        return found
+    if Path(_DEFAULT_WIN_VMRUN).is_file():
+        return _DEFAULT_WIN_VMRUN
+    raise BackendNotAvailable(
+        "vmrun is not available. Install VMware Workstation Pro or set vmrun_path."
+    )
+
+
+class WorkstationVmrunBackend:
+    """``vmrun -T ws`` backend for VMware Workstation Pro."""
+
+    def __init__(self, vmrun_path: str | None = None) -> None:
+        self._vmrun_path = _resolve_vmrun(vmrun_path)
+
+    # ------------------------------------------------------------------ utils
+    @property
+    def vmrun_path(self) -> str:
+        return self._vmrun_path
+
+    def _run(
+        self,
+        operation: str,
+        *args: str,
+        check: bool = True,
+        timeout: float | None = None,
+    ) -> subprocess.CompletedProcess[str]:
+        """Run ``vmrun -T ws <operation> <args...>`` and capture output."""
+        cmd = [self._vmrun_path, "-T", "ws", operation, *args]
+        result = subprocess.run(
+            cmd,
+            check=False,
+            capture_output=True,
+            text=True,
+            encoding="utf-8",
+            errors="replace",
+            timeout=timeout,
+        )
+        if check and result.returncode != 0:
+            raise BackendOperationFailed(
+                operation=operation,
+                returncode=result.returncode,
+                output=(result.stdout or "") + (result.stderr or ""),
+            )
+        return result
+
+    # ------------------------------------------------------------- VmBackend
+    def clone_linked(
+        self,
+        template: str,
+        snapshot: str,
+        name: str,
+        destination: str | None = None,
+    ) -> VmHandle:
+        if destination is None:
+            destination = str(Path(template).parent.parent / name / f"{name}.vmx")
+        # vmrun clone <srcVMX> <destVMX> linked -snapshot=<name> -cloneName=<name>
+        self._run(
+            "clone",
+            template,
+            destination,
+            "linked",
+            f"-snapshot={snapshot}",
+            f"-cloneName={name}",
+        )
+        return VmHandle(identifier=destination, name=name)
+
+    def start(self, handle: VmHandle, headless: bool = True) -> None:
+        mode = "nogui" if headless else "gui"
+        self._run("start", handle.identifier, mode)
+
+    def stop(self, handle: VmHandle, hard: bool = False) -> None:
+        mode = "hard" if hard else "soft"
+        # stop may legitimately fail if the VM is already off; treat that as ok
+        result = self._run("stop", handle.identifier, mode, check=False)
+        if result.returncode != 0:
+            stderr = (result.stderr or "").lower()
+            if "not powered on" in stderr or "is not running" in stderr:
+                return
+            raise BackendOperationFailed(
+                "stop",
+                result.returncode,
+                (result.stdout or "") + (result.stderr or ""),
+            )
+
+    def delete(self, handle: VmHandle) -> None:
+        self._run("deleteVM", handle.identifier)
+
+    def get_ip(self, handle: VmHandle, timeout: float = 0.0) -> str | None:
+        # ``getGuestIPAddress`` requires VMware Tools; tolerate failure.
+        args: list[str] = [handle.identifier]
+        if timeout > 0:
+            args.extend(["-wait"])
+        result = self._run("getGuestIPAddress", *args, check=False, timeout=timeout or None)
+        if result.returncode != 0:
+            return None
+        ip = (result.stdout or "").strip()
+        return ip or None
+
+    def list_snapshots(self, handle: VmHandle) -> list[str]:
+        result = self._run("listSnapshots", handle.identifier)
+        lines = [line.strip() for line in (result.stdout or "").splitlines() if line.strip()]
+        # First line is "Total snapshots: N"
+        if lines and lines[0].lower().startswith("total snapshots"):
+            lines = lines[1:]
+        return lines
+
+    def is_running(self, handle: VmHandle) -> bool:
+        """``vmrun list`` lookup — does NOT call ``getGuestIPAddress``.
+
+        See ``AGENTS.md`` error #10: ``getGuestIPAddress`` blocks for 30-60s
+        without VMware Tools. ``vmrun list`` returns immediately.
+        """
+        result = self._run("list", check=False)
+        if result.returncode != 0:
+            return False
+        target = Path(handle.identifier).resolve()
+        for line in (result.stdout or "").splitlines():
+            line = line.strip()
+            if not line or line.lower().startswith("total running"):
+                continue
+            try:
+                if Path(line).resolve() == target:
+                    return True
+            except OSError:
+                continue
+        return False
diff --git a/src/ci_orchestrator/config.py b/src/ci_orchestrator/config.py
new file mode 100644
index 0000000..df3744b
--- /dev/null
+++ b/src/ci_orchestrator/config.py
@@ -0,0 +1,163 @@
+"""Configuration loading for the CI orchestrator.
+
+Resolution order (later wins):
+  1. OS-aware defaults (Windows: F:\\CI\\..., Linux: /var/lib/ci/...).
+  2. Optional ``config.toml`` file (path via ``CI_CONFIG`` env var or
+     ``$CI_ROOT/config.toml`` if present).
+  3. Environment variables (``CI_ROOT``, ``CI_TEMPLATES``, ``CI_BUILD_VMS``,
+     ``CI_ARTIFACTS``, ``CI_KEYS``).
+
+Phase C hook: a ``[backend]`` section in ``config.toml`` selects the VM
+backend implementation; the field is read but currently only the
+``workstation`` value is supported.
+"""
+
+from __future__ import annotations
+
+import os
+import tomllib
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Any
+
+_ENV_KEYS = ("CI_ROOT", "CI_TEMPLATES", "CI_BUILD_VMS", "CI_ARTIFACTS", "CI_KEYS")
+
+
+@dataclass(frozen=True)
+class Paths:
+    """Filesystem paths used by the orchestrator."""
+
+    root: Path
+    templates: Path
+    build_vms: Path
+    artifacts: Path
+    keys: Path
+
+
+@dataclass(frozen=True)
+class BackendConfig:
+    """Backend selector. ``type`` is currently always 'workstation'."""
+
+    type: str = "workstation"
+    options: dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass(frozen=True)
+class Config:
+    """Top-level configuration object."""
+
+    paths: Paths
+    backend: BackendConfig
+    vmrun_path: str | None = None
+    ssh_key_path: Path | None = None
+    guest_cred_target: str = "BuildVMGuest"
+
+
+def _platform_defaults() -> Paths:
+    root = Path(r"F:\CI") if os.name == "nt" else Path("/var/lib/ci")
+    return Paths(
+        root=root,
+        templates=root / "Templates" if os.name == "nt" else root / "templates",
+        build_vms=root / "BuildVMs" if os.name == "nt" else root / "build-vms",
+        artifacts=root / "Artifacts" if os.name == "nt" else root / "artifacts",
+        keys=root / "keys" if os.name == "nt" else Path("/etc/ci/keys"),
+    )
+
+
+def _load_toml(path: Path) -> dict[str, Any]:
+    with path.open("rb") as fh:
+        return tomllib.load(fh)
+
+
+def _merge_paths(base: Paths, overrides: dict[str, Any]) -> Paths:
+    def pick(key: str, current: Path) -> Path:
+        val = overrides.get(key)
+        return Path(val) if val else current
+
+    return Paths(
+        root=pick("root", base.root),
+        templates=pick("templates", base.templates),
+        build_vms=pick("build_vms", base.build_vms),
+        artifacts=pick("artifacts", base.artifacts),
+        keys=pick("keys", base.keys),
+    )
+
+
+def _apply_env(paths: Paths, env: dict[str, str]) -> Paths:
+    mapping = {
+        "CI_ROOT": "root",
+        "CI_TEMPLATES": "templates",
+        "CI_BUILD_VMS": "build_vms",
+        "CI_ARTIFACTS": "artifacts",
+        "CI_KEYS": "keys",
+    }
+    overrides: dict[str, Any] = {}
+    for env_key, attr in mapping.items():
+        val = env.get(env_key)
+        if val:
+            overrides[attr] = val
+    return _merge_paths(paths, overrides)
+
+
+def load_config(
+    config_path: Path | None = None,
+    env: dict[str, str] | None = None,
+) -> Config:
+    """Build a :class:`Config` from defaults, optional TOML file, and env vars.
+
+    Parameters
+    ----------
+    config_path:
+        Explicit path to a TOML file. If ``None``, looks at ``$CI_CONFIG`` then
+        ``$CI_ROOT/config.toml``.
+    env:
+        Environment dict (defaults to :data:`os.environ`). Injected for tests.
+    """
+    if env is None:
+        env = dict(os.environ)
+
+    paths = _platform_defaults()
+
+    # Resolve config file
+    toml_path: Path | None = None
+    if config_path is not None:
+        toml_path = config_path
+    elif env.get("CI_CONFIG"):
+        toml_path = Path(env["CI_CONFIG"])
+    else:
+        candidate = paths.root / "config.toml"
+        if candidate.is_file():
+            toml_path = candidate
+
+    backend = BackendConfig()
+    vmrun_path: str | None = env.get("CI_VMRUN_PATH")
+    ssh_key_path = Path(env["CI_SSH_KEY_PATH"]) if env.get("CI_SSH_KEY_PATH") else None
+    guest_cred_target = env.get("CI_GUEST_CRED_TARGET", "BuildVMGuest")
+
+    if toml_path and toml_path.is_file():
+        data = _load_toml(toml_path)
+        paths = _merge_paths(paths, data.get("paths", {}))
+        backend_section = data.get("backend", {})
+        if backend_section:
+            backend = BackendConfig(
+                type=str(backend_section.get("type", "workstation")),
+                options={k: v for k, v in backend_section.items() if k != "type"},
+            )
+        if vmrun_path is None:
+            vmrun_path = data.get("vmrun_path")
+        if ssh_key_path is None and data.get("ssh_key_path"):
+            ssh_key_path = Path(data["ssh_key_path"])
+        guest_cred_target = data.get("guest_cred_target", guest_cred_target)
+
+    paths = _apply_env(paths, env)
+
+    return Config(
+        paths=paths,
+        backend=backend,
+        vmrun_path=vmrun_path,
+        ssh_key_path=ssh_key_path,
+        guest_cred_target=guest_cred_target,
+    )
+
+
+__all__ = ["BackendConfig", "Config", "Paths", "load_config"]
diff --git a/src/ci_orchestrator/credentials.py b/src/ci_orchestrator/credentials.py
new file mode 100644
index 0000000..d192e59
--- /dev/null
+++ b/src/ci_orchestrator/credentials.py
@@ -0,0 +1,59 @@
+"""Credential store abstraction.
+
+Wraps the ``keyring`` library so callers do not depend on it directly.
+Phase B note: the same interface is used on both Windows (Credential
+Manager) and Linux (Secret Service / file-based vault); see
+``plans/implementation-plan-A-B.md`` step B3.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Protocol
+
+
+@dataclass(frozen=True)
+class Credential:
+    """Username + secret pair retrieved from a credential store."""
+
+    username: str
+    password: str
+
+
+class CredentialStore(Protocol):
+    """Read-only credential lookup."""
+
+    def get(self, target: str) -> Credential:
+        """Return the credential associated with ``target``.
+
+        Raises :class:`KeyError` if the target is unknown.
+        """
+        ...
+
+
+class KeyringCredentialStore:
+    """Default :class:`CredentialStore` backed by the ``keyring`` library."""
+
+    def __init__(self, service: str = "ci") -> None:
+        self._service = service
+
+    def get(self, target: str) -> Credential:
+        try:
+            import keyring
+        except ImportError as exc:  # pragma: no cover - dep declared
+            raise RuntimeError(
+                "keyring is not installed; run `pip install keyring`."
+            ) from exc
+
+        cred = keyring.get_credential(target, None)
+        if cred is None:
+            # Fallback: some backends only support get_password and need the
+            # username to be the same as the target.
+            password = keyring.get_password(self._service, target)
+            if password is None:
+                raise KeyError(f"Credential '{target}' not found in keyring.")
+            return Credential(username=target, password=password)
+        return Credential(username=cred.username, password=cred.password)
+
+
+__all__ = ["Credential", "CredentialStore", "KeyringCredentialStore"]
diff --git a/src/ci_orchestrator/transport/__init__.py b/src/ci_orchestrator/transport/__init__.py
new file mode 100644
index 0000000..ba9b3eb
--- /dev/null
+++ b/src/ci_orchestrator/transport/__init__.py
@@ -0,0 +1,9 @@
+"""Guest transport layer (WinRM for Windows, SSH for Linux)."""
+
+from __future__ import annotations
+
+from ci_orchestrator.transport.errors import TransportError
+from ci_orchestrator.transport.ssh import SshTransport
+from ci_orchestrator.transport.winrm import WinRmTransport
+
+__all__ = ["SshTransport", "TransportError", "WinRmTransport"]
diff --git a/src/ci_orchestrator/transport/errors.py b/src/ci_orchestrator/transport/errors.py
new file mode 100644
index 0000000..1a5eb06
--- /dev/null
+++ b/src/ci_orchestrator/transport/errors.py
@@ -0,0 +1,23 @@
+"""Transport error hierarchy."""
+
+from __future__ import annotations
+
+
+class TransportError(RuntimeError):
+    """Base class for transport-layer (WinRM/SSH) failures."""
+
+
+class TransportConnectError(TransportError):
+    """Raised when the underlying connection cannot be established."""
+
+
+class TransportCommandError(TransportError):
+    """Raised when a remote command exits non-zero."""
+
+    def __init__(self, returncode: int, stdout: str, stderr: str) -> None:
+        super().__init__(
+            f"Remote command failed (exit={returncode}): {(stderr or stdout).strip()[:500]}"
+        )
+        self.returncode = returncode
+        self.stdout = stdout
+        self.stderr = stderr
diff --git a/src/ci_orchestrator/transport/ssh.py b/src/ci_orchestrator/transport/ssh.py
new file mode 100644
index 0000000..141cf69
--- /dev/null
+++ b/src/ci_orchestrator/transport/ssh.py
@@ -0,0 +1,150 @@
+"""SSH transport via ``paramiko``.
+
+Replaces the ``ssh.exe`` / ``scp.exe`` calls used in
+``scripts/_Transport.psm1``. By default the host-key policy is
+``AutoAddPolicy`` with an empty ``known_hosts`` file (i.e. permissive),
+which mirrors the ``StrictHostKeyChecking=no UserKnownHostsFile=NUL``
+default used for ephemeral CI build VMs.
+
+See ``AGENTS.md`` error #12: in PowerShell with ``$ErrorActionPreference =
+'Stop'`` the native ``ssh-keygen -R`` call could raise terminating errors
+on stderr output. With paramiko there is no equivalent issue.
+"""
+
+from __future__ import annotations
+
+import contextlib
+from dataclasses import dataclass
+from pathlib import Path
+from typing import TYPE_CHECKING
+
+from ci_orchestrator.transport.errors import TransportCommandError, TransportConnectError
+
+if TYPE_CHECKING:  # pragma: no cover
+    import paramiko
+
+
+@dataclass(frozen=True)
+class SshResult:
+    """Result of a remote SSH command."""
+
+    stdout: str
+    stderr: str
+    returncode: int
+
+    @property
+    def ok(self) -> bool:
+        return self.returncode == 0
+
+
+class SshTransport:
+    """Thin wrapper around :class:`paramiko.SSHClient`."""
+
+    def __init__(
+        self,
+        host: str,
+        *,
+        username: str = "ci_build",
+        key_path: str | Path | None = None,
+        port: int = 22,
+        connect_timeout: float = 10.0,
+        known_hosts: str | Path | None = None,
+    ) -> None:
+        self._host = host
+        self._username = username
+        self._key_path = Path(key_path) if key_path else None
+        self._port = port
+        self._connect_timeout = connect_timeout
+        self._known_hosts = Path(known_hosts) if known_hosts else None
+        self._client: paramiko.SSHClient | None = None
+
+    # ----------------------------------------------------------- connection
+    def _connect(self) -> paramiko.SSHClient:
+        if self._client is not None:
+            return self._client
+        try:
+            import paramiko
+        except ImportError as exc:  # pragma: no cover - dep declared
+            raise TransportConnectError(
+                "paramiko is not installed; run `pip install paramiko`."
+            ) from exc
+
+        client = paramiko.SSHClient()
+        if self._known_hosts is not None and self._known_hosts.is_file():
+            client.load_host_keys(str(self._known_hosts))
+            client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+        else:
+            # Permissive mode for ephemeral CI VMs (see _Transport.psm1).
+            client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+
+        try:
+            client.connect(
+                hostname=self._host,
+                port=self._port,
+                username=self._username,
+                key_filename=str(self._key_path) if self._key_path else None,
+                timeout=self._connect_timeout,
+                allow_agent=False,
+                look_for_keys=False,
+            )
+        except Exception as exc:
+            raise TransportConnectError(
+                f"SSH connection to {self._username}@{self._host}:{self._port} failed: {exc}"
+            ) from exc
+        self._client = client
+        return client
+
+    def close(self) -> None:
+        if self._client is not None:
+            with contextlib.suppress(Exception):
+                self._client.close()
+            self._client = None
+
+    def __enter__(self) -> SshTransport:
+        self._connect()
+        return self
+
+    def __exit__(self, *_exc: object) -> None:
+        self.close()
+
+    # --------------------------------------------------------------- ops
+    def run(self, command: str, *, check: bool = True, timeout: float | None = None) -> SshResult:
+        """Run ``command`` in the guest shell."""
+        client = self._connect()
+        try:
+            _stdin, stdout, stderr = client.exec_command(command, timeout=timeout)
+            out = stdout.read().decode("utf-8", errors="replace")
+            err = stderr.read().decode("utf-8", errors="replace")
+            rc = stdout.channel.recv_exit_status()
+        except Exception as exc:
+            raise TransportConnectError(f"SSH exec_command failed: {exc}") from exc
+        result = SshResult(stdout=out, stderr=err, returncode=rc)
+        if check and not result.ok:
+            raise TransportCommandError(result.returncode, result.stdout, result.stderr)
+        return result
+
+    def copy(self, local_path: str | Path, remote_path: str) -> None:
+        """Upload via SFTP."""
+        client = self._connect()
+        try:
+            with client.open_sftp() as sftp:
+                sftp.put(str(local_path), remote_path)
+        except Exception as exc:
+            raise TransportConnectError(f"SFTP put failed: {exc}") from exc
+
+    def fetch(self, remote_path: str, local_path: str | Path) -> None:
+        """Download via SFTP."""
+        client = self._connect()
+        try:
+            with client.open_sftp() as sftp:
+                sftp.get(remote_path, str(local_path))
+        except Exception as exc:
+            raise TransportConnectError(f"SFTP get failed: {exc}") from exc
+
+    def is_ready(self) -> bool:
+        """Lightweight readiness probe."""
+        try:
+            result = self.run("true", check=False, timeout=5.0)
+        except (TransportConnectError, TransportCommandError):
+            return False
+        return result.ok
diff --git a/src/ci_orchestrator/transport/winrm.py b/src/ci_orchestrator/transport/winrm.py
new file mode 100644
index 0000000..93e7750
--- /dev/null
+++ b/src/ci_orchestrator/transport/winrm.py
@@ -0,0 +1,156 @@
+"""WinRM transport via ``pypsrp``.
+
+Replaces the ``New-PSSession`` / ``Invoke-Command`` calls used in the
+PowerShell scripts. CI build VMs use a self-signed TLS certificate on
+WinRM port 5986, so SSL validation is disabled by default — appropriate
+for an isolated lab network (see ``scripts/_Common.psm1``).
+"""
+
+from __future__ import annotations
+
+import contextlib
+from dataclasses import dataclass
+from pathlib import Path
+from typing import TYPE_CHECKING, Any
+
+from ci_orchestrator.transport.errors import TransportCommandError, TransportConnectError
+
+if TYPE_CHECKING:  # pragma: no cover
+    from pypsrp.client import Client
+
+
+@dataclass(frozen=True)
+class WinRmResult:
+    """Result of a remote PowerShell invocation."""
+
+    stdout: str
+    stderr: str
+    returncode: int
+
+    @property
+    def ok(self) -> bool:
+        return self.returncode == 0
+
+
+class WinRmTransport:
+    """Thin wrapper around :class:`pypsrp.client.Client`.
+
+    Parameters
+    ----------
+    host:
+        IP or DNS name of the guest.
+    username, password:
+        Credentials. Pass via :class:`~ci_orchestrator.credentials.Credential`
+        in caller code; do not embed plaintext.
+    port:
+        WinRM HTTPS port (default 5986).
+    cert_validation:
+        When ``False`` (default), self-signed certs are accepted — required
+        for the ephemeral build VMs in this lab.
+    """
+
+    def __init__(
+        self,
+        host: str,
+        username: str,
+        password: str,
+        *,
+        port: int = 5986,
+        ssl: bool = True,
+        cert_validation: bool = False,
+        connection_timeout: int = 30,
+    ) -> None:
+        self._host = host
+        self._username = username
+        self._password = password
+        self._port = port
+        self._ssl = ssl
+        self._cert_validation = cert_validation
+        self._connection_timeout = connection_timeout
+        self._client: Client | None = None
+
+    # ----------------------------------------------------------- connection
+    def _connect(self) -> Client:
+        if self._client is not None:
+            return self._client
+        try:
+            from pypsrp.client import Client  # local import: optional dep at runtime
+        except ImportError as exc:  # pragma: no cover - dep declared in pyproject
+            raise TransportConnectError(
+                "pypsrp is not installed; run `pip install pypsrp`."
+            ) from exc
+        try:
+            self._client = Client(
+                self._host,
+                username=self._username,
+                password=self._password,
+                port=self._port,
+                ssl=self._ssl,
+                cert_validation=self._cert_validation,
+                connection_timeout=self._connection_timeout,
+            )
+        except Exception as exc:
+            raise TransportConnectError(
+                f"WinRM connection to {self._host}:{self._port} failed: {exc}"
+            ) from exc
+        return self._client
+
+    def close(self) -> None:
+        if self._client is not None:
+            with contextlib.suppress(Exception):
+                self._client.wsman.close()
+            self._client = None
+
+    def __enter__(self) -> WinRmTransport:
+        self._connect()
+        return self
+
+    def __exit__(self, *_exc: object) -> None:
+        self.close()
+
+    # --------------------------------------------------------------- ops
+    def run(self, script: str, *, check: bool = True) -> WinRmResult:
+        """Run a PowerShell script block in the guest."""
+        client = self._connect()
+        try:
+            stdout, stderr, returncode = client.execute_ps(script)
+        except Exception as exc:
+            raise TransportConnectError(f"WinRM execute_ps failed: {exc}") from exc
+        # pypsrp returns stderr as a list of PSRP error records in some versions;
+        # normalise to a string.
+        stderr_any: Any = stderr
+        if isinstance(stderr_any, str):
+            stderr_str = stderr_any
+        else:
+            try:
+                stderr_str = "\n".join(str(s) for s in stderr_any)
+            except TypeError:
+                stderr_str = str(stderr_any)
+        result = WinRmResult(stdout=stdout, stderr=stderr_str, returncode=int(returncode))
+        if check and not result.ok:
+            raise TransportCommandError(result.returncode, result.stdout, result.stderr)
+        return result
+
+    def copy(self, local_path: str | Path, remote_path: str) -> None:
+        """Upload a file to the guest via PSRP."""
+        client = self._connect()
+        try:
+            client.copy(str(local_path), remote_path)
+        except Exception as exc:
+            raise TransportConnectError(f"WinRM copy failed: {exc}") from exc
+
+    def fetch(self, remote_path: str, local_path: str | Path) -> None:
+        """Download a file from the guest via PSRP."""
+        client = self._connect()
+        try:
+            client.fetch(remote_path, str(local_path))
+        except Exception as exc:
+            raise TransportConnectError(f"WinRM fetch failed: {exc}") from exc
+
+    def is_ready(self) -> bool:
+        """Lightweight readiness probe: run ``$true`` and check exit code."""
+        try:
+            result = self.run("$true | Out-Null", check=False)
+        except (TransportConnectError, TransportCommandError):
+            return False
+        return result.ok
diff --git a/tests/python/__init__.py b/tests/python/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/python/conftest.py b/tests/python/conftest.py
new file mode 100644
index 0000000..8284c8e
--- /dev/null
+++ b/tests/python/conftest.py
@@ -0,0 +1,11 @@
+"""Shared pytest fixtures for ci_orchestrator unit tests."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+# Ensure src/ is on sys.path so `import ci_orchestrator` works without install.
+_SRC = Path(__file__).resolve().parents[2] / "src"
+if str(_SRC) not in sys.path:
+    sys.path.insert(0, str(_SRC))
diff --git a/tests/python/test_cli.py b/tests/python/test_cli.py
new file mode 100644
index 0000000..9739e4a
--- /dev/null
+++ b/tests/python/test_cli.py
@@ -0,0 +1,133 @@
+"""Smoke tests for the click CLI entry point.
+
+These do not hit any real VM — backend, transport, credentials and
+``time.sleep`` are all monkeypatched.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+import pytest
+from click.testing import CliRunner
+
+import ci_orchestrator.__main__ as cli_module
+from ci_orchestrator import __version__
+from ci_orchestrator.backends.protocol import VmHandle
+from ci_orchestrator.credentials import Credential
+
+
+class _FakeBackend:
+    def __init__(
+        self,
+        *,
+        running: bool = True,
+        ip: str | None = "10.0.0.42",
+    ) -> None:
+        self._running = running
+        self._ip = ip
+
+    def is_running(self, _h: VmHandle) -> bool:
+        return self._running
+
+    def get_ip(self, _h: VmHandle, timeout: float = 0.0) -> str | None:
+        return self._ip
+
+
+class _FakeTransport:
+    def __init__(self, *_a: Any, **_kw: Any) -> None:
+        pass
+
+    def __enter__(self) -> _FakeTransport:
+        return self
+
+    def __exit__(self, *_e: object) -> None:
+        pass
+
+    def is_ready(self) -> bool:
+        return True
+
+
+class _FakeStore:
+    def get(self, _target: str) -> Credential:
+        return Credential("user", "pwd")
+
+
+def _patch_common(monkeypatch: pytest.MonkeyPatch, backend: _FakeBackend) -> None:
+    monkeypatch.setattr(cli_module, "load_backend", lambda _cfg: backend)
+    monkeypatch.setattr(cli_module, "KeyringCredentialStore", lambda: _FakeStore())
+    monkeypatch.setattr(cli_module, "WinRmTransport", _FakeTransport)
+    monkeypatch.setattr(cli_module, "SshTransport", _FakeTransport)
+    monkeypatch.setattr(cli_module.time, "sleep", lambda _s: None)
+
+
+def test_help_lists_wait_ready() -> None:
+    result = CliRunner().invoke(cli_module.cli, ["--help"])
+    assert result.exit_code == 0
+    assert "wait-ready" in result.output
+
+
+def test_version() -> None:
+    result = CliRunner().invoke(cli_module.cli, ["--version"])
+    assert result.exit_code == 0
+    assert __version__ in result.output
+
+
+def test_wait_ready_windows_success(monkeypatch: pytest.MonkeyPatch) -> None:
+    _patch_common(monkeypatch, _FakeBackend(running=True, ip="10.0.0.42"))
+    result = CliRunner().invoke(
+        cli_module.cli,
+        ["wait-ready", "--vmx", "x.vmx", "--guest-os", "windows", "--timeout", "1"],
+    )
+    assert result.exit_code == 0, result.output
+    assert "WinRM ready" in result.output
+
+
+def test_wait_ready_linux_success(monkeypatch: pytest.MonkeyPatch) -> None:
+    _patch_common(monkeypatch, _FakeBackend(running=True, ip="10.0.0.42"))
+    result = CliRunner().invoke(
+        cli_module.cli,
+        ["wait-ready", "--vmx", "x.vmx", "--guest-os", "linux", "--timeout", "1"],
+    )
+    assert result.exit_code == 0, result.output
+    assert "SSH ready" in result.output
+
+
+def test_wait_ready_timeout_when_not_running(monkeypatch: pytest.MonkeyPatch) -> None:
+    _patch_common(monkeypatch, _FakeBackend(running=False))
+    result = CliRunner().invoke(
+        cli_module.cli,
+        [
+            "wait-ready",
+            "--vmx",
+            "x.vmx",
+            "--guest-os",
+            "windows",
+            "--timeout",
+            "0.01",
+            "--poll-interval",
+            "0.001",
+        ],
+    )
+    assert result.exit_code == 2
+    assert "timeout waiting for VM" in result.output
+
+
+def test_wait_ready_timeout_no_ip(monkeypatch: pytest.MonkeyPatch) -> None:
+    _patch_common(monkeypatch, _FakeBackend(running=True, ip=None))
+    result = CliRunner().invoke(
+        cli_module.cli,
+        [
+            "wait-ready",
+            "--vmx",
+            "x.vmx",
+            "--guest-os",
+            "windows",
+            "--timeout",
+            "0.01",
+            "--poll-interval",
+            "0.001",
+        ],
+    )
+    assert result.exit_code == 3
+    assert "timeout waiting for guest IP" in result.output
diff --git a/tests/python/test_config.py b/tests/python/test_config.py
new file mode 100644
index 0000000..5eaf57e
--- /dev/null
+++ b/tests/python/test_config.py
@@ -0,0 +1,62 @@
+"""Tests for ci_orchestrator.config."""
+
+from __future__ import annotations
+
+import os
+from pathlib import Path
+
+from ci_orchestrator.config import load_config
+
+
+def test_defaults_are_os_aware() -> None:
+    cfg = load_config(env={})
+    if os.name == "nt":
+        assert str(cfg.paths.root) == r"F:\CI"
+    else:
+        assert str(cfg.paths.root) == "/var/lib/ci"
+
+
+def test_env_overrides_paths(tmp_path: Path) -> None:
+    cfg = load_config(
+        env={
+            "CI_ROOT": str(tmp_path / "root"),
+            "CI_TEMPLATES": str(tmp_path / "tpl"),
+            "CI_BUILD_VMS": str(tmp_path / "bvm"),
+            "CI_ARTIFACTS": str(tmp_path / "art"),
+            "CI_KEYS": str(tmp_path / "keys"),
+        }
+    )
+    assert cfg.paths.root == tmp_path / "root"
+    assert cfg.paths.templates == tmp_path / "tpl"
+    assert cfg.paths.build_vms == tmp_path / "bvm"
+    assert cfg.paths.artifacts == tmp_path / "art"
+    assert cfg.paths.keys == tmp_path / "keys"
+
+
+def test_toml_overrides_defaults(tmp_path: Path) -> None:
+    toml = tmp_path / "config.toml"
+    toml.write_text(
+        '[paths]\n'
+        f'root = "{(tmp_path / "altroot").as_posix()}"\n'
+        '[backend]\n'
+        'type = "workstation"\n'
+        'extra = "value"\n',
+        encoding="utf-8",
+    )
+    cfg = load_config(config_path=toml, env={})
+    assert cfg.paths.root == tmp_path / "altroot"
+    assert cfg.backend.type == "workstation"
+    assert cfg.backend.options == {"extra": "value"}
+
+
+def test_env_wins_over_toml(tmp_path: Path) -> None:
+    toml = tmp_path / "config.toml"
+    toml.write_text(
+        f'[paths]\nroot = "{(tmp_path / "fromtoml").as_posix()}"\n',
+        encoding="utf-8",
+    )
+    cfg = load_config(
+        config_path=toml,
+        env={"CI_ROOT": str(tmp_path / "fromenv")},
+    )
+    assert cfg.paths.root == tmp_path / "fromenv"
diff --git a/tests/python/test_credentials.py b/tests/python/test_credentials.py
new file mode 100644
index 0000000..a48271c
--- /dev/null
+++ b/tests/python/test_credentials.py
@@ -0,0 +1,58 @@
+"""Tests for KeyringCredentialStore (mocked keyring backend)."""
+
+from __future__ import annotations
+
+import sys
+import types
+from typing import Any
+
+import pytest
+
+from ci_orchestrator.credentials import KeyringCredentialStore
+
+
+def _install_fake_keyring(monkeypatch: pytest.MonkeyPatch, **behaviour: Any) -> None:
+    fake = types.ModuleType("keyring")
+
+    def get_credential(target: str, _username: str | None) -> Any:
+        return behaviour.get("credential_map", {}).get(target)
+
+    def get_password(service: str, target: str) -> str | None:
+        return behaviour.get("password_map", {}).get((service, target))
+
+    fake.get_credential = get_credential  # type: ignore[attr-defined]
+    fake.get_password = get_password  # type: ignore[attr-defined]
+    monkeypatch.setitem(sys.modules, "keyring", fake)
+
+
+class _FakeCred:
+    def __init__(self, username: str, password: str) -> None:
+        self.username = username
+        self.password = password
+
+
+def test_get_returns_credential(monkeypatch: pytest.MonkeyPatch) -> None:
+    _install_fake_keyring(
+        monkeypatch,
+        credential_map={"BuildVMGuest": _FakeCred("Administrator", "s3cret")},
+    )
+    cred = KeyringCredentialStore().get("BuildVMGuest")
+    assert cred.username == "Administrator"
+    assert cred.password == "s3cret"
+
+
+def test_get_falls_back_to_password(monkeypatch: pytest.MonkeyPatch) -> None:
+    _install_fake_keyring(
+        monkeypatch,
+        credential_map={},
+        password_map={("ci", "GiteaPAT"): "tokentoken"},
+    )
+    cred = KeyringCredentialStore().get("GiteaPAT")
+    assert cred.username == "GiteaPAT"
+    assert cred.password == "tokentoken"
+
+
+def test_get_raises_when_missing(monkeypatch: pytest.MonkeyPatch) -> None:
+    _install_fake_keyring(monkeypatch, credential_map={}, password_map={})
+    with pytest.raises(KeyError):
+        KeyringCredentialStore().get("Unknown")
diff --git a/tests/python/test_load_backend.py b/tests/python/test_load_backend.py
new file mode 100644
index 0000000..0457c84
--- /dev/null
+++ b/tests/python/test_load_backend.py
@@ -0,0 +1,36 @@
+"""Factory test: load_backend dispatches on config.backend.type."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+
+import pytest
+
+from ci_orchestrator.backends import load_backend
+from ci_orchestrator.backends.workstation import WorkstationVmrunBackend
+
+
+@dataclass
+class _BE:
+    type: str
+
+
+@dataclass
+class _Cfg:
+    backend: _BE
+    vmrun_path: str | None = None
+
+
+def test_load_backend_returns_workstation(tmp_path: Path) -> None:
+    fake = tmp_path / "vmrun.exe"
+    fake.write_bytes(b"")
+    backend = load_backend(_Cfg(backend=_BE("workstation"), vmrun_path=str(fake)))
+    assert isinstance(backend, WorkstationVmrunBackend)
+
+
+def test_load_backend_rejects_unknown(tmp_path: Path) -> None:
+    fake = tmp_path / "vmrun.exe"
+    fake.write_bytes(b"")
+    with pytest.raises(NotImplementedError):
+        load_backend(_Cfg(backend=_BE("esxi"), vmrun_path=str(fake)))
diff --git a/tests/python/test_ssh_transport.py b/tests/python/test_ssh_transport.py
new file mode 100644
index 0000000..609dddb
--- /dev/null
+++ b/tests/python/test_ssh_transport.py
@@ -0,0 +1,159 @@
+"""Tests for SshTransport (paramiko mocked).
+
+Covers AGENTS.md error #12 indirectly: with paramiko there is no native
+``ssh-keygen`` invocation, so the PowerShell stderr-handling pitfall does
+not apply. The default permissive host-key policy mirrors the
+``StrictHostKeyChecking=no`` / ``UserKnownHostsFile=NUL`` defaults of
+``scripts/_Transport.psm1``.
+"""
+
+from __future__ import annotations
+
+import sys
+import types
+from typing import Any
+
+import pytest
+
+from ci_orchestrator.transport.errors import TransportCommandError, TransportConnectError
+from ci_orchestrator.transport.ssh import SshTransport
+
+
+class _FakeChannel:
+    def __init__(self, rc: int) -> None:
+        self._rc = rc
+
+    def recv_exit_status(self) -> int:
+        return self._rc
+
+
+class _FakeStream:
+    def __init__(self, data: bytes, rc: int = 0) -> None:
+        self._data = data
+        self.channel = _FakeChannel(rc)
+
+    def read(self) -> bytes:
+        return self._data
+
+
+class _FakeSFTP:
+    def __init__(self) -> None:
+        self.puts: list[tuple[str, str]] = []
+        self.gets: list[tuple[str, str]] = []
+
+    def __enter__(self) -> _FakeSFTP:
+        return self
+
+    def __exit__(self, *_e: object) -> None:
+        pass
+
+    def put(self, local: str, remote: str) -> None:
+        self.puts.append((local, remote))
+
+    def get(self, remote: str, local: str) -> None:
+        self.gets.append((remote, local))
+
+
+class _FakeSSHClient:
+    def __init__(self) -> None:
+        self.connect_kwargs: dict[str, Any] = {}
+        self.policy: Any = None
+        self.next_stdout = b""
+        self.next_stderr = b""
+        self.next_rc = 0
+        self.commands: list[str] = []
+        self.sftp = _FakeSFTP()
+        self.closed = False
+
+    def set_missing_host_key_policy(self, policy: Any) -> None:
+        self.policy = policy
+
+    def load_host_keys(self, _path: str) -> None:
+        pass
+
+    def connect(self, **kwargs: Any) -> None:
+        self.connect_kwargs = kwargs
+
+    def exec_command(self, command: str, timeout: float | None = None) -> Any:
+        self.commands.append(command)
+        return (
+            None,
+            _FakeStream(self.next_stdout, self.next_rc),
+            _FakeStream(self.next_stderr, self.next_rc),
+        )
+
+    def open_sftp(self) -> _FakeSFTP:
+        return self.sftp
+
+    def close(self) -> None:
+        self.closed = True
+
+
+def _install_fake_paramiko(monkeypatch: pytest.MonkeyPatch, client: _FakeSSHClient) -> Any:
+    fake = types.ModuleType("paramiko")
+    fake.SSHClient = lambda: client  # type: ignore[attr-defined]
+    fake.AutoAddPolicy = lambda: "auto-add"  # type: ignore[attr-defined]
+    monkeypatch.setitem(sys.modules, "paramiko", fake)
+    return fake
+
+
+def test_run_returns_stdout(monkeypatch: pytest.MonkeyPatch) -> None:
+    client = _FakeSSHClient()
+    client.next_stdout = b"hello\n"
+    _install_fake_paramiko(monkeypatch, client)
+    t = SshTransport("10.0.0.2", username="ci_build", key_path="/tmp/key")
+    result = t.run("echo hello")
+    assert result.ok
+    assert result.stdout == "hello\n"
+    assert client.commands == ["echo hello"]
+
+
+def test_run_raises_on_nonzero(monkeypatch: pytest.MonkeyPatch) -> None:
+    client = _FakeSSHClient()
+    client.next_rc = 2
+    client.next_stderr = b"oops"
+    _install_fake_paramiko(monkeypatch, client)
+    t = SshTransport("10.0.0.2", key_path="/tmp/key")
+    with pytest.raises(TransportCommandError):
+        t.run("bad")
+
+
+def test_default_policy_is_auto_add(monkeypatch: pytest.MonkeyPatch) -> None:
+    """Mirrors permissive `StrictHostKeyChecking=no` default for ephemeral CI VMs."""
+    client = _FakeSSHClient()
+    _install_fake_paramiko(monkeypatch, client)
+    SshTransport("10.0.0.2", key_path="/tmp/key").run("true")
+    assert client.policy == "auto-add"
+
+
+def test_copy_and_fetch(monkeypatch: pytest.MonkeyPatch) -> None:
+    client = _FakeSSHClient()
+    _install_fake_paramiko(monkeypatch, client)
+    t = SshTransport("10.0.0.2", key_path="/tmp/key")
+    t.copy("local.bin", "/remote/local.bin")
+    t.fetch("/remote/out.bin", "out.bin")
+    assert client.sftp.puts == [("local.bin", "/remote/local.bin")]
+    assert client.sftp.gets == [("/remote/out.bin", "out.bin")]
+
+
+def test_is_ready_returns_false_on_connect_failure(monkeypatch: pytest.MonkeyPatch) -> None:
+    fake = types.ModuleType("paramiko")
+
+    class _Boom:
+        def set_missing_host_key_policy(self, _p: object) -> None:
+            pass
+
+        def connect(self, **_kw: Any) -> None:
+            raise OSError("refused")
+
+        def close(self) -> None:
+            pass
+
+    fake.SSHClient = lambda: _Boom()  # type: ignore[attr-defined]
+    fake.AutoAddPolicy = lambda: object()  # type: ignore[attr-defined]
+    monkeypatch.setitem(sys.modules, "paramiko", fake)
+
+    t = SshTransport("10.0.0.2", key_path="/tmp/key")
+    assert t.is_ready() is False
+    with pytest.raises(TransportConnectError):
+        t.run("x")
diff --git a/tests/python/test_winrm_transport.py b/tests/python/test_winrm_transport.py
new file mode 100644
index 0000000..1fa2e23
--- /dev/null
+++ b/tests/python/test_winrm_transport.py
@@ -0,0 +1,100 @@
+"""Tests for WinRmTransport (pypsrp client mocked)."""
+
+from __future__ import annotations
+
+import sys
+import types
+from typing import Any
+
+import pytest
+
+from ci_orchestrator.transport.errors import TransportCommandError, TransportConnectError
+from ci_orchestrator.transport.winrm import WinRmTransport
+
+
+class _FakeClient:
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        self.args = args
+        self.kwargs = kwargs
+        self.copies: list[tuple[str, str]] = []
+        self.fetches: list[tuple[str, str]] = []
+        self.scripts: list[str] = []
+        self.next_result: tuple[str, str, int] = ("ok", "", 0)
+        self.wsman = types.SimpleNamespace(close=lambda: None)
+
+    def execute_ps(self, script: str) -> tuple[str, str, int]:
+        self.scripts.append(script)
+        return self.next_result
+
+    def copy(self, local: str, remote: str) -> None:
+        self.copies.append((local, remote))
+
+    def fetch(self, remote: str, local: str) -> None:
+        self.fetches.append((remote, local))
+
+
+def _install_fake_pypsrp(monkeypatch: pytest.MonkeyPatch, client: _FakeClient) -> None:
+    module = types.ModuleType("pypsrp")
+    client_module = types.ModuleType("pypsrp.client")
+    client_module.Client = lambda *a, **kw: client  # type: ignore[attr-defined]
+    monkeypatch.setitem(sys.modules, "pypsrp", module)
+    monkeypatch.setitem(sys.modules, "pypsrp.client", client_module)
+
+
+def test_run_returns_result(monkeypatch: pytest.MonkeyPatch) -> None:
+    fake = _FakeClient()
+    fake.next_result = ("hello\n", "", 0)
+    _install_fake_pypsrp(monkeypatch, fake)
+    t = WinRmTransport("10.0.0.1", "user", "pwd")
+    result = t.run("Write-Output 'hello'")
+    assert result.ok
+    assert result.stdout == "hello\n"
+    assert fake.scripts == ["Write-Output 'hello'"]
+
+
+def test_run_raises_on_failure(monkeypatch: pytest.MonkeyPatch) -> None:
+    fake = _FakeClient()
+    fake.next_result = ("", "boom", 7)
+    _install_fake_pypsrp(monkeypatch, fake)
+    t = WinRmTransport("10.0.0.1", "user", "pwd")
+    with pytest.raises(TransportCommandError) as exc:
+        t.run("bad")
+    assert exc.value.returncode == 7
+
+
+def test_run_check_false_does_not_raise(monkeypatch: pytest.MonkeyPatch) -> None:
+    fake = _FakeClient()
+    fake.next_result = ("", "boom", 7)
+    _install_fake_pypsrp(monkeypatch, fake)
+    t = WinRmTransport("10.0.0.1", "user", "pwd")
+    result = t.run("bad", check=False)
+    assert not result.ok
+
+
+def test_copy_and_fetch(monkeypatch: pytest.MonkeyPatch) -> None:
+    fake = _FakeClient()
+    _install_fake_pypsrp(monkeypatch, fake)
+    t = WinRmTransport("10.0.0.1", "user", "pwd")
+    t.copy("local.txt", "C:/remote.txt")
+    t.fetch("C:/remote.txt", "downloaded.txt")
+    assert fake.copies == [("local.txt", "C:/remote.txt")]
+    assert fake.fetches == [("C:/remote.txt", "downloaded.txt")]
+
+
+def test_is_ready_handles_connect_failure(monkeypatch: pytest.MonkeyPatch) -> None:
+    # Make the local import inside _connect succeed but Client raise.
+    module = types.ModuleType("pypsrp")
+    client_module = types.ModuleType("pypsrp.client")
+
+    def _boom(*_a: object, **_kw: object) -> None:
+        raise OSError("connection refused")
+
+    client_module.Client = _boom  # type: ignore[attr-defined]
+    monkeypatch.setitem(sys.modules, "pypsrp", module)
+    monkeypatch.setitem(sys.modules, "pypsrp.client", client_module)
+
+    t = WinRmTransport("10.0.0.1", "user", "pwd")
+    assert t.is_ready() is False
+    # Direct .run should raise.
+    with pytest.raises(TransportConnectError):
+        t.run("x")
diff --git a/tests/python/test_workstation_backend.py b/tests/python/test_workstation_backend.py
new file mode 100644
index 0000000..9842936
--- /dev/null
+++ b/tests/python/test_workstation_backend.py
@@ -0,0 +1,149 @@
+"""Unit tests for WorkstationVmrunBackend.
+
+Cover AGENTS.md error #10: ``is_running`` MUST use ``vmrun list`` and
+NOT ``getGuestIPAddress`` (which would block 30-60s without VMware Tools).
+"""
+
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+from typing import Any
+
+import pytest
+
+from ci_orchestrator.backends.errors import BackendNotAvailable, BackendOperationFailed
+from ci_orchestrator.backends.protocol import VmHandle
+from ci_orchestrator.backends.workstation import WorkstationVmrunBackend
+
+
+@pytest.fixture
+def fake_vmrun(tmp_path: Path) -> str:
+    """A real (empty) file we can pass as vmrun_path."""
+    p = tmp_path / "vmrun.exe"
+    p.write_bytes(b"")
+    return str(p)
+
+
+def _make_completed(returncode: int = 0, stdout: str = "", stderr: str = "") -> Any:
+    return subprocess.CompletedProcess(args=[], returncode=returncode, stdout=stdout, stderr=stderr)
+
+
+def test_init_raises_when_vmrun_missing(tmp_path: Path) -> None:
+    missing = tmp_path / "nope.exe"
+    with pytest.raises(BackendNotAvailable):
+        WorkstationVmrunBackend(vmrun_path=str(missing))
+
+
+def test_init_uses_explicit_path(fake_vmrun: str) -> None:
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.vmrun_path == fake_vmrun
+
+
+def test_clone_linked_invokes_vmrun(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None:
+    captured: dict[str, list[str]] = {}
+
+    def fake_run(cmd: list[str], **_kwargs: object) -> Any:
+        captured["cmd"] = cmd
+        return _make_completed(0, stdout="")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    handle = backend.clone_linked(
+        template=r"C:\tpl\WinBuild2025\WinBuild2025.vmx",
+        snapshot="BaseClean",
+        name="job-123",
+        destination=r"C:\bvm\job-123\job-123.vmx",
+    )
+    assert handle.identifier == r"C:\bvm\job-123\job-123.vmx"
+    assert handle.name == "job-123"
+    assert captured["cmd"][0] == fake_vmrun
+    assert captured["cmd"][1:4] == ["-T", "ws", "clone"]
+    assert "linked" in captured["cmd"]
+    assert "-snapshot=BaseClean" in captured["cmd"]
+    assert "-cloneName=job-123" in captured["cmd"]
+
+
+def test_clone_failure_raises(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None:
+    monkeypatch.setattr(
+        subprocess,
+        "run",
+        lambda *a, **kw: _make_completed(1, stderr="Error: source not found"),
+    )
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    with pytest.raises(BackendOperationFailed) as exc_info:
+        backend.clone_linked("src.vmx", "snap", "name", destination="dst.vmx")
+    assert exc_info.value.returncode == 1
+    assert "source not found" in exc_info.value.output
+
+
+def test_stop_tolerates_already_off(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None:
+    monkeypatch.setattr(
+        subprocess,
+        "run",
+        lambda *a, **kw: _make_completed(255, stderr="Error: The virtual machine is not powered on"),
+    )
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    # Should NOT raise — VM already off is treated as success.
+    backend.stop(VmHandle("x.vmx"))
+
+
+def test_get_ip_returns_none_on_failure(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None:
+    monkeypatch.setattr(
+        subprocess, "run", lambda *a, **kw: _make_completed(1, stderr="Tools not running")
+    )
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.get_ip(VmHandle("x.vmx")) is None
+
+
+def test_get_ip_returns_address(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None:
+    monkeypatch.setattr(subprocess, "run", lambda *a, **kw: _make_completed(0, stdout="192.168.79.42\n"))
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.get_ip(VmHandle("x.vmx")) == "192.168.79.42"
+
+
+def test_list_snapshots_strips_header(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None:
+    monkeypatch.setattr(
+        subprocess,
+        "run",
+        lambda *a, **kw: _make_completed(0, stdout="Total snapshots: 2\nBaseClean\nDirty\n"),
+    )
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.list_snapshots(VmHandle("x.vmx")) == ["BaseClean", "Dirty"]
+
+
+def test_is_running_uses_list_not_getip(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path, fake_vmrun: str
+) -> None:
+    """Regression for AGENTS.md error #10."""
+    vmx = tmp_path / "job1" / "job1.vmx"
+    vmx.parent.mkdir()
+    vmx.write_text("")
+
+    calls: list[str] = []
+
+    def fake_run(cmd: list[str], **_kwargs: object) -> Any:
+        calls.append(cmd[3])  # operation name
+        if cmd[3] == "list":
+            return _make_completed(
+                0, stdout=f"Total running VMs: 1\n{vmx}\n"
+            )
+        raise AssertionError(f"Unexpected vmrun op: {cmd[3]}")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.is_running(VmHandle(str(vmx))) is True
+    assert calls == ["list"]
+    assert "getGuestIPAddress" not in calls
+
+
+def test_is_running_returns_false_when_absent(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path, fake_vmrun: str
+) -> None:
+    vmx = tmp_path / "job1.vmx"
+    vmx.write_text("")
+    monkeypatch.setattr(
+        subprocess, "run", lambda *a, **kw: _make_completed(0, stdout="Total running VMs: 0\n")
+    )
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.is_running(VmHandle(str(vmx))) is False