bot_bottle/backend/__init__.py

@@ -36,10 +36,10 @@ import os
 import shlex
 import sys
 from abc import ABC, abstractmethod
-from contextlib import AbstractContextManager
+from contextlib import AbstractContextManager, contextmanager
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Generic, Sequence, TypeVar
+from typing import Any, Generator, Generic, Sequence, TypeVar
 
 from ..agent_provider import AgentProvisionPlan, get_provider, build_agent_provision_plan
 from ..egress import EgressPlan
@@ -78,6 +78,9 @@ class BottleSpec:
     # True when launched via --headless (no TTY, no interactive prompts).
     # The git-gate host-key preflight uses this to error rather than prompt.
     headless: bool = False
+    # Image startup policy. "fresh" preserves the normal build path;
+    # "cached" reuses the current local image/artifact without rebuilding.
+    image_policy: str = "fresh"
 
 
 @dataclass(frozen=True)
@@ -273,6 +276,18 @@ PlanT = TypeVar("PlanT", bound=BottlePlan)
 CleanupT = TypeVar("CleanupT", bound=BottleCleanupPlan)
 
 
+@dataclass(frozen=True)
+class BottleImages:
+    """Resolved image references (or artifact paths) for a bottle launch.
+
+    For Docker/macOS-container backends, `agent` and `sidecar` are string
+    image refs. For the smolmachines backend they are Path objects pointing
+    to pre-built `.smolmachine` artifacts."""
+
+    agent: str | Path
+    sidecar: str | Path
+
+
 class BottleBackend(ABC, Generic[PlanT, CleanupT]):
     """Abstract base for selectable bottle backends. Concrete subclasses
     (e.g. DockerBottleBackend) own their own prepare/launch impls.
@@ -432,9 +447,27 @@ class BottleBackend(ABC, Generic[PlanT, CleanupT]):
         prompt file, Dockerfile path, and guest home all live on
         `agent_provision_plan` — the source of truth."""
 
+    def prelaunch_checks(self, plan: PlanT) -> None:
+        """Raise StaleImageError if any cached image used by this plan is stale.
+        No-op default; backends override to call the shared check_stale*
+        helpers on their image/artifact timestamps. Called by the CLI before
+        launch so the operator can be prompted outside the launch context."""
+
+    @contextmanager
+    def launch(self, plan: PlanT) -> Generator[Bottle, None, None]:
+        """Template: build or load images, then delegate to _launch_impl."""
+        images = self._build_or_load_images(plan)
+        with self._launch_impl(plan, images) as bottle:
+            yield bottle
+
     @abstractmethod
-    def launch(self, plan: PlanT) -> AbstractContextManager[Bottle]:
+    def _build_or_load_images(self, plan: PlanT) -> BottleImages:
-        """Build/run the bottle and yield a handle; tear down on exit."""
+        """Return the agent and sidecar image references (or artifact paths)
+        for this plan, building fresh images when the policy requires it."""
+
+    @abstractmethod
+    def _launch_impl(self, plan: PlanT, images: BottleImages) -> AbstractContextManager[Bottle]:
+        """Bring up the bottle using pre-resolved images; yield a handle; tear down on exit."""
 
     def provision(self, plan: PlanT, bottle: "Bottle") -> str | None:
         """Copy host-side files (CA cert, prompt, skills, .git) into

bot_bottle/backend/docker/backend.py

@@ -31,7 +31,7 @@ from ...env import ResolvedEnv
 from ...git_gate import GitGatePlan
 from ...supervise import SupervisePlan
 from ...manifest import Manifest
-from .. import ActiveAgent, BottleBackend, BottleSpec
+from .. import ActiveAgent, BottleBackend, BottleImages, BottleSpec
 from . import cleanup as _cleanup
 from . import enumerate as _enumerate
 from . import launch as _launch
@@ -85,9 +85,15 @@ class DockerBottleBackend(BottleBackend["DockerBottlePlan", "DockerBottleCleanup
             stage_dir=stage_dir,
         )
 
+    def prelaunch_checks(self, plan: DockerBottlePlan) -> None:
+        _launch.stale_checks(plan)
+
+    def _build_or_load_images(self, plan: DockerBottlePlan) -> BottleImages:
+        return _launch.build_or_load_images(plan)
+
     @contextmanager
-    def launch(self, plan: DockerBottlePlan) -> Generator[DockerBottle, None, None]:
+    def _launch_impl(self, plan: DockerBottlePlan, images: BottleImages) -> Generator[DockerBottle, None, None]:
-        with _launch.launch(plan, provision=self.provision) as bottle:
+        with _launch.launch(plan, images, provision=self.provision) as bottle:
             yield bottle
 
     def supervise_mcp_url(self, plan: DockerBottlePlan) -> str:

bot_bottle/backend/docker/compose.py

@@ -180,10 +180,6 @@ def _sidecar_bundle_service(plan: DockerBottlePlan) -> dict[str, Any]:
 
     service: dict[str, Any] = {
         "image": SIDECAR_BUNDLE_IMAGE,
-        "build": {
-            "context": _REPO_DIR,
-            "dockerfile": SIDECAR_BUNDLE_DOCKERFILE,
-        },
         "container_name": sidecar_bundle_container_name(plan.slug),
         "networks": {
             "internal": {"aliases": internal_aliases},
@@ -192,6 +188,11 @@ def _sidecar_bundle_service(plan: DockerBottlePlan) -> dict[str, Any]:
         "environment": env,
         "volumes": volumes,
     }
+    if plan.spec.image_policy != "cached":
+        service["build"] = {
+            "context": _REPO_DIR,
+            "dockerfile": SIDECAR_BUNDLE_DOCKERFILE,
+        }
     return service
 
 

bot_bottle/backend/docker/launch.py

@@ -41,7 +41,9 @@ from ...git_gate import (
     provision_git_gate_dynamic_keys,
     revoke_git_gate_provisioned_keys,
 )
-from ...log import info, warn
+from ...image_cache import check_stale
+from ...log import die, info, warn
+from .. import BottleImages
 from . import network as network_mod
 from . import util as docker_mod
 from .bottle import DockerBottle
@@ -63,22 +65,57 @@ from .compose import (
     write_compose_file,
 )
 from .egress import egress_tls_init
+from .sidecar_bundle import SIDECAR_BUNDLE_IMAGE
 
 
 # Where the repo root lives, for `docker build` context. Computed once.
 _REPO_DIR = str(Path(__file__).resolve().parent.parent.parent.parent)
 
 
+def build_or_load_images(plan: DockerBottlePlan) -> BottleImages:
+    """Resolve the agent and sidecar image refs for this plan.
+
+    Returns the committed snapshot if one exists, the local cached images
+    when the policy is 'cached', or builds fresh images and returns those."""
+    committed = read_committed_image(plan.slug)
+    if committed and docker_mod.image_exists(committed):
+        info(f"using committed image {committed!r}")
+        return BottleImages(agent=committed, sidecar=SIDECAR_BUNDLE_IMAGE)
+    if plan.spec.image_policy == "cached":
+        if not docker_mod.image_exists(plan.image):
+            die(
+                f"cached agent image {plan.image!r} not found; "
+                "run without --cached-images to build it"
+            )
+        if not docker_mod.image_exists(SIDECAR_BUNDLE_IMAGE):
+            die(
+                f"cached sidecar image {SIDECAR_BUNDLE_IMAGE!r} not found; "
+                "run without --cached-images to build it"
+            )
+        info(f"using cached agent image {plan.image!r}")
+        info(f"using cached sidecar image {SIDECAR_BUNDLE_IMAGE!r}")
+        return BottleImages(agent=plan.image, sidecar=SIDECAR_BUNDLE_IMAGE)
+    docker_mod.build_image(plan.image, _REPO_DIR, dockerfile=plan.dockerfile_path)
+    return BottleImages(agent=plan.image, sidecar=SIDECAR_BUNDLE_IMAGE)
+
+
 @contextmanager
 def launch(
     plan: DockerBottlePlan,
+    images: BottleImages,
     *,
     provision: Callable[[DockerBottlePlan, "DockerBottle"], str | None],
 ) -> Generator[DockerBottle, None, None]:
-    """Build, launch, and provision a Docker bottle via compose.
+    """Launch and provision a Docker bottle via compose. Teardown on exit."""
-    Teardown on exit."""
     stack = ExitStack()
 
+    # Stamp the resolved agent image ref into the plan so compose rendering
+    # picks up the right image (may be a committed snapshot or cached ref).
+    plan = dataclasses.replace(
+        plan,
+        agent_provision=dataclasses.replace(plan.agent_provision, image=str(images.agent)),
+    )
+
     _bottle_for_revoke = plan.manifest.bottle
     _git_gate_dir_for_revoke = git_gate_state_dir(plan.slug)
 
@@ -95,22 +132,6 @@ def launch(
         )
 
     try:
-        # Step 1: agent image. Use a committed snapshot when one exists
-        # and is present in the local daemon; otherwise build from the
-        # Dockerfile. Sidecar images get built lazily by `docker compose
-        # up` via the renderer's `build:` directives.
-        committed = read_committed_image(plan.slug)
-        if committed and docker_mod.image_exists(committed):
-            info(f"using committed image {committed!r}")
-            plan = dataclasses.replace(
-                plan,
-                agent_provision=dataclasses.replace(plan.agent_provision, image=committed),
-            )
-        else:
-            docker_mod.build_image(
-                plan.image, _REPO_DIR,
-                dockerfile=plan.dockerfile_path,
-            )
 
         internal_network = network_mod.network_name_for_slug(plan.slug)
         egress_network = network_mod.network_egress_name_for_slug(plan.slug)
@@ -207,3 +228,21 @@ def launch(
         yield bottle
     finally:
         teardown()
+
+
+def stale_checks(plan: DockerBottlePlan) -> None:
+    """Raise StaleImageError if a cached image is older than the configured
+    threshold. Only runs when image_policy is 'cached'. Called by the backend
+    class's _image_stale_checks before _launch_impl starts any resources."""
+    if plan.spec.image_policy != "cached":
+        return
+    committed = read_committed_image(plan.slug)
+    if committed and docker_mod.image_exists(committed):
+        check_stale(f"agent image {committed!r}", docker_mod.image_created_at(committed))
+        return
+    for label, ref in [
+        ("agent image", plan.image),
+        ("sidecar image", SIDECAR_BUNDLE_IMAGE),
+    ]:
+        if docker_mod.image_exists(ref):
+            check_stale(f"{label} {ref!r}", docker_mod.image_created_at(ref))

bot_bottle/backend/docker/util.py

@@ -4,6 +4,7 @@ existence, and building images."""
 
 from __future__ import annotations
 
+from datetime import datetime, timezone
 import re
 import shutil
 import subprocess
@@ -186,6 +187,45 @@ def image_id(ref: str) -> str:
     return r.stdout.strip()
 
 
+def image_created_at(ref: str) -> datetime:
+    """Return Docker's image Created timestamp as an aware UTC datetime."""
+    r = subprocess.run(
+        ["docker", "image", "inspect", "--format", "{{.Created}}", ref],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    if r.returncode != 0:
+        die(
+            f"docker image inspect for {ref!r} failed: "
+            f"{(r.stderr or '').strip() or '<no stderr>'}"
+        )
+    raw = r.stdout.strip()
+    try:
+        return _parse_docker_timestamp(raw)
+    except ValueError:
+        die(f"docker image inspect for {ref!r} returned invalid Created timestamp: {raw!r}")
+
+
+def _parse_docker_timestamp(raw: str) -> datetime:
+    text = raw.strip()
+    if text.endswith("Z"):
+        text = text[:-1] + "+00:00"
+    dot = text.find(".")
+    if dot != -1:
+        tz_plus = text.find("+", dot)
+        tz_minus = text.find("-", dot)
+        tz_candidates = [pos for pos in (tz_plus, tz_minus) if pos != -1]
+        if tz_candidates:
+            tz_pos = min(tz_candidates)
+            frac = text[dot + 1:tz_pos]
+            text = text[:dot + 1] + frac[:6].ljust(6, "0") + text[tz_pos:]
+    dt = datetime.fromisoformat(text)
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    return dt.astimezone(timezone.utc)
+
+
 def save(ref: str, output: str) -> None:
     """`docker save REF -o OUTPUT`. Writes a tarball of the image
     layers + manifest to the host path. Used by smolmachines

bot_bottle/backend/macos_container/backend.py

@@ -12,7 +12,7 @@ from ...env import ResolvedEnv
 from ...git_gate import GitGatePlan
 from ...supervise import SupervisePlan
 from ...manifest import Manifest
-from .. import ActiveAgent, BottleBackend, BottleSpec
+from .. import ActiveAgent, BottleBackend, BottleImages, BottleSpec
 from . import cleanup as _cleanup
 from . import enumerate as _enumerate
 from . import launch as _launch
@@ -67,11 +67,17 @@ class MacosContainerBottleBackend(
             stage_dir=stage_dir,
         )
 
+    def prelaunch_checks(self, plan: MacosContainerBottlePlan) -> None:
+        _launch.stale_checks(plan)
+
+    def _build_or_load_images(self, plan: MacosContainerBottlePlan) -> BottleImages:
+        return _launch.build_or_load_images(plan)
+
     @contextmanager
-    def launch(
+    def _launch_impl(
-        self, plan: MacosContainerBottlePlan
+        self, plan: MacosContainerBottlePlan, images: BottleImages
     ) -> Generator[MacosContainerBottle, None, None]:
-        with _launch.launch(plan, provision=self.provision) as bottle:
+        with _launch.launch(plan, images, provision=self.provision) as bottle:
             yield bottle
 
     def prepare_cleanup(self) -> MacosContainerBottleCleanupPlan:

bot_bottle/backend/macos_container/launch.py

@@ -32,7 +32,9 @@ from ...git_gate import (
     provision_git_gate_dynamic_keys,
     revoke_git_gate_provisioned_keys,
 )
+from ...image_cache import check_stale
 from ...log import die, info, warn
+from .. import BottleImages
 from ...supervise import DB_PATH_IN_CONTAINER, SUPERVISE_PORT
 from ...util import expand_tilde
 from ..docker.egress import EGRESS_CA_IN_CONTAINER, EGRESS_PORT
@@ -71,17 +73,51 @@ def sidecar_container_name(slug: str) -> str:
     return f"bot-bottle-sidecars-{slug}"
 
 
+def build_or_load_images(plan: MacosContainerBottlePlan) -> BottleImages:
+    """Resolve agent and sidecar image refs. Builds the sidecar when needed,
+    but never builds the agent when policy is 'cached'."""
+    committed = read_committed_image(plan.slug)
+    if committed and container_mod.image_exists(committed):
+        info(f"using committed image {committed!r}")
+        if plan.spec.image_policy != "cached":
+            container_mod.build_image(SIDECAR_BUNDLE_IMAGE, _REPO_DIR, dockerfile=SIDECAR_BUNDLE_DOCKERFILE)
+        return BottleImages(agent=committed, sidecar=SIDECAR_BUNDLE_IMAGE)
+    if plan.spec.image_policy == "cached":
+        if not container_mod.image_exists(plan.image):
+            die(
+                f"cached agent image {plan.image!r} not found; "
+                "run without --cached-images to build it"
+            )
+        if not container_mod.image_exists(SIDECAR_BUNDLE_IMAGE):
+            die(
+                f"cached sidecar image {SIDECAR_BUNDLE_IMAGE!r} not found; "
+                "run without --cached-images to build it"
+            )
+        info(f"using cached agent image {plan.image!r}")
+        info(f"using cached sidecar image {SIDECAR_BUNDLE_IMAGE!r}")
+        return BottleImages(agent=plan.image, sidecar=SIDECAR_BUNDLE_IMAGE)
+    container_mod.build_image(SIDECAR_BUNDLE_IMAGE, _REPO_DIR, dockerfile=SIDECAR_BUNDLE_DOCKERFILE)
+    container_mod.build_image(plan.image, _REPO_DIR, dockerfile=plan.dockerfile_path)
+    return BottleImages(agent=plan.image, sidecar=SIDECAR_BUNDLE_IMAGE)
+
+
 @contextmanager
 def launch(
     plan: MacosContainerBottlePlan,
+    images: BottleImages,
     *,
     provision: Callable[[MacosContainerBottlePlan, "MacosContainerBottle"], str | None],
 ) -> Generator[MacosContainerBottle, None, None]:
-    """Build, run, provision, and yield an Apple Container bottle."""
+    """Run, provision, and yield an Apple Container bottle."""
     stack = ExitStack()
     bottle_for_revoke = plan.manifest.bottle
     git_gate_dir_for_revoke = git_gate_state_dir(plan.slug)
 
+    plan = dataclasses.replace(
+        plan,
+        agent_provision=dataclasses.replace(plan.agent_provision, image=str(images.agent)),
+    )
+
     def teardown() -> None:
         teardown_exc: BaseException | None = None
         try:
@@ -95,7 +131,6 @@ def launch(
 
     try:
         plan = _mint_certs(plan)
-        plan = _build_images(plan)
 
         internal_network = internal_network_name(plan.slug)
         egress_network = egress_network_name(plan.slug)
@@ -148,28 +183,23 @@ def _mint_certs(plan: MacosContainerBottlePlan) -> MacosContainerBottlePlan:
     return dataclasses.replace(plan, egress_plan=egress_plan)
 
 
-def _build_images(plan: MacosContainerBottlePlan) -> MacosContainerBottlePlan:
+
-    container_mod.build_image(
+def stale_checks(plan: MacosContainerBottlePlan) -> None:
-        SIDECAR_BUNDLE_IMAGE,
+    """Raise StaleImageError if a cached image is older than the configured
-        _REPO_DIR,
+    threshold. Only runs when image_policy is 'cached'. Called by the backend
-        dockerfile=SIDECAR_BUNDLE_DOCKERFILE,
+    class's _image_stale_checks before _launch_impl starts any resources."""
-    )
+    if plan.spec.image_policy != "cached":
+        return
     committed = read_committed_image(plan.slug)
     if committed and container_mod.image_exists(committed):
-        info(f"using committed image {committed!r}")
+        check_stale(f"agent image {committed!r}", container_mod.image_created_at(committed))
-        return dataclasses.replace(
+        return
-            plan,
+    for label, ref in [
-            agent_provision=dataclasses.replace(
+        ("agent image", plan.image),
-                plan.agent_provision,
+        ("sidecar image", SIDECAR_BUNDLE_IMAGE),
-                image=committed,
+    ]:
-            ),
+        if container_mod.image_exists(ref):
-        )
+            check_stale(f"{label} {ref!r}", container_mod.image_created_at(ref))
-    container_mod.build_image(
-        plan.image,
-        _REPO_DIR,
-        dockerfile=plan.dockerfile_path,
-    )
-    return plan
 
 
 def _create_networks(

bot_bottle/backend/macos_container/util.py

@@ -10,6 +10,7 @@ import shutil
 import subprocess
 import tempfile
 import time
+from datetime import datetime, timezone
 from typing import Iterable
 
 from ...log import die, info
@@ -458,6 +459,39 @@ def image_id(ref: str) -> str:
     raise AssertionError("unreachable")
 
 
+def image_created_at(ref: str) -> datetime:
+    """Return the image creation timestamp as an aware UTC datetime.
+
+    Parses the `created` field from `container image inspect` JSON output."""
+    result = subprocess.run(
+        [_CONTAINER, "image", "inspect", ref],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    if result.returncode != 0:
+        die(
+            f"container image inspect for {ref!r} failed: "
+            f"{(result.stderr or '').strip() or '<no stderr>'}"
+        )
+    try:
+        data = json.loads(result.stdout or "{}")
+    except json.JSONDecodeError as exc:
+        die(f"container image inspect for {ref!r} returned malformed JSON: {exc}")
+    if isinstance(data, list) and data:
+        data = data[0]
+    if isinstance(data, dict):
+        value = data.get("created") or data.get("Created")
+        if isinstance(value, str) and value:
+            try:
+                ts = value.rstrip("Z")
+                return datetime.fromisoformat(ts).replace(tzinfo=timezone.utc)
+            except ValueError:
+                pass
+    die(f"container image inspect for {ref!r} did not include a creation timestamp")
+    raise AssertionError("unreachable")
+
+
 def save(ref: str, output: str) -> None:
     subprocess.run([_CONTAINER, "image", "save", ref, "-o", output], check=True)
 

bot_bottle/backend/smolmachines/backend.py

@@ -19,7 +19,7 @@ from ...env import ResolvedEnv
 from ...git_gate import GitGatePlan
 from ...supervise import SupervisePlan
 from ...manifest import Manifest
-from .. import ActiveAgent, BottleBackend, BottleSpec
+from .. import ActiveAgent, BottleBackend, BottleImages, BottleSpec
 from . import cleanup as _cleanup
 from . import enumerate as _enumerate
 from . import launch as _launch
@@ -77,11 +77,14 @@ class SmolmachinesBottleBackend(
             stage_dir=stage_dir,
         )
 
+    def _build_or_load_images(self, plan: SmolmachinesBottlePlan) -> BottleImages:
+        return _launch.build_or_load_images(plan)
+
     @contextmanager
-    def launch(
+    def _launch_impl(
-        self, plan: SmolmachinesBottlePlan
+        self, plan: SmolmachinesBottlePlan, images: BottleImages
     ) -> Generator[SmolmachinesBottle, None, None]:
-        with _launch.launch(plan, provision=self.provision) as bottle:
+        with _launch.launch(plan, images, provision=self.provision) as bottle:
             yield bottle
 
     def supervise_mcp_url(self, plan: SmolmachinesBottlePlan) -> str:

bot_bottle/backend/smolmachines/launch.py

@@ -52,6 +52,7 @@ from ...bottle_state import (
     git_gate_state_dir,
     read_committed_image,
 )
+from .. import BottleImages
 from . import loopback_alias as _loopback
 from . import sidecar_bundle as _bundle
 from . import smolvm as _smolvm
@@ -79,13 +80,20 @@ _GIT_HTTP_PORT = 9420
 _SUPERVISE_PORT = SUPERVISE_PORT
 
 
+def build_or_load_images(plan: SmolmachinesBottlePlan) -> BottleImages:
+    """Build or resolve the agent smolmachine artifact and sidecar bundle image."""
+    _bundle.ensure_bundle_image()
+    return BottleImages(agent=_agent_from_path(plan), sidecar=_bundle.SIDECAR_BUNDLE_IMAGE)
+
+
 @contextmanager
 def launch(
     plan: SmolmachinesBottlePlan,
+    images: BottleImages,
     *,
     provision: Callable[[SmolmachinesBottlePlan, "SmolmachinesBottle"], str | None],
 ) -> Generator[SmolmachinesBottle, None, None]:
-    """Build + run the bottle and yield a handle; tear everything
+    """Run the bottle from pre-built images and yield a handle; tear everything
     down on exit. Errors during bringup unwind any partial state
     via the ExitStack."""
     stack = ExitStack()
@@ -96,9 +104,7 @@ def launch(
         plan = _start_bundle(plan, network, proxy_host, stack)
         plan = _discover_urls(plan, proxy_host)
 
-        agent_from_path = _agent_from_path(plan)
+        _launch_vm(plan, Path(images.agent), proxy_host, stack)
-
-        _launch_vm(plan, agent_from_path, proxy_host, stack)
         _init_vm(plan)
 
         bottle = SmolmachinesBottle(
@@ -184,7 +190,6 @@ def _start_bundle(
     plan = _provision_git_gate_keys(plan)
     bundle_spec = _bundle_launch_spec(plan, network, proxy_host)
     token_env = _resolve_token_env(plan, dict(os.environ))
-    _bundle.ensure_bundle_image(bundle_spec.image)
     _bundle.start_bundle(bundle_spec, env={**os.environ, **token_env})
     stack.callback(_bundle.stop_bundle, plan.slug)
     return plan

bot_bottle/cli/start.py

@@ -36,6 +36,7 @@ from ..bottle_state import (
     is_preserved,
     mark_preserved,
 )
+from ..image_cache import StaleImageError
 from ..log import info, die
 from ..manifest import Manifest, ManifestIndex
 from ._common import PROG, USER_CWD, read_tty_line
@@ -63,6 +64,14 @@ def cmd_start(argv: list[str]) -> int:
             "skip all prompts. For orchestrators, CI, and webhooks."
         ),
     )
+    parser.add_argument(
+        "--cached-images",
+        action="store_true",
+        help=(
+            "quickstart with existing local agent and sidecar images; "
+            "only valid with --headless"
+        ),
+    )
     parser.add_argument(
         "--bottle",
         action="append",
@@ -95,6 +104,8 @@ def cmd_start(argv: list[str]) -> int:
         help="agent name defined in bot-bottle.json (omit to pick interactively)",
     )
     args = parser.parse_args(argv)
+    if args.cached_images and not args.headless:
+        die("--cached-images is only supported with --headless")
 
     dry_run = args.dry_run or os.environ.get("BOT_BOTTLE_DRY_RUN") == "1"
 
@@ -142,6 +153,10 @@ def cmd_start(argv: list[str]) -> int:
     label, color = tui.name_color_modal(default_label=agent_name)
     label, color = _resolve_unique_label(label, color)
 
+    image_policy = _select_image_policy()
+    if image_policy is None:
+        return 0
+
     spec = BottleSpec(
         manifest=manifest,
         agent_name=agent_name,
@@ -150,6 +165,7 @@ def cmd_start(argv: list[str]) -> int:
         label=label,
         color=color,
         bottle_names=bottle_names,
+        image_policy=image_policy,
     )
     return _launch_bottle(
         spec,
@@ -210,6 +226,7 @@ def _start_headless(
         color=args.color or "",
         bottle_names=bottle_names,
         headless=True,
+        image_policy="cached" if args.cached_images else "fresh",
     )
     return _launch_bottle(
         spec,
@@ -390,6 +407,13 @@ def _text_prompt_yes() -> bool:
     return reply in ("y", "Y", "yes", "YES")
 
 
+def _select_image_policy() -> str | None:
+    return tui.filter_select(
+        ["fresh", "cached"],
+        title="Select image startup mode",
+    )
+
+
 def _text_render_preflight():
     def _render(plan: DockerBottlePlan, backend_name: str) -> None:
         print(file=sys.stderr)
@@ -532,6 +556,15 @@ def _launch_bottle(
             return 0
 
         backend = get_bottle_backend(backend_name)
+        try:
+            backend.prelaunch_checks(plan)
+        except StaleImageError as exc:
+            if assume_yes:
+                die(str(exc))
+            sys.stderr.write(f"bot-bottle: {exc}\nLaunch anyway? [y/N] ")
+            sys.stderr.flush()
+            if read_tty_line() not in ("y", "Y", "yes", "YES"):
+                return 0
         with backend.launch(plan) as bottle:
             agent_provider_template = getattr(plan, "agent_provider_template", "claude")
             extra_args: tuple[str, ...] = ()
@@ -550,10 +583,6 @@ def _launch_bottle(
                 f"session ended (exit {exit_code}); "
                 f"container {bottle.name} will be removed"
             )
-            # While the container is still alive: always snapshot the
-            # transcript and — if the agent exited non-zero — mark
-            # the state for preservation. This picks up crashes /
-            # Ctrl-Cs / OOM kills before cleanup removes the state dir.
             if agent_provider_template == "claude":
                 capture_claude_session_state(identity, exit_code)
         return 0

bot_bottle/config_store.py

@@ -0,0 +1,71 @@
+"""SQLite-backed bot-bottle configuration store."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+try:
+    from .db_store import DbStore
+    from .migrations import TableMigrations
+    from .supervise_types import host_db_path
+except ImportError:
+    from db_store import DbStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from migrations import TableMigrations  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from supervise_types import host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+
+
+DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS = 1
+
+
+class ConfigStore(DbStore):
+    """SQLite configuration for host-side bot-bottle settings."""
+
+    def __init__(self, db_path: Path | None = None) -> None:
+        migrations = TableMigrations("config_store", [
+            # v1 — host-side bot-bottle settings
+            """
+            CREATE TABLE IF NOT EXISTS bot_bottle_config (
+                id INTEGER PRIMARY KEY CHECK (id = 1),
+                cached_image_stale_warning_days INTEGER NOT NULL DEFAULT 1
+            )
+            """,
+        ])
+        super().__init__(db_path or host_db_path(), migrations)
+
+    def cached_image_stale_warning_days(self) -> int:
+        if not self.db_path.is_file():
+            return DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS
+        with self._connect() as conn:
+            row = conn.execute(
+                """
+                SELECT cached_image_stale_warning_days
+                FROM bot_bottle_config
+                WHERE id = 1
+                """,
+            ).fetchone()
+        if row is None:
+            return DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS
+        try:
+            return int(row["cached_image_stale_warning_days"])
+        except (TypeError, ValueError):
+            return DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS
+
+    def set_cached_image_stale_warning_days(self, days: int) -> Path:
+        with self._connect() as conn:
+            conn.execute(
+                """
+                INSERT INTO bot_bottle_config (id, cached_image_stale_warning_days)
+                VALUES (1, ?)
+                ON CONFLICT(id) DO UPDATE SET
+                    cached_image_stale_warning_days = excluded.cached_image_stale_warning_days
+                """,
+                (days,),
+            )
+        self._chmod()
+        return self.db_path
+
+
+__all__ = [
+    "DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS",
+    "ConfigStore",
+]

bot_bottle/image_cache.py

@@ -0,0 +1,42 @@
+"""Shared helpers for cached-image quickstart stale checks."""
+
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from pathlib import Path
+
+try:
+    from .config_store import ConfigStore
+except ImportError:
+    from config_store import ConfigStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+
+
+class StaleImageError(Exception):
+    """Raised when a cached image or artifact exceeds the configured staleness
+    threshold. Callers can catch this to prompt interactively; headless paths
+    let it propagate as a fatal error."""
+
+
+def check_stale(label: str, created_at: datetime) -> None:
+    """Raise StaleImageError if `created_at` is older than the configured
+    stale-warning threshold. Negative threshold disables the check."""
+    threshold_days = ConfigStore().cached_image_stale_warning_days()
+    if threshold_days < 0:
+        return
+    now = datetime.now(timezone.utc)
+    created = created_at.astimezone(timezone.utc)
+    age = now - created
+    if age.total_seconds() <= threshold_days * 86400:
+        return
+    raise StaleImageError(
+        f"cached {label} is {age.days} day(s) old; "
+        "quickstart does not verify it matches the current Dockerfile/context"
+    )
+
+
+def check_stale_path(label: str, path: Path) -> None:
+    """Raise StaleImageError if `path`'s mtime exceeds the staleness threshold."""
+    check_stale(label, datetime.fromtimestamp(path.stat().st_mtime, tz=timezone.utc))
+
+
+__all__ = ["StaleImageError", "check_stale", "check_stale_path"]

bot_bottle/store_manager.py

@@ -6,9 +6,11 @@ from pathlib import Path
 
 try:
     from .audit_store import AuditStore
+    from .config_store import ConfigStore
     from .queue_store import QueueStore
 except ImportError:
     from audit_store import AuditStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from config_store import ConfigStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
     from queue_store import QueueStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
 
 _instance: StoreManager | None = None
@@ -50,11 +52,13 @@ class StoreManager:
         return (
             QueueStore("", self.db_path).is_migrated()
             and AuditStore(self.db_path).is_migrated()
+            and ConfigStore(self.db_path).is_migrated()
         )
 
     def migrate(self) -> None:
         QueueStore("", self.db_path).migrate()
         AuditStore(self.db_path).migrate()
+        ConfigStore(self.db_path).migrate()
 
 
 __all__ = ["StoreManager"]

tests/unit/test_cli_start_headless.py

@@ -184,6 +184,18 @@ class TestCmdStartHeadless(unittest.TestCase):
         )
         self.assertEqual("docker", self._launch_mock.call_args[1]["backend_name"])
 
+    def test_cached_images_sets_cached_policy(self):
+        start_mod.cmd_start(
+            ["--headless", "--cached-images", "researcher", "--bottle", "claude",
+             "--prompt", "Do it"]
+        )
+        self.assertEqual("cached", self._spec().image_policy)
+
+    def test_cached_images_requires_headless(self):
+        with self.assertRaises(Die):
+            start_mod.cmd_start(["--cached-images", "researcher"])
+        self._launch_mock.assert_not_called()
+
 
 class TestPrepareWithPreflight(unittest.TestCase):
     """prepare_with_preflight calls render_preflight with the plan and backend name."""

tests/unit/test_cli_start_selector.py

@@ -57,6 +57,12 @@ class TestCmdStartSelector(unittest.TestCase):
         self._bottle_picker_mock = self._bottle_picker_patch.start()
         self._bottle_picker_mock.return_value = ["claude"]  # default: one bottle selected
 
+        self._image_policy_patch = patch(
+            "bot_bottle.cli.start._select_image_policy",
+            return_value="fresh",
+        )
+        self._image_policy_patch.start()
+
         self._env_patch = patch.dict(os.environ, {}, clear=False)
         self._env_patch.start()
         os.environ.pop("BOT_BOTTLE_BACKEND", None)
@@ -66,6 +72,7 @@ class TestCmdStartSelector(unittest.TestCase):
         self._launch_patch.stop()
         self._agent_picker_patch.stop()
         self._bottle_picker_patch.stop()
+        self._image_policy_patch.stop()
         self._env_patch.stop()
 
     # ------------------------------------------------------------------
@@ -124,6 +131,19 @@ class TestCmdStartSelector(unittest.TestCase):
         spec = self._launch_mock.call_args[0][0]
         self.assertEqual(("claude", "dev"), spec.bottle_names)
 
+    def test_image_policy_forwarded_to_spec(self):
+        with patch("bot_bottle.cli.start._select_image_policy", return_value="cached"):
+            start_mod.cmd_start(["researcher"])
+        self._launch_mock.assert_called_once()
+        spec = self._launch_mock.call_args[0][0]
+        self.assertEqual("cached", spec.image_policy)
+
+    def test_image_policy_cancel_returns_0(self):
+        with patch("bot_bottle.cli.start._select_image_policy", return_value=None):
+            rc = start_mod.cmd_start(["researcher"])
+        self.assertEqual(0, rc)
+        self._launch_mock.assert_not_called()
+
     def test_empty_bottle_selection_forwarded(self):
         self._bottle_picker_mock.return_value = []
         start_mod.cmd_start(["researcher"])
@@ -215,6 +235,7 @@ class TestCmdStartLabelCollision(unittest.TestCase):
         ).start()
         # Stub the bottle picker to always return a selection.
         patch.object(tui_mod, "filter_multiselect", return_value=["claude"]).start()
+        patch("bot_bottle.cli.start._select_image_policy", return_value="fresh").start()
         self.addCleanup(patch.stopall)
 
     def test_no_collision_proceeds_without_reprompt(self):

tests/unit/test_cli_start_stale.py

@@ -0,0 +1,146 @@
+"""Unit: _launch_bottle StaleImageError handling.
+
+Exercises prelaunch_checks / backend.launch flow:
+  - headless mode → die on stale
+  - interactive mode, user declines → stop without launching
+  - interactive mode, user confirms → skip stale check and launch once
+"""
+
+from __future__ import annotations
+
+import io
+import tempfile
+import unittest
+from types import SimpleNamespace
+from typing import Any, cast
+from unittest.mock import MagicMock, patch
+
+from bot_bottle.image_cache import StaleImageError
+from bot_bottle.log import Die
+
+
+def _fake_plan() -> Any:
+    provision = SimpleNamespace(startup_args=())
+    return cast(Any, SimpleNamespace(
+        agent_provision=provision,
+        agent_provider_template="claude",
+        slug="dev-abc",
+    ))
+
+
+def _ok_cm(bottle: Any) -> MagicMock:
+    """Return a context-manager mock that yields `bottle`."""
+    cm = MagicMock()
+    cm.__enter__ = MagicMock(return_value=bottle)
+    cm.__exit__ = MagicMock(return_value=False)
+    return cm
+
+
+class TestLaunchBottleStaleHandling(unittest.TestCase):
+    def setUp(self) -> None:
+        self._tmp = tempfile.mkdtemp(prefix="cli-stale-test.")
+
+    def _spec(self) -> Any:
+        from bot_bottle.backend import BottleSpec
+        from bot_bottle.manifest import ManifestIndex
+        idx = ManifestIndex.from_json_obj({
+            "bottles": {"dev": {}},
+            "agents": {"demo": {"skills": [], "prompt": "", "bottle": "dev"}},
+        })
+        return BottleSpec(
+            manifest=idx,
+            agent_name="demo",
+            copy_cwd=False,
+            user_cwd=self._tmp,
+            identity="dev-abc",
+        )
+
+    def _run_launch(self, **patch_kwargs: Any) -> int:
+        import bot_bottle.cli.start as start_mod
+        spec = self._spec()
+        with patch.object(start_mod, "prepare_with_preflight",
+                          return_value=(_fake_plan(), "dev-abc")), \
+             patch.object(start_mod, "settle_state"), \
+             patch.object(start_mod, "info"):
+            return start_mod._launch_bottle(
+                spec,
+                dry_run=False,
+                backend_name="docker",
+                **patch_kwargs,
+            )
+
+    def test_headless_stale_calls_die(self) -> None:
+        """In headless mode (assume_yes=True), a StaleImageError from prelaunch_checks must call die()."""
+        import bot_bottle.cli.start as start_mod
+
+        backend_mock = MagicMock()
+        backend_mock.prelaunch_checks.side_effect = StaleImageError("image is 5 day(s) old")
+
+        with patch.object(start_mod, "get_bottle_backend", return_value=backend_mock), \
+             patch.object(start_mod, "die", side_effect=Die()):
+            with self.assertRaises(Die):
+                self._run_launch(assume_yes=True)
+
+        backend_mock.launch.assert_not_called()
+
+    def test_interactive_user_declines_stops_before_launch(self) -> None:
+        """Interactive user answering 'n' → launch is never called."""
+        import bot_bottle.cli.start as start_mod
+
+        backend_mock = MagicMock()
+        backend_mock.prelaunch_checks.side_effect = StaleImageError("image is 5 day(s) old")
+
+        with patch.object(start_mod, "get_bottle_backend", return_value=backend_mock), \
+             patch.object(start_mod, "read_tty_line", return_value="n"), \
+             patch("sys.stderr", new_callable=io.StringIO):
+            rc = self._run_launch(assume_yes=False)
+
+        self.assertEqual(0, rc)
+        backend_mock.launch.assert_not_called()
+
+    def test_interactive_user_confirms_launches_once(self) -> None:
+        """Interactive user answering 'y' → prelaunch stale error is bypassed; launch called once."""
+        import bot_bottle.cli.start as start_mod
+
+        bottle_mock = MagicMock()
+        bottle_mock.name = "dev-abc"
+
+        backend_mock = MagicMock()
+        backend_mock.prelaunch_checks.side_effect = StaleImageError("image is 5 day(s) old")
+        backend_mock.launch.return_value = _ok_cm(bottle_mock)
+
+        with patch.object(start_mod, "get_bottle_backend", return_value=backend_mock), \
+             patch.object(start_mod, "read_tty_line", return_value="y"), \
+             patch.object(start_mod, "attach_agent", return_value=0), \
+             patch.object(start_mod, "capture_claude_session_state"), \
+             patch("sys.stderr", new_callable=io.StringIO):
+            rc = self._run_launch(assume_yes=False)
+
+        self.assertEqual(0, rc)
+        backend_mock.prelaunch_checks.assert_called_once()
+        backend_mock.launch.assert_called_once()
+
+    def test_interactive_yes_uppercase_also_accepted(self) -> None:
+        """'Y' or 'YES' should also be accepted as confirmation."""
+        import bot_bottle.cli.start as start_mod
+
+        bottle_mock = MagicMock()
+        bottle_mock.name = "dev-abc"
+
+        backend_mock = MagicMock()
+        backend_mock.prelaunch_checks.side_effect = StaleImageError("image is 5 day(s) old")
+        backend_mock.launch.return_value = _ok_cm(bottle_mock)
+
+        with patch.object(start_mod, "get_bottle_backend", return_value=backend_mock), \
+             patch.object(start_mod, "read_tty_line", return_value="YES"), \
+             patch.object(start_mod, "attach_agent", return_value=0), \
+             patch.object(start_mod, "capture_claude_session_state"), \
+             patch("sys.stderr", new_callable=io.StringIO):
+            rc = self._run_launch(assume_yes=False)
+
+        self.assertEqual(0, rc)
+        backend_mock.launch.assert_called_once()
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/unit/test_compose.py

@@ -118,6 +118,7 @@ def _plan(
     with_egress: bool = False,
     supervise: bool = False,
     canary: bool = False,
+    image_policy: str = "fresh",
 ) -> DockerBottlePlan:
     """Build a fully-resolved DockerBottlePlan. Toggles cover the
     matrix the renderer's conditional-service logic branches on."""
@@ -148,6 +149,7 @@ def _plan(
         agent_name="demo",
         copy_cwd=False,
         user_cwd="/tmp/x",
+        image_policy=image_policy,
     )
     return DockerBottlePlan(
         spec=spec,
@@ -265,7 +267,8 @@ class TestAgentAlwaysPresent(unittest.TestCase):
     def test_agent_depends_only_on_sidecars(self):
         # Bundle shape: the init supervisor owns intra-bundle daemon
         # ordering, so the agent waits on the bundle container alone.
-        for kwargs in [{}, {"with_git": True, "with_egress": True, "supervise": True}]:
+        cases: list[dict[str, Any]] = [{}, {"with_git": True, "with_egress": True, "supervise": True}]
+        for kwargs in cases:
             with self.subTest(**kwargs):
                 s = bottle_plan_to_compose(_plan(**kwargs))["services"]["agent"]
                 self.assertEqual(["sidecars"], s["depends_on"])
@@ -300,6 +303,11 @@ class TestSidecarBundleShape(unittest.TestCase):
         self.assertEqual("bot-bottle-sidecars:latest", sc["image"])
         self.assertEqual("Dockerfile.sidecars", sc["build"]["dockerfile"])
 
+    def test_cached_policy_omits_bundle_build(self):
+        sc = self._render(image_policy="cached")["services"]["sidecars"]
+        self.assertEqual("bot-bottle-sidecars:latest", sc["image"])
+        self.assertNotIn("build", sc)
+
     def test_bundle_container_name_uses_sidecars_prefix(self):
         sc = self._render()["services"]["sidecars"]
         self.assertEqual(f"bot-bottle-sidecars-{SLUG}", sc["container_name"])

tests/unit/test_config_store.py

@@ -0,0 +1,86 @@
+"""Unit tests for the host-side configuration store."""
+
+from __future__ import annotations
+
+import sqlite3
+import tempfile
+import unittest
+from pathlib import Path
+
+from bot_bottle.config_store import (
+    DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS,
+    ConfigStore,
+)
+from bot_bottle.store_manager import StoreManager
+
+
+class TestConfigStore(unittest.TestCase):
+    def test_cached_image_warning_days_defaults_to_one(self) -> None:
+        with tempfile.TemporaryDirectory(prefix="config-store.") as tmp:
+            store = ConfigStore(Path(tmp) / "bot-bottle.db")
+            store.migrate()
+            self.assertEqual(
+                DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS,
+                store.cached_image_stale_warning_days(),
+            )
+
+    def test_cached_image_warning_days_reads_value(self) -> None:
+        with tempfile.TemporaryDirectory(prefix="config-store.") as tmp:
+            store = ConfigStore(Path(tmp) / "bot-bottle.db")
+            store.migrate()
+            store.set_cached_image_stale_warning_days(7)
+            self.assertEqual(7, store.cached_image_stale_warning_days())
+
+    def test_config_schema_uses_explicit_settings_columns(self) -> None:
+        with tempfile.TemporaryDirectory(prefix="config-store.") as tmp:
+            store = ConfigStore(Path(tmp) / "bot-bottle.db")
+            store.migrate()
+            with sqlite3.connect(store.db_path) as conn:
+                conn.row_factory = sqlite3.Row
+                columns = [
+                    row["name"]
+                    for row in conn.execute("PRAGMA table_info(bot_bottle_config)")
+                ]
+            self.assertEqual([
+                "id",
+                "cached_image_stale_warning_days",
+            ], columns)
+
+    def test_store_manager_includes_config_store(self) -> None:
+        with tempfile.TemporaryDirectory(prefix="config-store.") as tmp:
+            db = Path(tmp) / "bot-bottle.db"
+            manager = StoreManager(db)
+            self.assertFalse(manager.is_migrated())
+            manager.migrate()
+            self.assertTrue(manager.is_migrated())
+
+    def test_cached_image_warning_days_returns_default_when_db_missing(self) -> None:
+        # When the db file doesn't exist yet (parent exists, file doesn't),
+        # the store returns the default without touching the file.
+        with tempfile.TemporaryDirectory(prefix="config-store.") as tmp:
+            store = ConfigStore(Path(tmp) / "missing.db")
+            self.assertEqual(
+                DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS,
+                store.cached_image_stale_warning_days(),
+            )
+
+    def test_cached_image_warning_days_returns_default_on_null_value(self) -> None:
+        # If the row exists but the value is NULL (or not castable to int),
+        # the store falls back to the default.
+        with tempfile.TemporaryDirectory(prefix="config-store.") as tmp:
+            db_path = Path(tmp) / "bot-bottle.db"
+            store = ConfigStore(db_path)
+            store.migrate()
+            # Write a NULL value directly.
+            with sqlite3.connect(db_path) as conn:
+                conn.execute(
+                    "UPDATE bot_bottle_config SET cached_image_stale_warning_days = NULL WHERE id = 1"
+                )
+            self.assertEqual(
+                DEFAULT_CACHED_IMAGE_STALE_WARNING_DAYS,
+                store.cached_image_stale_warning_days(),
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/unit/test_docker_launch_committed_image.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import contextlib
+import dataclasses
 import io
 import tempfile
 import unittest
@@ -16,6 +17,7 @@ from bot_bottle.backend.docker import launch as launch_mod
 from bot_bottle.backend.docker.bottle_plan import DockerBottlePlan
 from bot_bottle.egress import EgressPlan
 from bot_bottle.git_gate import GitGatePlan
+from bot_bottle.log import Die
 from bot_bottle.manifest import ManifestIndex
 
 
@@ -88,7 +90,7 @@ class TestLaunchCommittedImage(unittest.TestCase):
         committed_tag: str | None = None,
         image_present: bool = True,
     ) -> list[str]:
-        """Drive launch() through its full sequence with the committed-image
+        """Drive build_or_load_images() + launch() with the committed-image
         behaviour controlled by the arguments. Returns the images that were
         passed to `build_image` (empty list if it was never called)."""
         built: list[str] = []
@@ -122,8 +124,9 @@ class TestLaunchCommittedImage(unittest.TestCase):
            mock.patch.object(launch_mod, "compose_dump_logs"), \
            mock.patch.object(launch_mod, "compose_down"), \
            contextlib.redirect_stderr(io.StringIO()):
+            images = launch_mod.build_or_load_images(plan)
             provision = mock.Mock(return_value=None)
-            with launch_mod.launch(plan, provision=provision):
+            with launch_mod.launch(plan, images, provision=provision):
                 pass
 
         return built
@@ -168,8 +171,9 @@ class TestLaunchCommittedImage(unittest.TestCase):
            mock.patch.object(launch_mod, "compose_dump_logs"), \
            mock.patch.object(launch_mod, "compose_down"), \
            contextlib.redirect_stderr(io.StringIO()):
+            images = launch_mod.build_or_load_images(plan)
             provision = mock.Mock(return_value=None)
-            with launch_mod.launch(plan, provision=provision):
+            with launch_mod.launch(plan, images, provision=provision):
                 pass
 
         self.assertEqual(1, len(captured_plans))
@@ -180,6 +184,24 @@ class TestLaunchCommittedImage(unittest.TestCase):
         built = self._run_launch(plan, committed_tag=None)
         self.assertEqual([_DEFAULT_IMAGE], built)
 
+    def test_cached_images_skip_build_when_present(self) -> None:
+        base = _plan(self._tmp)
+        plan = dataclasses.replace(
+            base,
+            spec=dataclasses.replace(base.spec, image_policy="cached"),
+        )
+        built = self._run_launch(plan, committed_tag=None, image_present=True)
+        self.assertEqual([], built)
+
+    def test_cached_images_die_when_agent_missing(self) -> None:
+        base = _plan(self._tmp)
+        plan = dataclasses.replace(
+            base,
+            spec=dataclasses.replace(base.spec, image_policy="cached"),
+        )
+        with self.assertRaises(Die):
+            self._run_launch(plan, committed_tag=None, image_present=False)
+
     def test_falls_back_to_build_when_committed_image_missing_from_daemon(self) -> None:
         plan = _plan(self._tmp)
         built = self._run_launch(

tests/unit/test_docker_launch_teardown.py

@@ -16,7 +16,7 @@ from pathlib import Path
 from unittest import mock
 
 from bot_bottle.agent_provider import AgentProvisionPlan
-from bot_bottle.backend import BottleSpec
+from bot_bottle.backend import BottleImages, BottleSpec
 from bot_bottle.backend.docker import launch as launch_mod
 from bot_bottle.backend.docker.bottle_plan import DockerBottlePlan
 from bot_bottle.egress import EgressPlan
@@ -86,6 +86,8 @@ class TestTeardownWarning(unittest.TestCase):
         plan = _plan(self._tmp)
         buf = io.StringIO()
 
+        images = BottleImages(agent="bot-bottle-claude:latest", sidecar="bot-bottle-sidecars:latest")
+
         with mock.patch.object(launch_mod.docker_mod, "build_image"), \
              mock.patch.object(
                  launch_mod, "egress_tls_init",
@@ -115,7 +117,7 @@ class TestTeardownWarning(unittest.TestCase):
              ), \
              contextlib.redirect_stderr(buf):
             provision = mock.Mock(return_value=None)
-            with launch_mod.launch(plan, provision=provision):
+            with launch_mod.launch(plan, images, provision=provision):
                 pass
 
         output = buf.getvalue()

tests/unit/test_docker_util_image.py

@@ -9,6 +9,7 @@ from __future__ import annotations
 
 import subprocess
 import unittest
+from datetime import timezone
 from unittest.mock import patch
 
 from bot_bottle.backend.docker import util as docker_mod
@@ -54,6 +55,51 @@ class TestImageId(unittest.TestCase):
             self.assertIn("missing:tag", die.call_args.args[0])
 
 
+class TestImageCreatedAt(unittest.TestCase):
+    def test_parses_docker_timestamp_with_nanoseconds(self):
+        with patch.object(
+            docker_mod.subprocess, "run",
+            return_value=_ok(stdout="2026-07-06T15:33:47.123456789Z\n"),
+        ) as run:
+            created = docker_mod.image_created_at("bot-bottle-claude:latest")
+        self.assertEqual(2026, created.year)
+        self.assertEqual(123456, created.microsecond)
+        self.assertEqual(timezone.utc, created.tzinfo)
+        self.assertEqual(
+            ["docker", "image", "inspect", "--format", "{{.Created}}", "bot-bottle-claude:latest"],
+            run.call_args.args[0],
+        )
+
+    def test_dies_on_inspect_failure(self):
+        with patch.object(
+            docker_mod.subprocess, "run", return_value=_fail("No such image"),
+        ), patch.object(
+            docker_mod, "die", side_effect=SystemExit("die"),
+        ) as die:
+            with self.assertRaises(SystemExit):
+                docker_mod.image_created_at("missing:tag")
+        die.assert_called_once()
+        self.assertIn("missing:tag", die.call_args.args[0])
+
+    def test_dies_on_invalid_timestamp(self):
+        with patch.object(
+            docker_mod.subprocess, "run",
+            return_value=_ok(stdout="not-a-timestamp\n"),
+        ), patch.object(
+            docker_mod, "die", side_effect=SystemExit("die"),
+        ) as die:
+            with self.assertRaises(SystemExit):
+                docker_mod.image_created_at("some:tag")
+        die.assert_called_once()
+        self.assertIn("some:tag", die.call_args.args[0])
+
+    def test_parse_docker_timestamp_no_tzinfo_defaults_to_utc(self):
+        # A bare datetime with no tz offset should be treated as UTC.
+        dt = docker_mod._parse_docker_timestamp("2024-05-01T10:00:00.000000")
+        self.assertIsNotNone(dt.tzinfo)
+        self.assertEqual(timezone.utc, dt.tzinfo)
+
+
 class TestSave(unittest.TestCase):
     def test_save_runs_docker_save(self):
         with patch.object(

tests/unit/test_image_cache.py

@@ -0,0 +1,81 @@
+"""Unit: image_cache.py — check_stale / check_stale_path."""
+
+from __future__ import annotations
+
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+from unittest.mock import patch
+
+from bot_bottle.image_cache import StaleImageError, check_stale, check_stale_path
+
+
+class TestCheckStale(unittest.TestCase):
+    def _run(self, threshold: int, age_days: float) -> None:
+        created = datetime.now(tz=timezone.utc) - timedelta(days=age_days)
+        with patch("bot_bottle.image_cache.ConfigStore") as cs:
+            cs.return_value.cached_image_stale_warning_days.return_value = threshold
+            check_stale("test image", created)
+
+    def test_negative_threshold_never_raises(self):
+        # Threshold < 0 means the check is disabled — always passes.
+        self._run(threshold=-1, age_days=9999)
+
+    def test_zero_threshold_raises_immediately(self):
+        # threshold=0 means any image is stale the moment it exists.
+        with self.assertRaises(StaleImageError):
+            self._run(threshold=0, age_days=0.1)
+
+    def test_within_threshold_does_not_raise(self):
+        # Age well under threshold — should pass silently.
+        self._run(threshold=7, age_days=2)
+
+    def test_at_threshold_does_not_raise(self):
+        # Exactly at the boundary is fine (<=, not <).
+        self._run(threshold=1, age_days=0.9999)
+
+    def test_exceeds_threshold_raises(self):
+        created = datetime.now(tz=timezone.utc) - timedelta(days=3)
+        with patch("bot_bottle.image_cache.ConfigStore") as cs:
+            cs.return_value.cached_image_stale_warning_days.return_value = 1
+            with self.assertRaises(StaleImageError) as ctx:
+                check_stale("agent image 'bot-bottle:latest'", created)
+        self.assertIn("agent image", str(ctx.exception))
+        self.assertIn("day(s) old", str(ctx.exception))
+
+    def test_naive_datetime_treated_as_utc(self):
+        # check_stale calls .astimezone(utc) on the input; naive datetimes
+        # that would be interpreted as local time should still work.
+        # We can't control the local tz in a unit test, so just ensure
+        # no exception is thrown for a very recent naive datetime.
+        naive_now = datetime(2099, 1, 1)  # far future, always "fresh"
+        with patch("bot_bottle.image_cache.ConfigStore") as cs:
+            cs.return_value.cached_image_stale_warning_days.return_value = 1
+            # Should not raise — the image is brand new.
+            check_stale("test image", naive_now)
+
+
+class TestCheckStalePath(unittest.TestCase):
+    def test_delegates_to_check_stale_with_mtime(self):
+        with tempfile.NamedTemporaryFile() as f:
+            path = Path(f.name)
+            with patch("bot_bottle.image_cache.check_stale") as mock_check:
+                check_stale_path("some artifact", path)
+            mock_check.assert_called_once()
+            label, dt = mock_check.call_args.args
+            self.assertEqual("some artifact", label)
+            self.assertIsInstance(dt, datetime)
+            self.assertIsNotNone(dt.tzinfo)
+
+    def test_raises_stale_for_old_file(self):
+        with tempfile.NamedTemporaryFile() as f:
+            path = Path(f.name)
+            with patch("bot_bottle.image_cache.ConfigStore") as cs:
+                cs.return_value.cached_image_stale_warning_days.return_value = 0
+                with self.assertRaises(StaleImageError):
+                    check_stale_path("cached artifact", path)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/unit/test_macos_container_launch.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import dataclasses
 import unittest
 import tempfile
 from pathlib import Path
@@ -15,6 +16,7 @@ from bot_bottle.backend.macos_container import launch
 from bot_bottle.backend.macos_container.bottle_plan import MacosContainerBottlePlan
 from bot_bottle.egress import EgressPlan
 from bot_bottle.git_gate import GitGatePlan
+from bot_bottle.log import Die
 from bot_bottle.manifest import ManifestIndex
 
 _MANIFEST = ManifestIndex.from_json_obj({
@@ -81,7 +83,7 @@ def _plan(
         provisioned_env={"CODEX_HOME": "/run/codex-home"},
     )
     return cast(MacosContainerBottlePlan, SimpleNamespace(
-        spec=SimpleNamespace(),
+        spec=SimpleNamespace(image_policy="fresh"),
         manifest=_MANIFEST,
         stage_dir=stage_dir,
         slug="dev-abc",
@@ -292,7 +294,7 @@ class TestMacosContainerLaunchArgv(unittest.TestCase):
 
 def _build_plan(stage_dir: Path) -> MacosContainerBottlePlan:
     return MacosContainerBottlePlan(
-        spec=cast(BottleSpec, SimpleNamespace()),
+        spec=cast(BottleSpec, SimpleNamespace(image_policy="fresh")),
         manifest=_MANIFEST,
         stage_dir=stage_dir,
         git_gate_plan=cast(GitGatePlan, SimpleNamespace(upstreams=())),
@@ -337,9 +339,9 @@ class TestMacosContainerLaunchCommittedImage(unittest.TestCase):
         ), patch.object(
             launch.container_mod, "build_image", side_effect=fake_build,
         ), patch.object(launch, "info"):
-            updated = launch._build_images(plan)
+            images = launch.build_or_load_images(plan)
 
-        self.assertEqual("bot-bottle-committed-dev-abc:latest", updated.image)
+        self.assertEqual("bot-bottle-committed-dev-abc:latest", images.agent)
         self.assertEqual(1, len(calls))
         self.assertEqual(launch.SIDECAR_BUNDLE_IMAGE, calls[0][0])
 
@@ -358,12 +360,89 @@ class TestMacosContainerLaunchCommittedImage(unittest.TestCase):
         ), patch.object(
             launch.container_mod, "build_image", side_effect=fake_build,
         ):
-            updated = launch._build_images(plan)
+            images = launch.build_or_load_images(plan)
 
-        self.assertEqual("bot-bottle-agent:latest", updated.image)
+        self.assertEqual("bot-bottle-agent:latest", images.agent)
         self.assertEqual(2, len(calls))
         self.assertEqual("bot-bottle-agent:latest", calls[1][0])
 
 
+class TestMacosContainerLaunchCachedImages(unittest.TestCase):
+    def setUp(self):
+        self._tmp = tempfile.TemporaryDirectory()
+        self.stage_dir = Path(self._tmp.name)
+
+    def tearDown(self):
+        self._tmp.cleanup()
+
+    def _cached_plan(self) -> MacosContainerBottlePlan:
+        return dataclasses.replace(
+            _build_plan(self.stage_dir),
+            spec=cast(BottleSpec, SimpleNamespace(image_policy="cached")),
+        )
+
+    def test_cached_mode_dies_when_agent_image_missing(self) -> None:
+        plan = self._cached_plan()
+
+        def image_exists(ref: str) -> bool:  # pylint: disable=unused-argument
+            return False  # Nothing cached.
+
+        with patch.object(
+            launch, "read_committed_image", return_value="",
+        ), patch.object(
+            launch.container_mod, "image_exists", side_effect=image_exists,
+        ), patch.object(
+            launch, "die", side_effect=Die(),
+        ):
+            with self.assertRaises(Die):
+                launch.build_or_load_images(plan)
+
+    def test_cached_mode_dies_when_sidecar_image_missing(self) -> None:
+        plan = self._cached_plan()
+
+        def image_exists(ref: str) -> bool:
+            return ref == plan.image  # Agent present; sidecar missing.
+
+        with patch.object(
+            launch, "read_committed_image", return_value="",
+        ), patch.object(
+            launch.container_mod, "image_exists", side_effect=image_exists,
+        ), patch.object(
+            launch, "die", side_effect=Die(),
+        ):
+            with self.assertRaises(Die):
+                launch.build_or_load_images(plan)
+
+    def test_cached_mode_both_present_returns_unchanged_plan(self) -> None:
+        plan = self._cached_plan()
+        with patch.object(
+            launch, "read_committed_image", return_value="",
+        ), patch.object(
+            launch.container_mod, "image_exists", return_value=True,
+        ), patch.object(
+            launch.container_mod, "build_image",
+        ) as build, patch.object(launch, "info"):
+            images = launch.build_or_load_images(plan)
+
+        build.assert_not_called()
+        self.assertEqual(plan.image, images.agent)
+
+    def test_committed_image_plus_cached_skips_sidecar_build(self) -> None:
+        plan = self._cached_plan()
+        with patch.object(
+            launch, "read_committed_image",
+            return_value="bot-bottle-committed-dev-abc:latest",
+        ), patch.object(
+            launch.container_mod, "image_exists", return_value=True,
+        ), patch.object(
+            launch.container_mod, "build_image",
+        ) as build, patch.object(launch, "info"):
+            images = launch.build_or_load_images(plan)
+
+        # In cached mode with a committed image, no builds should fire.
+        build.assert_not_called()
+        self.assertEqual("bot-bottle-committed-dev-abc:latest", images.agent)
+
+
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_macos_container_util.py

@@ -273,5 +273,71 @@ resolver #2
             )
 
 
+class TestMacosContainerImageCreatedAt(unittest.TestCase):
+    def _ok(self, stdout: str) -> "util.subprocess.CompletedProcess":  # type: ignore
+        return util.subprocess.CompletedProcess(
+            args=[], returncode=0, stdout=stdout, stderr="",
+        )
+
+    def _fail(self, stderr: str = "no such image") -> "util.subprocess.CompletedProcess":  # type: ignore
+        return util.subprocess.CompletedProcess(
+            args=[], returncode=1, stdout="", stderr=stderr,
+        )
+
+    def test_parses_iso_timestamp_from_dict(self):
+        payload = '[{"created": "2025-06-01T12:00:00"}]'
+        with patch.object(util.subprocess, "run", return_value=self._ok(payload)):
+            dt = util.image_created_at("bot-bottle-agent:latest")
+        self.assertEqual(2025, dt.year)
+        self.assertEqual(6, dt.month)
+        self.assertEqual(1, dt.day)
+
+    def test_accepts_list_or_dict_input(self):
+        # Container CLI may return a list; we take the first element.
+        payload = '[{"created": "2024-01-15T08:30:00"}]'
+        with patch.object(util.subprocess, "run", return_value=self._ok(payload)):
+            dt = util.image_created_at("some-image:latest")
+        self.assertEqual(2024, dt.year)
+
+    def test_accepts_uppercase_Created_field(self):
+        payload = '[{"Created": "2024-03-20T10:00:00"}]'
+        with patch.object(util.subprocess, "run", return_value=self._ok(payload)):
+            dt = util.image_created_at("some-image:latest")
+        self.assertEqual(2024, dt.year)
+        self.assertEqual(3, dt.month)
+
+    def test_dies_on_nonzero_returncode(self):
+        with patch.object(util.subprocess, "run", return_value=self._fail("not found")), \
+             patch.object(util, "die", side_effect=SystemExit("die")) as die:
+            with self.assertRaises(SystemExit):
+                util.image_created_at("missing:tag")
+        die.assert_called_once()
+        self.assertIn("missing:tag", die.call_args.args[0])
+
+    def test_dies_on_malformed_json(self):
+        with patch.object(util.subprocess, "run", return_value=self._ok("not-json {")), \
+             patch.object(util, "die", side_effect=SystemExit("die")) as die:
+            with self.assertRaises(SystemExit):
+                util.image_created_at("some:tag")
+        die.assert_called_once()
+
+    def test_dies_when_no_created_field(self):
+        payload = '[{"id": "sha256:abc123"}]'
+        with patch.object(util.subprocess, "run", return_value=self._ok(payload)), \
+             patch.object(util, "die", side_effect=SystemExit("die")) as die:
+            with self.assertRaises(SystemExit):
+                util.image_created_at("some:tag")
+        die.assert_called_once()
+        self.assertIn("creation timestamp", die.call_args.args[0])
+
+    def test_dies_on_invalid_timestamp_format(self):
+        payload = '[{"created": "not-a-date"}]'
+        with patch.object(util.subprocess, "run", return_value=self._ok(payload)), \
+             patch.object(util, "die", side_effect=SystemExit("die")) as die:
+            with self.assertRaises(SystemExit):
+                util.image_created_at("some:tag")
+        die.assert_called_once()
+
+
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_stale_checks.py

@@ -0,0 +1,206 @@
+"""Unit: stale-image check functions across backends, and the
+BottleBackend.launch template method (prelaunch_checks + build_or_load_images).
+
+No real images or containers are used — all Docker/container/smolmachine
+calls are mocked at the module boundary."""
+
+from __future__ import annotations
+
+import unittest
+from pathlib import Path
+from types import SimpleNamespace
+from typing import Any, cast
+from unittest.mock import MagicMock, patch
+
+
+def _bottle_cm(bottle: Any) -> MagicMock:
+    """Return a mock context manager that yields `bottle`."""
+    cm = MagicMock()
+    cm.__enter__ = MagicMock(return_value=bottle)
+    cm.__exit__ = MagicMock(return_value=False)
+    return cm
+
+
+# ---------------------------------------------------------------------------
+# BottleBackend.launch template — prelaunch_checks + _build_or_load_images
+# ---------------------------------------------------------------------------
+
+class TestBottleBackendLaunchTemplate(unittest.TestCase):
+    """Verify the concrete launch() method on BottleBackend calls
+    _build_or_load_images and _launch_impl, and that prelaunch_checks is a no-op
+    on the base class."""
+
+    def _make_backend(self) -> Any:
+        from bot_bottle.backend.docker.backend import DockerBottleBackend
+        return DockerBottleBackend()
+
+    def test_launch_delegates_to_build_or_load_and_launch_impl(self) -> None:
+        from bot_bottle.backend import BottleImages
+        backend = self._make_backend()
+        plan = cast(Any, SimpleNamespace())
+        bottle = MagicMock()
+        images = BottleImages(agent="agent:latest", sidecar="sidecar:latest")
+        with patch.object(
+            backend, "_build_or_load_images", return_value=images,
+        ) as build_mock, patch.object(
+            backend, "_launch_impl",
+            return_value=_bottle_cm(bottle),
+        ) as impl_mock:
+            with backend.launch(plan):
+                pass
+        build_mock.assert_called_once_with(plan)
+        impl_mock.assert_called_once_with(plan, images)
+
+    def test_noop_default_prelaunch_checks(self) -> None:
+        from bot_bottle.backend.docker.backend import DockerBottleBackend
+        from bot_bottle.backend import BottleBackend
+        backend = DockerBottleBackend()
+        # Base-class prelaunch_checks is a no-op — must not raise.
+        BottleBackend.prelaunch_checks(backend, cast(Any, SimpleNamespace()))  # type: ignore[arg-type]
+
+
+# ---------------------------------------------------------------------------
+# Docker backend stale_checks
+# ---------------------------------------------------------------------------
+
+class TestDockerStaleChecks(unittest.TestCase):
+    def _plan(self, policy: str = "cached", slug: str = "dev-abc") -> Any:
+        spec = SimpleNamespace(image_policy=policy)
+        provision = SimpleNamespace(image="bot-bottle-agent:latest")
+        return cast(Any, SimpleNamespace(
+            spec=spec,
+            slug=slug,
+            image="bot-bottle-agent:latest",
+            agent_provision=provision,
+        ))
+
+    def test_fresh_policy_is_noop(self) -> None:
+        from bot_bottle.backend.docker import launch as mod
+        with patch.object(mod, "read_committed_image") as rci, \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan("fresh"))
+        rci.assert_not_called()
+        cs.assert_not_called()
+
+    def test_committed_image_present_checks_only_committed(self) -> None:
+        from bot_bottle.backend.docker import launch as mod
+        from datetime import datetime, timezone
+        ts = datetime(2025, 1, 1, tzinfo=timezone.utc)
+        with patch.object(mod, "read_committed_image", return_value="committed:latest"), \
+             patch.object(mod.docker_mod, "image_exists", return_value=True), \
+             patch.object(mod.docker_mod, "image_created_at", return_value=ts), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan())
+        cs.assert_called_once()
+        self.assertIn("committed:latest", cs.call_args.args[0])
+
+    def test_no_committed_image_checks_agent_and_sidecar(self) -> None:
+        from bot_bottle.backend.docker import launch as mod
+        from datetime import datetime, timezone
+        ts = datetime(2025, 1, 1, tzinfo=timezone.utc)
+        with patch.object(mod, "read_committed_image", return_value=""), \
+             patch.object(mod.docker_mod, "image_exists", return_value=True), \
+             patch.object(mod.docker_mod, "image_created_at", return_value=ts), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan())
+        # Should have been called for both agent and sidecar images.
+        self.assertEqual(2, cs.call_count)
+
+    def test_image_not_present_skips_check(self) -> None:
+        from bot_bottle.backend.docker import launch as mod
+        with patch.object(mod, "read_committed_image", return_value=""), \
+             patch.object(mod.docker_mod, "image_exists", return_value=False), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan())
+        cs.assert_not_called()
+
+    def test_only_sidecar_missing_checks_only_agent(self) -> None:
+        from bot_bottle.backend.docker import launch as mod
+        from datetime import datetime, timezone
+        ts = datetime(2025, 1, 1, tzinfo=timezone.utc)
+        plan = self._plan()
+
+        def image_exists(ref: str) -> bool:
+            return ref == plan.image  # Only agent present; sidecar missing.
+
+        with patch.object(mod, "read_committed_image", return_value=""), \
+             patch.object(mod.docker_mod, "image_exists", side_effect=image_exists), \
+             patch.object(mod.docker_mod, "image_created_at", return_value=ts), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(plan)
+        self.assertEqual(1, cs.call_count)
+        self.assertIn(plan.image, cs.call_args.args[0])
+
+    def test_backend_prelaunch_checks_delegates(self) -> None:
+        from bot_bottle.backend.docker.backend import DockerBottleBackend
+        from bot_bottle.backend.docker import launch as mod
+        backend = DockerBottleBackend()
+        plan = self._plan()
+        with patch.object(mod, "stale_checks") as sc:
+            backend.prelaunch_checks(plan)  # type: ignore[arg-type]
+        sc.assert_called_once_with(plan)
+
+
+# ---------------------------------------------------------------------------
+# macOS container backend stale_checks
+# ---------------------------------------------------------------------------
+
+class TestMacosContainerStaleChecks(unittest.TestCase):
+    def _plan(self, policy: str = "cached", slug: str = "dev-abc") -> Any:
+        return cast(Any, SimpleNamespace(
+            spec=SimpleNamespace(image_policy=policy),
+            slug=slug,
+            image="bot-bottle-agent:latest",
+        ))
+
+    def test_fresh_policy_is_noop(self) -> None:
+        from bot_bottle.backend.macos_container import launch as mod
+        with patch.object(mod, "read_committed_image") as rci, \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan("fresh"))
+        rci.assert_not_called()
+        cs.assert_not_called()
+
+    def test_committed_image_present_checks_only_committed(self) -> None:
+        from bot_bottle.backend.macos_container import launch as mod
+        from datetime import datetime, timezone
+        ts = datetime(2025, 1, 1, tzinfo=timezone.utc)
+        with patch.object(mod, "read_committed_image", return_value="committed:latest"), \
+             patch.object(mod.container_mod, "image_exists", return_value=True), \
+             patch.object(mod.container_mod, "image_created_at", return_value=ts), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan())
+        cs.assert_called_once()
+        self.assertIn("committed:latest", cs.call_args.args[0])
+
+    def test_no_committed_image_checks_agent_and_sidecar(self) -> None:
+        from bot_bottle.backend.macos_container import launch as mod
+        from datetime import datetime, timezone
+        ts = datetime(2025, 1, 1, tzinfo=timezone.utc)
+        with patch.object(mod, "read_committed_image", return_value=""), \
+             patch.object(mod.container_mod, "image_exists", return_value=True), \
+             patch.object(mod.container_mod, "image_created_at", return_value=ts), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan())
+        self.assertEqual(2, cs.call_count)
+
+    def test_image_not_present_skips_check(self) -> None:
+        from bot_bottle.backend.macos_container import launch as mod
+        with patch.object(mod, "read_committed_image", return_value=""), \
+             patch.object(mod.container_mod, "image_exists", return_value=False), \
+             patch.object(mod, "check_stale") as cs:
+            mod.stale_checks(self._plan())
+        cs.assert_not_called()
+
+    def test_backend_prelaunch_checks_delegates(self) -> None:
+        from bot_bottle.backend.macos_container.backend import MacosContainerBottleBackend
+        from bot_bottle.backend.macos_container import launch as mod
+        backend = MacosContainerBottleBackend()
+        plan = self._plan()
+        with patch.object(mod, "stale_checks") as sc:
+            backend.prelaunch_checks(plan)  # type: ignore[arg-type]
+        sc.assert_called_once_with(plan)
+
+
+if __name__ == "__main__":
+    unittest.main()