diff --git a/xr_rm_teleop/test/test_act_episode_recorder.py b/xr_rm_teleop/test/test_act_episode_recorder.py
index 4913871..18b135f 100644
--- a/xr_rm_teleop/test/test_act_episode_recorder.py
+++ b/xr_rm_teleop/test/test_act_episode_recorder.py
@@ -14,6 +14,7 @@ from xr_rm_teleop.act_episode_recorder import (
     EpisodeMetadata,
     EpisodeStore,
     QualityError,
+    QualityLimits,
     RecordingSession,
     RecordingState,
     TaskDirectoryLock,
@@ -23,6 +24,7 @@ from xr_rm_teleop.act_episode_recorder import (
     recover_partial_files,
     select_camera_pair,
     select_frame,
+    validate_episode,
 )
 
 
@@ -477,3 +479,122 @@ def test_task_directory_lock_rejects_second_recorder(tmp_path):
             second.acquire()
     finally:
         first.release()
+
+
+def _quality_limits():
+    return QualityLimits(min_samples=3, max_samples=100)
+
+
+def _valid_episode(tmp_path):
+    path = tmp_path / "episode_0.partial.hdf5"
+    store = EpisodeStore.create(path, _metadata())
+    for index, seq in enumerate((100, 103, 106)):
+        sample = _episode_sample(seq)
+        sample["debug/cameras/cam_high_frame_number"] = 200 + index
+        sample["debug/cameras/cam_wrist_frame_number"] = 300 + index
+        store.append(sample)
+    store.close()
+    with h5py.File(path, "r+") as root:
+        root.attrs["camera_high_fps"] = 30.0
+        root.attrs["camera_right_wrist_fps"] = 30.0
+        root.attrs["camera_high_drop_ratio"] = 0.0
+        root.attrs["camera_right_wrist_drop_ratio"] = 0.0
+    return path
+
+
+@requires_h5py
+def test_validate_episode_accepts_valid_file(tmp_path):
+    report = validate_episode(_valid_episode(tmp_path), _quality_limits())
+
+    assert report.accepted
+    assert report.reason is None
+    assert report.metrics["control_hz"] == pytest.approx(30.0, rel=1e-5)
+
+
+def _mutate_episode(path, mutation):
+    with h5py.File(path, "r+") as root:
+        if mutation == "short_episode":
+            root.visititems(
+                lambda _name, item: item.resize(2, axis=0)
+                if isinstance(item, h5py.Dataset)
+                else None
+            )
+        elif mutation == "control_seq_gap":
+            root["debug/control/control_seq"][1] = 104
+        elif mutation == "nonfinite_qpos":
+            root["observations/qpos"][1, 0] = np.nan
+        elif mutation == "joint_limit":
+            root["action"][1, 0] = 4.0
+        elif mutation == "invalid_gripper":
+            root["action"][1, 7] = 0.5
+        elif mutation == "feedback_age":
+            control_ns = root["debug/timestamps/control_monotonic_ns"][1]
+            root["debug/timestamps/feedback_monotonic_ns"][1] = (
+                control_ns - 60_000_000
+            )
+        elif mutation == "action_invalid":
+            root["debug/control/action_valid"][1] = 0
+        elif mutation == "control_fault":
+            root["debug/control/control_fault"][1] = 1
+        elif mutation == "camera_fps":
+            root.attrs["camera_high_fps"] = 20.0
+        elif mutation == "camera_drop":
+            root.attrs["camera_right_wrist_drop_ratio"] = 0.02
+        elif mutation == "camera_age":
+            root["debug/timestamps/cam_high_age_ms"][1] = 60.0
+        elif mutation == "camera_skew":
+            root["debug/timestamps/inter_camera_skew_ms"][1] = 60.0
+        elif mutation == "final_gripper_closed":
+            root["observations/qpos"][-1, 7] = 0.0
+        else:
+            raise AssertionError(f"unknown mutation: {mutation}")
+
+
+@requires_h5py
+@pytest.mark.parametrize(
+    ("mutation", "reason"),
+    [
+        ("short_episode", "too_few_samples"),
+        ("control_seq_gap", "control_sequence_gap"),
+        ("nonfinite_qpos", "nonfinite_qpos"),
+        ("joint_limit", "joint_limit_violation"),
+        ("invalid_gripper", "invalid_gripper_state"),
+        ("feedback_age", "feedback_too_old"),
+        ("action_invalid", "invalid_action"),
+        ("control_fault", "control_fault"),
+        ("camera_fps", "camera_fps"),
+        ("camera_drop", "camera_drop_ratio"),
+        ("camera_age", "camera_frame_too_old"),
+        ("camera_skew", "camera_skew"),
+        ("final_gripper_closed", "final_gripper_not_open"),
+    ],
+)
+def test_validate_episode_reports_stable_reason(
+    tmp_path,
+    mutation,
+    reason,
+):
+    path = _valid_episode(tmp_path)
+    _mutate_episode(path, mutation)
+
+    report = validate_episode(path, _quality_limits())
+
+    assert not report.accepted
+    assert report.reason == reason
+
+
+@requires_h5py
+def test_validate_episode_reports_qp_failures_without_rejecting(tmp_path):
+    path = _valid_episode(tmp_path)
+    with h5py.File(path, "r+") as root:
+        root["debug/qp/attempted"][:] = (1, 1, 1)
+        root["debug/qp/success"][:] = (0, 0, 1)
+        root["debug/control/target_clamped"][:] = (1, 0, 1)
+
+    report = validate_episode(path, _quality_limits())
+
+    assert report.accepted
+    assert report.metrics["qp_failure_count"] == 2
+    assert report.metrics["qp_failure_ratio"] == pytest.approx(2.0 / 3.0)
+    assert report.metrics["qp_longest_failure_streak"] == 2
+    assert report.metrics["target_clamped_count"] == 2
diff --git a/xr_rm_teleop/xr_rm_teleop/act_episode_recorder.py b/xr_rm_teleop/xr_rm_teleop/act_episode_recorder.py
index b34eb4c..fc353c9 100644
--- a/xr_rm_teleop/xr_rm_teleop/act_episode_recorder.py
+++ b/xr_rm_teleop/xr_rm_teleop/act_episode_recorder.py
@@ -102,6 +102,26 @@ class EpisodeMetadata:
             raise ValueError("joint lower limits must be below upper limits")
 
 
+@dataclass(frozen=True)
+class QualityLimits:
+    min_samples: int = 60
+    max_samples: int = 1800
+    min_control_hz: float = 27.0
+    max_control_gap_ms: float = 100.0
+    min_camera_fps: float = 27.0
+    max_drop_ratio: float = 0.01
+    max_feedback_age_ms: float = 50.0
+    max_camera_age_ms: float = 50.0
+    max_camera_skew_ms: float = 50.0
+
+
+@dataclass(frozen=True)
+class QualityReport:
+    accepted: bool
+    reason: str | None
+    metrics: dict[str, int | float]
+
+
 class EpisodeStore:
     def __init__(self, path: Path, root: Any) -> None:
         self.path = path
@@ -305,6 +325,196 @@ def recover_partial_files(
     return recovered
 
 
+def longest_true_run(values: np.ndarray) -> int:
+    longest = 0
+    current = 0
+    for value in values:
+        current = current + 1 if value else 0
+        longest = max(longest, current)
+    return longest
+
+
+def _quality_failure(
+    reason: str,
+    metrics: dict[str, int | float],
+) -> QualityReport:
+    return QualityReport(False, reason, metrics)
+
+
+def validate_episode(path: Path, limits: QualityLimits) -> QualityReport:
+    metrics: dict[str, int | float] = {}
+    try:
+        root = _h5py().File(path, "r")
+    except OSError:
+        return _quality_failure("invalid_hdf5", metrics)
+
+    with root:
+        try:
+            datasets = {name: root[name] for name in DATA_LAYOUT}
+        except KeyError:
+            return _quality_failure("schema_error", metrics)
+
+        lengths = {dataset.shape[0] for dataset in datasets.values()}
+        if len(lengths) != 1:
+            return _quality_failure("time_axis_length_mismatch", metrics)
+        sample_count = lengths.pop()
+        metrics["sample_count"] = sample_count
+        if sample_count < limits.min_samples:
+            return _quality_failure("too_few_samples", metrics)
+        if sample_count >= limits.max_samples:
+            return _quality_failure("max_duration", metrics)
+
+        for name, (dtype, sample_shape, _chunks) in DATA_LAYOUT.items():
+            dataset = datasets[name]
+            if dataset.shape != (sample_count, *sample_shape):
+                return _quality_failure("schema_error", metrics)
+            if dataset.dtype != np.dtype(dtype):
+                return _quality_failure("schema_error", metrics)
+
+        qpos = datasets["observations/qpos"][:]
+        action = datasets["action"][:]
+        if not np.all(np.isfinite(qpos)):
+            return _quality_failure("nonfinite_qpos", metrics)
+        if not np.all(np.isfinite(action)):
+            return _quality_failure("nonfinite_action", metrics)
+
+        lower = np.asarray(root.attrs.get("joint_lower_limits", ()))
+        upper = np.asarray(root.attrs.get("joint_upper_limits", ()))
+        if lower.shape != (7,) or upper.shape != (7,):
+            return _quality_failure("joint_limits_missing", metrics)
+        if (
+            np.any(qpos[:, :7] < lower)
+            or np.any(qpos[:, :7] > upper)
+            or np.any(action[:, :7] < lower)
+            or np.any(action[:, :7] > upper)
+        ):
+            return _quality_failure("joint_limit_violation", metrics)
+        if not (
+            np.all(np.isin(qpos[:, 7], (0.0, 1.0)))
+            and np.all(np.isin(action[:, 7], (0.0, 1.0)))
+        ):
+            return _quality_failure("invalid_gripper_state", metrics)
+
+        attempted = datasets["debug/qp/attempted"][:].astype(bool)
+        success = datasets["debug/qp/success"][:].astype(bool)
+        failed = attempted & ~success
+        failure_count = int(failed.sum())
+        metrics["qp_failure_count"] = failure_count
+        metrics["qp_failure_ratio"] = float(
+            failure_count / max(1, int(attempted.sum()))
+        )
+        metrics["qp_longest_failure_streak"] = longest_true_run(failed)
+        metrics["target_clamped_count"] = int(
+            datasets["debug/control/target_clamped"][:].sum()
+        )
+
+        control_seq = datasets["debug/control/control_seq"][:].astype(
+            np.int64
+        )
+        if not np.all(np.diff(control_seq) == 3):
+            return _quality_failure("control_sequence_gap", metrics)
+        control_ns = datasets[
+            "debug/timestamps/control_monotonic_ns"
+        ][:].astype(np.int64)
+        control_gap_ns = np.diff(control_ns)
+        if np.any(control_gap_ns <= 0):
+            return _quality_failure("control_timestamp_invalid", metrics)
+        elapsed_ns = int(control_ns[-1] - control_ns[0])
+        control_hz = (sample_count - 1) * 1e9 / elapsed_ns
+        max_control_gap_ms = float(control_gap_ns.max() * 1e-6)
+        metrics["control_hz"] = float(control_hz)
+        metrics["max_control_gap_ms"] = max_control_gap_ms
+        if control_hz < limits.min_control_hz:
+            return _quality_failure("control_rate", metrics)
+        if max_control_gap_ms > limits.max_control_gap_ms:
+            return _quality_failure("control_gap", metrics)
+
+        feedback_ns = datasets[
+            "debug/timestamps/feedback_monotonic_ns"
+        ][:].astype(np.int64)
+        feedback_age_ms = (control_ns - feedback_ns) * 1e-6
+        metrics["max_feedback_age_ms"] = float(feedback_age_ms.max())
+        if np.any(feedback_age_ms < 0) or np.any(
+            feedback_age_ms > limits.max_feedback_age_ms
+        ):
+            return _quality_failure("feedback_too_old", metrics)
+        if not np.all(datasets["debug/control/action_valid"][:] == 1):
+            return _quality_failure("invalid_action", metrics)
+        if np.any(datasets["debug/control/control_fault"][:] != 0):
+            return _quality_failure("control_fault", metrics)
+        if np.any(datasets["debug/gripper/command_failed"][:] != 0):
+            return _quality_failure("gripper_command_failed", metrics)
+        if datasets["debug/gripper/command_pending"][-1] != 0:
+            return _quality_failure("gripper_command_pending", metrics)
+
+        camera_stats = (
+            ("camera_high_fps", limits.min_camera_fps, "camera_fps"),
+            (
+                "camera_right_wrist_fps",
+                limits.min_camera_fps,
+                "camera_fps",
+            ),
+            (
+                "camera_high_drop_ratio",
+                limits.max_drop_ratio,
+                "camera_drop_ratio",
+            ),
+            (
+                "camera_right_wrist_drop_ratio",
+                limits.max_drop_ratio,
+                "camera_drop_ratio",
+            ),
+        )
+        for name, threshold, reason in camera_stats:
+            if name not in root.attrs:
+                return _quality_failure("camera_stats_missing", metrics)
+            value = float(root.attrs[name])
+            metrics[name] = value
+            if not np.isfinite(value):
+                return _quality_failure("camera_stats_missing", metrics)
+            if reason == "camera_fps" and value < threshold:
+                return _quality_failure(reason, metrics)
+            if reason == "camera_drop_ratio" and value > threshold:
+                return _quality_failure(reason, metrics)
+
+        high_age_ms = datasets[
+            "debug/timestamps/cam_high_age_ms"
+        ][:]
+        wrist_age_ms = datasets[
+            "debug/timestamps/cam_wrist_age_ms"
+        ][:]
+        max_camera_age_ms = float(max(high_age_ms.max(), wrist_age_ms.max()))
+        metrics["max_camera_age_ms"] = max_camera_age_ms
+        if (
+            np.any(high_age_ms < 0)
+            or np.any(wrist_age_ms < 0)
+            or max_camera_age_ms > limits.max_camera_age_ms
+        ):
+            return _quality_failure("camera_frame_too_old", metrics)
+        camera_skew_ms = datasets[
+            "debug/timestamps/inter_camera_skew_ms"
+        ][:]
+        metrics["max_camera_skew_ms"] = float(camera_skew_ms.max())
+        if np.any(camera_skew_ms < 0) or np.any(
+            camera_skew_ms > limits.max_camera_skew_ms
+        ):
+            return _quality_failure("camera_skew", metrics)
+
+        for camera in ("cam_high", "cam_wrist"):
+            frame_numbers = datasets[
+                f"debug/cameras/{camera}_frame_number"
+            ][:].astype(np.int64)
+            discontinuities = int((np.diff(frame_numbers) != 1).sum())
+            ratio = discontinuities / max(1, sample_count - 1)
+            metrics[f"{camera}_sample_discontinuity_ratio"] = float(ratio)
+            if ratio > limits.max_drop_ratio:
+                return _quality_failure("camera_sample_drop_ratio", metrics)
+
+        if qpos[-1, 7] != 1.0:
+            return _quality_failure("final_gripper_not_open", metrics)
+        return QualityReport(True, None, metrics)
+
+
 class QualityError(RuntimeError):
     pass