diff --git a/dimos/message_codegen/test_builtin_catalog.py b/dimos/message_codegen/test_builtin_catalog.py
index fbc37ed8c5f..ecb824c5805 100644
--- a/dimos/message_codegen/test_builtin_catalog.py
+++ b/dimos/message_codegen/test_builtin_catalog.py
@@ -36,7 +36,7 @@ def test_unlisted_sources_do_not_expand_the_public_catalog(tmp_path):
     manifest = json.loads(
         (source / "dimos_generated_schemas/package/message-package.json").read_text()
     )
-    assert len(manifest["owned"]) == 83
+    assert len(manifest["owned"]) == 84
     assert "extra_msgs/msg/NotExported" not in manifest["owned"]
     assert "builtin_interfaces/msg/Time" in manifest["owned"]
 
diff --git a/dimos/message_codegen/test_builtin_install.py b/dimos/message_codegen/test_builtin_install.py
index d5c862d7271..5f8ea7db22b 100644
--- a/dimos/message_codegen/test_builtin_install.py
+++ b/dimos/message_codegen/test_builtin_install.py
@@ -38,7 +38,7 @@
 assert type(r.header) is Header and r == m
 assert type(pickle.loads(pickle.dumps(m)).header) is Header
 assert 'MSG: std_msgs/Header' in schema(m.__msgtype__)
-assert len(message_types()) == 83
+assert len(message_types()) == 84
 assert 'visualization_msgs/msg/Marker' not in message_types()
 root = Path(package_root())
 assert (root / 'schema-sources.json').is_file()
diff --git a/dimos/message_codegen/test_builtin_preparation.py b/dimos/message_codegen/test_builtin_preparation.py
index 20c948ad673..8ceefba3822 100644
--- a/dimos/message_codegen/test_builtin_preparation.py
+++ b/dimos/message_codegen/test_builtin_preparation.py
@@ -48,12 +48,12 @@ def no_network(*args, **kwargs):
 
     monkeypatch.setattr("dimos_cdrgen.source_inputs.requests.get", no_network)
     inputs = prepare(cache, offline=True, project=project)
-    assert len(list(inputs.rglob("*.msg"))) == 83
+    assert len(list(inputs.rglob("*.msg"))) == 84
     output = generate(project)
     resources = output / "dimos_generated_schemas/package"
     manifest = json.loads((resources / "message-package.json").read_text())
-    assert len(manifest["owned"]) == 83
-    assert len(list(project.glob("custom/dimos_msgs/msg/*.msg"))) == 21
+    assert len(manifest["owned"]) == 84
+    assert len(list(project.glob("custom/dimos_msgs/msg/*.msg"))) == 22
     lock = json.loads((project / "schema-sources.json").read_text())
     assert all(len(item["sha256"]) == 64 for item in lock["sources"])
     assert (resources / "dimos_msgs-LICENSE").is_file()
diff --git a/examples/episode_status/README.md b/examples/episode_status/README.md
new file mode 100644
index 00000000000..6a6719b1c51
--- /dev/null
+++ b/examples/episode_status/README.md
@@ -0,0 +1,44 @@
+# EpisodeStatus
+
+Add `packages/dimos-generated/custom/dimos_msgs/msg/EpisodeStatus.msg`:
+
+```text
+float64 ts
+string state
+int64 episodes_saved
+int64 episodes_discarded
+string last_event "init"
+string[] task_label
+```
+
+Add the type to `packages/dimos-generated/catalog.json`, then prepare and generate locally. Commit the definition and catalog; generated output stays ignored:
+
+```sh
+uv run python -m scripts.prepare_builtin_sources
+uv run python -m scripts.generate_builtin_messages
+uv run python -m scripts.generate_builtin_messages --check
+```
+
+Use the generated Python value from the editable checkout or matching message wheel:
+
+```python
+from dimos_generated.dimos_msgs.msg import EpisodeStatus
+from dimos_cdrgen.registry import encode, decode
+
+status = EpisodeStatus(ts=17.25, state="recording", episodes_saved=2,
+                       episodes_discarded=1, last_event="start", task_label=["inspection"])
+assert len(status.task_label) <= 1
+assert decode(encode(status), EpisodeStatus) == status
+```
+
+`ts` is seconds. `task_label=[]` represents None; `[""]` preserves an empty label.
+The published Python backend cannot encode bounded sequences. The unbounded sequence
+has the same CDR bytes; applications enforce zero or one label before encoding or after decoding.
+Counters use signed 64-bit storage. Applications enforce finite timestamps and
+`state` (`idle/recording`) and `last_event` (`start/save/discard/init`) values.
+Generated values require explicit fields and retain their wire values without Pydantic coercion. The source model's JSON `schema_version` envelope is not a
+message field; adding this type does not migrate the robot-learning collector.
+
+The fields follow the [EpisodeStatus model](https://github.com/dimensionalOS/dimos/blob/ef5e5f2710c482fb1d43d43ec50fd73b0fbe1dde/dimos/imitation/collection/episode.py).
+See the [built-in message guide](/docs/development/messages-in-repository.md) for
+checkout prerequisites and the existing package/consumer workflow.
diff --git a/examples/episode_status/test_episode_status.py b/examples/episode_status/test_episode_status.py
new file mode 100644
index 00000000000..3f4222c7e93
--- /dev/null
+++ b/examples/episode_status/test_episode_status.py
@@ -0,0 +1,60 @@
+# Copyright 2026 Dimensional Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""The supported sequence schema retains the nullable label wire contract."""
+
+import sys
+
+from dimos_cdrgen.registry import decode, encode, schema
+from dimos_generated.dimos_msgs.msg import EpisodeStatus
+import pytest
+from rosbags.typesys import Stores, get_types_from_msg, get_typestore
+
+
+@pytest.fixture(autouse=True)
+def restore_reference_types_module():
+    previous = sys.modules.get("rosbags.usertypes")
+    try:
+        yield
+    finally:
+        if previous is None:
+            sys.modules.pop("rosbags.usertypes", None)
+        else:
+            sys.modules["rosbags.usertypes"] = previous
+
+
+@pytest.mark.parametrize("labels", [[], [""], ["inspection"]])
+def test_nullable_labels_and_signed_counters_preserve_bounded_wire_layout(labels):
+    message = EpisodeStatus(
+        ts=17.25,
+        state="recording",
+        episodes_saved=-2,
+        episodes_discarded=-1,
+        last_event="start",
+        task_label=labels,
+    )
+    reference = get_typestore(Stores.EMPTY)
+    bounded = schema(message.__msgtype__).replace("string[] task_label", "string[<=1] task_label")
+    reference.register(get_types_from_msg(bounded, message.__msgtype__))
+    wire = encode(message)
+    assert wire == bytes(reference.serialize_cdr(message, message.__msgtype__))
+    restored = decode(wire, EpisodeStatus)
+    assert restored.task_label == labels
+    assert (restored.ts, restored.state, restored.episodes_saved, restored.episodes_discarded) == (
+        17.25,
+        "recording",
+        -2,
+        -1,
+    )
+    assert restored.last_event == "start"
diff --git a/packages/dimos-generated/catalog.json b/packages/dimos-generated/catalog.json
index af5d96e666f..0881c3d8a54 100644
--- a/packages/dimos-generated/catalog.json
+++ b/packages/dimos-generated/catalog.json
@@ -79,6 +79,7 @@
     "dimos_msgs/msg/ControlValues": "Published runtime consumer: dimos/control/contract/validate.py",
     "geometry_msgs/msg/PoseWithCovarianceStamped": "Published native runtime consumer: dimos/experimental/memory/rust/src/decoding.rs",
     "geometry_msgs/msg/TwistWithCovarianceStamped": "Published native runtime consumer: dimos/experimental/memory/rust/src/decoding.rs",
-    "geometry_msgs/msg/WrenchStamped": "Published native runtime consumer: dimos/experimental/memory/rust/src/decoding.rs"
+    "geometry_msgs/msg/WrenchStamped": "Published native runtime consumer: dimos/experimental/memory/rust/src/decoding.rs",
+    "dimos_msgs/msg/EpisodeStatus": "Built-in authoring example: examples/episode_status/README.md"
   }
 }
diff --git a/packages/dimos-generated/custom/dimos_msgs/msg/EpisodeStatus.msg b/packages/dimos-generated/custom/dimos_msgs/msg/EpisodeStatus.msg
new file mode 100644
index 00000000000..c62d17138d7
--- /dev/null
+++ b/packages/dimos-generated/custom/dimos_msgs/msg/EpisodeStatus.msg
@@ -0,0 +1,13 @@
+# EpisodeStatus internal model from robot-learning PR4343, ef5e5f2710c482fb1d43d43ec50fd73b0fbe1dde.
+# Seconds; application validation requires a finite value.
+float64 ts
+# Application values: idle, recording. Required by the source model.
+string state
+# Source Python ints use signed 64-bit wire storage; negative values are retained.
+int64 episodes_saved
+int64 episodes_discarded
+# Application values: start, save, discard, init.
+string last_event "init"
+# Nullable string: [] means None; [""] preserves an explicitly empty label.
+# Applications validate at most one element; the published Python backend cannot encode bounded sequences.
+string[] task_label