[DE-8304] Deprecate synchronous upload capability

CHANGELOG.md

@@ -5,6 +5,19 @@ All notable changes to the [Nucleus Python Client](https://github.com/scaleapi/n
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.19.0](https://github.com/scaleapi/nucleus-python-client/releases/tag/v0.19.0) - 2026-07-07
+
+### Changed
+- **Breaking:** `dataset.append()` now always uses the async pipeline and returns an `AsyncJob`. The `asynchronous` and `batch_size` parameters are deprecated and ignored. All uploads (local and remote) go through the async Step Function pipeline, which handles phash computation, image optimization, and NLS search indexing.
+
+### Removed
+- Synchronous upload paths for images and videos. All uploads now use the async pipeline. Use `job.sleep_until_complete()` to block until processing finishes.
+- `UploadResponse` class — `append()` now returns `AsyncJob`.
+- `construct_append_payload()` and `construct_append_scenes_payload()` functions.
+- `check_all_paths_remote()` function.
+- The already deprecated `dataset.append_scenes()` method — use `dataset.append()` instead.
+- Synchronous branches from `_append_scenes()` and `_append_video_scenes()`.
+
 ## [0.18.8](https://github.com/scaleapi/nucleus-python-client/releases/tag/v0.18.8) - 2026-06-17
 
 ### Fixed

nucleus/__init__.py

@@ -171,7 +171,6 @@
 from .model_run import ModelRun
 from .payload_constructor import (
     construct_annotation_payload,
-    construct_append_payload,
     construct_box_predictions_payload,
     construct_model_creation_payload,
     construct_segmentation_payload,
@@ -190,7 +189,6 @@
 from .retry_strategy import RetryStrategy
 from .scene import Frame, LidarScene, VideoScene
 from .slice import Slice
-from .upload_response import UploadResponse
 from .utils import create_items_from_folder_crawl
 from .validate import Validate
 
@@ -605,19 +603,6 @@ def delete_dataset_item(self, dataset_id: str, reference_id) -> dict:
         dataset = self.get_dataset(dataset_id)
         return dataset.delete_item(reference_id)
 
-    @deprecated("Use Dataset.append instead.")
-    def populate_dataset(
-        self,
-        dataset_id: str,
-        dataset_items: List[DatasetItem],
-        batch_size: int = 20,
-        update: bool = False,
-    ):
-        dataset = self.get_dataset(dataset_id)
-        return dataset.append(
-            dataset_items, batch_size=batch_size, update=update
-        )
-
     @deprecated(msg="Use Dataset.ingest_tasks instead")
     def ingest_tasks(self, dataset_id: str, payload: dict):
         dataset = self.get_dataset(dataset_id)

nucleus/async_job.py

@@ -51,8 +51,8 @@ class AsyncJob:
         client = nucleus.NucleusClient(YOUR_SCALE_API_KEY)
         dataset = client.get_dataset("ds_bwkezj6g5c4g05gqp1eg")
 
-        # When kicking off an asynchronous job, store the return value as a variable
-        job = dataset.append(items=YOUR_DATASET_ITEMS, asynchronous=True)
+        # dataset.append() always returns an AsyncJob
+        job = dataset.append(items=YOUR_DATASET_ITEMS)
 
         # Poll for status or errors
         print(job.status())