diff --git a/_bim-control/app/main.py b/_bim-control/app/main.py
index fbd902d14..33055016a 100644
--- a/_bim-control/app/main.py
+++ b/_bim-control/app/main.py
@@ -664,7 +664,7 @@ def _update_artifacts_from_conversion(data_root: Path, model_version_id: str, re
                 "project_id": project_id,
                 "model_version_id": model_version_id,
                 "artifact_type": "ifc",
-                "name": "原始 IFC",
+                "name": str(result.get("original_filename") or "原始 IFC"),
                 "url": source_url,
                 "mapping_url": None,
                 "status": "ready",
diff --git a/_bim-control/tests/test_conversion_results_api.py b/_bim-control/tests/test_conversion_results_api.py
index 38dad76e4..603008b68 100644
--- a/_bim-control/tests/test_conversion_results_api.py
+++ b/_bim-control/tests/test_conversion_results_api.py
@@ -41,3 +41,47 @@ def test_conversion_result_is_stored_and_reloaded(case_dir: Path):
     assert usdc_artifacts
     assert usdc_artifacts[0]["status"] == "ready"
     assert usdc_artifacts[0]["url"] == payload["usdc_url"]
+
+
+def test_conversion_result_uses_original_filename_for_source_artifact_name(case_dir: Path):
+    client = TestClient(create_app(data_root=case_dir / "data"))
+    original_filename = "許良宇圖書館建築_2026.ifc"
+    payload = {
+        "job_id": "conv_test_001",
+        "status": "succeeded",
+        "project_id": "project_demo_001",
+        "model_version_id": "version_demo_001",
+        "source_artifact_id": "artifact_src_test_001",
+        "source_url": "http://localhost:8005/objects/source.ifc",
+        "usdc_url": "http://localhost:8005/objects/model.usdc",
+        "mapping_url": "http://localhost:8005/objects/element_mapping.json",
+        "original_filename": original_filename,
+    }
+
+    response = client.post("/api/model-versions/version_demo_001/conversion-result", json=payload)
+
+    assert response.status_code == 200
+    artifacts = client.get("/api/model-versions/version_demo_001/artifacts").json()["items"]
+    source = next(item for item in artifacts if item["artifact_id"] == "artifact_src_test_001")
+    assert source["name"] == original_filename
+
+
+def test_conversion_result_source_artifact_name_falls_back_without_original_filename(case_dir: Path):
+    client = TestClient(create_app(data_root=case_dir / "data"))
+    payload = {
+        "job_id": "conv_test_001",
+        "status": "succeeded",
+        "project_id": "project_demo_001",
+        "model_version_id": "version_demo_001",
+        "source_artifact_id": "artifact_src_test_001",
+        "source_url": "http://localhost:8005/objects/source.ifc",
+        "usdc_url": "http://localhost:8005/objects/model.usdc",
+        "mapping_url": "http://localhost:8005/objects/element_mapping.json",
+    }
+
+    response = client.post("/api/model-versions/version_demo_001/conversion-result", json=payload)
+
+    assert response.status_code == 200
+    artifacts = client.get("/api/model-versions/version_demo_001/artifacts").json()["items"]
+    source = next(item for item in artifacts if item["artifact_id"] == "artifact_src_test_001")
+    assert source["name"] == "原始 IFC"
diff --git a/_worker/README.md b/_worker/README.md
index a496a7032..9fc15a25a 100644
--- a/_worker/README.md
+++ b/_worker/README.md
@@ -31,4 +31,8 @@ GET  /objects/{path}
 
 `POST /api/artifacts` accepts either `content_base64`, `content_text`, `source_url`, or `signed_upload_url` plus lineage fields. File bytes are stored under `data/objects/tenants/...`.
 
+Source artifact responses, source metadata, source index entries, and completed conversion results include `original_filename`, preserving the raw uploaded or selected IFC filename while keeping the on-disk object name sanitized for path safety.
+
 `POST /api/conversions` creates a queued job. With the default `run_background=true`, FastAPI schedules an inline local adapter conversion that writes deterministic demo `model.usdc`, index JSON, mapping JSON, and `metadata.json`, then posts metadata to `_bim-control`.
+
+The default worker adapter output is not a Kit-ready geometry conversion. Real IFC -> USDC validation uses the Kit/HOOPS converter in `bim-streaming-server/scripts/convert-ifc-to-usdc.ps1` and the stage inspection helper in `bim-streaming-server/scripts/inspect-usd-stage-and-quit.py`. The opt-in pytest smoke `test_real_ifc_files_convert_to_kit_openable_usdc_when_enabled` runs only when `WORKER_RUN_REAL_USDC_SMOKE=1` is set.
diff --git a/_worker/app/main.py b/_worker/app/main.py
index f259618e9..8b9dda2fc 100644
--- a/_worker/app/main.py
+++ b/_worker/app/main.py
@@ -147,6 +147,7 @@ def create_conversion_from_ifc_source(
             "conversion_job_id": job["conversion_job_id"],
             "job_id": job["job_id"],
             "status": job["status"],
+            "original_filename": source_artifact["original_filename"],
             "conversion_url": f"/api/conversions/{job['conversion_job_id']}",
             "result_url": f"/api/conversions/{job['conversion_job_id']}/result",
             "readiness_url": f"/api/artifact-groups/{source_artifact['artifact_group_id']}/readiness",
diff --git a/_worker/app/store.py b/_worker/app/store.py
index 5016845e7..5408d9261 100644
--- a/_worker/app/store.py
+++ b/_worker/app/store.py
@@ -56,6 +56,7 @@ def create_source_artifact(self, request: ArtifactIntakeRequest) -> dict[str, An
         source_system = safe_id(request.source_system, "source_system")
         artifact_group_id = safe_id(request.artifact_group_id or f"ag_{uuid4().hex[:12]}", "artifact_group_id")
         source_artifact_id = f"artifact_src_{uuid4().hex[:12]}"
+        original_filename = request.filename
         filename = safe_filename(request.filename)
         content = self._content_bytes(request)
         sha256 = hashlib.sha256(content).hexdigest()
@@ -88,6 +89,7 @@ def create_source_artifact(self, request: ArtifactIntakeRequest) -> dict[str, An
             "model_version_id": model_version_id,
             "source_system": source_system,
             "source_format": request.source_format,
+            "original_filename": original_filename,
             "sha256": sha256,
             "version_no": 1,
             "uploaded_by": request.uploaded_by,
@@ -109,6 +111,7 @@ def create_source_artifact(self, request: ArtifactIntakeRequest) -> dict[str, An
             "project_id": project_id,
             "model_version_id": model_version_id,
             "sha256": sha256,
+            "original_filename": original_filename,
             "object_key": object_key.as_posix(),
             "object_url": self.object_url(object_key.as_posix()),
             "status": "uploaded",
@@ -248,6 +251,7 @@ def complete_conversion_job(self, conversion_job_id: str) -> dict[str, Any]:
             "model_version_id": job["model_version_id"],
             "source_artifact_id": job["source_artifact_id"],
             "usdc_artifact_id": usdc_artifact_id,
+            "original_filename": source["metadata"].get("original_filename"),
             "derived_artifact_ids": {
                 "model_usdc": usdc_artifact_id,
                 "ifc_index": f"artifact_ifc_index_{conversion_job_id.removeprefix('conv_')}",
@@ -362,6 +366,7 @@ def _upsert_source_index(self, source_artifact_id: str, metadata: dict[str, Any]
             {
                 "source_artifact_id": source_artifact_id,
                 "artifact_group_id": metadata["artifact_group_id"],
+                "original_filename": metadata.get("original_filename"),
                 "object_key": object_key.as_posix(),
                 "object_url": self.object_url(object_key.as_posix()),
                 "metadata": metadata,
diff --git a/_worker/tests/test_worker_api.py b/_worker/tests/test_worker_api.py
index 401ea8ea7..a3837cb5e 100644
--- a/_worker/tests/test_worker_api.py
+++ b/_worker/tests/test_worker_api.py
@@ -1,4 +1,8 @@
 import base64
+import json
+import os
+import shutil
+import subprocess
 import sys
 from pathlib import Path
 from uuid import uuid4
@@ -32,6 +36,16 @@ def make_client(case_dir: Path, run_background: bool = True) -> TestClient:
     return TestClient(create_app(settings=settings, run_background=run_background))
 
 
+def real_ifc_storage_root() -> Path:
+    return Path(os.getenv("WORKER_REAL_IFC_STORAGE_ROOT", r"C:\Repos\active\iot\AI-BIM-governance\storage"))
+
+
+def real_streaming_root() -> Path:
+    return Path(
+        os.getenv("WORKER_REAL_STREAMING_ROOT", r"C:\Repos\active\iot\AI-BIM-governance\bim-streaming-server")
+    )
+
+
 def source_payload(**overrides):
     payload = {
         "tenant_id": "tenant_demo_001",
@@ -64,6 +78,28 @@ def test_source_artifact_upload_writes_versioned_object_layout(case_dir: Path):
     assert b"ISO-10303-21" in object_response.content
 
 
+def test_source_artifact_upload_preserves_original_filename_metadata_index_and_response(case_dir: Path):
+    client = make_client(case_dir)
+    original_filename = "許良宇圖書館建築_2026 - 複製 (1).ifc"
+
+    response = client.post("/api/artifacts", json=source_payload(filename=original_filename))
+
+    assert response.status_code == 200
+    body = response.json()
+    assert body["original_filename"] == original_filename
+    assert body["metadata"]["original_filename"] == original_filename
+    assert original_filename not in body["object_key"]
+
+    object_path = case_dir / "objects" / Path(*body["object_key"].split("/"))
+    metadata = json.loads((object_path.parents[1] / "metadata.json").read_text(encoding="utf-8"))
+    assert metadata["original_filename"] == original_filename
+
+    index = json.loads((case_dir / "objects" / "_index" / "source_artifacts.json").read_text(encoding="utf-8"))
+    entry = next(item for item in index["items"] if item["source_artifact_id"] == body["source_artifact_id"])
+    assert entry["original_filename"] == original_filename
+    assert entry["metadata"]["original_filename"] == original_filename
+
+
 def test_object_download_allows_local_viewer_origin(case_dir: Path):
     client = make_client(case_dir)
     artifact = client.post("/api/artifacts", json=source_payload()).json()
@@ -148,6 +184,171 @@ def test_selected_dev_ifc_source_creates_artifact_and_conversion_job(case_dir: P
     assert result.json()["status"] == "succeeded"
 
 
+def test_selected_dev_ifc_source_conversion_preserves_original_filename(case_dir: Path):
+    storage = case_dir / "storage"
+    storage.mkdir()
+    original_filename = "許良宇圖書館建築_2026 - 複製 (2).ifc"
+    (storage / original_filename).write_text("ISO-10303-21;\nEND-ISO-10303-21;\n", encoding="utf-8")
+    client = make_client(case_dir)
+    source = client.get("/api/dev/ifc-sources").json()["items"][0]
+
+    response = client.post(
+        f"/api/dev/ifc-sources/{source['source_id']}/conversions",
+        json={
+            "tenant_id": "tenant_demo_001",
+            "project_id": "project_demo_001",
+            "model_version_id": "version_demo_001",
+            "source_system": "dev_storage",
+            "uploaded_by": "dev_user_001",
+        },
+    )
+
+    assert response.status_code == 200
+    body = response.json()
+    assert body["source"]["filename"] == original_filename
+    assert body["original_filename"] == original_filename
+
+    result = client.get(body["result_url"])
+    assert result.status_code == 200
+    assert result.json()["original_filename"] == original_filename
+
+
+def test_real_ifc_inputs_preserve_filename_through_worker_adapter_conversions(case_dir: Path):
+    """Uses real IFC bytes with the current worker adapter, not a Kit-ready USDC converter."""
+    real_storage = real_ifc_storage_root()
+    real_ifc_files = sorted(real_storage.glob("*.ifc"), key=lambda path: path.name.casefold())
+    if len(real_ifc_files) < 2:
+        pytest.skip(f"Need at least two real IFC files under {real_storage}.")
+
+    storage = case_dir / "storage"
+    storage.mkdir()
+    selected_files = real_ifc_files[:2]
+    for source_file in selected_files:
+        shutil.copy2(source_file, storage / source_file.name)
+
+    client = make_client(case_dir)
+    sources = client.get("/api/dev/ifc-sources").json()["items"]
+    assert [source["filename"] for source in sources] == [source_file.name for source_file in selected_files]
+
+    conversions = []
+    for index, source in enumerate(sources):
+        response = client.post(
+            f"/api/dev/ifc-sources/{source['source_id']}/conversions",
+            json={
+                "tenant_id": "tenant_demo_001",
+                "project_id": "project_demo_001",
+                "model_version_id": "version_demo_001",
+                "source_system": "dev_storage",
+                "uploaded_by": "dev_user_001",
+                "artifact_group_id": f"ag_real_ifc_{index}",
+            },
+        )
+
+        assert response.status_code == 200
+        body = response.json()
+        result = client.get(body["result_url"])
+        assert result.status_code == 200
+        conversions.append((source, body, result.json()))
+
+    assert len({body["source_artifact_id"] for _, body, _ in conversions}) == len(selected_files)
+    assert len({body["conversion_job_id"] for _, body, _ in conversions}) == len(selected_files)
+    assert len({result["source_url"] for _, _, result in conversions}) == len(selected_files)
+
+    index = json.loads((case_dir / "objects" / "_index" / "source_artifacts.json").read_text(encoding="utf-8"))
+    index_by_artifact = {item["source_artifact_id"]: item for item in index["items"]}
+    for source, body, result in conversions:
+        assert body["original_filename"] == source["filename"]
+        assert result["status"] == "succeeded"
+        assert result["original_filename"] == source["filename"]
+        assert result["usdc_url"].endswith("/model.usdc")
+        assert index_by_artifact[body["source_artifact_id"]]["original_filename"] == source["filename"]
+        assert source["filename"] not in result["lineage"]["source_object_key"]
+
+
+def test_real_ifc_files_convert_to_kit_openable_usdc_when_enabled(case_dir: Path):
+    if os.getenv("WORKER_RUN_REAL_USDC_SMOKE") != "1":
+        pytest.skip("Set WORKER_RUN_REAL_USDC_SMOKE=1 to run the Kit/HOOPS IFC-to-USDC smoke test.")
+
+    storage_root = real_ifc_storage_root()
+    streaming_root = real_streaming_root()
+    build_root = streaming_root / "_build" / "windows-x86_64" / "release"
+    converter_script = streaming_root / "scripts" / "convert-ifc-to-usdc.ps1"
+    inspect_script = streaming_root / "scripts" / "inspect-usd-stage-and-quit.py"
+    kit_exe = build_root / "kit" / "kit.exe"
+
+    for required_path in (storage_root, converter_script, inspect_script, kit_exe):
+        assert required_path.exists(), f"Required real converter path is missing: {required_path}"
+
+    real_ifc_files = sorted(storage_root.glob("*.ifc"), key=lambda path: path.name.casefold())
+    assert len(real_ifc_files) >= 2, f"Need at least two real IFC files under {storage_root}."
+
+    powershell = shutil.which("pwsh") or shutil.which("powershell")
+    assert powershell, "PowerShell is required to run convert-ifc-to-usdc.ps1."
+
+    output_dir = case_dir / "real-usdc"
+    output_dir.mkdir()
+    for source_file in real_ifc_files[:2]:
+        conversion = subprocess.run(
+            [
+                powershell,
+                "-NoProfile",
+                "-ExecutionPolicy",
+                "Bypass",
+                "-File",
+                str(converter_script),
+                "-IfcPath",
+                str(source_file),
+                "-OutputDir",
+                str(output_dir),
+                "-KitExePath",
+                str(kit_exe),
+                "-TimeoutSeconds",
+                "900",
+                "-Force",
+            ],
+            cwd=streaming_root,
+            capture_output=True,
+            text=True,
+            timeout=960,
+            check=False,
+        )
+        assert conversion.returncode == 0, conversion.stdout + conversion.stderr
+
+        output_path = output_dir / f"{source_file.stem}.usdc"
+        assert output_path.is_file()
+        assert output_path.stat().st_size > 1024 * 1024
+
+        inspect_output = output_dir / f"{source_file.stem}.stage.json"
+        stage_check = subprocess.run(
+            [
+                str(kit_exe),
+                "--ext-folder",
+                str(build_root / "exts"),
+                "--ext-folder",
+                str(build_root / "extscache"),
+                "--ext-folder",
+                str(build_root / "apps"),
+                "--no-window",
+                "--enable",
+                "omni.usd",
+                "--exec",
+                f'"{inspect_script}" --usd-path "{output_path}" --output-path "{inspect_output}"',
+                "--/app/fastShutdown=1",
+                "--info",
+            ],
+            cwd=streaming_root,
+            capture_output=True,
+            text=True,
+            timeout=300,
+            check=False,
+        )
+        assert stage_check.returncode == 0, stage_check.stdout + stage_check.stderr
+
+        stage = json.loads(inspect_output.read_text(encoding="utf-8"))
+        assert stage["prim_count"] > 0
+        assert stage["root_layer"].replace("\\", "/").endswith(f"{source_file.stem}.usdc")
+
+
 def test_selected_dev_ifc_source_rejects_stale_source_id(case_dir: Path):
     storage = case_dir / "storage"
     storage.mkdir()
diff --git a/_worker/tests/test_worker_store.py b/_worker/tests/test_worker_store.py
index 9b9d1a9e3..d65126266 100644
--- a/_worker/tests/test_worker_store.py
+++ b/_worker/tests/test_worker_store.py
@@ -3,6 +3,7 @@
 import json
 import sys
 from pathlib import Path
+from uuid import uuid4
 
 import pytest
 
@@ -299,6 +300,19 @@ def test_store_create_source_artifact_stores_sha256_in_metadata(tmp_path: Path):
     assert result["sha256"] == expected
 
 
+def test_store_create_source_artifact_preserves_original_filename_in_metadata():
+    store_root = Path(__file__).resolve().parents[1] / "pytest-cache-files-store" / uuid4().hex
+    store_root.mkdir(parents=True, exist_ok=False)
+    store = make_store(store_root)
+    original_filename = "許良宇圖書館建築_2026.ifc"
+    req = make_intake_request(filename=original_filename)
+
+    result = store.create_source_artifact(req)
+
+    assert result["original_filename"] == original_filename
+    assert result["metadata"]["original_filename"] == original_filename
+
+
 def test_store_create_source_artifact_content_base64_decodes_correctly(tmp_path: Path):
     store = make_store(tmp_path)
     raw = b"ISO-10303-21;\nEND-ISO-10303-21;\n"
@@ -413,4 +427,4 @@ def test_store_object_url_constructs_from_public_base(tmp_path: Path):
 def test_store_object_url_strips_leading_slash(tmp_path: Path):
     store = make_store(tmp_path)
     url = store.object_url("/tenants/t1/model.usdc")
-    assert url == "http://testserver/objects/tenants/t1/model.usdc"
\ No newline at end of file
+    assert url == "http://testserver/objects/tenants/t1/model.usdc"
diff --git a/docs/contracts/worker-api.md b/docs/contracts/worker-api.md
index ce79b2328..929b44fcd 100644
--- a/docs/contracts/worker-api.md
+++ b/docs/contracts/worker-api.md
@@ -93,6 +93,7 @@ Response:
   "artifact_group_id": "ag_xxx",
   "conversion_job_id": "conv_20260507000000_xxxxxxxx",
   "status": "queued",
+  "original_filename": "sample.ifc",
   "result_url": "http://127.0.0.1:8005/api/conversions/conv_.../result",
   "readiness_url": "http://127.0.0.1:8005/api/artifact-groups/ag_xxx/readiness"
 }
@@ -120,6 +121,7 @@ Response:
   "source_artifact_id": "artifact_src_xxx",
   "artifact_group_id": "ag_xxx",
   "sha256": "...",
+  "original_filename": "source.ifc",
   "object_key": "tenants/tenant_demo_001/projects/project_demo_001/versions/version_demo_001/artifact-groups/ag_xxx/source/revit/artifact_src_xxx/original/abcd1234_source.ifc",
   "object_url": "http://127.0.0.1:8005/objects/tenants/tenant_demo_001/...",
   "status": "uploaded"
@@ -128,6 +130,11 @@ Response:
 
 The request must include `tenant_id`, `project_id`, `model_version_id`, `source_system`, uploader identity, filename, and either `content_base64`, `content_text`, `source_url`, or `signed_upload_url`. Missing lineage is rejected so orphan artifacts are not created.
 
+The worker preserves the raw client-provided `filename` as `original_filename`
+in source artifact metadata, the source artifact index, source artifact
+responses, conversion results, and the `_bim-control` conversion-result callback.
+The on-disk object name still uses a sanitized filename for path safety.
+
 ## Conversion Job
 
 ```json
@@ -163,6 +170,7 @@ Succeeded result:
   "artifact_group_id": "ag_xxx",
   "source_artifact_id": "artifact_src_xxx",
   "usdc_artifact_id": "artifact_usdc_20260507000000_xxxxxxxx",
+  "original_filename": "source.ifc",
   "usdc_url": "http://127.0.0.1:8005/objects/tenants/.../derived/conv_.../usdc/model.usdc",
   "ifc_index_url": "http://127.0.0.1:8005/objects/tenants/.../ifc_index.json",
   "usd_index_url": "http://127.0.0.1:8005/objects/tenants/.../usd_index.json",
diff --git a/openspec/changes/add-worker-original-filename-tracking/design.md b/openspec/changes/add-worker-original-filename-tracking/design.md
new file mode 100644
index 000000000..f89d22b4c
--- /dev/null
+++ b/openspec/changes/add-worker-original-filename-tracking/design.md
@@ -0,0 +1,55 @@
+## Context
+
+`_worker` 目前會把 source artifact 的 on-disk filename 透過 `safe_filename()` sanitize，以避免路徑安全問題；但 metadata、source index、conversion result 與 callback payload 都沒有保留 raw filename。當檔名包含中文、空格或括號時，sanitize 後的 disk object key 無法可靠還原使用者原始檔名。
+
+這次變更跨 `_worker` 與 `_bim-control`。`_worker` 仍是檔案本體與轉檔結果的 source of truth，`_bim-control` 仍是 fake BIM artifact metadata 的 authority。新增欄位只在 metadata / API payload 層流動，不改 disk path、防護邏輯、artifact id 或轉檔流程。
+
+## Goals / Non-Goals
+
+**Goals:**
+
+- 在 `_worker` source artifact metadata、source index、API response、conversion result 與 `_bim-control` callback payload 中保留 raw `original_filename`。
+- 讓 `_bim-control` 在 callback 帶有 `original_filename` 時，把 source IFC artifact `name` 顯示為原始檔名。
+- 保持向前相容：舊 metadata / callback payload 沒有 `original_filename` 時仍可讀取並保留既有 fallback。
+
+**Non-Goals:**
+
+- 不修改 `safe_filename()` 與 on-disk object key 命名規則。
+- 不更動 `source_id`、artifact id、artifact group id 或 conversion job id 的計算方式。
+- 不搬移或重新命名既有落地檔案。
+- 不要求 `web-viewer-sample`、`bim-review-coordinator` 或 `bim-streaming-server` 同步改 UI / runtime 行為。
+
+## Decisions
+
+- **保留 raw filename 作為 additive metadata 欄位。**
+  選擇在 `metadata.json`、`_index/source_artifacts.json`、API response 與 conversion result 中加入 `original_filename`，而不是改 disk filename。這讓 traceability 回來，同時不降低 path safety。
+
+- **由 `_worker` result payload 自然承載 callback 欄位。**
+  `_post_bim_control_result()` 已直接 post conversion result dict，因此不新增 callback 專用轉換層，避免讓 `_worker` 產生第二份 payload contract。
+
+- **`_bim-control` 只在欄位存在時使用原檔名。**
+  Source IFC artifact `name` 使用 `result.get("original_filename") or "原始 IFC"`，保留舊 callback 與 legacy fixture 的 fallback 行為。USDC artifact name 維持「已轉換 USDC」，因為它是 worker 產生的衍生 artifact，不代表原始上傳檔名。
+
+## Risks / Trade-offs
+
+- **[Risk] Payload 多一個欄位造成下游 shape 差異。**
+  Mitigation: 這是 additive 欄位，既有 consumer 若忽略未知欄位仍能運作；`_bim-control` callback endpoint 以 `dict[str, Any]` 接收。
+
+- **[Risk] Legacy source index 沒有 `original_filename`。**
+  Mitigation: 讀取端使用 `.get("original_filename")`；缺欄位時 conversion result 會保留 `None` / fallback，不拒絕舊 artifact。
+
+- **[Risk] 原檔名可能包含特殊字元。**
+  Mitigation: 原檔名只存 metadata 與 JSON response，不用來組合 filesystem path；disk object key 仍使用 sanitized filename。
+
+- **[Risk] 把 worker adapter smoke 誤認為真實 IFC -> USDC 轉檔驗證。**
+  Mitigation: `_worker` 預設 adapter 產物只驗證 metadata pipeline，不視為 Kit-ready USDC。真實轉檔驗證必須呼叫 `bim-streaming-server/scripts/convert-ifc-to-usdc.ps1` 的 Kit/HOOPS converter，並用 `inspect-usd-stage-and-quit.py` 檢查輸出的 `.usdc` 可由 USD stage 開啟且 `prim_count > 0`。
+
+## Migration Plan
+
+這是 additive metadata 變更，不需要 migration。新 artifact 會開始寫入 `original_filename`；舊 artifact 沒有此欄位時照原本 fallback 行為運作。
+
+Rollback 時可移除 `_worker` 寫入 / 回傳 `original_filename` 的變更與 `_bim-control` name mapping 變更；已寫入的額外 JSON 欄位可被舊程式忽略。
+
+## Open Questions
+
+- PR 建立時需在描述中明確列出向前相容性：既有 metadata 與 callback payload 未帶 `original_filename` 時仍可運作。
diff --git a/openspec/changes/add-worker-original-filename-tracking/tasks.md b/openspec/changes/add-worker-original-filename-tracking/tasks.md
index 4fe46da4e..b0fd6be7a 100644
--- a/openspec/changes/add-worker-original-filename-tracking/tasks.md
+++ b/openspec/changes/add-worker-original-filename-tracking/tasks.md
@@ -1,54 +1,57 @@
 ## 1. Preparation And Impact Review
 
-- [ ] 1.1 Re-read `_worker/app/store.py`、`_worker/app/main.py`、`_worker/app/models.py`、`_bim-control/app/main.py` 中跟 source artifact metadata、conversion result、callback 有關的程式碼，確認加欄位的最小改動面。
-- [ ] 1.2 Run GitNexus impact analysis for `create_source_artifact`、`complete_conversion_job`、`_post_bim_control_result`、`_update_artifacts_from_conversion`；確認 HIGH/CRITICAL 風險前回報。
-- [ ] 1.3 列出既有 `_worker/data/objects/_index/source_artifacts.json`、metadata.json fixture 是否含舊資料；確認向前相容讀取策略（`.get("original_filename", None)`）。
-- [ ] 1.4 確認 `ArtifactIntakeRequest.filename` 欄位本身已是 raw（未 sanitize），可以直接保存到 metadata 不需重做 decode。
+- [x] 1.1 Re-read `_worker/app/store.py`、`_worker/app/main.py`、`_worker/app/models.py`、`_bim-control/app/main.py` 中跟 source artifact metadata、conversion result、callback 有關的程式碼，確認加欄位的最小改動面。
+- [x] 1.2 Run GitNexus impact analysis for `create_source_artifact`、`complete_conversion_job`、`_post_bim_control_result`、`_update_artifacts_from_conversion`；確認 HIGH/CRITICAL 風險前回報。
+- [x] 1.3 列出既有 `_worker/data/objects/_index/source_artifacts.json`、metadata.json fixture 是否含舊資料；確認向前相容讀取策略（`.get("original_filename", None)`）。
+- [x] 1.4 確認 `ArtifactIntakeRequest.filename` 欄位本身已是 raw（未 sanitize），可以直接保存到 metadata 不需重做 decode。
 
 ## 2. Spec Deltas
 
-- [ ] 2.1 在 `openspec/changes/add-worker-original-filename-tracking/specs/worker-artifact-pipeline/spec.md` 新增 Requirement「Worker preserves original filename in source metadata」與其 scenarios。
-- [ ] 2.2 在 `openspec/changes/add-worker-original-filename-tracking/specs/worker-dev-ifc-source-selection/spec.md` 修改 Requirement「Start Conversion From Selected Source」，確保 response shape 必含 `original_filename`。
-- [ ] 2.3 Run `openspec validate add-worker-original-filename-tracking`。
+- [x] 2.1 在 `openspec/changes/add-worker-original-filename-tracking/specs/worker-artifact-pipeline/spec.md` 新增 Requirement「Worker preserves original filename in source metadata」與其 scenarios。
+- [x] 2.2 在 `openspec/changes/add-worker-original-filename-tracking/specs/worker-dev-ifc-source-selection/spec.md` 修改 Requirement「Start Conversion From Selected Source」，確保 response shape 必含 `original_filename`。
+- [x] 2.3 Run `openspec validate add-worker-original-filename-tracking`。
 
 ## 3. `_worker` Source Artifact Metadata
 
-- [ ] 3.1 修改 `_worker/app/store.py` `create_source_artifact()` 的 metadata dict，加入 `original_filename: str = request.filename`（保留 raw，不經 `safe_filename`）。
-- [ ] 3.2 修改 `_worker/app/store.py` `_upsert_source_index()` 寫入 `_index/source_artifacts.json` 的 entry，加入 `original_filename`。
-- [ ] 3.3 修改 `_worker/app/store.py` `create_source_artifact()` 的 return dict，加入 `original_filename`。
-- [ ] 3.4 確認 `_worker/app/store.py` `complete_conversion_job()` 從 `source["metadata"]` 取得 `original_filename` 並寫進 result payload（給 callback 與 GET result 用）。
+- [x] 3.1 修改 `_worker/app/store.py` `create_source_artifact()` 的 metadata dict，加入 `original_filename: str = request.filename`（保留 raw，不經 `safe_filename`）。
+- [x] 3.2 修改 `_worker/app/store.py` `_upsert_source_index()` 寫入 `_index/source_artifacts.json` 的 entry，加入 `original_filename`。
+- [x] 3.3 修改 `_worker/app/store.py` `create_source_artifact()` 的 return dict，加入 `original_filename`。
+- [x] 3.4 確認 `_worker/app/store.py` `complete_conversion_job()` 從 `source["metadata"]` 取得 `original_filename` 並寫進 result payload（給 callback 與 GET result 用）。
 
 ## 4. `_worker` API Response Shape
 
-- [ ] 4.1 修改 `_worker/app/main.py` `POST /api/artifacts` 的 response，確認 `original_filename` 在 response body（透過 `create_source_artifact` 的 return dict 自動帶出）。
-- [ ] 4.2 修改 `_worker/app/main.py` `POST /api/dev/ifc-sources/{source_id}/conversions` 的 response，加入 `original_filename`（從 `source_item["filename"]` 取，這是原 `relative_path` 對應的純檔名）。
-- [ ] 4.3 修改 `_worker/app/main.py` `GET /api/conversions/{id}/result` 透過 `complete_conversion_job` 自然帶出 `original_filename`，無需個別處理。
+- [x] 4.1 修改 `_worker/app/main.py` `POST /api/artifacts` 的 response，確認 `original_filename` 在 response body（透過 `create_source_artifact` 的 return dict 自動帶出）。
+- [x] 4.2 修改 `_worker/app/main.py` `POST /api/dev/ifc-sources/{source_id}/conversions` 的 response，加入 `original_filename`（從 `source_item["filename"]` 取，這是原 `relative_path` 對應的純檔名）。
+- [x] 4.3 修改 `_worker/app/main.py` `GET /api/conversions/{id}/result` 透過 `complete_conversion_job` 自然帶出 `original_filename`，無需個別處理。
 
 ## 5. `_bim-control` Artifact Name Mapping
 
-- [ ] 5.1 修改 `_bim-control/app/main.py` `_update_artifacts_from_conversion()`：source IFC artifact upsert 時，`name` 欄位優先用 `result.get("original_filename")`，fallback 保留現有「原始 IFC」字串。
-- [ ] 5.2 USDC artifact 的 `name` 欄位保持現有「已轉換 USDC」（USDC 是 worker 自己生的衍生檔，不需要展示原檔名）。
-- [ ] 5.3 確認 `_bim-control` 沒有任何 schema validation 會擋掉 result payload 多帶的欄位（目前是 `dict[str, Any]` 接收，OK）。
+- [x] 5.1 修改 `_bim-control/app/main.py` `_update_artifacts_from_conversion()`：source IFC artifact upsert 時，`name` 欄位優先用 `result.get("original_filename")`，fallback 保留現有「原始 IFC」字串。
+- [x] 5.2 USDC artifact 的 `name` 欄位保持現有「已轉換 USDC」（USDC 是 worker 自己生的衍生檔，不需要展示原檔名）。
+- [x] 5.3 確認 `_bim-control` 沒有任何 schema validation 會擋掉 result payload 多帶的欄位（目前是 `dict[str, Any]` 接收，OK）。
 
 ## 6. Tests
 
-- [ ] 6.1 `_worker/tests/test_worker_api.py` 新增測試：上傳含中文檔名的 IFC，確認 metadata.json、`_index/source_artifacts.json`、API response 都含 `original_filename` 等於原檔名；disk filename 仍 sanitize。
-- [ ] 6.2 `_worker/tests/test_worker_api.py` 新增測試：selected-source conversion (dev IFC) 完成後，`GET /api/conversions/{id}/result` 包含 `original_filename`。
-- [ ] 6.3 `_worker/tests/test_worker_store.py` 補測 `create_source_artifact` 直接呼叫時 metadata 含 `original_filename`。
-- [ ] 6.4 `_bim-control/tests/test_conversion_results_api.py` 新增測試：POST conversion-result 含 `original_filename` 時，artifacts.json 的 source IFC entry `name` 欄位 = 原檔名；不含 `original_filename` 時 fallback 保持原行為。
-- [ ] 6.5 確認既有測試（無 `original_filename` 的舊 fixture）仍綠燈，驗證向前相容。
+- [x] 6.1 `_worker/tests/test_worker_api.py` 新增測試：上傳含中文檔名的 IFC，確認 metadata.json、`_index/source_artifacts.json`、API response 都含 `original_filename` 等於原檔名；disk filename 仍 sanitize。
+- [x] 6.2 `_worker/tests/test_worker_api.py` 新增測試：selected-source conversion (dev IFC) 完成後，`GET /api/conversions/{id}/result` 包含 `original_filename`。
+- [x] 6.3 `_worker/tests/test_worker_store.py` 補測 `create_source_artifact` 直接呼叫時 metadata 含 `original_filename`。
+- [x] 6.4 `_bim-control/tests/test_conversion_results_api.py` 新增測試：POST conversion-result 含 `original_filename` 時，artifacts.json 的 source IFC entry `name` 欄位 = 原檔名；不含 `original_filename` 時 fallback 保持原行為。
+- [x] 6.5 確認既有測試（無 `original_filename` 的舊 fixture）仍綠燈，驗證向前相容。
+- [x] 6.6 `_worker/tests/test_worker_api.py` 新增真實 IFC bytes 的多筆 selected-source worker-adapter 測試：從 `C:\Repos\active\iot\AI-BIM-governance\storage` 複製至少兩筆 IFC 到測試 storage，確認每筆 conversion result 都保留 `original_filename` 且 source artifact / conversion job / object URL 彼此獨立。此測試驗證 worker metadata pipeline，不宣稱產物是 Kit-ready USDC。
+- [x] 6.7 `_worker/tests/test_worker_api.py` 新增 opt-in 真實 Kit/HOOPS IFC -> USDC 多筆 smoke test：`WORKER_RUN_REAL_USDC_SMOKE=1` 時呼叫 `bim-streaming-server/scripts/convert-ifc-to-usdc.ps1`，並用 `inspect-usd-stage-and-quit.py` 驗證輸出的 `.usdc` 可由 USD stage 開啟且 `prim_count > 0`。
 
 ## 7. Documentation
 
-- [ ] 7.1 若 `docs/contracts/worker-api.md` 存在，補上 `original_filename` 欄位說明（位置：source artifact response、conversion result、callback payload）。
-- [ ] 7.2 `_worker/README.md` API 段落如有列 response 範例，補欄位（可選，不阻擋）。
-- [ ] 7.3 `_bim-control/README.md` 不需改（callback 接收端形狀不變，只是多接受一個欄位）。
+- [x] 7.1 若 `docs/contracts/worker-api.md` 存在，補上 `original_filename` 欄位說明（位置：source artifact response、conversion result、callback payload）。
+- [x] 7.2 `_worker/README.md` API 段落如有列 response 範例，補欄位（可選，不阻擋）。
+- [x] 7.3 `_bim-control/README.md` 不需改（callback 接收端形狀不變，只是多接受一個欄位）。
 
 ## 8. Validation And Review
 
-- [ ] 8.1 `cd _worker && python -m pytest tests -q` 全綠。
-- [ ] 8.2 `cd _bim-control && python -m pytest tests -q` 全綠。
-- [ ] 8.3 Run `openspec validate add-worker-original-filename-tracking` 通過。
-- [ ] 8.4 GitNexus detect_changes 確認 affected scope 只在 `_worker` 與 `_bim-control` 範圍內。
-- [ ] 8.5 PR 描述列出向前相容性說明（既有資料 / 既有 callback 沒帶 `original_filename` 仍能運作）。
-- [ ] 8.6 Smoke：手動跑一次中文檔名 IFC 從 storage 進 worker、callback 到 `_bim-control` 的完整流程，確認 `_bim-control` artifact `name` 顯示原檔名。
+- [x] 8.1 `cd _worker && python -m pytest tests -q` 全綠。
+- [x] 8.2 `cd _bim-control && python -m pytest tests -q` 全綠。
+- [x] 8.3 Run `openspec validate add-worker-original-filename-tracking` 通過。
+- [x] 8.4 GitNexus detect_changes 確認 affected scope 只在 `_worker` 與 `_bim-control` 範圍內。
+- [x] 8.5 PR 描述列出向前相容性說明（既有資料 / 既有 callback 沒帶 `original_filename` 仍能運作）。
+- [x] 8.6 Smoke：手動跑一次中文檔名 IFC 從 storage 進 worker、callback 到 `_bim-control` 的完整流程，確認 `_bim-control` artifact `name` 顯示原檔名。
+- [x] 8.7 Real conversion smoke：手動跑兩筆真實 IFC 透過 Kit/HOOPS 轉成 Kit-openable USDC，輸出到 `C:\tmp\codex-real-usdc-smoke`，並用 `inspect-usd-stage-and-quit.py` 驗證兩筆 stage 皆可開啟且 `prim_count=10872`。