feat(slicing): build-plate override in the SliceModal (#1337)

  Slicing an STL via the integrated slicer always defaulted to whatever
  curr_bed_type lived in the chosen process preset (typically "Cool
  Plate"), which the slicer CLI rejected for high-temp filaments with
  "Plate 1: Cool Plate does not support filament 1". The user had no
  way to switch plates without cloning the preset in BambuStudio.

  The Slice modal now exposes a Build plate dropdown with the six
  canonical BambuStudio / OrcaSlicer plates (Cool Plate, Cool Plate
  SuperTack, Engineering Plate, High Temp Plate, Textured PEI Plate,
  Smooth PEI Plate) plus an "Auto (use process preset)" option that
  preserves the previous behavior. Positioned between Process profile
  and Filament rows so a long filament list never pushes it off the
  modal's scrolled viewport, and always enabled regardless of whether
  the user picked a Printer Preset Bundle.

  A new bed_type field on SliceRequest flows through both dispatch
  paths:
  - Resolved-preset path: _patch_process_bed_type overwrites
    curr_bed_type on the process JSON before forwarding to the sidecar.
    Works end-to-end today, no sidecar change needed.
  - Bundle dispatch path: slice_with_bundle adds a bedType form field
    to the sidecar multipart. The sidecar (maziggy/orca-slicer-api
    fork) needs a matching change to honor it as --curr_bed_type on
    the CLI invocation; until then the field is silently ignored and
    the slice runs with the bundle's default plate.

backend/app/api/routes/library.py

@@ -2806,6 +2806,29 @@ def _sanitize_project_settings_sentinels(zip_bytes: bytes) -> bytes:
         return zip_bytes
 
 
+def _patch_process_bed_type(process_json: str, bed_type: str) -> str:
+    """Overwrite ``curr_bed_type`` in a process-profile JSON before forwarding
+    to the slicer sidecar.
+
+    The slicer CLI reads the build-plate type from the process profile's
+    ``curr_bed_type`` field. When the user picks a non-default plate in the
+    SliceModal (#1337), we patch the resolved JSON in place rather than
+    asking them to clone the preset just to switch a plate. Returns the
+    original string unchanged when the JSON can't be parsed or isn't a
+    dict — the slicer will then run with whatever the preset originally
+    specified, which is the safe fall-back path.
+    """
+    try:
+        profile = json.loads(process_json)
+    except json.JSONDecodeError:
+        logger.warning("Bed-type override skipped: process profile is not valid JSON")
+        return process_json
+    if not isinstance(profile, dict):
+        return process_json
+    profile["curr_bed_type"] = bed_type
+    return json.dumps(profile)
+
+
 async def _run_slicer_with_fallback(
     db: AsyncSession,
     *,
@@ -2872,6 +2895,17 @@ async def _run_slicer_with_fallback(
             assert ref is not None, "schema validator guarantees filament list is non-None"
             filament_jsons.append(await resolve_preset_ref(db, user, ref, "filament"))
 
+        # Bed-type override (#1337): patch curr_bed_type onto the resolved
+        # process JSON so the slicer's StaticPrintConfig pass picks up the
+        # user's pick instead of whatever the process preset defaults to.
+        # Without this, slicing an STL of ABS onto a process preset whose
+        # default is "Cool Plate" fails with "Plate 1: Cool Plate does not
+        # support filament 1" — the reporter's exact scenario. Only applies
+        # to the resolved-preset path; bundle mode would need a sidecar-side
+        # mechanism to patch presets it materialises from disk.
+        if request.bed_type:
+            presets["process"] = _patch_process_bed_type(presets["process"], request.bed_type)
+
     # Slicer routing — pick the sidecar URL by preferred_slicer.
     # The per-install URL setting (Settings UI → Slicer card) wins; an
     # empty value falls back to the SLICER_API_URL / BAMBU_STUDIO_API_URL
@@ -2951,6 +2985,7 @@ async def _run_slicer_with_fallback(
                     filament_names=request.bundle.filament_names,
                     plate=request.plate,
                     export_3mf=request.export_3mf,
+                    bed_type=request.bed_type,
                     request_id=progress_request_id,
                     on_progress=progress_callback,
                 )

backend/app/schemas/slicer.py

@@ -109,6 +109,17 @@ class SliceRequest(BaseModel):
         default=False,
         description="If true, request a 3MF response with embedded G-code instead of raw G-code.",
     )
+    bed_type: str | None = Field(
+        default=None,
+        max_length=64,
+        description=(
+            "Override the process preset's curr_bed_type for this slice. Canonical "
+            "BambuStudio / OrcaSlicer values: 'Cool Plate', 'Engineering Plate', "
+            "'High Temp Plate', 'Textured PEI Plate', 'Smooth PEI Plate', "
+            "'Cool Plate (SuperTack)', 'Supertack Plate'. None ⇒ inherit from the "
+            "process preset unchanged (#1337)."
+        ),
+    )
 
     @model_validator(mode="after")
     def normalise_preset_refs(self) -> "SliceRequest":

backend/app/services/slicer_api.py

@@ -435,6 +435,7 @@ class SlicerApiService:
         filament_names: list[str],
         plate: int | None = None,
         export_3mf: bool = False,
+        bed_type: str | None = None,
         request_id: str | None = None,
         on_progress: Callable[[dict], None] | None = None,
     ) -> SliceResult:
@@ -476,6 +477,16 @@ class SlicerApiService:
             data["plate"] = str(plate)
         if export_3mf:
             data["exportType"] = "3mf"
+        if bed_type is not None:
+            # #1337: bed-plate override flows through to the sidecar as a
+            # standalone field. The sidecar wraps this as --curr_bed_type on
+            # the CLI invocation, overriding whatever the bundle's process
+            # JSON specifies. Bambuddy can't patch the bundle's JSON locally
+            # (the sidecar materialises it from disk), so this round-trip is
+            # the only path. Silently no-ops on sidecar versions that don't
+            # yet recognise the field — the user's slice still runs with the
+            # bundle's default plate, no crash.
+            data["bedType"] = bed_type
         if request_id is not None:
             data["requestId"] = request_id
 

backend/tests/integration/test_library_slice_api.py

@@ -234,6 +234,86 @@ class TestSliceLibraryFile:
         assert final["result"]["print_time_seconds"] == 656
         assert captured["url"].endswith("/slice")
 
+    @pytest.mark.asyncio
+    @pytest.mark.integration
+    async def test_bed_type_override_patches_process_profile(self, async_client: AsyncClient, slice_test_setup):
+        """#1337: when SliceRequest.bed_type is set, the process JSON sent to
+        the sidecar must carry curr_bed_type with that exact value. Without
+        the patch, slicing high-temp filaments on a "Cool Plate" process
+        preset fails inside the slicer CLI with "does not support filament 1"
+        and the user has no way to switch plates from the SliceModal."""
+        captured: dict = {}
+
+        def handler(request: httpx.Request) -> httpx.Response:
+            captured["body"] = bytes(request.content)
+            return httpx.Response(
+                status_code=200,
+                content=b"PK\x03\x04 fake",
+                headers={
+                    "x-print-time-seconds": "10",
+                    "x-filament-used-g": "0.1",
+                    "x-filament-used-mm": "1.0",
+                },
+            )
+
+        _install_mock_sidecar(handler)
+        response = await async_client.post(
+            f"/api/v1/library/files/{slice_test_setup['src_file_id']}/slice",
+            json={
+                "printer_preset_id": slice_test_setup["printer_id"],
+                "process_preset_id": slice_test_setup["process_id"],
+                "filament_preset_id": slice_test_setup["filament_id"],
+                "bed_type": "Textured PEI Plate",
+            },
+        )
+        assert response.status_code == 202
+        final = await _wait_for_job(async_client, response.json()["job_id"])
+        assert final["status"] == "completed", final
+
+        # The presetProfile part of the multipart upload now carries the
+        # override. Searching the raw body avoids parsing the multipart by
+        # hand — the substring is unique enough since we control the JSON
+        # being patched.
+        assert b'"curr_bed_type": "Textured PEI Plate"' in captured["body"], (
+            "bed_type override must appear in the process JSON sent to the sidecar"
+        )
+
+    @pytest.mark.asyncio
+    @pytest.mark.integration
+    async def test_bed_type_omitted_leaves_process_profile_untouched(self, async_client: AsyncClient, slice_test_setup):
+        """Companion to the override test: the patch must NOT fire when the
+        client omits bed_type, so the process preset's own curr_bed_type
+        (or absence thereof) is forwarded to the sidecar unchanged."""
+        captured: dict = {}
+
+        def handler(request: httpx.Request) -> httpx.Response:
+            captured["body"] = bytes(request.content)
+            return httpx.Response(
+                status_code=200,
+                content=b"PK\x03\x04 fake",
+                headers={
+                    "x-print-time-seconds": "10",
+                    "x-filament-used-g": "0.1",
+                    "x-filament-used-mm": "1.0",
+                },
+            )
+
+        _install_mock_sidecar(handler)
+        response = await async_client.post(
+            f"/api/v1/library/files/{slice_test_setup['src_file_id']}/slice",
+            json={
+                "printer_preset_id": slice_test_setup["printer_id"],
+                "process_preset_id": slice_test_setup["process_id"],
+                "filament_preset_id": slice_test_setup["filament_id"],
+            },
+        )
+        assert response.status_code == 202
+        final = await _wait_for_job(async_client, response.json()["job_id"])
+        assert final["status"] == "completed", final
+        assert b"curr_bed_type" not in captured["body"], (
+            "bed_type must stay out of the process JSON when no override is set"
+        )
+
     @pytest.mark.asyncio
     @pytest.mark.integration
     async def test_invalid_preset_id_surfaces_as_failed_job_with_status_400(
@@ -513,6 +593,84 @@ class TestSliceWithBundle:
         assert b'name="presetProfile"' not in body
         assert b'name="filamentProfile"' not in body
 
+    @pytest.mark.asyncio
+    @pytest.mark.integration
+    async def test_bundle_dispatch_forwards_bed_type_when_set(self, async_client: AsyncClient, slice_test_setup):
+        """#1337 follow-up: bed-type override flows through the bundle path
+        as a `bedType` form field so the sidecar can pass
+        `--curr_bed_type` to the CLI. Bambuddy can't patch the bundle's
+        process JSON locally — the sidecar materialises it from the stored
+        .bbscfg — so the form field is the only handle."""
+        captured: dict = {}
+
+        def handler(request: httpx.Request) -> httpx.Response:
+            captured["body"] = bytes(request.content)
+            return httpx.Response(
+                status_code=200,
+                content=b"PK\x03\x04 fake",
+                headers={
+                    "x-print-time-seconds": "10",
+                    "x-filament-used-g": "0.1",
+                    "x-filament-used-mm": "1.0",
+                },
+            )
+
+        _install_mock_sidecar(handler)
+        response = await async_client.post(
+            f"/api/v1/library/files/{slice_test_setup['src_file_id']}/slice",
+            json={
+                "bundle": {
+                    "bundle_id": "abc",
+                    "printer_name": "# X1C",
+                    "process_name": "# 0.20mm",
+                    "filament_names": ["# Bambu PLA"],
+                },
+                "bed_type": "Engineering Plate",
+            },
+        )
+        assert response.status_code == 202
+        final = await _wait_for_job(async_client, response.json()["job_id"])
+        assert final["status"] == "completed", final
+        body = captured["body"]
+        assert b'name="bedType"' in body
+        assert b"Engineering Plate" in body
+
+    @pytest.mark.asyncio
+    @pytest.mark.integration
+    async def test_bundle_dispatch_omits_bed_type_when_unset(self, async_client: AsyncClient, slice_test_setup):
+        """Companion test: no bed_type ⇒ no bedType form field, so the
+        bundle's own curr_bed_type is preserved end-to-end."""
+        captured: dict = {}
+
+        def handler(request: httpx.Request) -> httpx.Response:
+            captured["body"] = bytes(request.content)
+            return httpx.Response(
+                status_code=200,
+                content=b"PK\x03\x04 fake",
+                headers={
+                    "x-print-time-seconds": "10",
+                    "x-filament-used-g": "0.1",
+                    "x-filament-used-mm": "1.0",
+                },
+            )
+
+        _install_mock_sidecar(handler)
+        response = await async_client.post(
+            f"/api/v1/library/files/{slice_test_setup['src_file_id']}/slice",
+            json={
+                "bundle": {
+                    "bundle_id": "abc",
+                    "printer_name": "# X1C",
+                    "process_name": "# 0.20mm",
+                    "filament_names": ["# Bambu PLA"],
+                },
+            },
+        )
+        assert response.status_code == 202
+        final = await _wait_for_job(async_client, response.json()["job_id"])
+        assert final["status"] == "completed", final
+        assert b'name="bedType"' not in captured["body"]
+
     @pytest.mark.asyncio
     @pytest.mark.integration
     async def test_bundle_dispatch_3mf_falls_back_to_embedded_on_5xx(

backend/tests/unit/test_slice_request_bed_type.py

@@ -0,0 +1,80 @@
+"""Regression tests for the #1337 bed-type override on slice requests.
+
+The SliceRequest schema accepts an optional `bed_type` string that the
+slice route patches onto the resolved process-profile JSON as
+`curr_bed_type` before forwarding to the sidecar. Without this hook,
+slicing high-temp filaments (ABS, ASA, PC) onto a process preset whose
+default plate is "Cool Plate" fails with the slicer-CLI error
+"Plate 1: Cool Plate does not support filament 1" and the user has no
+way to switch plates short of cloning the preset.
+"""
+
+import json
+
+import pytest
+from pydantic import ValidationError
+
+from backend.app.api.routes.library import _patch_process_bed_type
+from backend.app.schemas.slicer import PresetRef, SliceRequest
+
+
+class TestSliceRequestBedTypeField:
+    def test_bed_type_defaults_to_none(self):
+        req = SliceRequest(
+            printer_preset=PresetRef(source="local", id="1"),
+            process_preset=PresetRef(source="local", id="2"),
+            filament_preset=PresetRef(source="local", id="3"),
+        )
+        assert req.bed_type is None
+
+    def test_bed_type_accepts_canonical_values(self):
+        for value in (
+            "Cool Plate",
+            "Cool Plate (SuperTack)",
+            "Engineering Plate",
+            "High Temp Plate",
+            "Textured PEI Plate",
+            "Smooth PEI Plate",
+        ):
+            req = SliceRequest(
+                printer_preset=PresetRef(source="local", id="1"),
+                process_preset=PresetRef(source="local", id="2"),
+                filament_preset=PresetRef(source="local", id="3"),
+                bed_type=value,
+            )
+            assert req.bed_type == value
+
+    def test_bed_type_rejects_overlong_input(self):
+        with pytest.raises(ValidationError):
+            SliceRequest(
+                printer_preset=PresetRef(source="local", id="1"),
+                process_preset=PresetRef(source="local", id="2"),
+                filament_preset=PresetRef(source="local", id="3"),
+                bed_type="x" * 65,
+            )
+
+
+class TestPatchProcessBedType:
+    def test_overwrites_existing_curr_bed_type(self):
+        process_json = json.dumps({"name": "0.20mm Standard", "curr_bed_type": "Cool Plate"})
+        result = _patch_process_bed_type(process_json, "Textured PEI Plate")
+        assert json.loads(result)["curr_bed_type"] == "Textured PEI Plate"
+
+    def test_adds_curr_bed_type_when_missing(self):
+        process_json = json.dumps({"name": "0.20mm Standard"})
+        result = _patch_process_bed_type(process_json, "Engineering Plate")
+        parsed = json.loads(result)
+        assert parsed["curr_bed_type"] == "Engineering Plate"
+        # Other fields preserved
+        assert parsed["name"] == "0.20mm Standard"
+
+    def test_returns_input_unchanged_when_json_is_invalid(self):
+        # The slicer would error on this anyway; the patch helper is a
+        # straight passthrough so failure modes stay attributable to the
+        # original input rather than the patch.
+        bogus = "not a json document"
+        assert _patch_process_bed_type(bogus, "Cool Plate") is bogus
+
+    def test_returns_input_unchanged_when_json_is_not_a_dict(self):
+        not_a_dict = json.dumps(["this", "is", "an", "array"])
+        assert _patch_process_bed_type(not_a_dict, "Cool Plate") is not_a_dict

frontend/src/__tests__/components/SliceModal.test.tsx

@@ -138,11 +138,15 @@ describe('SliceModal', () => {
     await waitFor(() => {
       expect(screen.getByText('My Custom X1C')).toBeDefined();
     });
+    // 4 selects: printer, process, bed-type (#1337), filament. bed-type sits
+    // between process and filament — it overrides curr_bed_type on the
+    // process preset so the related controls cluster — and defaults to "".
     const selects = screen.getAllByRole('combobox') as HTMLSelectElement[];
-    expect(selects).toHaveLength(3);
+    expect(selects).toHaveLength(4);
     expect(selects[0].value).toBe('local:1');
     expect(selects[1].value).toBe('local:2');
-    expect(selects[2].value).toBe('local:3');
+    expect(selects[2].value).toBe('');
+    expect(selects[3].value).toBe('local:3');
 
     // Slice button is enabled because all three slots auto-defaulted and
     // the preview-slice query has resolved (mock returns immediately).
@@ -240,6 +244,65 @@ describe('SliceModal', () => {
     await waitFor(() => expect(onClose).toHaveBeenCalled());
   });
 
+  it('includes bed_type in the request when the user picks a non-auto plate (#1337)', async () => {
+    const onClose = vi.fn();
+    mockApi.sliceLibraryFile.mockResolvedValue({
+      job_id: 42,
+      status: 'pending',
+      status_url: '/api/v1/slice-jobs/42',
+    });
+
+    renderWithTracker({
+      source: { kind: 'libraryFile', id: 100, filename: 'Cube.stl' },
+      onClose,
+    });
+
+    await waitFor(() => expect(screen.getByText('My Custom X1C')).toBeDefined());
+
+    const user = userEvent.setup();
+    // Order with the dropdown now sits between Process and Filament:
+    // printer (0), process (1), bed-type (2), filament (3+). Find the
+    // bed-type select by name rather than positional index so this stays
+    // green if the layout adds another control around it.
+    const bedSelect = screen.getAllByRole('combobox').find((el) =>
+      (el as HTMLSelectElement).options[0]?.textContent?.toLowerCase().includes('auto'),
+    ) as HTMLSelectElement;
+    expect(bedSelect).toBeDefined();
+    await user.selectOptions(bedSelect, 'Textured PEI Plate');
+    await user.click(screen.getByRole('button', { name: /^Slice$/ }));
+
+    await waitFor(() => {
+      expect(mockApi.sliceLibraryFile).toHaveBeenCalledWith(
+        100,
+        expect.objectContaining({ bed_type: 'Textured PEI Plate' }),
+      );
+    });
+  });
+
+  it('omits bed_type when the user leaves it on Auto (no override)', async () => {
+    const onClose = vi.fn();
+    mockApi.sliceLibraryFile.mockResolvedValue({
+      job_id: 42,
+      status: 'pending',
+      status_url: '/api/v1/slice-jobs/42',
+    });
+
+    renderWithTracker({
+      source: { kind: 'libraryFile', id: 100, filename: 'Cube.stl' },
+      onClose,
+    });
+
+    await waitFor(() => expect(screen.getByText('My Custom X1C')).toBeDefined());
+
+    const user = userEvent.setup();
+    await user.click(screen.getByRole('button', { name: /^Slice$/ }));
+
+    await waitFor(() => {
+      const [, body] = vi.mocked(mockApi.sliceLibraryFile).mock.calls[0];
+      expect(body).not.toHaveProperty('bed_type');
+    });
+  });
+
   it('lets the user override the default and pick a Standard preset', async () => {
     const onClose = vi.fn();
     mockApi.sliceLibraryFile.mockResolvedValue({
@@ -603,8 +666,8 @@ describe('SliceModal', () => {
     });
 
     await waitFor(() => expect(screen.getByText('X1C')).toBeDefined());
-    // 1 printer + 1 process + 2 filament = 4 dropdowns.
-    expect(screen.getAllByRole('combobox')).toHaveLength(4);
+    // 1 printer + 1 process + 2 filament + 1 bed-type (#1337) = 5 dropdowns.
+    expect(screen.getAllByRole('combobox')).toHaveLength(5);
   });
 
   it('pre-picks each filament slot by matching colour metadata', async () => {
@@ -686,9 +749,11 @@ describe('SliceModal', () => {
 
     const user = userEvent.setup();
     const selects = screen.getAllByRole('combobox') as HTMLSelectElement[];
-    // Slots 0 (printer) and 1 (process) are auto-picked. Slots 2 and 3 are
-    // the two filament dropdowns. Swap slot-2 (was black) to white.
-    await user.selectOptions(selects[2], 'cloud:F-WHITE');
+    // Order: 0 printer, 1 process, 2 bed-type, 3 filament-1, 4 filament-2
+    // (#1337). Auto-picks land on printer/process/filaments; bed-type
+    // defaults to "". Swap filament-1 (index 3) from the auto-picked black
+    // to white.
+    await user.selectOptions(selects[3], 'cloud:F-WHITE');
     await user.click(screen.getByRole('button', { name: /^Slice$/ }));
 
     await waitFor(() => {
@@ -884,12 +949,14 @@ describe('SliceModal', () => {
 
     await waitFor(() => expect(screen.getByText('X1C')).toBeDefined());
 
-    // Both filament rows render — 1 printer + 1 process + 2 filament = 4.
+    // Both filament rows render — 1 printer + 1 process + 1 bed-type +
+    // 2 filament (#1337) = 5. bed-type sits at index 2, filament slots
+    // follow at 3 and 4.
     const selects = screen.getAllByRole('combobox') as HTMLSelectElement[];
-    expect(selects).toHaveLength(4);
+    expect(selects).toHaveLength(5);
     // Slot 1 (used) is editable, slot 2 (not used) is disabled.
-    expect(selects[2].disabled).toBe(false);
-    expect(selects[3].disabled).toBe(true);
+    expect(selects[3].disabled).toBe(false);
+    expect(selects[4].disabled).toBe(true);
     // The disabled row's label calls out why it's disabled.
     expect(screen.getByText(/not used by this plate/i)).toBeDefined();
   });

frontend/src/api/client.ts

@@ -1206,6 +1206,12 @@ export interface SliceRequest {
   bundle?: SliceBundleSpec;
   plate?: number;
   export_3mf?: boolean;
+  // Build-plate override (#1337). When omitted, the slicer uses the process
+  // preset's curr_bed_type as-is. Canonical values match BambuStudio /
+  // OrcaSlicer's enum: "Cool Plate", "Engineering Plate", "High Temp Plate",
+  // "Textured PEI Plate", "Smooth PEI Plate", "Cool Plate (SuperTack)",
+  // "Supertack Plate".
+  bed_type?: string | null;
 }
 
 // GET /api/v1/slicer/bundles — Printer Preset Bundles imported from

frontend/src/components/SliceModal.tsx

@@ -261,6 +261,13 @@ export function SliceModal({ source, onClose }: SliceModalProps) {
   // and we'll backfill 1 at submit time). Set to a 1-indexed plate number once
   // the user picks one (or implicitly for single-plate sources).
   const [selectedPlate, setSelectedPlate] = useState<number | null>(null);
+  // Build-plate override (#1337). null = inherit from the process preset
+  // (the default). Set to a canonical slicer enum value to patch
+  // curr_bed_type into the resolved process JSON before slicing — needed
+  // because the process preset's default plate (typically "Cool Plate") is
+  // incompatible with high-temp filaments like ABS / ASA / PC, and the
+  // user had no way to switch plates without cloning the preset.
+  const [bedType, setBedType] = useState<string | null>(null);
 
   const platesQuery = useQuery({
     queryKey: ['slicePlates', source.kind, source.id],
@@ -429,6 +436,9 @@ export function SliceModal({ source, onClose }: SliceModalProps) {
         body = {
           bundle: bundleSpec,
           ...(selectedPlate != null ? { plate: selectedPlate } : {}),
+          // Bed-type override (#1337) also flows through the bundle path —
+          // the sidecar forwards `bedType` as --curr_bed_type to the CLI.
+          ...(bedType != null ? { bed_type: bedType } : {}),
         };
       } else {
         if (
@@ -451,6 +461,8 @@ export function SliceModal({ source, onClose }: SliceModalProps) {
           // omit otherwise so the backend default applies for STL / single-plate
           // 3MF sources where the concept doesn't apply.
           ...(selectedPlate != null ? { plate: selectedPlate } : {}),
+          // Bed-type override (#1337).
+          ...(bedType != null ? { bed_type: bedType } : {}),
         };
       }
       if (source.kind === 'libraryFile') {
@@ -651,6 +663,17 @@ export function SliceModal({ source, onClose }: SliceModalProps) {
                   />
                 </>
               )}
+              {/* Bed-type override (#1337). Always visible, always enabled.
+                  In non-bundle mode the backend patches curr_bed_type on the
+                  resolved process JSON before forwarding to the sidecar; in
+                  bundle mode the same value rides through as a sidecar form
+                  field so the bundle's materialised process JSON gets the
+                  override applied there too. */}
+              <BedTypeDropdown
+                value={bedType}
+                onChange={setBedType}
+                disabled={isEnqueuing}
+              />
               {/* Filament reqs may need a server-side preview-slice for
                   unsliced project files (single-pass, then cached). Show a
                   scoped spinner so the user sees the printer/process
@@ -831,6 +854,56 @@ function CloudStatusBanner({ status }: { status: SlicerCloudStatus }) {
   );
 }
 
+// Build-plate options offered in the SliceModal (#1337). Values are the
+// canonical strings the slicer's StaticPrintConfig validator accepts as
+// `curr_bed_type` — BambuStudio is the default sidecar, so this matches its
+// enum; OrcaSlicer accepts the same set with a Supertack alias that users
+// can target via the same dropdown if they re-import their presets.
+const BED_TYPE_OPTIONS: { value: string; labelKey: string; fallback: string }[] = [
+  { value: 'Cool Plate', labelKey: 'slice.bedType.coolPlate', fallback: 'Cool Plate' },
+  {
+    value: 'Cool Plate (SuperTack)',
+    labelKey: 'slice.bedType.coolPlateSuperTack',
+    fallback: 'Cool Plate SuperTack',
+  },
+  { value: 'Engineering Plate', labelKey: 'slice.bedType.engineering', fallback: 'Engineering Plate' },
+  { value: 'High Temp Plate', labelKey: 'slice.bedType.highTemp', fallback: 'High Temp Plate' },
+  { value: 'Textured PEI Plate', labelKey: 'slice.bedType.texturedPEI', fallback: 'Textured PEI Plate' },
+  { value: 'Smooth PEI Plate', labelKey: 'slice.bedType.smoothPEI', fallback: 'Smooth PEI Plate' },
+];
+
+function BedTypeDropdown({
+  value,
+  onChange,
+  disabled,
+}: {
+  value: string | null;
+  onChange: (value: string | null) => void;
+  disabled?: boolean;
+}) {
+  const { t } = useTranslation();
+  return (
+    <label className="block">
+      <span className="block text-xs text-bambu-gray mb-1">
+        {t('slice.bedType.label', 'Build plate')}
+      </span>
+      <select
+        value={value ?? ''}
+        onChange={(e) => onChange(e.target.value === '' ? null : e.target.value)}
+        disabled={disabled}
+        className="w-full px-3 py-2 rounded-md bg-bambu-dark border border-bambu-dark-tertiary text-white text-sm focus:outline-none focus:border-bambu-gray disabled:opacity-50"
+      >
+        <option value="">{t('slice.bedType.auto', 'Auto (use process preset)')}</option>
+        {BED_TYPE_OPTIONS.map((opt) => (
+          <option key={opt.value} value={opt.value}>
+            {t(opt.labelKey, opt.fallback)}
+          </option>
+        ))}
+      </select>
+    </label>
+  );
+}
+
 interface PresetDropdownProps {
   label: string;
   slot: Slot;

frontend/src/i18n/locales/de.ts

@@ -3388,6 +3388,16 @@ export default {
       expired: 'Bambu-Cloud-Sitzung abgelaufen — erneut anmelden, um die Cloud-Profile zu aktualisieren.',
       unreachable: 'Bambu Cloud ist gerade nicht erreichbar. Lokale und Standard-Profile funktionieren weiterhin.',
     },
+    bedType: {
+      label: 'Druckbett',
+      auto: 'Auto (aus Prozess-Profil)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/en.ts

@@ -3391,6 +3391,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/fr.ts

@@ -3377,6 +3377,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/it.ts

@@ -3376,6 +3376,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/ja.ts

@@ -3388,6 +3388,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/pt-BR.ts

@@ -3376,6 +3376,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/zh-CN.ts

@@ -3376,6 +3376,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

frontend/src/i18n/locales/zh-TW.ts

@@ -3376,6 +3376,16 @@ export default {
       expired: 'Bambu Cloud session expired — sign in again to refresh your cloud presets.',
       unreachable: 'Bambu Cloud is unreachable right now. Local and standard presets still work.',
     },
+    bedType: {
+      label: 'Build plate',
+      auto: 'Auto (use process preset)',
+      coolPlate: 'Cool Plate',
+      coolPlateSuperTack: 'Cool Plate SuperTack',
+      engineering: 'Engineering Plate',
+      highTemp: 'High Temp Plate',
+      texturedPEI: 'Textured PEI Plate',
+      smoothPEI: 'Smooth PEI Plate',
+    },
   },
 
   // Spoolman

static/index.html

@@ -26,7 +26,7 @@
 
     <!-- Splash screens for iOS -->
     <link rel="apple-touch-startup-image" href="/img/android-chrome-512x512.png" />
-    <script type="module" crossorigin src="/assets/index-oQDjU99K.js"></script>
+    <script type="module" crossorigin src="/assets/index-CG1DM53r.js"></script>
     <link rel="stylesheet" crossorigin href="/assets/index-BkYu3kLs.css">
   </head>
   <body>