feat: configure modal gpu type via env

README.md

@@ -101,6 +101,7 @@ Important distinction:
 - the Modal image now installs the core ComfyUI runtime Python packages automatically, including packages ComfyUI and custom/API nodes commonly import at startup such as `alembic`, `pydantic-settings`, `spandrel`, `kornia`, and `comfy-kitchen`
 - the Modal image now includes `comfy-kitchen>=0.2.7` because ComfyUI's FP8/FP4 weight-loading path crashes with `NoneType.Params` if quantized layout support is missing
 - the Modal image now pins `torch==2.10.0`, `torchvision==0.25.0`, and `torchaudio==2.10.0` from PyTorch's CUDA 12.8 wheel index instead of floating `latest`, which keeps the remote runtime aligned with the local ComfyUI `+cu128` stack and avoids newer wheel/driver mismatches
+- the deployed remote class now takes its GPU type from `COMFY_MODAL_GPU` instead of hardcoding `A100`, so you can choose Modal GPU classes such as `L40S`, `A100`, or any other Modal-supported GPU string before app creation
 - the deployed remote class now enables Modal memory snapshots by default so later cold starts can skip more initialization work after the first deployed invocations; GPU memory snapshots remain opt-in because they are still an alpha feature in Modal
 - the deployed remote class now defaults to a `scaledown_window` of 600 seconds with `min_containers=0`, which keeps recently used containers warm for a while without forcing a permanently warm GPU
 - the Modal image filter now preserves internal ComfyUI Python packages such as `comfy/ldm/models` while still excluding top-level runtime asset folders like `models/` and `output/`
@@ -235,9 +236,12 @@ These environment variables are supported:
 - `COMFY_MODAL_ALLOW_EPHEMERAL_FALLBACK`: Re-enable slow `app.run()` fallback in remote mode. Default: `false`.
 - `COMFY_MODAL_ENABLE_MEMORY_SNAPSHOT`: Enable Modal CPU memory snapshots for the deployed remote class. Default: `true`.
 - `COMFY_MODAL_ENABLE_GPU_MEMORY_SNAPSHOT`: Opt into Modal GPU memory snapshots. Default: `false`.
+- `COMFY_MODAL_GPU`: Modal GPU type to request when deploying the remote class. Default: `A100`.
 - `COMFY_MODAL_SCALEDOWN_WINDOW`: Keep idle Modal containers warm for this many seconds after a request. Default: `600`.
 - `COMFY_MODAL_MIN_CONTAINERS`: Keep at least this many containers warm at all times. Default: `0`.
 
+If you change `COMFY_MODAL_GPU`, redeploy the Modal app or delete it and let first-run auto-deploy recreate it. Modal deployment hardware is fixed at deploy time, so changing the environment variable locally does not mutate an already-deployed app in place.
+
 ## Development
 
 - Run tests with `uv run pytest`.

comfyui_modal_sync_cloud.py

@@ -870,7 +870,7 @@ def _prewarm_restored_runtime() -> None:
 def _remote_engine_cls_options(settings: Any, vol: Any, image: Any) -> dict[str, Any]:
     """Build the Modal class options for the deployed remote execution runtime."""
     options: dict[str, Any] = {
-        "gpu": "A100",
+        "gpu": settings.modal_gpu,
         "volumes": {settings.remote_storage_root: vol},
         "scaledown_window": settings.scaledown_window_seconds,
         "min_containers": settings.min_containers,

docs/LEARNINGS.md

@@ -43,4 +43,5 @@
 - Modal volume SDK calls should not run directly on the aiohttp request event loop. Running them in a worker thread avoids `AsyncUsageWarning`, and a missing path from `Volume.listdir()` should be treated as an ordinary "not uploaded yet" cache miss instead of a hard failure.
 - The Modal container can pick up a non-package `utils` module before ComfyUI initializes. Preloading ComfyUI's own top-level `utils` package from the bundled source tree prevents `utils.install_util` import failures during `init_extra_nodes(...)`.
 - If the goal is "no idle billing, but no minute-long rebuild every run", the right Modal pattern is a deployed app with `min_containers=0`, not ephemeral `app.run()`. That lets Modal reuse the built image and deployed objects while still scaling compute down to zero between executions.
+- Modal hardware selection belongs in deployment configuration, not in request payloads. For this repo, the remote class should read a configurable GPU string from environment at deploy time, and changing it later requires a redeploy or app recreation because existing deployed app hardware does not update in place.
 - Modal memory snapshots only help once the app is deployed. They are a good default for CPU-side initialization work, while GPU memory snapshots should remain opt-in because Modal still labels them alpha and they may require additional runtime refactors.

settings.py

@@ -30,6 +30,7 @@ class ModalSyncSettings:
     custom_nodes_archive_name: str
     comfyui_root: Path | None
     custom_nodes_dir: Path | None
+    modal_gpu: str = "A100"
     scaledown_window_seconds: int = 600
     min_containers: int = 0
 
@@ -150,6 +151,7 @@ def get_settings() -> ModalSyncSettings:
         ),
         comfyui_root=comfyui_root,
         custom_nodes_dir=custom_nodes_dir,
+        modal_gpu=os.getenv("COMFY_MODAL_GPU", "A100").strip() or "A100",
         scaledown_window_seconds=_read_int_env("COMFY_MODAL_SCALEDOWN_WINDOW", 600),
         min_containers=_read_int_env("COMFY_MODAL_MIN_CONTAINERS", 0),
     )

tests/test_modal_executor_node.py

@@ -348,6 +348,7 @@ def test_modal_cloud_builds_snapshot_enabled_cls_options(
         remote_storage_root="/storage",
         enable_memory_snapshot=True,
         enable_gpu_memory_snapshot=False,
+        modal_gpu="L40S",
         scaledown_window_seconds=600,
         min_containers=0,
     )
@@ -356,6 +357,7 @@ def test_modal_cloud_builds_snapshot_enabled_cls_options(
 
     assert options["enable_memory_snapshot"] is True
     assert "experimental_options" not in options
+    assert options["gpu"] == "L40S"
     assert options["volumes"] == {"/storage": "volume"}
     assert options["scaledown_window"] == 600
     assert options["min_containers"] == 0
@@ -364,6 +366,7 @@ def test_modal_cloud_builds_snapshot_enabled_cls_options(
         remote_storage_root="/storage",
         enable_memory_snapshot=True,
         enable_gpu_memory_snapshot=True,
+        modal_gpu="A100",
         scaledown_window_seconds=900,
         min_containers=1,
     )
@@ -373,6 +376,7 @@ def test_modal_cloud_builds_snapshot_enabled_cls_options(
         "image",
     )
     assert gpu_snapshot_options["experimental_options"] == {"enable_gpu_snapshot": True}
+    assert gpu_snapshot_options["gpu"] == "A100"
     assert gpu_snapshot_options["scaledown_window"] == 900
     assert gpu_snapshot_options["min_containers"] == 1
 

tests/test_settings.py

@@ -43,3 +43,17 @@ def test_settings_prefers_modal_specific_comfyui_root_env(
 
     assert resolved == env_root.resolve()
 
+
+def test_settings_reads_modal_gpu_override(
+    settings_module: Any,
+    monkeypatch: Any,
+) -> None:
+    """The Modal GPU type should be configurable via environment variable."""
+    monkeypatch.setenv("COMFY_MODAL_GPU", "L40S")
+    settings_module.get_settings.cache_clear()
+    try:
+        settings = settings_module.get_settings()
+    finally:
+        settings_module.get_settings.cache_clear()
+
+    assert settings.modal_gpu == "L40S"