fix: detect MPS automatically and document macOS setup

README.md

@@ -24,6 +24,9 @@ sudo apt install libopus-dev
 
 # Fedora/RHEL
 sudo dnf install opus-devel
+
+# macOS (Homebrew)
+brew install opus
 ```
 
 ### Installation
@@ -46,6 +49,26 @@ Then set up your Huggingface authentication:
 export HF_TOKEN=<YOUR_HUGGINGFACE_TOKEN>
 ```
 
+### Device Selection
+
+`moshi.server` now auto-selects `cuda`, then `mps`, then `cpu`.
+
+On Apple Silicon, you can also force Metal explicitly:
+```bash
+SSL_DIR=$(mktemp -d); python -m moshi.server --ssl "$SSL_DIR" --device mps
+```
+
+`moshi.offline` accepts the same `--device` flag, for example:
+```bash
+python -m moshi.offline --device mps \
+  --voice-prompt "NATF2.pt" \
+  --input-wav "assets/test/input_assistant.wav" \
+  --output-wav "output.wav" \
+  --output-text "output.json"
+```
+
+Note: MPS support depends on the local PyTorch build and Apple Metal support available on the host machine.
+
 ### Launch Server
 
 Launch server for live interaction (temporary SSL certs for https):

moshi/moshi/server.py

@@ -52,16 +52,16 @@
 
 
 logger = setup_logger(__name__)
-DeviceString = Literal["cuda"] | Literal["cpu"] #| Literal["mps"]
+DeviceString = Literal["cuda"] | Literal["cpu"] | Literal["mps"]
 
 def torch_auto_device(requested: Optional[DeviceString] = None) -> torch.device:
     """Return a torch.device based on the requested string or availability."""
     if requested is not None:
         return torch.device(requested)
     if torch.cuda.is_available():
         return torch.device("cuda")
-    #elif hasattr(torch.backends, "mps") and torch.backends.mps.is_available():
-    #    return torch.device("mps")
+    if hasattr(torch.backends, "mps") and torch.backends.mps.is_available():
+        return torch.device("mps")
     return torch.device("cpu")