feat: Python version-aware Docker image selection

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
+        python-version: ['3.10', '3.11', '3.12']
     timeout-minutes: 15
 
     steps:

README.md

@@ -155,6 +155,14 @@ Browse working examples: **[github.com/runpod/flash-examples](https://github.com
 - macOS or Linux (Windows support in development)
 - [Runpod account](https://runpod.io/console) with API key
 
+### Python version in deployed workers
+
+Your local Python version does not affect what runs in the cloud. `flash build` downloads wheels for the container's Python version automatically.
+
+- **GPU workers**: Python 3.12 only. The GPU base image ships multiple interpreters (3.9-3.14) for interactive pod use, but torch and CUDA libraries are installed only for 3.12. Using a different version would require reinstalling torch (~2GB) and matching all C-extension wheel ABIs.
+- **CPU workers**: Python 3.10, 3.11, or 3.12. Configurable via the `PYTHON_VERSION` build arg.
+- **Image tags**: `py{version}-{tag}` (e.g., `runpod/flash:py3.12-latest`).
+
 ## Contributing
 
 We welcome contributions! See [RELEASE_SYSTEM.md](RELEASE_SYSTEM.md) for development workflow.

pyproject.toml

@@ -8,12 +8,12 @@ authors = [
 readme = "README.md"
 license = { text = "MIT" }
 classifiers = [
-    "Development Status :: 3 - Alpha",
+    "Development Status :: 4 - Beta",
     "Programming Language :: Python :: 3",
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.10,<3.15"
+requires-python = ">=3.10,<3.13"
 
 dependencies = [
     "cloudpickle>=3.1.1",