Use ONNX APIs in Windows ML

In C#, the namespaces of the ONNX APIs are the same as when using ONNX Runtime directly.

using Microsoft.ML.OnnxRuntime;

In C++, the ONNX Runtime headers are included in a winml/ directory to avoid conflicts with other versions of ONNX Runtime.

#include <winml/onnxruntime_cxx_api.h>

If you have existing code that uses ONNX headers and do not want to update your includes, you can tell WinML to expose the headers without the winml/ prefix by setting the WinMLEnableDefaultOrtHeaderIncludePath property in your project:

<PropertyGroup>
  <WinMLEnableDefaultOrtHeaderIncludePath>true</WinMLEnableDefaultOrtHeaderIncludePath>
</PropertyGroup>

Then, the headers will be the same as standalone ONNX Runtime:

#include <onnxruntime_cxx_api.h>

In Python, the name of the ONNX Runtime module is the same as when using ONNX Runtime directly.

import onnxruntime as ort

// Create inference session using compiled model
using InferenceSession session = new(compiledModelPath, sessionOptions);

// Create inference session using compiled model
Ort::Session session(env, compiledModelPath.c_str(), sessionOptions);

# Create inference session using compiled model
session = ort.InferenceSession(output_model_path, sess_options=options)