---

name: reference-and-backend-tests description: "Guides ONNX ReferenceEvaluator usage, reference-op behavior, backend test corpus, and bounded backend-data generation." disable-model-invocation: true metadata: disco-role: operating license: Apache 2.0

ONNX Reference and Backend Tests

Use this sub-skill when a task needs to execute ONNX with the pure-Python ReferenceEvaluator, compare outputs against expected NumPy values, inspect reference operator behavior, work with the backend test corpus, or generate small backend-test data sets.

Workflow

1. Use ReferenceEvaluator when you need a local execution baseline that follows ONNX semantics rather than a framework runtime.
2. If the model already exists, load it and run a tiny, deterministic input dictionary first.
3. For backend-test corpus work, distinguish between safe local node/model cases and real model downloads. Prefer small, source-defined cases for smoke tests.
4. Keep optional dependencies optional: install onnx[reference] only when image-decoder/reference workflows need Pillow.
5. When a result differs from a backend/runtime, treat the ONNX spec and reference operator as the source of truth.
6. Use the bounded helper script to create a small backend-test data directory or to smoke-check a tiny model.

Route to References and Helpers

• Read references/reference-evaluator.md for ReferenceEvaluator and debugging details.
• Read references/backend-test-workflows.md for backend-interface concepts and test-data generation patterns.
• Read references/troubleshooting.md before retrying a missing-op, optional-dependency, or download-based backend issue.
• Run scripts/reference_eval_smoke.py --help to see the safe tiny-model smoke options.
• Run scripts/generate_backend_test_subset.py --help to see the bounded backend-data generator options.

Scope Boundaries

• Use model-authoring for creating or saving models and fixtures.
• Use validation-and-conversion for checker, parser/printer, shape inference, and opset conversion.
• Use operator-spec-maintenance when the task changes the reference operator implementations or backend node tests themselves.