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name: stan_model_contract description: Extract a structured contract from simple Stan programs so score-model workflows can identify data, constrained parameters, transforms, model terms, and generated quantities.

Stan Model Contract

Use this skill when a recovery or algorithm needs a lightweight, language-neutral contract for a small Stan model. Do not use it as a general Stan compiler or full parser.

Inputs

• Stan source text or a path to a .stan file.
• Optional observed data dictionary for downstream validation.

Outputs

• JSON with data, parameters, transformed_parameters, model_terms, and generated_quantities.
• Diagnostics for unsupported or missing sections.

Workflow

1. Read the Stan source.
2. Call scripts/stan_contract.py --stan <path> --output <json>.
3. Inspect the output contract before passing it to transform or score-evaluation modules.
4. Treat unsupported syntax as a blocker for this reduced parser, not as evidence about real BridgeStan.

Validation

Run python tests/test_stan_contract.py from this skill directory.

Limitations

The parser intentionally supports the Bernoulli-style recovery subset: scalar bounded real parameters, integer data arrays, simple transformed-parameter assignments, distribution statements, and generated-quantity assignments.