Understand consumer contracts

Payne supports one bounded consumer-contract shape for the official finance scenario. A versioned contract names the consumer, required output fields, known type and nullability evidence, semantic mappings and their approval state, source evidence references, and a checksum.

The replacement comparison evaluates field name, normalized type, nullability, output presence, and semantic mapping separately. Missing type or nullability evidence remains review-required; it is not filled by model text.

Artifact preparation is eligible only for the official supported consumer and the single unambiguous field mapping captured by the current evidence. Payne is not an arbitrary SQL or dbt generator.