Grape Idioms

Iron Laws

1. Define input contracts in params do.
2. Use declared(params, include_missing: false) or equivalent explicit shaping before passing data inward.
3. Keep endpoints thin and push business rules into application code.
4. Standardize error envelopes and auth behavior per version.

Good Defaults

• namespaced versioning
• rescue_from for predictable API errors
• presenters/entities only when they clarify response shape
• request specs for transport behavior