Schema validation

form0-core validates schemas before running the engine. Validation focuses on structure and attribute correctness, not UI concerns.

What is validated

• Required attributes per field type
• Allowed values for attributes (for example, display options)
• Unique key and data_name
• data_name format (lowercase a-z, 0-9, underscore, max length 42)
• Default values match field type rules
• Condition operators are valid for the referenced field type
• AI metadata shape and allowed keys

Runtime validation

At runtime, fields also validate their values when the engine evaluates:

• Numeric min/max checks
• Pattern matches for text fields
• Choice values must match defined choices

Typical errors

• Missing required attributes
• Duplicate key or data_name
• Invalid operators (for example, contains on a numeric field)
• Default values that do not match the field type