# ContractCustomField

A model the API reference uses in a request or a response. The operation pages link every field typed as this model here.

One merchant-defined custom field value carried on a recurring billing contract: the merchant's
field definition, and the value to stamp onto the transactions the contract bills.

## Fields
- `definitionId` (string(uuid)): The merchant custom-field definition this value belongs to, or `null` when  the value could not be matched to one. (nullable)
- `name` (string): The name of the merchant's custom-field definition, matched case-insensitively. This is the  canonical key the platform uses for custom fields. (nullable, max length 50)
- `value` (string) required: The value captured for the field. At most `TrxCustomFieldConsts.MaxValueLength`  characters and free of control characters. (nullable, max length 300)
- `legacyKey` (integer(int32)): The v1 API caller's own integer `CustomKey` for this field, preserved verbatim, or  `null` for a value that never came through the v1 facade. (nullable)

## See also

- [All documentation](https://devportal.demo.winkpg.io/llms.txt): the machine-readable index of every public page on this site.