# INVALID_UNIQUE_KEY_DEFINITION — unique key definition is structurally invalid

Each unique key on a model must have a non-empty list of field paths, a unique name within the model, and field paths that resolve to existing, non-ambigu…

<em>cyoda-go version <a href="https://github.com/Cyoda/cyoda-go/releases/tag/v0.8.2">0.8.2</a></em>

# errors.INVALID_UNIQUE_KEY_DEFINITION

## NAME

INVALID_UNIQUE_KEY_DEFINITION — a model's unique key definition is structurally invalid and cannot be used.

## SYNOPSIS

HTTP: `422` `Unprocessable Entity`. Retryable: `no`.

## DESCRIPTION

Each unique key on a model must have a non-empty list of field paths, a unique name within the model, and field paths that resolve to existing, non-ambiguous fields in the model schema. This error is returned when a submitted model definition violates one of these structural requirements.

To resolve: correct the unique key definition — ensure every key has a name, at least one field path, no duplicate key names within the model, and that all referenced field paths exist in the model schema.

## SEE ALSO

- errors
- errors.INVALID_UNIQUE_KEY
- errors.COMPOSITE_KEY_UNSUPPORTED

## See also

- [`cyoda help errors`](/help/errors/) — Every error response from the Cyoda REST API carries a structured `errorCode` in the `properties` object. Multiple codes may share the same HTTP status. Programmatic handling keys on `errorCode`, not HTTP status.
- [`cyoda help errors INVALID_UNIQUE_KEY`](/help/errors/invalid_unique_key/) — A composite unique key requires every declared field to be present and non-null. This error is returned when the entity payload is missing a value for at least one key field, or the value cannot be normalized to a valid claim (for example, a NaN or ±Infinity for a numeric key field).
- [`cyoda help errors COMPOSITE_KEY_UNSUPPORTED`](/help/errors/composite_key_unsupported/) — Composite unique key enforcement is an optional capability that storage backends may or may not implement. This error is returned when a model defines one or more unique keys but the backend does not implement the `CompositeUniqueKeyCapable` interface.

## Raw formats

- [`/help/errors/invalid_unique_key_definition.json`](/help/errors/invalid_unique_key_definition.json) — full descriptor (matches `GET /help/{topic}` envelope)
- [`/help/errors/invalid_unique_key_definition.md`](/help/errors/invalid_unique_key_definition.md) — body only