# errors.INVALID_UNIQUE_KEY

## NAME

INVALID_UNIQUE_KEY — the engine could not compute a complete composite unique key because one or more required key fields are null or carry an unsupported value type.

## SYNOPSIS

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

## DESCRIPTION

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).

To resolve: ensure every field listed in the model's unique key definition has a valid, non-null value in the submitted entity payload.

## SEE ALSO

- errors
- errors.UNIQUE_VIOLATION
- errors.INVALID_UNIQUE_KEY_DEFINITION