# Field Transforms

Directus contains special flags that can be used to alter the I/O of a field's value when it's being used through the API. This can be used to cast boolean values to JSON true / false, convert DB-date formats to ISO8601, and more.

These flags are stored in the special field of directus_fields.

# Hash

hash

Hash the value using argon2 on create/update.

# UUID

uuid

Generate a new UUID on creation.

# Boolean

boolean

Cast the value to/from a JSON boolean (true / false).

# JSON

json

Cast the value to/from a JSON object.

# CSV

csv

Cast the value from a JSON array of strings to a CSV in the database (and vice versa).

# Conceal

conceal

Return the value concealed in the API. This will replace the true stored value with ********.

# User Created

user-created

Save the currently authenticated user on creation.

# User Updated

user-updated

Save the currently authenticated user on update.

# Role Created

role-created

Save the currently authenticated user's role on create.

# Role Updated

role-updated

Save the currently authenticated user's role on update.

# Date Created

date-created

Save the current date on create.

# Date Updated

date-updated

Save the current date on update.