The

patchIdentity

endpoint uses JSON Patch to partially update an identity's field. The difference between "add" and "replace" operations in JSON Patch is as follows: - "add": This operation is used to add a new key-value pair to the target object or insert a new value into an array. If the target location already contains a value, the new value will overwrite the existing value. - "replace": This operation is used to replace an existing value at the target location with a new value. In the context of the

patchIdentity

endpoint, you would use "add" if you want to add a new field to the identity or insert a value into an array, and "replace" if you want to update the value of an existing field. Here's the relevant extract from the documentation:

oprequired | string The operation to be performed. One of "add", "remove", "replace", "move", "copy", or "test".

Source: [API Reference > kratos > reference > api > identity > Patch an Identity](https://www.ory.sh/docs/kratos/reference/api#tag/identity/operation/patchIdentity)

@chilly-king-10285 I want to set add a new field user_id in metadata_public when metadata_public exists already and create metadata_public with user_id when it does not exist in an identity

To add a new field

user_id

in

metadata_public

when it already exists or create

metadata_public

with

user_id

when it doesn't exist, you can use the

patchIdentity

endpoint with the "add" operation. Here's an example of how to do this: 1. First, retrieve the identity using the

GET /admin/identities/{id}

endpoint to check if

metadata_public

exists or not. Source: [API Reference > kratos > reference > api > identity > Get an Identity](https://www.ory.sh/docs/kratos/reference/api#operation/getIdentity) 2. If

metadata_public

exists, use the "add" operation to add the

user_id

field to

metadata_public

. If

metadata_public

doesn't exist, use the "add" operation to create

metadata_public

with the

user_id

field. Here's an example JSON Patch request for adding or updating the

user_id

field in `metadata_public`:

json [   {     "op": "add",     "path": "/metadata_public/user_id",     "value": "your_user_id_value"   } ]

Send this JSON Patch request to the

PATCH /admin/identities/{id}

endpoint to update the identity. Source: [API Reference > kratos > reference > api > identity > Patch an Identity](https://www.ory.sh/docs/kratos/reference/api#operation/patchIdentity)