---
title: "Add an ACS User to a User Identity"
method: POST
path: "/user_identities/add_acs_user"
tags: ["/user_identities"]
---

# Add an ACS User to a User Identity

`POST /user_identities/add_acs_user`

Adds a specified [access system user](/low-level-apis/access-systems/user-management) to a specified [user identity](/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity).

You must specify either `user_identity_id` or `user_identity_key` to identify the user identity.

If `user_identity_key` is provided, but the user identity doesn't exist, a new user identity will be created automatically using information from the ACS user.

## Request body

- object
  - `acs_user_id` string, uuid, required — ID of the access system user that you want to add to the user identity.
  - `user_identity_id` string, uuid — ID of the user identity to which you want to add an access system user.
  - `user_identity_key` string — Key of the user identity to which you want to add an access system user.

## Response `200`

OK

- object

## Other responses

- `400` — Bad Request
- `401` — Unauthorized

---

[API](https://skmtc.net/seam/apis/seam-connect.md) · [All operations](https://skmtc.net/seam/apis/seam-connect/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/seam/seam-connect/versions/00c35395ce12/schema)