---
title: "Add an involved user to a case instance"
method: POST
path: "/cmmn-runtime/case-instances/{caseInstanceId}/identitylinks"
tags: ["Case Instance Identity Links"]
---

# Add an involved user to a case instance

`POST /cmmn-runtime/case-instances/{caseInstanceId}/identitylinks`

## Request

- Base URL: `https://developer-docs.flowable.com/cmmn-api`
- URL: `https://developer-docs.flowable.com/cmmn-api/cmmn-runtime/case-instances/{caseInstanceId}/identitylinks`
- Auth: HTTP basic
- TypeScript: <https://skmtc.dev/flowable/apis/flowable-cmmn-rest-api/docs/cmmn-runtime/case-instances/:caseInstanceId/identitylinks/post.ts> (a function with typed inputs; its response is checked against the schema)

Note that the groupId in Response Body will always be null, as it’s only possible to involve users with a case instance.

## Path parameters

- `caseInstanceId` string, required

## Request body

- RestIdentityLink
  - `url` string
  - `user` string
  - `group` string
  - `type` string

## Response `201`

Indicates the case instance was found and the link is created.

- RestIdentityLink
  - `url` string
  - `user` string
  - `group` string
  - `type` string

## Other responses

- `400`: Indicates the requested body did not contain a userId or a type.
- `404`: Indicates the requested case instance was not found.

---

[API](https://skmtc.dev/flowable/apis/flowable-cmmn-rest-api.md) - [All operations](https://skmtc.dev/flowable/apis/flowable-cmmn-rest-api/llms.txt) - [OpenAPI document](https://skmtc.dev/flowable/apis/flowable-cmmn-rest-api/revisions/afdfa1fcacd0?raw)