# Assign role member

Assign a user to a role within an organization. The user must be an existing member of the organization.

#### Path Parameters

**`organization_id`** string required

Organization ID (org_ prefixed string).

**`role_id`** string required

Role ID (role_ prefixed string).

#### Request Body

**`user_id`** string required

The ID of the user to assign to this role (usr_ prefixed string). The user must be a member of the organization.

## Returns

A role assignment object with the assignment details including `id`, `user_id`, `role_id`, `organization_id`, and `assigned_at`.

Request

```bash cURL
curl -X POST "https://api.aitronos.com/v1/organizations/org_abc123/roles/role_xyz789/members" \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"user_id": "usr_target456"}'
```


```python Python SDK
from aitronos import Aitronos

client = Aitronos(api_key="your-api-key")

assignment = client.organizations.roles.assign_member(
    organization_id="org_abc123",
    role_id="role_xyz789",
    user_id="usr_target456",
)
print(assignment)
```


```python Python
import requests

response = requests.post(
    "https://api.aitronos.com/v1/organizations/org_abc123/roles/role_xyz789/members",
    headers={
        "Authorization": "Bearer YOUR_ACCESS_TOKEN",
        "Content-Type": "application/json",
    },
    json={"user_id": "usr_target456"},
)
print(response.json())
```


```javascript JavaScript
const response = await fetch(
  "https://api.aitronos.com/v1/organizations/org_abc123/roles/role_xyz789/members",
  {
    method: "POST",
    headers: {
      Authorization: "Bearer YOUR_ACCESS_TOKEN",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ user_id: "usr_target456" }),
  }
);
const assignment = await response.json();
console.log(assignment);
```

Response

```json 201 Created
{
  "id": "urol_abc123def456",
  "user_id": "usr_target456",
  "role_id": "role_xyz789",
  "organization_id": "org_abc123",
  "assigned_at": "2026-01-15T10:30:00+00:00"
}
```


```json 409 Conflict
{
  "success": false,
  "error": {
    "code": "ROLE_ASSIGNMENT_DUPLICATE",
    "message": "This user is already assigned to this role.",
    "system_message": "this user is already assigned to this role.",
    "type": "client_error",
    "status": 409,
    "details": {
      "user_id": "usr_target456",
      "role_id": "role_xyz789",
      "organization_id": "org_abc123"
    },
    "trace_id": "abc-123-def",
    "timestamp": "2026-01-15T10:30:00Z"
  }
}
```


```json 404 Not Found
{
  "success": false,
  "error": {
    "code": "MEMBER_NOT_FOUND",
    "message": "The specified user is not a member of this organization.",
    "system_message": "the specified user is not a member of this organization.",
    "type": "client_error",
    "status": 404,
    "details": { "user_id": "usr_nonexistent" },
    "trace_id": "abc-123-def",
    "timestamp": "2026-01-15T10:30:00Z"
  }
}
```

## Related Resources

- [Retrieve role](/docs/api-reference/organizations/roles/retrieve)
- [Create custom role](/docs/api-reference/organizations/roles/create-role)
- [List role members](/docs/api-reference/organizations/roles/list-members)
- [Remove role member](/docs/api-reference/organizations/roles/remove-member)
- [Effective permissions](/docs/api-reference/organizations/roles/effective-permissions)