Create a membership role
Identity module
POST/membership-rolesmembershipRoles.create
A role held through a membership. A person may hold several; capabilities are the union. A person cannot grant themselves a role. Creates a membership role. Requires `Idempotency-Key`; a replay returns the original response. The organization is derived from the credential or the parent row, never from the body.
- Requires the capability org.members.manage.
- OAuth scopes: org.
- Send an Idempotency-Key header. A replay with the same key returns the original response.
- Error statuses: 400, 401, 409, 422, 429. Errors are RFC 9457 problem details.
Request body: MembershipRoleCreate
| Field | Type | Required | Description |
|---|---|---|---|
| membership_id | string (uuid) | Yes | Identifier of the membership. |
| role_id | string (uuid) | Yes | Identifier of the held role: a system role or a custom role of the same org. |
{
"membership_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"role_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f"
}Response 201: MembershipRole
| Field | Type | Required | Description |
|---|---|---|---|
| id | string (uuid) | Yes | Identifier of the membership role. |
| org_id | string (uuid) | Yes | Identifier of the owning organization, derived from the parent row and never accepted from the caller. |
| created_at | string (date-time) | Yes | When the row was created. |
| created_by | string (uuid) | null | Yes | Identifier of the person who created the row; null when a seed, platform or system process created it. |
| updated_at | string (date-time) | Yes | When the row was last updated. |
| updated_by | string (uuid) | null | Yes | Identifier of the person who last updated the row; null when a seed, platform or system process updated it. |
| membership_id | string (uuid) | Yes | Identifier of the membership. |
| role_id | string (uuid) | Yes | Identifier of the held role: a system role or a custom role of the same org. |
| granted_by | string (uuid) | null | Yes | Identifier of the person accountable for the grant; null when the platform granted the first Owner of a new org. |
{
"id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"org_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"created_at": "2026-10-08T14:30:00Z",
"created_by": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"updated_at": "2026-10-08T14:30:00Z",
"updated_by": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"membership_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"role_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"granted_by": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f"
}Code samples
curl -X POST "$XOS_BASE_URL/membership-roles" \
-H "Authorization: Bearer $XOS_API_KEY" \
-H "Idempotency-Key: $(uuidgen)" \
-H "Content-Type: application/json" \
-d '{"membership_id":"0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f","role_id":"0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f"}'const { data } = await xos.membershipRoles.create({
"membership_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
"role_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f"
});response = xos.membership_roles.create({"membership_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f", "role_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f"})xos membership-roles create --data '{"membership_id":"0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f","role_id":"0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f"}'