## Update group

**patch** `/v1/groups/{group_id}`

Partially updates a group's name or external reference ID. Returns 404 if the group does not belong to the authenticated organization.

### Path Parameters

- `group_id: string`

  Unique group identifier (grp_*)

### Body Parameters

- `external_reference_id: optional string`

- `name: optional string`

### Returns

- `GroupResponse  { data }`

  Response containing a single group resource.

  - `data: Group`

    - `id: string`

      Prefixed group identifier (`grp_<base64-encoded-uuid>`).

    - `created_at: string`

      Group creation timestamp (ISO 8601, UTC).

    - `external_reference_id: string`

      Stable identifier for this group in the integrator's own system.

    - `name: string`

      Human-readable group name.

    - `organization_id: string`

      Prefixed organization identifier (`org_<base64-encoded-uuid>`).

    - `updated_at: string`

      Last-update timestamp (ISO 8601, UTC).

### Example

```http
curl https://api.vitablehealth.com/v1/groups/$GROUP_ID \
    -X PATCH \
    -H "Authorization: Bearer $VITABLE_CONNECT_API_KEY"
```

#### Response

```json
{
  "data": {
    "id": "grp_abc123def456",
    "organization_id": "org_abc123def456",
    "name": "Tier 1 (renamed)",
    "external_reference_id": "mol_seg_001_v2",
    "created_at": "2026-01-15T10:30:00Z",
    "updated_at": "2026-01-16T09:12:00Z"
  }
}
```