---
title: "Get a cycler's open service event, if any"
method: GET
path: "/cyclers/{cycler_id}/service_events/open"
tags: ["Cyclers"]
---

# Get a cycler's open service event, if any

`GET /cyclers/{cycler_id}/service_events/open`

## Request

- Base URL: `https://api.ionworks.com`
- URL: `https://api.ionworks.com/cyclers/{cycler_id}/service_events/open`
- Auth: none declared

Return the cycler's current service, or ``null`` when it is in service.

A dedicated read rather than making the caller scan the history: that list is
ordered newest-created first and paginated, so an event recorded after the
fact sorts ahead of an older open one and would eventually hide it — the
cycler would read as in service while it is out. At most one open event can
exist, so this is exact.

## Path parameters

- `cycler_id` string, uuid, required

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

## Changes

- **2026-09-30** `ea3d377fec1a`: 1 breaking
  - for the `path` request parameter `cycler_id`, the format changed from no format to `uuid`

[Operation history](https://skmtc.dev/ionworks/apis/ionworks-api/changes/cyclers/:cycler_id/service_events/open/get.md)

---

[API](https://skmtc.dev/ionworks/apis/ionworks-api.md) - [All operations](https://skmtc.dev/ionworks/apis/ionworks-api/llms.txt) - [OpenAPI document](https://skmtc.dev/ionworks/apis/ionworks-api/revisions/abebbbc5f60a?raw)