Who's on call

To see who is on call — the computed rotation with overrides and swaps already applied — call the schedule endpoint for a rotation and a date window:

curl "http://localhost:3000/api/rotations/<rotationId>/schedule?start=2026-07-27T00:00:00.000Z&end=2026-08-24T00:00:00.000Z" \
  -H "Cookie: <your-session-cookie>"

The response has one entry per on-call period. effectiveEngineerId is who is actually on call for that period (after overrides/swaps); override is set when the period was changed:

{
  "rotation": { "id": "...", "name": "Platform on-call", "cadenceDays": 7 },
  "entries": [
    {
      "periodStart": "2026-07-27T00:00:00.000Z",
      "periodEnd": "2026-08-03T00:00:00.000Z",
      "baseEngineerId": "eng-ada",
      "effectiveEngineerId": "eng-ada",
      "override": null
    },
    {
      "periodStart": "2026-08-03T00:00:00.000Z",
      "periodEnd": "2026-08-10T00:00:00.000Z",
      "baseEngineerId": "eng-grace",
      "effectiveEngineerId": "eng-alan",
      "override": { "id": "...", "swapGroupId": null, "reason": "covering" }
    }
  ]
}

The period containing today tells you who's on call right now.

Just the current + next on-call

If you only need who's on call now and next (e.g. a Slack bot), use the convenience endpoint instead of computing it from the schedule:

curl "http://localhost:3000/api/rotations/<rotationId>/on-call" \
  -H "Cookie: <your-session-cookie>"

It returns { current, next }, each { engineer, periodStart, periodEnd } (or null) with overrides/swaps already applied — so current.engineer is who to page right now, and current.engineer.slackUserId is what a Slack bot needs to @mention them.

In the app

The /rotations/[id] page renders this data two ways: a calendar overview (each on-call period is a colored bar) that you can page through and switch between a 2 weeks and a Month view, and a schedule list below it. Times are shown in the rotation's timezone. Every engineer has a stable color used consistently across the calendar bars, the schedule-list dots, and the home-page preview, so the same person always reads as the same color. On the calendar, an overridden or swapped period keeps the covering engineer's color with an (override) / (swap) suffix, and stacks a separate muted, struck-through bar for the originally scheduled engineer above it — so overrides read separately from who is really on call. Tapping the on-call (main person) bar opens the same pre-filled Swap shifts dialog as clicking a row in the schedule list.

Following the Opsgenie / incident.io convention, the schedule list surfaces overrides separately from who is really on call. Each On-call cell shows the engineer actually on call (effectiveEngineerId) as the prominent line, with a color dot; when an override or swap changed the assignment, the originally scheduled engineer (baseEngineerId) appears struck-through in gray above it. A period with no override shows just the single on-call name. Clicking a row opens a pre-filled Swap shifts dialog suggesting a trade between that shift's engineer and you.

You can edit a rotation's settings — name, description, cadence, handoff time, and timezone — via the Edit rotation button on its page, or the Edit button on its card on the home page (both save via PATCH /api/rotations/[id]).

The home page (/) lists rotations as cards, each showing the rotation's cadence as a caption (e.g. Weekly rotation, Biweekly rotation, or Every N days rotation) plus a compact "… is on call until …" preview (shown as "You are on call until …" when you are the one on call). Full schedule details — the calendar and this table — live on the rotation's own /rotations/[id] page, not on the home page.