Create, list, pause and delete QStash schedules (cron) via the REST API

Documented steps

1. Get QSTASH_TOKEN from the console QStash tab and send it on every call as 'Authorization: Bearer <QSTASH_TOKEN>' (the qstash_token query parameter also works). Base URL is https://qstash.upstash.io or a regional host such as https://qstash-us-east-1.upstash.io.
2. Create a schedule: POST /v2/schedules/{destination}, where destination is either a full http:// or https:// URL or a URL Group (topic) name/id to fan out. Required header: 'Upstash-Cron: <cron expression>'. The request body is the raw payload delivered on every trigger.
3. Set Content-Type to match the payload. Example: curl -XPOST -H 'Authorization: Bearer XXX' -H 'Content-Type: application/json' -H 'Upstash-Cron: */5 * * * *' -d '{"hello":"world"}' 'https://qstash.upstash.io/v2/schedules/https://example.com'.
4. Optional create headers: Upstash-Schedule-Id (custom id; alphanumeric, hyphen, period, underscore), Upstash-Method (default POST), Upstash-Timeout, Upstash-Retries, Upstash-Retry-Delay (math expression using the 'retried' variable), Upstash-Delay, Upstash-Forward-* (headers forwarded to the destination), Upstash-Callback, Upstash-Failure-Callback, Upstash-Redact-Fields and Upstash-Label.
5. Timezones: cron is evaluated in UTC by default. Prefix the expression to run in local time, e.g. 'Upstash-Cron: CRON_TZ=America/New_York 0 4 * * *'. Standard 5-field cron syntax; 1-minute minimum resolution.
6. Create response is 200 {"scheduleId":"<string>"}. Error 400 means an invalid schedule-id format; 412 means you exceeded the maximum number of schedules for your plan.
7. List: GET /v2/schedules returns an array of Schedule objects with scheduleId, cron, destination, createdAt (unix ms), method, isPaused, header, body, retries, delay, callback, failureCallback, labels, lastScheduleTime, nextScheduleTime and lastScheduleStates.
8. Get one: GET /v2/schedules/{scheduleId} returns the same object shape; 404 if the id does not exist.
9. Pause: POST /v2/schedules/{scheduleId}/pause — the cron trigger is ignored until resumed; pausing an already-paused schedule is a no-op.
10. Resume: POST /v2/schedules/{scheduleId}/resume — marks it active so future triggers fire; a no-op if already active.
11. Delete: DELETE /v2/schedules/{scheduleId} — stops future triggers but does not retract messages already dispatched by a prior trigger.
12. To route scheduled items through a queue rather than straight to a URL, add 'Upstash-Queue-Name: <queueName>' alongside Upstash-Cron at create time.
13. Deliveries carry Upstash-Schedule-Id, Upstash-Retried, Upstash-Message-Id and the signed Upstash-Signature header — verify scheduled deliveries exactly like any other QStash message.
14. Official docs: https://upstash.com/docs/qstash/api-reference/schedules/create-a-schedule | https://upstash.com/docs/qstash/features/schedules | https://upstash.com/docs/qstash/api-reference/schedules/pause-a-schedule | https://upstash.com/pricing/qstash