Guides

Follow-up watchers

Some watches only make sense in order: "when the store lists the new keyboard, tell me when it's under $200". Until it's listed, there's no page to watch for a price.

Put the second watcher in then. When the first one matches, we create it on the page that matched.

JSON

{
  "target": { "query": "Q6 HE", "match": "line" },
  "conditions": { "all": [{ "field": "availability", "op": "=", "value": "in_stock" }] },
  "where": { "sites": ["keychron.com"], "aggregate": "first" },
  "schedule": { "every": "1h", "until": "+180d" },
  "then": {
    "conditions": { "all": [{ "field": "price", "op": "<", "value": 200 }] },
    "schedule": { "every": "6h", "until": "+90d" }
  }
}

What the follow-up gets

Field	Value
`target`	`match: url` on the page that matched, with the parent's `attributes`
`conditions`, `schedule`	From `then`
`where`	From `then`, or the site that matched
`notify`	From `then`, or the parent's
`location`, `fetch`	The parent's

The parent's matched event names it:

JSON

"then": [{ "url": "https://www.keychron.com/products/keychron-q6-he-wireless-custom-keyboard", "child_id": "wch_8s1d4f6g7h2j3k5l9q0w" }]

The follow-up has parent_id set and works like any other watcher.

Rules

The parent must stop at its first match: until: "after_first_match", or aggregate: "first".
One level only. A then can't hold another then.
then is checked when you create the parent, so a bad one fails right away.
If the account is at its watcher limit, the event says "then_skipped": "limit" instead.