Fire only when it actually matters.

Simplest - trigger on any difference

Any field changes

A notification fires whenever any extracted field has a different value compared to the previous run. Good starting point if you're not sure which fields will change.

diff_predicate

{ "type": "any_field_changes" }

Watch one field, ignore the rest

Specific field changes

Only trigger when a specific field changes. Useful when a page has multiple extracted fields but you only care about one - for example, watching a version number while ignoring the timestamp.

diff_predicate

{ "type": "field_changes", "field": "version" }

Catch significant upward moves

Field increases by %

Fires only when a numeric field increases by at least the specified percentage. Useful for stock alerts, engagement metrics, or usage spikes.

diff_predicate

{
  "type": "field_increases_by_percent",
  "field": "price",
  "threshold": 10
}

Catch price drops and downward moves

Field decreases by %

Fires only when a numeric field drops by at least the specified percentage. The classic use case: trigger a repricing workflow when a competitor's price drops by 5% or more.

diff_predicate

{
  "type": "field_decreases_by_percent",
  "field": "price",
  "threshold": 5
}

Numeric threshold without percentages

Field increases by absolute value

Fires when a field increases by at least a fixed amount. Useful for counters, counts, or quantities where percentage doesn't make sense.

diff_predicate

{
  "type": "field_increases_by_absolute",
  "field": "open_issues",
  "threshold": 50
}

Drop by at least a fixed amount

Field decreases by absolute value

Fires when a field decreases by at least a fixed amount. The mirror of field_increases_by_absolute - useful for stock counts, ratings, or any countable that you want to alert on when it falls.

diff_predicate

{
  "type": "field_decreases_by_absolute",
  "field": "stock_count",
  "threshold": 10
}

Pattern-based triggering

Field matches regex

Fires when an extracted field's value matches the given regular expression. Use to detect specific keywords, error codes, status strings, or format changes.

diff_predicate

{
  "type": "field_matches_regex",
  "field": "status",
  "pattern": "^(error|failed|critical)"
}

Exact match triggering

Field equals value

Fires only when a field reaches an exact value. Useful for status transitions - e.g., trigger when availability changes to exactly "In Stock".

diff_predicate

{
  "type": "field_equals",
  "field": "availability",
  "value": "In Stock"
}

AND / OR logic for complex rules

Composite conditions

Combine any of the above predicates with AND (all must be true) or OR (any must be true) logic. Nest composites to build arbitrarily complex conditions.

diff_predicate

{
  "type": "composite",
  "operator": "AND",
  "conditions": [
    { "type": "field_decreases_by_percent", "field": "price", "threshold": 5 },
    { "type": "field_equals", "field": "availability", "value": "In Stock" }
  ]
}