REST API
Preview a subscription
Dry run of a subscription body over the recorded events of the last `window_days`.
POST
/v1/subscriptions/previewParameters
namestringrequiredtriggeranyrequiredendpoint_idstringoptionalnot needed for a preview
sinksany[]optionalwhere matches go: a webhook endpoint and/or a people list (at least one sink, or endpoint_id) (up to 4 items)
clientstringoptionalscopeanyoptionalpredicateobjectoptionalactionsany[]optional(up to 6 items)
payloadobjectoptionaldedupeobjectoptionallimitsobjectoptionaldeliveryobjectoptionalbackfill_daysintegeroptionaldeliver events already recorded this many days back (≤ plan); IGNORED for scope.kind ‘monitor’ — a monitor-scoped subscription starts at its oldest monitor’s creation, so nothing collected before it is missed (min 0, max 30)
window_daysintegeroptionalthe window of recorded events to size on (default 7, max 30) (min 1, max 30)
What your agent reads
The tool description exactly as an MCP client receives it in tools/list — it doubles as the full behaviour of the endpoint.
Dry run of a subscription body (endpoint_id optional, nothing is stored) over the recorded events of the last `window_days` (default 7, max 30): the events of each subscribed type in the window, how many the scope and `where` keep (`narrowed`, counted over the WHOLE window), and — the predicate run on a sample of up to 2,000 narrowed events per type — `estimated_matches_in_window`, `estimated_per_day` and `estimated_records_per_day` (what the deliveries would charge: use it for limits.max_records_per_day). A type with zero events in the window is named as such. Returns a sample of up to 10 matching events. No record cost. search_diff triggers cannot be previewed (the first run seeds).
Errors follow one format.