Count matching events without returning event payloads.
Validated count request.
Exact/approximate count metadata, or a number for an exact count.
OptionalisOptional refusal policy for unsupported or too-expensive filters.
Return true to allow the filter, false for a generic refusal, or a
string with the refusal reason.
Filter being evaluated.
Filter index in the OR filter set.
Maximum number of OR filters accepted before refusing the request.