Metadata is a flat key–value map you attach to each transaction, available to local rules but not sent to backends. Any signal your checkout or PSP already computes – IP geolocation, an anonymizer flag, BIN country, an email-risk band, a reshipper flag, MIT or CIT type – can be passed once and consumed by local rules.

This is the migration workhorse: it lets the large majority of a legacy ruleset run locally even though Specter itself does no IP, email, or BIN enrichment. You bring the enriched signal; Specter turns it into fast, free decisioning.

→ See how metadata powers local rules