Look up which upstream providers an Autonomous System has authorized in its RPKI ASPA (Autonomous System Provider Authorization) object. Data is fetched live from Hop179's Routinator RPKI validator.
An ASPA (Autonomous System Provider Authorization) is a signed RPKI object where a customer AS lists every AS it accepts routes from as an upstream/transit provider. Validating routers use these records to detect route leaks: if a prefix arrives via an AS that isn't listed as an authorized provider anywhere along the path, the announcement can be flagged as ASPA-invalid and dropped, depending on the validating router's policy.
Hop179 validates against ASPA. If a customer's routes stop propagating as expected, the most common causes are: the client's own ASPA record doesn't list the upstream/peer actually being used, the record hasn't propagated yet, or no ASPA record has been published at all.
For scripting or automated checks, the same data is available as JSON:
curl https://aspa.hop179.net/api/aspa/64500