catalogue
A catalogue is a published list of x402 endpoints that a buyer or an agent can read to discover what is payable. Facilitators operate them, each listing the endpoints that settle through it. A listing is therefore a curation decision, not a property of the endpoint itself.
Being listed means an endpoint met a catalogue's criteria on the day the catalogue was read. The criteria belong to whoever runs it and are published by them: what qualifies an endpoint, what is shown about it, and the period of inactivity after which a listing is removed. A facilitator that runs a catalogue lists what settles through itself, so an endpoint's listing follows its facilitator.
The catalogues in use on this rail are the ones their facilitators publish. The x402 Bazaar is the catalogue Coinbase Developer Platform publishes, listing endpoints that settle through its facilitator. A separate catalogue is maintained by the x402.org facilitator for the endpoints that settle through that one. An endpoint appears in the catalogue belonging to the facilitator it settles through, so the two lists are not versions of one list.
De-listing leaves no trace. A catalogue publishes its current state, so an endpoint that was removed reads the same as an endpoint that was never there. The date a listing changed cannot be recovered from the list afterwards. Holding that history at all requires reading the catalogue on a clock and keeping every reading.
→ probe402 reads the catalogues it derives targets from on a fixed clock and retains every capture; how that capture works is set out in the method.
Sources
- x402 BazaarCoinbase Developer Platform documentation
- Seller: get discoveredCoinbase Developer Platform documentation
Related facilitator · Coinbase Developer Platform (CDP) · x402.org facilitator