What is FAS-1?
FAS-1, the Financial Address Standard, is an open (CC BY 4.0) specification that defines how a human-readable pay: name resolves into payment instructions: the rail, address, routing, and ISO 20022 hint. DNS://Money runs its reference implementation.
Which FAS-1 do you mean?
The acronym is overloaded. On this site, FAS-1 = Financial Address Standard. It is not:
- FASB accounting, the Financial Accounting Standards Board's Statement No. 1.
- Lumber grading, where "FAS" means First and Seconds, a hardwood grade.
- A medical term, unrelated biological and clinical uses of the letters.
Those are different fields. The rest of this page is about the payments protocol called FAS-1.
What does the Financial Address Standard do?
FAS-1 specifies the resolution contract: given a pay: name, what a resolver must return so a payment can execute on the right rail.
- Input: a name like
pay:vendor.alpha. - Output: rail (XRPL and RLUSD settle today; x402 on five networks), address, routing, fee estimate, ISO 20022 hint.
- Property: the resolver returns instructions and records settlement; the payer signs from their own wallet.
Is it real, or just a draft?
Real. FAS-1 is published openly (CC BY 4.0) and has a reference implementation live on XRPL mainnet since 2026-03-13, including the first autonomous AI-to-AI payment. View the genesis transaction →
Related
- pay:
- The namespace FAS-1 resolves, e.g.
pay:agent.compute. - payment name resolution
- What FAS-1 enables: turning a name into executable payment instructions.
- rail
- A settlement network a resolved name can point to. XRPL and RLUSD settle today; x402 payments run on XRPL, Base, Solana, Algorand and X Layer.