Learn
Learn PATH
The ideas behind the protocol, in the order that makes them easiest to hold — what breaks today, how the pieces fit, and why the directory is the one part that cannot be fully open.
This section explains the protocol. The Docs section explains how to implement it.
Read these in order if PATH is new to you. Each page assumes the one before it, and the whole sequence is about an hour.
The problem
Money moves. What breaks is everything around the movement.
Open →Architecture
Five pillars, three transverse layers, and where the boundary of the protocol sits.
Open →Reachability
Two questions, two answerers, and why they must stay apart.
Open →Networks and members
The protocol is open. A directory is a club. Both are true.
Open →Privacy
What is protected, what is not, and which promises are properties.
Open →Trust and signatures
Why nearly everything is signed, and what a signature buys.
Open →Glossary
Every term, defined once.
Open →The shortest possible summary
PATH standardises the handful of things that have to cross an organisational boundary before value can move:
| Question | Pillar |
|---|---|
| Who are you? | PATH ID |
| Where do I send, and on what standing terms? | PATH ADDRESS |
| What is owed, to whom, until when? | PATH REQUEST |
| Who is allowed to act, within what limits? | PATH CONNECT |
| How is the outcome proven? | PATH SETTLEMENT |
Everything else — rails, custody, pricing, screens, the ledger, the licence — stays with the operator. That boundary is not modesty. A protocol that also specified how to run a payment company would be implemented by nobody, because no two payment companies are run the same way.
One thing to keep in mind while reading
Two claims run through every page, and they only look contradictory until you separate them:
The protocol is open. Every format is public, implementable without asking anyone, and testable by a third party.
A directory is not. Being listed in one means exposing a resolvable pointer to your customer base, and institutions do not do that without reciprocity, contract and audit.
Both are true at once, and the card industry has run on exactly that arrangement for decades: ISO 8583 is an open specification, Visa is a closed network, and nobody finds it strange. Networks and members is the page that unpacks it.