Docs
Documentation
The PATH specification — pillars, transverse layers, and the conventions every implementation follows.
This section specifies the protocol. If you are new to PATH, Learn explains the ideas first; this section assumes them.
Quickstart
A working integration in about fifteen minutes.
Open →Versioning
Two version lines, and which one to pin.
Open →The pillars
PATH ID
Subjects, verified identifiers, attestations.
Open →PATH ADDRESS
Opaque addresses, receive targets, standing intent.
Open →PATH REQUEST
Payment requests and checkout sessions.
Open →PATH CONNECT
Bounded, revocable authorisation.
Open →PATH SETTLEMENT
Signed receipts and reconciliation.
Open →Transverse
PATH FINDER
Reachability: SONAR, RESOLVER, then a payee check.
Open →PATH CROSSWAY
Resolution on external networks: Pix, PI-SPI, UPI, SEPA.
Open →PATH INTEROP
One URI across QR, deeplink and in-app.
Open →Discovery
What an operator publishes about itself.
Open →Working with it
Errors
The error registry and what to do with each code.
Open →Conformance
Declaring profiles, and how a third party checks.
Open →Security
Threat model and review checklist.
Open →Conventions used throughout
Requirement levels. MUST, SHOULD and MAY carry their RFC 2119 meanings. A SHOULD that you do not follow is a decision to document, not a detail.
Status labels. Every section carries one:
Times are RFC 3339 in UTC. Amounts are decimal strings, never floats — a binary float cannot
represent 0.1. Under protocol_version 0.2.0 the string is the value of an Amount. Under
0.1.0 the string sits beside currency. See Versioning.
Identifiers in examples are fictional.
Two rules that explain most of the design
PATH standardises what crosses a boundary between two organisations, and nothing else. Rails, custody, pricing, screens and ledgers belong to operators. A specification that reached into those would need renegotiating in every jurisdiction and would never ship.
INTEROP carries the envelope; the pillar owns the object. One URI grammar, one signature scheme, one reading algorithm, over objects that belong to different pillars. It is why adding a new kind of object does not mean inventing a new QR format.