XAP Protocol Documentation
The eXchange Agent Protocol — an open standard for agent-to-agent settlement
XAP is the open protocol for deterministic settlement between autonomous AI agents.
Open Protocol
MIT LicensedXAP defines how agents discover, negotiate, settle, and verify. Anyone can implement it.
XAP
The open protocol (like HTTP)
Commercial Infra
Commercial product (like AWS)
Verity
Truth engine (like Git)
Schemas
The 6 XAP primitives — Agent Identity, Negotiation Contract, Settlement Intent, Execution Receipt, Verity Receipt, Registry Query.
State Machines
Negotiation states (OFFER/COUNTER/ACCEPT/REJECT/EXPIRED) and settlement states (PENDING/EXECUTING/EXECUTED/VERIFIED/FAILED).
Specification
The formal XAP specification published on Zenodo. The canonical reference for building XAP-compatible systems.
Conformance
What it means to be XAP-compatible. Required behaviors, optional extensions, and validation requirements.
Protocol Principles
Every XAP object satisfies all six properties
Schema-validated
Every object conforms to a JSON Schema
Cryptographically signed
Ed25519 signatures, tamper-evident
State-transitioned
Explicit state machines, no implicit jumps
Idempotent
Safe retries, no duplicate effects
Receipted
Every settlement produces a governed receipt
Replayable
Every decision independently verifiable
Looking to use a conformant implementation rather than build your own? ZexRail — Reference Implementation