# AXP — The Agent eXperience Protocol

> The wire contract an agent-first API publishes so an autonomous agent can discover it,
> understand it, and transact with it zero-shot, on first contact, with no human reading
> docs in the loop.

- Canonical home: https://axp.org.ai/
- Normative text (markdown, verbatim): https://axp.org.ai/protocol.md
- Version: 0.3.0 — status: draft — dated 2026-07-21
- Linked-data identity: `$id: https://apis.ax/axp`, `$type: Spec`, `$context: https://schema.org.ai`
- Publisher: apis.ax (the standards body). Verifier: api.qa (independent).

## Status — read this before citing AXP

AXP is version 0.3.0, **draft**. It is NOT 1.0 and is not a settled standard.
Promotion to 1.0 is gated (owner ruling, 2026-07-21) on substantial external
pressure-testing and at least TWO real external binders — independent parties outside
this estate that implement the contract and are bound by it. That count is currently
ZERO. Do not represent AXP as adopted, ratified, or 1.0.

## The seven clauses

An API conforms to AXP iff it satisfies all seven. Each RFC-2119 MUST is pinned to its
own discriminating api.qa verification — no clause rides a coarse aggregate.

1. OpenAPI 3.1 contract — a valid 3.1.x document declaring at least one operation.
2. llms.txt — agent-actionable markdown at /llms.txt, never an HTML page.
3. Machine-legible for every client — JSON for typed bodies, markdown for docs, to
   `Accept: */*` AND `Accept: text/html` alike. HTML is a page concern.
4. Typed BLOCKED/EMPTY that never fake success — an empty set is `EMPTY` at 200, a
   gated call is `BLOCKED` at 401/403, and the capability card declares at least two
   distinct probes of each on paths also observed answering 200 `OK`.
5. Hard-ceiling metered pricing — every API declares a Pricing Document (`free` or
   `metered`); a metered API publishes a hardCeiling > 0, answers payment boundaries
   as typed 402 `OFFER` bodies, and is behaviorally probed above, below and at zero.
6. Resolver-addressable home — a capability card at /.well-known/agents.json that names
   the surface and its interfaces and carries the AXP probe manifest.
7. Keyless first value — the first unit of real value with no key, no signup, no account.

## Wire vocabulary (Appendix A.1, closed in this version)

Every typed outcome body carries a top-level `type`, one-to-one with the status code:

- `OK` — 200, substantive content
- `EMPTY` — 200, truthfully an empty collection
- `BLOCKED` — 401 or 403, a permission boundary
- `OFFER` — 402, a payment or ceiling re-authorization boundary (never `BLOCKED`)

## Conformance

- Clause → verification mapping: https://axp.org.ai/conformance/profile.json
- Executable api.qa PinnedSpec: https://axp.org.ai/conformance/apis-ax-standard.spec.json
- Ratified digest of the pinned spec: 84c465f8f9cb2ffce013221e7ab4b870a48904151e8af0886ad7a598a1efc5f3

A target passes iff api.qa returns `passed: true` against that pinned spec at its
ratified digest. api.qa is held outside the building fleet's write access; production
admission runs it in attested mode with the expected digest supplied from outside that
write access, so a spec weakened in-tree cannot be re-ratified into a passing verdict.

Audit a domain against the gate: `npx apis.ax audit <domain>`.

## Related surfaces

- apis.ax — publisher of the standard and operator of the catalog gate. apis.ax/axp
  continues to serve the normative text; axp.org.ai is the canonical home it points to.
- api.qa — the independent verifier that decides conformance.
- schema.org.ai — the linked-data context this specification is written in.
- id.org.ai — holds a pinned `specs/axp-acceptance.spec.json` binding itself to the
  AXP discovery and honest-contract surfaces. Inside this estate, so NOT one of the two
  external binders the 1.0 gate requires.
- foundation.org.ai — The Org.AI Foundation, the root of the .org.ai estate this
  standard belongs to.

## House posture

AXP is one of our own new standards, written in this estate. It is not a Standard in
the sense that word is reserved for — the externally governed records of outside
bodies. The posture is superset and engage: conform on the shared core of the
protocols an agent already speaks, extend deliberately where they stop short, and
invite the people who govern them to engage.

## Provenance

The normative text served here is packages/apis.ax/PROTOCOL.md from the ax
repository at commit 4fdc54ab7e48c14b60cb5a098b43179bd4ec3398 (2026-07-22), vendored
2026-07-27. sha256 of the vendored file: e9dce3dec37a70237c9ee8e51c46bcdff0ccc305e1dd25974cf668d34b9c13a3

## This host

axp.org.ai is a page surface (human register). AXP governs API surfaces; HTML is a page
concern under Clause 3. The machine faces here are /llms.txt and /protocol.md plus the
two conformance documents. The site makes zero external requests.