---
title: ACP Validator
description: Validate your Agentic Commerce Protocol discovery document. Confirm /.well-known/acp.json declares the protocol version, transports, and capabilities agents need before checkout.
last_updated: 2026-06-19
canonical_url: https://agent-ready.dev/acp-validator
---

# ACP Validator

> Validate your Agentic Commerce Protocol discovery document. Confirm `/.well-known/acp.json` declares the protocol version, transports, and capabilities agents need before checkout.

## What is ACP?

ACP — the Agentic Commerce Protocol — is the open standard maintained by OpenAI and Stripe for completing purchases through AI agents: agentic checkout, carts, delegated payment, and order management. It powers Instant Checkout in ChatGPT. The discovery document at `/.well-known/acp.json` is how an agent learns you support ACP — and where your API lives — from just your domain.

## Why should I publish an ACP discovery document?

Without it, an agent has to attempt a checkout session blind just to find out whether you speak ACP at all — wasting calls and risking version mismatches. A static `/.well-known/acp.json` lets it pre-flight the compatibility check, bootstrap your `api_base_url`, and pick the right version and transport before it transacts.

## What does the ACP validator check?

**C21 — ACP profile.** `/.well-known/acp.json` returns 200 with a valid `DiscoveryResponse`. Per the discovery RFC's §10 conformance checklist:

- `protocol.name` is `"acp"`
- `protocol.version` is a `YYYY-MM-DD` date
- `protocol.supported_versions` is a non-empty array
- `api_base_url` is present
- `transports` is an array that includes `"rest"`
- `capabilities.services` is present

C21 is **proposal-stage and unscored** — the discovery RFC is currently a Proposal (status: `unreleased`). A site that doesn't serve the document isn't graded against it; a `404` correctly means "does not support ACP".

## Minimal valid example

```json
{
  "protocol": {
    "name": "acp",
    "version": "2026-01-30",
    "supported_versions": ["2025-09-29", "2026-01-30"]
  },
  "api_base_url": "https://api.example.com",
  "transports": ["rest"],
  "capabilities": {
    "services": ["checkout"]
  }
}
```

## Specifications

- [Agentic Commerce Protocol](https://www.agenticcommerce.dev/)
- [ACP discovery RFC — /.well-known/acp.json](https://github.com/agentic-commerce-protocol/agentic-commerce-protocol/blob/main/rfcs/rfc.discovery.md) (Proposal)
- [RFC 8615 — Well-Known URIs](https://datatracker.ietf.org/doc/html/rfc8615)

---

Validate your ACP discovery document: <https://agent-ready.dev/acp-validator>

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