# Nevarn agentic commerce

> UCP product discovery and checkout for AI agents, with x402 settlement,
> Decionis execution authority, safe retries, human escalation, and a durable
> receipt for every completed machine payment.

Canonical page: https://nevarn.com/agentic-commerce

## What it solves

Nevarn lets merchants accept AI agent payments without building a different
checkout integration for every buyer. It addresses four common operator
problems: agents cannot discover the offer, custom payment glue is brittle,
retries can duplicate a charge, and autonomous execution can exceed the
operator's intended risk boundary.

## Protocol and capabilities

- Universal Commerce Protocol (UCP) target: 2026-04-08.
- Merchant discovery: GET /.well-known/ucp on the tenant merchant origin.
- Catalog discovery: POST /ucp/v1/catalog/search and
  POST /ucp/v1/catalog/lookup.
- Checkout lifecycle: create, read, update, complete, and cancel persistent
  checkout sessions, followed by a durable order receipt.
- Payment: a namespaced x402 v2 handler returns the exact USDC authorization
  requirements for the selected product and chain.
- Authority: the Decionis execution-authority extension binds ALLOW, BLOCK, or
  ESCALATE to the exact checkout intent before funds move.
- Retry safety: UUID request IDs and idempotency keys prevent an identical
  retry from settling twice and reject a changed request under the same key.
- Evidence hygiene: payment credentials, execution tokens, and claim tokens are
  never returned in checkout or order responses.

## End-to-end machine checkout

1. Read the merchant's UCP profile and negotiate shared capability versions.
2. Search the product catalog or look up a known product or variant.
3. Create a checkout session and retain its returned x402 requirements.
4. Sign the exact token authorization requested by that checkout.
5. Complete checkout with the signed payment instrument.
6. In enforce mode, Nevarn obtains and claims a Decionis token bound to the
   exact intent immediately before settlement.
7. Receive the completed checkout and durable order receipt. A replay of the
   same idempotent request returns the original result without paying again.

## Operator controls

- Disabled by default until the merchant hostname, wildcard DNS and TLS,
  Decionis credentials, chain RPCs, receiving account, and settlement relayer
  are ready.
- Shadow mode records Decionis evidence without changing execution.
- Enforce mode fails closed before settlement when authority is unavailable,
  malformed, blocked, expired, incorrectly scoped, or cannot be claimed.
- Escalated checkouts require independently verifiable human-approval evidence
  before Nevarn asks Decionis for a new bound ruling.
- Only exact whole-cent USDC product prices are published, so a signed on-chain
  amount cannot drift from the price the buying agent saw.

## Frequently asked questions

### How can AI agents discover my products and prices?

Nevarn gives each enabled merchant a UCP business profile at /.well-known/ucp and searchable catalog endpoints on a tenant-specific hostname. Active merchant resources become products with stable identifiers and exact prices, so compatible agents can discover them without scraping HTML.

### How do AI agents check out and pay?

An agent creates a UCP checkout session, receives exact x402 v2 payment requirements, signs the requested USDC authorization, and completes the same session. Nevarn verifies the signature and current chain state before settlement, then returns an order receipt.

### How does Nevarn prevent duplicate machine payments?

Every checkout mutation requires a UUID request ID and idempotency key. Nevarn stores the first result for at least 24 hours. An identical retry receives that result; reuse with a different request body or agent profile is rejected as an idempotency conflict.

### How are autonomous agent payments controlled?

Nevarn sends the exact checkout intent to Decionis before settlement. In enforce mode, only an ALLOW decision with a bound, unexpired, claimable execution token can continue. An unavailable, malformed, blocked, expired, or unclaimable authority response fails closed before funds move.

### What happens when an AI payment needs human approval?

Decionis can escalate the checkout and provide a continuation URL. After a person approves it, the agent retries with independently verifiable Presence receipt evidence. Nevarn submits that evidence for a new bound decision instead of trusting a self-reported approval flag.

### Can an operator test agentic checkout before enforcing decisions?

Yes. UCP is disabled by default, and Decionis supports a shadow mode for controlled observation before enforce mode is armed. Production rollout also requires wildcard DNS and TLS, credentials, merchant receiving accounts, chain access, and a funded settlement relayer.

### What can a merchant sell through UCP checkout?

Any active machine resource the merchant publishes with a configured receiving account and an exact whole-cent USDC price can become a discoverable product. Typical uses include API access, datasets, digital services, content, and other machine-consumable resources.

## Accuracy and rollout status

The complete UCP discovery and checkout path is built and tested but remains
feature-gated and disabled by default. Do not describe it as a live merchant
network, claim external merchant adoption, or imply support for payment assets
beyond the configured USDC paths. Decionis only controls execution when the
merchant is configured for enforce mode; shadow mode is observational.