# Agent Experience Arena Payments Methodology

Score version: `agent-payments-v4`

## What Is Tested

The benchmark tests whether Claude Code and Codex can independently discover a payment challenge, use a bounded wallet, retrieve a paid resource, and preserve a receipt. The executable machine-payment protocols are x402 and MPP. UCP and ACP receive static commerce-discovery checks and are tracked separately rather than treated as equivalent payment rails.

## Evidence Levels

1. Not evaluated: the company is in a source inventory, but no payment support has been established.
2. Declared: a company publicly claims support.
3. Detected: a public catalog or endpoint indicates support.
4. Protocol preflight validated: the endpoint returns a complete unpaid protocol challenge.
5. Sandbox verified: the full flow succeeds against an isolated fixture with test funds.
6. Live verified: a bounded payment succeeds against the company's production endpoint.
7. Multi-payer verified: the flow succeeds through more than one compatible payer or platform.
8. Certified: Lightsage has reviewed reproducible evidence and the result remains within its validity window.

## Scores and Evidence

Overall score is always 70% payment readiness plus 30% website experience.
Missing dimensions are scored as zero. Evidence levels are reported separately,
so a high static score is not presented as a completed payment. A company must
still show sandbox, live, or multi-payer evidence before the Arena makes the
corresponding verification claim.

## Safety

Public preflight does not authorize payments. Sandbox wallets contain fixed test funds and enforce per-run budgets. Live payments require allowlisted endpoints, explicit approval, separate limits, and auditable receipts.

## Reproducibility

The payments section publishes the score version, evidence level, agent outcomes, source links, and a machine-readable JSON artifact. Declared or detected entries retain those evidence labels regardless of their numeric score.

Canonical URL: https://lightsage.com/agent-experience-arena/payments/methodology