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Independent MeasurementPublic-good contribution, verifiable
vet402State of x402 · DecisionsEvery figure links to its API

Impact

Abstract

vet402 measures the x402 agent-payment economy by actually using it, and gives the results away: the data is public, the code is MIT, the ledger is hash-anchored (a daily prev-hash chain; on-chain anchoring is not yet enabled — see §4) so nobody can quietly rewrite it. This page states the contribution as numbers — and every number below links to the endpoint that produces it, so you can check it rather than trust it.

1.Coverage of the ecosystem

21,445 endpoints on record; 14,967 currently listed. 6,143 of them (41%) carry an independent L0 measurement from the last 7 days — the machine definition of "under regular verification". /api/v1/observatory/state

2.Real purchases, published with evidence

2,374 real purchase attempts across 1,340 endpoints; 1,102 settled with an on-chain receipt. Successes and non-settling losses are published with the same weight — a receipt series per endpoint, transaction hashes included. export.csv

Latest settled receipts

3.Losses an agent avoids by reading the signals

In the last 30 days vet402 refused 1 payments before signing (overcharging or unpayable walls) and published every decision. Across the whole ledger, 467 signed attempts carried a prior public failure signal and none of them settled ($16.71 that an agent honoring the signals would not have lost), while 10 signalled attempts settled anyway. /decisions

4.Integrity: the record cannot be quietly rewritten

The purchase ledger is a daily hash chain. Latest root (2026-08-31): da6b35abeb1e7c7a over 94 entries. Rewriting any past row breaks every later root, and the projection is open source, so a third party can verify the chain from the public API alone. /anchors

5.What is free, and reproducible

All measurement surfaces above are key-less and public. The verification stack is MIT and self-hostable (docker compose up), and anyone can reproduce a probe or see exactly what a buyer would sign without signing anything — source (cli/). SDKs for TypeScript and Python, plus MCP / LangChain / ElizaOS / solana-agent-kit adapters, make "check trust before paying" a one-liner — API reference. The operating model is stated openly at /operations.