vet402-check MCP server

vet402-delivery

Before an AI agent pays for an API, vet402 has already bought it with its own money and shows what came back, with the payment on chain.

On Solana, Tempo and Base since 2026-09-28 (UTC). The current counts (purchases, sellers, payments settled, answers that came back, and payments that settled with nothing usable back) are at the top of the site's first page and in site/rank.json: the groups[] entry with id main, its totals (the top-level totals include Algorand).

• See the results: https://kzmttkc.github.io/vet402-delivery/ (Solana, Tempo and Base first; Algorand on its own page)
• Check one record yourself, no account and no payment: from a clone of this repository, npx tsx scripts/verify-receipt.ts https://kzmttkc.github.io/vet402-delivery/records/obs2026-09-28000001.json
• Look a seller up before paying, in one line (CLI, MCP server, x402 fetch hook): see Try it in 60 seconds and packages/check/
• Use it in an agent, between "search" and "pay": skills/vet402-check/

Who it is for:

• People who build agents that pay: look a seller up before your agent pays it.
• Sellers: see whether a real outside payment to your API settled and what your API answered. It costs you nothing, and there is nothing to sign up for.

"Came back with an answer" means the payment settled and the seller answered 2xx with a non-empty body (for the Tempo census purchases, whose runner kept no body: 2xx; the Tempo re-purchases are tested for an empty body). On Solana, Tempo and Base the runner checked each payment on chain before calling it settled. vet402 did not check that the answer is what the listing promised; whether its keys matched what the seller declared is a separate column.

How vet402 pays for this: Grades come only from vet402's own purchases. vet402 also sells paid checks (paid in USDC on Algorand or Base); a paid check is a separate report and never moves a grade.

Where Solana comes in: vet402 pays Solana sellers in USDC on Solana, and writes the Merkle root of each day's signed delivery records into one Solana memo, so a record of that day cannot be added or dropped later without the root changing.

This README carries no counts: the daily publish commits only data/ and site/, so counts written here would fall behind. The site is rebuilt from data/ on every push to main, so it shows the purchases whose results have been committed to data/, not ones still waiting to be copied there.

This repository is the multi-chain part of vet402. It buys the sellers it can on Solana (from the PayAI, CDP Bazaar and Pay.sh catalogs) and Tempo (from Tempo's Mercator directory), and on Base the sellers registered in ERC-8004 (8 purchases from 8 sellers on 2026-09-28, each bought once). Rebuy plan from UTC day 2026-09-29, with no end date: every day, twice on Solana and once on Tempo, one purchase per payTo per slot per UTC day among the Solana and Tempo sellers whose earlier payment settled (which ones: the rows in data/remeasure/), within a cap of 70 USDC per calendar month on Solana and 30 USDC.e on Tempo. It keeps every result with its payment, and grades sellers by what was actually delivered, not by how popular a listing is.

Try it in 60 seconds

Node 22 or newer. Nothing to sign up for, no key, no payment: the check reads rank.json, the signed records and the records index, and nothing else.

npx -y @vet402/check https://api.xona-agent.com/token/pumpfun-trending

It prints what vet402's record holds about that seller: purchases tried, settled and answered, the failures counted against the seller and the ones that are not, the grade (measuring while there are too few purchases), the newest purchase with its tx, and the signed records. For a seller vet402 never bought from, it prints "vet402 has no record of this seller". The first run installs from GitHub (about 30 seconds on an empty npm cache).

Shortened. The full README is on GitHub.