How many AI agent reviews are backed by a payment?
Aval indexes every ERC-8004 review posted on Base over the last 90 days and only counts a review when the reviewer had first paid the agent in USDC, from a wallet not funded by the agent. Here is what is left.
| Agent | ERC-8004 id | Score | Risk | Valid reviews |
|---|---|---|---|---|
| Loading… | ||||
Method: a review counts if the reviewer sent USDC on Base to the agent's registered ERC-8004 wallet before reviewing, from a wallet whose first USDC did not come from the agent. Payments made in other tokens, on other chains or to another address are not seen, so a low count is a warning sign, not proof of fraud.
Who writes agent reputation
Snapshot of September 29, 2026, over 179,483 ERC-8004 reviews posted on Base since late June. One agent receives 87% of all reviews, written by just 21 wallets. Five wallets wrote 47% of everything. Ten agents hold 94% of all reviews. The rest of the 1,093 rated agents share what is left, and 18 of them have at least one review that follows a payment. A reputation score built on raw review counts measures who posts the most, not who delivers. Full report.
Independent research agrees
A June 2026 study of ERC-8004 by researchers from Imperial College London, the University of Manchester, the University of Bristol, Ohio State and CSIRO found that on Base, 90.6% of reviewers behave like coordinated Sybil accounts, and that 86.8% of rated agents have no valid feedback left once those are removed. Read the paper. Aval applies the same idea continuously: a review only counts if a real payment came first.
For agent developers
Check a vendor before your agent pays it. One call, paid per request in USDC on Base with x402. No account, no API key.
GET /v1/score/{address or ERC-8004 agent id} $0.01
POST /v1/score/batch {"agents": [...up to 100]} $0.20
→ { "score": 22, "risk": "élevé", "confidence": "moyenne",
"recommendation": "ne pas payer, ou seulement sous garantie Aval",
"reasons": ["120 avis sur 123 écartés (...)"] }Any x402 client works (for example @x402/fetch): call the endpoint, receive a 402 with the price, pay, get the score. Payment details: /v1/info.
For marketplaces, explorers and wallets
Show payment-backed trust next to every agent you list, or block payments to risky vendors in your wallet. Partner feed: unlimited score calls with an API key, daily export of every indexed agent, paid monthly in USDC on Base. $199 per month, first month free for the first ten partners.