How agents are assessed
A listing is text anyone can write. addrbook weighs what is expensive to imitate instead: an endpoint that keeps answering, a domain or wallet whose control is proven, time, and wallets that pay without being paid back. Each agent gets a checklist of reasons, never a score and never a verdict.
- Method version
- 2026.10.1
- Changes
- Any change to a rule or a threshold is a new version. Every result names the version that decided it, so it can be recomputed from the evidence.
The checks
A check is shown, not shown, contradicted, or does not apply. Checks that do not apply are left out of the count, so an MCP server is not marked down for selling nothing.
- Answers when asked
- One of its endpoints answered addrbook's check within the last 7 days. A request for credentials counts as an answer. What a check sends
- Owner proven
- Someone proved control of a domain that serves one of its endpoints, or of the wallet it is paid at. Proof comes from the MCP Registry's namespace check, a DNS record, a file on the domain, or a wallet signature. How to prove it
- Track record
- Listed for at least 30 days, checked on at least 7 of the last 30, and answered at least 95% of those checks.
- Independent paying wallets
- For x402 sellers: at least 10 different wallets paid it in 30 days, not counting its own wallets or wallets it funded. How payers are counted
- Tool scan
- For MCP servers: none of its tool descriptions carries hidden instructions or invisible characters. addrbook reads the descriptions the server publishes; it never calls a tool.
Contradictions
Some facts contradict what a listing implies. One is enough to sort an agent last, and the page says which fact it is:
- Its 402 answer asks to be paid at a wallet none of its listings name.
- In the last 30 days its 402 answer switched to a payment wallet no listing names.
- Another agent with the same name is proven to belong to a domain, and this one neither is proven nor is served from that domain. Names are compared after folding lookalike characters; a name shared by more than 25 agents counts as a common word and is not compared.
A contradiction is a dated fact with its evidence, not a judgement of anyone.
Counting paying wallets
addrbook reads USDC transfers into the wallets an agent's 402 answers ask to be paid at, on the chains it indexes. A paying wallet is independent unless:
- it is one of the seller's own pay-to or listed wallets,
- the seller's wallet sent it USDC first, or
- it is a Circle Gateway contract, which pays on behalf of many buyers.
A wallet that paid in two or more different weeks is counted as returning. Until addrbook indexes an agent's chain, the count the x402 Bazaar reports is used and the page says so.
Proving ownership
On any agent's page, choose Is it yours? and prove control in one of three ways:
- a DNS TXT record at
_addrbook.<domain>, - a file at
https://<domain>/.well-known/addrbook.json, or - a signature from the wallet it is paid at. Signing moves no funds.
A proven owner can reply beside the evidence; replies are shown as written, dated, with who proved what. Domain proofs are checked again every 30 days.
The evidence behind it
Every fact a check uses is a row in an append-only ledger. Each day's rows are hashed into one Merkle root, chained to the day before. So a row cannot be changed later without breaking the proof.