The field guide

How NEZI works. Plainly, with nothing hidden in the small print.

NEZI keeps AI agents that pay for things on Robinhood Chain out of the Sheriff's ledger. Below is every tool, where its numbers come from, and the line between what code guarantees and what you still have to trust.

IThe short version

Services for AI agents increasingly charge per question using HTTP 402 ("pay first", standardised as x402). The agent signs a small USDG payment and the service answers. Each of those payments sits on a public blockchain forever, carrying the paying wallet, the service, the sum and the time. Read enough of them and you know what the agent does, who it works for, and which wallet keeps it funded.

NEZI is a small kit against that:

The Ledger looks any purse up the way an outside observer would and scores its exposure from 0 to 100.
The Greenwood puts ETH or USDG through the Privacy Cash pools so the way in and the way out are not linked on chain.
A Borrowed Name forges an alias key in your browser, fills it from the pool, and lets it pay.
The Toll House is NEZI's own x402 service: every lookup above can be bought per question by an agent, and an MCP server lets Claude, Cursor and similar clients use it directly.

You never make an account, and nothing moves unless your own wallet signs it.

IIThe Ledger (wallet lookups)

Lookups on this site run inside your browser, which asks the public Blockscout explorer directly. NEZI's server is never told which purse you looked up. (Agents buying the trace tool at the toll house get the same code, run on the server.)

First coins in. The earliest incoming ETH, internal ETH or token transfer. From there the lookup walks up to two more steps back, stopping at any named contract.
The stretch read. The newest 150 transactions and 150 ERC-20 transfers, cut to the period both lists cover. Every result says how much it read.
Houses visited. The ten addresses it deals with most in that stretch.
Hours kept. When it sends, by hour of the day in UTC.
Toll habits. Repeated identical USDG payments of 1 USDG or less to the same address, which is what per-question payments look like. Notes signed with transferWithAuthorization (EIP-3009) are counted on their own.
Trips into the wood. Entries into and exits from the Privacy Cash pools, each checked for how many other entries used the same sum.
The purse. Balances for ETH, USDG and WETH. Anything else shows up as a plain count, because most stray tokens are spam nobody asked for.

IIIThe exposure score

Each reason below adds its weight; the total is capped between 0 and 100. The same code runs in your browser and on the server (nezi.score/1), so both always agree.

Reason	Weight	Applies when
The first coins came from one purse	+22	An ordinary address paid in first.
The first coins came across a bridge or venue	+14	Those keep books of their own.
The first coins came out of the greenwood	+4 / +20	+20 if that exit's sum was used by only one entry.
The trail runs further back	+6	Two or more earlier steps can be followed.
A thick page in the ledger	+2 to +15	Grows in steps as the transaction count passes 1, 10, 100 and 1,000.
It mostly visits one house	+10	One address takes at least 50% of its dealings (minimum five).
Same hours, every day	+10	24+ moves with 60% inside the same six hours.
It never sleeps	+6	Busy in 22+ hours of the day, spread evenly. Agents look like this.
Its usual stops have names	+3 each	For every kind of named contract it has used, capped at +12.
It pays tolls like an agent	+10	Three or more small identical USDG payments.
Seen walking into the wood	+5	Entries always show the purse and the sum.
It came out holding the same odd sum	+25	An exit it received used a sum only one entry ever used.
Its exits blend into the crowd	−10	It received exits and none had a one-of-a-kind sum.
It is a contract	+8	Code and calls are all visible.

Three bands: Marked (60 and up), Followed (30 to 59), Unseen (under 30). The score describes public data at the moment you looked; it is not a guarantee about the future.

IVNamed stops

The lookup only puts names on public contracts from this list, never on anyone's personal wallet. Every entry was checked for deployed code.

Name	Kind	Address

VThe Greenwood (privacy pool)

The Greenwood is a front end for the Privacy Cash ETH and USDG pools on Robinhood Chain, built on their official privacycash-evm SDK. NEZI does not operate the pools or the relay and never holds anyone's coins or keys.

Signing in. One gas-free signature from your wallet; the SDK derives your note key from it. The derived key exists only while the tab is open.
Proofs. Generated locally. The page re-reads every transaction against the sum and address you typed and lays it out for you to approve; only then does your wallet or the relay get it.
Fees right now: reading…
Minimums: reading…

Counting hoods

NEZI indexes every transact() call to both pools and counts entries by exact sum, so you can see how crowded a sum is before you use it.

Ten or more earlier entries with the same sum: well hidden. Fewer: a thinner crowd.
Exactly one earlier entry with that sum: anyone can match them.
An entry and an exit of the same sum within ten minutes count as a quick pair.

Still visible to everyone: the purse and sum going in; the receiving purse, sum and fee coming out. Sums and timing are what an observer can still work with, which is why NEZI shows both before you send.

VIA Borrowed Name (alias keys)

The key comes from your browser's random number generator and lives in memory. Tick "keep through a reload" and it also goes into this tab's session storage. Long-term storage and network requests never see it.
You can reveal the private key exactly once.
Its purse is filled by a pool exit sent straight to it: some ETH for gas, USDG for tolls.
Paying means the alias signs an EIP-3009 note. The resulting tally carries the alias and the service, not your wallet.

VIIThe Toll House (x402)

Every lookup is also sold per question over x402, priced in USDG. Live prices and status: GET /api/desk.

POST /api/desk  { "id": "fresh_check", "input": { "address": "0x…" } }
→ 402  { x402Version: 1, accepts: [{ scheme: "exact", network: "robinhood",
          maxAmountRequired, payTo, asset: USDG, extra: { name, version, settlement } }] }

sign  TransferWithAuthorization(from, to, value, validAfter, validBefore, nonce)
      on USDG's domain { name: "Global Dollar", version: "1", chainId: 4663 }

POST /api/desk  + header X-PAYMENT: base64({ x402Version: 1, scheme: "exact",
                 network: "robinhood", payload: { signature, authorization } })
→ 200  answer + header X-PAYMENT-RESPONSE: base64({ success, transaction, payer })

Who submits the payment. Normally the toll house submits transferWithAuthorization and pays the gas, as in standard x402. If its gas wallet runs dry, the 402 says extra.settlement: "payer"; then the payer submits the transfer and passes settlement.tx, which the house verifies on chain.
Order of events. Check the signature, run the tool, then settle. If a tool fails, nothing is charged.
No double spending. A signed note's nonce works once; the house refuses repeats and so does the USDG contract.
Its own tallies. Everything the house earns is listed at /receipts. It is all on chain regardless.

VIIIAsk Nezi

Nezi runs on … and only has read-only tools. She can't sign, send or hold anything.
Each figure in an answer is tagged with the tool result it came from, like [r1]. A separate, deterministic reader compares her figures with those results and flags any that do not appear.
The conversation stays in your tab. The server only counts how many questions each visitor asked this hour.
…

IXThe Charter of the Greenwood

Promise	What backs it
Ledger lookups skip NEZI	Code: your browser talks to the explorer itself. Check the network tab.
A toll can be paid only once	Code: EIP-3009 nonces, enforced by the toll house and the USDG contract.
The alias key stays in your tab	Code: generated and held in the browser, never included in a request.
Nezi can't make numbers up	Code: the second reader flags figures her tools never returned.
The pool hides the path	Trust: Privacy Cash's contracts, relay and operator. The operator can screen entries; its admin can pause or upgrade the pools.
The toll house answers honestly	Trust, with sources: every answer links to the chain reads behind it.

X$NEZI

…

What holding it does today: with … $NEZI or more, your free questions with Nezi go from … to … per hour. You sign a message to prove the purse is yours (no gas) and the toll house checks the balance on chain. Nothing is staked or locked, and nobody promises you a price.

The contract shows up on this site and the official X account before anywhere else. If you saw an address somewhere first, it isn't ours.

XIWhere the numbers come from

Purses and tallies: Robinhood Chain RPC and the public Blockscout API.
Pool history: NEZI's own index of transact() calls; fees and minimums from the Privacy Cash indexer.
Pons launches: TokenLaunched events from the Pons V2 factory.
NEZI has no affiliation with Privacy Cash, Blockscout, Pons or Robinhood.

XIIWhy "Nezi"

A chain named after Robin Hood deserves one archer who takes nothing but the trail. Nezi hides in a crowd of green hoods, pays in sealed notes, and leaves the Sheriff's clerks a ledger full of strangers.