Built
What exists, and what each thing actually is right now. If an entry sounds narrow, that is the entry being accurate.
Snapshot — the Circle x402 catalog, 2 dated readings
2 one-off measurements, newest 11 September 2026. Not maintained, and each page says so.
On 2026-09-11: 1,162 listings, 4,215 accepts rows, 16 networks, 1,094 URLs across just 48 hosts. Arc: 0. The earlier reading is still there, unedited, at its own dated URL — the pair is the point, and the newest never overwrites it. Composition only: liveness and advertised-vs-live price were NOT measured, because both need calls to 1,094 third-party endpoints that have not been made, and each page lists that as a gap rather than leaving it blank. Where two readings exist they are compared, led by the question worth asking: which offers now name a different payout address. That comparison refuses to render at all if either reading fails its testnet self-check, because a filtered reading has a different denominator.
/snapshot/2026-08-27 · /snapshot/2026-09-11 · what differs: 2026-08-27..2026-09-11 · JSON
DD — on-chain due diligence
Live on Arc testnet.
POST an address, pay $0.06 USDC over x402, get one signed report with a coverage manifest that says exactly what was and was not checked. The manifest is inside the signed payload, so it cannot be stripped.
app.tikpema.xyz/dd · OpenAPI · identity (ERC-8004 agentId 851891)
Vanilla x402 seller
Live on Arc testnet, settling real testnet USDC.
A minimal EIP-3009 seller — 0.01 USDC per call, receiveWithAuthorization, no Gateway and no batching. Built to prove the plain path works end to end.
A call with no payment returns the 402 and the full terms. It costs nothing.
x402 quote — Gateway nanopayment
Live on Arc testnet, settling real testnet USDC.
The same shape over Circle Gateway's batched rail instead: 0.001 USDC per call, GatewayWalletBatched.
Same — an unpaid call returns the terms.
The x402 seller census
A finished measurement of Base mainnet. Not a service.
Seven days of USDC transfers to every payout address in Circle's discovery index — what x402 sellers actually receive. Published with its per-address rows and both directory harvests, so every number in it can be re-checked. It has been corrected twice since publication and both corrections are in it, including one claim withdrawn as unrecoverable.
What x402 services disclose when a check fails
A finished measurement. Not a service.
What four paid endpoints return when one of their inputs was unavailable — whether a failed check is named or silently dropped. One purchased report, three free calls, two unpaid probes, every response committed verbatim. It finds the disclosure is uneven within a single seller, and it does not resolve the case it set out to test.
Includes DD, which is built here — its section leads with what it cannot do.
arc-x402-reference
A library, not a service. v0.2.0.
A standalone vanilla x402 (EIP-3009) buyer and seller for Arc testnet, extracted so it can be read without the rest of this repo around it.
Hyperliquid top-shorts
Scripts. No endpoint, nothing published.
Reads the largest short positions among the top Hyperliquid accounts, and drafts posts a human sends. Facts only — it does not classify strategy, because a basis trade and a directional short are indistinguishable in a position object.
There is nothing to visit.
Arc on Circle's mainnet Gateway
Waiting on a dependency nobody here controls.
As of 2026-08-24, Arc has no Gateway domain on Circle's mainnet list — twelve chains are listed and Arc is not one of them, so the unified balance has no rail on Arc mainnet. A daily job checks and posts a beat to a private channel on every tick, which means silence there indicates it did not run.
Nothing to visit. Listed because it gates what can move to mainnet.