api.nexismvp.com/market/gas-preflight
1.Catalog declaration
| Resource URL | https://api.nexismvp.com/market/gas-preflight |
| Source | cdp_bazaar |
| Declared method | POST |
| Catalog network | eip155:8453 |
| Receiving address | 0x3b59f268ebc38c5f43b8b9be37238bf43378ad87 |
| Declared price (base units) | 1000 |
| Catalog status | active |
| First seen / last seen | 2026-08-14 08:39 UTC / 2026-11-12 18:05 UTC |
| Catalog-reported calls / payers (30d) | 1 / 1 |
2.Probe history
| Probed at | Method | Verdict | HTTP | Latency | Reason |
|---|---|---|---|---|---|
| 2026-11-10 22:40 UTC | POST | pass | 402 | 2244 ms | — |
| 2026-11-08 16:40 UTC | POST | pass | 402 | 503 ms | — |
| 2026-11-06 13:40 UTC | POST | pass | 402 | 475 ms | — |
| 2026-11-04 06:41 UTC | POST | pass | 402 | 365 ms | — |
| 2026-11-01 13:40 UTC | POST | pass | 402 | 310 ms | — |
| 2026-10-30 13:40 UTC | POST | pass | 402 | 541 ms | — |
| 2026-09-25 16:40 UTC | POST | fail | 530 | 79 ms | no_402HTTP 530 instead of 402 to an unpaid POST. |
| 2026-09-24 22:40 UTC | POST | pass | 402 | 402 ms | — |
| 2026-09-24 04:40 UTC | POST | pass | 402 | 437 ms | — |
| 2026-09-23 13:40 UTC | POST | pass | 402 | 558 ms | — |
| 2026-09-22 16:40 UTC | POST | pass | 402 | 415 ms | — |
| 2026-09-21 22:40 UTC | POST | pass | 402 | 317 ms | — |
| 2026-09-21 04:40 UTC | POST | pass | 402 | 465 ms | — |
| 2026-09-20 13:40 UTC | POST | pass | 402 | 396 ms | — |
| 2026-09-19 16:40 UTC | POST | pass | 402 | 383 ms | — |
| 2026-09-18 22:40 UTC | POST | pass | 402 | 179 ms | — |
| 2026-09-18 13:40 UTC | POST | pass | 402 | 479 ms | — |
| 2026-09-17 16:40 UTC | POST | pass | 402 | 548 ms | — |
| 2026-09-16 22:40 UTC | POST | pass | 402 | 455 ms | — |
| 2026-09-16 13:40 UTC | POST | pass | 402 | 884 ms | — |
| 2026-09-15 11:24 UTC | POST | pass | 402 | 530 ms | — |
| 2026-08-14 08:53 UTC | POST | fail | 402 | 138 ms | accepts_invalid402 without a payable accept in the header or the body (which part was missing was not recorded before the 2026-09-29 change). |
3.L1 — real purchases
1 of 2 paid attempts settled on-chain, and 1 of those also returned a deliverable 2xx response (delivered: other than 202 Accepted with a non-empty body). Each settled row carries its on-chain transaction hash, and that transaction is the evidence. On this page a receipt means the seller's own settlement receipt (PAYMENT-RESPONSE); a settled row can have none (see “tx from our index”). A settled row reads as nonce-bound when the on-chain re-read matched the one-time value stored for that purchase, so the transaction is the one for this purchase. Stellar is not in this count. The Stellar re-read checks payer, payee, amount and asset. A row reads as amount + payee when the re-read matched payer, payee, amount and asset and did not bind a one-time value. That tier holds rows from before 2026-09-04 and Stellar rows. They keep the settled label rather than being demoted (methodology). settled is the transfer vet402 confirmed on-chain. delivered is a 2xx other than 202 with a non-empty body. A settled row whose paid request answered 5xx counts as settled and not as delivered. definitions.
1 of those paid attempts are held as inconclusive rather than counted against this seller (0 settled and answered 4xx, 1 answered 4xx with no settlement receipt, 0 answered 402 or 5xx while our own payer wallet was out of USDC, 2026-09-13 00:00 to 2026-09-15 23:49 UTC). A 4xx says the request was not one the server would accept, and we cannot rule out that the request was ours to get wrong: vet402 buys with no API key of the seller's, and sends a POST body only when the seller declares one. This is the same principle the methodology already applied to path_template URLs, applied to the body and the authentication header as well. The rows are not deleted and not hidden — they are below, with their status and HTTP code, and they are out of the denominator for delivered (corrections).
1 of the paid attempts failed on vet402's side (for example our wallet was out of USDC, or we did not send the input the listing declares). The rows stay in the table; the embeddable badge below leaves them out of its count and names them as “vet402 side”.
Terms in this table
settled (nonce-bound)- vet402 re-read the transfer on-chain in that chain's pinned settlement asset, and the on-chain re-read matched the one-time value stored for that purchase, so the transaction is the one for this purchase. Stellar is not in this count.
settle_failed- vet402 signed a payment and got no settlement receipt back.
unsettled_4xx- held_reason in the export: the paid request got a 4xx with no settlement receipt and no transaction.
L2 match- the response parsed as JSON and had the keys the listing marks as required. With an example that marks no key as required, a JSON object or array is enough.
L2 not_checked- not checked: the paid request did not answer 200, so there was no response to check against the listing's output schema.
Whose side- the same words as the seller page: seller's side only after failures on two different days (UTC), marked “attribution under review”; vet402's side; or not sorted (the rules).
| Attempted at | Result | HTTP | On-chain tx | Payment chain | Latency |
|---|---|---|---|---|---|
| 10-30 15:322026-10-30 15:32 UTC | settled (nonce-bound) | 200 | 0xdc1bd92f…4747 | Base | 4209 ms |
| 1000 units (≈ $0.001 USDC) · L2 matchWhose side: no failure (delivered) | |||||
| 09-16 12:082026-09-16 12:08 UTC | settle_failed | 400 | — | Base | 936 ms |
| 1000 units (≈ $0.001 USDC) · L2 not_checkedWhose side: vet402's side | |||||
Embed this record
Run this endpoint? Show the settle-through record vet402 measured — the badge reads 1/1 settled · 1 delivered · vet402 side 1 and updates as the record grows. It carries the host it is about and the date it was last measured, so a saved copy cannot pass itself off as current. It states a measurement, not a rating.
[](https://vet402.com/observatory/e/65a6e3f4-a285-41aa-a12b-60e77e40bc7f)4.Catalog listing events
| Detected on | Event | Before | After |
|---|---|---|---|
| 2026-10-27 | relisted | {"status":"delisted"} | {"status":"active"} |
| 2026-09-26 | delisted | {"status":"active"} | {"status":"delisted"} |
| 2026-09-15 | relisted | {"status":"delisted"} | {"status":"active"} |
| 2026-08-18 | delisted | {"status":"active"} | {"status":"delisted"} |
unverified is not a failure; a fail is published only after two consecutive failing probes. Definitions: methodology.
5.Dispute this record
A dispute does not start a purchase. The signed dispute route runs one fresh L0 check, an unpaid request.
Think a measurement above is wrong? Say which probe or purchase and what you observed instead. One person reads it and replies. The record is never deleted on dispute: if it was wrong, the correction is published with the same weight. If it was right, it stands. A dispute filed on the record form puts an active listing on a priority list. L0 runs probe that list before their ordinary queue, one run at a time. A listing whose URL has an unfilled path parameter is not put on that list. One run measures up to 50 priority listings, at most 5 from one site. Published fails whose catalog declaration changed, or that rest on probes recorded under earlier rules, take places first, and disputes fill the places left. A listing probed in the past 60 minutes waits for a later run. A dispute that no run reaches within 7 days leaves the list. The scheduled L0 run is at 10:30 UTC, and an L0 run at another time can measure the listing first. The record stays on this page. When a run measures the listing, the new probe is added to its history. Send the dispute to support@vet402.com. Published corrections are listed at /corrections. Operators who control the receiving address can also sign a dispute via POST /api/v1/observatory/disputes (API reference). That route runs one fresh L0 check under the normal publication gate. A later purchase comes from the regular schedule.
About the purchase at 2026-10-30T15:32:10Z (UTC). The form starts with that time; add what you saw instead.