x402 census · x402engine.app · be7fa20056f7 · JSON
POST /api/tx/simulate
open
x402engine — Simulate EVM transactions before sending — get gas estimates, execution traces, and revert reasons
Verdict: not verified by an unpaid GET. 200: serves without a payment challenge. This says nothing about whether the route works when called as declared.
Facts from the catalogs
| Field | Value |
|---|---|
| URL | https://x402engine.app/api/tx/simulate |
| Method | POST |
| Price | $0.01 USDC = 10000 atomic units of 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 |
| Network | eip155:8453 (base); also accepts eip155:4326, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| payTo | 0x7dd5Be069f2d2eAd75eC7C3423B116fF043c2629 |
| Seller | x402engine.app |
| Catalogs | cdp (row updated 2026-10-11) |
| Listed since (lower bound) | 2026-10-11 (earliest catalog timestamp; catalogs report last-update times only) |
| Last catalog update | 2026-10-11 |
| CDP quality counters | 2 calls and 2 unique payers in 30 days, last call 2026-10-11 (catalog-reported, not verified on chain) |
| Category (keyword rule) | chain-rpc |
| Templated path | no |
| x402Version in catalog | 2 |
| Service name / tags | none |
Unpaid probe (census of 2026-10-22)
| Field | Value |
|---|---|
| Probed at | 2026-10-22T00:19:41.752Z |
| HEAD | 200 |
| GET | 200 |
| Verdict | open 200: serves without a payment challenge |
| 402 carried in | n/a |
| x402Version in the 402 | n/a |
| accepts[0] | none |
| Live amount equals catalog price | not comparable |
| Live payTo equals catalog payTo | not comparable |
| extensions.bazaar in the 402 | no |
| PAYMENT-REQUIRED header | no |
| WWW-Authenticate offer | none |
| Content type / server / CORS | application/json / cloudflare / * |
| Latency | 116 ms |
| Error | none |
No hourly re-probe has reached this resource yet; the cron covers a rotating slice of 150 per hour.
On-chain facts for the payTo (public address)
| Field | Value |
|---|---|
| Distinct payers | 86 |
| Payments | 231 |
| USDC volume | $11.48 |
| Median payment | $0.01 |
| First / last payment | 2026-05-25 / 2026-09-30 |
| Sampler-shaped share of payments | 100.0% |
| Payers that are not samplers | 0 |
| Source | forensics-2026-09-30 |
| Address | 0x7dd5Be069f2d2eAd75eC7C3423B116fF043c2629 |
Declared input and output (extensions.bazaar)
{
"input": {
"body": {
"from": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
"network_id": "1",
"to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
"value": "0"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
}
Try it (unpaid: shows the 402)
curl -si -X POST 'https://x402engine.app/api/tx/simulate' -H 'accept: application/json' -H 'content-type: application/json' --data '{}'
The catalog declares POST. A 402 answer carries the payment requirements in the JSON body and, for x402 v2, base64 in the PAYMENT-REQUIRED header. This page never sends a payment.
Paid checks (x402, USDC on Base)
GET https://bazaar.agentexchange.work/r/be7fa20056f7/probe.json re-runs this probe right now for $0.01 and writes the result here. POST https://bazaar.agentexchange.work/featured with {"id":"be7fa20056f7"} places this resource at the top of the report and search pages for 30 days for $1.00, labelled. Unpaid requests answer 402 with the terms. Pricing.
Catalog references: agentic.market (CDP Bazaar front end) · this record as JSON · all resources on x402engine.app.