x402 census · mcp.dropenginehq.com · 52a9bb724fa9 · JSON
POST /api/simulate-transaction
live
Simulates an unsigned Base or Base Sepolia EVM transaction with read-only RPC calls before an agent signs or broadcasts it. Returns execution/revert status, gas estimate, decoded top-level ERC-20 transfers and approvals, unlimited-approval warnings, and a risk signal. It never signs, holds keys, or broadcasts. Standard RPC does not expose complete internal/token state diffs.
Verdict: live. The unpaid GET reached a valid 402 (confirmed by the re-probe of 2026-10-01).
Facts from the catalogs
| Field | Value |
|---|---|
| URL | https://mcp.dropenginehq.com/api/simulate-transaction |
| Method | POST |
| Price | $0.02 USDC = 20000 atomic units of 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 |
| Network | eip155:8453 (base) |
| payTo | 0xc7693f1ba43E6D1F1885292E1194dc1FDc6e7585 |
| Seller | mcp.dropenginehq.com |
| Catalogs | cdp (row updated 2026-09-28) |
| Listed since (lower bound) | 2026-09-28 (earliest catalog timestamp; catalogs report last-update times only) |
| Last catalog update | 2026-09-28 |
| CDP quality counters | 1 calls and 1 unique payers in 30 days, last call 2026-09-28 (catalog-reported, not verified on chain) |
| Category (keyword rule) | trading-signals |
| Templated path | no |
| x402Version in catalog | 2 |
| Service name / tags | Transaction Preflight · transaction, simulation, security |
Unpaid probe (census of )
| Field | Value |
|---|---|
| Probe | not probed in this build |
Latest re-probe
| Field | Value |
|---|---|
| Re-probed at | 2026-10-01T04:13:18.000Z (cron) |
| Verdict now | live changed from unprobed |
| HEAD / GET | 402 / 402 |
| accepts[0] | {"scheme":"exact","network":"eip155:8453","amount":"20000","payTo":"0xc7693f1ba43E6D1F1885292E1194dc1FDc6e7585","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","maxTimeoutSeconds":300,"extra":{"name":"USD Coin","version":"2"}} |
| Live amount equals catalog price | yes |
| Latency | 955 ms |
| Error | none |
On-chain facts for the payTo (public address)
| Field | Value |
|---|---|
| Distinct payers | 2 |
| Payments | 29 |
| USDC volume | $0.46 |
| Median payment | n/a |
| First / last payment | 2026-09-27 / 2026-09-28 |
| Sampler-shaped share of payments | n/a |
| Payers that are not samplers | n/a |
| Source | blockscout-sample — newest page of inbound ERC-20 transfers only (<=50); counts are a floor, not a total |
| Address | 0xc7693f1ba43E6D1F1885292E1194dc1FDc6e7585 |
Declared input and output (extensions.bazaar)
{
"input": {
"body": {
"chain": "base",
"data": "0x",
"from": "0x1111111111111111111111111111111111111111",
"to": "0x1111111111111111111111111111111111111111",
"value": "0"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
}
Try it (unpaid: shows the 402)
curl -si -X POST 'https://mcp.dropenginehq.com/api/simulate-transaction' -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/52a9bb724fa9/probe.json re-runs this probe right now for $0.01 and writes the result here. POST https://bazaar.agentexchange.work/featured with {"id":"52a9bb724fa9"} 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 mcp.dropenginehq.com.