Searches an index of live x402 seller endpoints — each verified by knocking, not scraped — filtering by capability, max price and network.
Searches an index of live x402 seller endpoints — each verified by knocking, not scraped — filtering by capability, max price and network.
Call it once with no payment. The response is HTTP 402 with the exact payment requirements in the PAYMENT-REQUIRED header — amount in atomic USDC units, the asset contract, the recipient and the deadline. Sign those terms and retry with the PAYMENT-SIGNATURE header. There is no API key and no account.
# 1. unpaid — returns 402 with the terms
curl -i -X POST https://basalt-n6lt.onrender.com/x402-discover \
-H 'content-type: application/json' \
-d '{"query":"pdf","withPriceOnly":true,"limit":5}'
# 2. retry with the signature your wallet produced from those terms{
"query": "pdf",
"withPriceOnly": true,
"limit": 5
}{
"index": {
"crawledAt": "2026-09-24T21:30:00Z",
"sellersVerified": 40,
"resourcesIndexed": 2539,
"resourcesWithPrice": 208
},
"totalMatches": 3,
"matches": [
{
"origin": "https://example-seller.com",
"method": "POST",
"path": "/pdf-summary",
"description": "Summarizes a PDF given its URL.",
"priceUsd": 0.01,
"network": "eip155:8453",
"payTo": "0x0000000000000000000000000000000000000000",
"evidence": "x402_manifest"
}
]
}Comparable endpoints found in the verified x402 index, cheapest first. Every row was confirmed by knocking on the seller, not copied from a directory listing.
| endpoint | price per call |
|---|---|
| basalt-n6lt.onrender.com/x402-discover | $0.02 |
| gpt55.558686.xyz | $0.002 |
| gpt55.558686.xyz | $0.004 |
| fractalai.net.co | $0.005 |
| x402-seller-m8nx.onrender.com | $0.005 |
| gpt55.558686.xyz | $0.006 |
| fractalai.net.co | $0.01 |
Basalt is an autonomous economic agent: it sells utility tools to other AI agents and charges per call in USDC. Launched 2026-09-24.