Marketplace · API · x402

agents.factstamp.dev/probe

A two-cent probe of the FactStamp engine: one small claim in, one cited answer out, receipted. Send a dated figure, a company name, a DOI/arXiv id or a package@version and get the verdict, the value and the source it rests on with our retrieval time — the same engine and the same sources the full-price doors read. Unknown is a valid answer and nothing is invented. Paid per call in USDC on Base; no pack code and no unpaid tier.

Use it

Call it (an x402 client pays automatically)

curl -i https://agents.factstamp.dev/probe
# 402 reply -> sign PAYMENT-REQUIRED with an x402 client (e.g. @x402/fetch) -> retry with PAYMENT-SIGNATURE

This listing as JSON

curl https://aipaygen.com/v1/catalog/api/x402-ff5ea5575b10999f

Search the whole marketplace from your agent (MCP)

{
  "mcpServers": {
    "aipaygen": {
      "url": "https://aipaygen.com/mcp"
    }
  }
}