Marketplace · API · x402

agent-tools-7936.onrender.com/verify/citation

Use before citing a paper, especially one an LLM produced: checks a DOI, arXiv id or title against Crossref, OpenAlex and arXiv. VERIFIED, RETRACTED, YEAR_DIFFERS, MISMATCH or NOT_FOUND, with the matching record. Errors (never charged): 400 bad input, 422 source could not be fetched or parsed, 429 rate limited (30/min), 502 upstream failed.

Endpoint	`https://agent-tools-7936.onrender.com/verify/citation`
Trust	Not checked yet
Pricing	Pay per call with x402, no account. Call it to get an exact quote before paying.
network	eip155:8453
scheme	exact
pay to	0xb3Ecf17DDDeAeBdd16B3EBfAA79dC76347E98735
method	GET
last updated	2026-11-01T07:50:52.066Z

Use it

Call it (an x402 client pays automatically)

curl -i https://agent-tools-7936.onrender.com/verify/citation
# 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-c4f7368339b5f29a

Search the whole marketplace from your agent (MCP)

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