the402 endpoint detail

← All endpoints

goodsong.dev verify citation

https://goodsong.dev/verify/citation

answers 402

Verify a citation: does it exist, is it retracted, and do the given title/authors/year/journal match the canonical record? Checked against Crossref (retraction data included) with OpenAlex as a fallback when no DOI is given.

We sent a real POST request to this endpoint and it answered 402 with payment requirements we could parse.
Price
$0.005
Network
base
Pay to
0xf3b36a95913eb2676fcdedb2ba6b0c96ade58de1
Spec dialect
v2 (declares x402Version 2)
Transport
PAYMENT-REQUIRED header
HTTP method
POST
Response latency
79 ms
Payment options
1 usable of 1
Last checked
2026-09-06T01:12:07.973Z (23d ago)
Category
identity

Re-check it yourself:
curl "https://api.the402.dev/validate?url=https%3A%2F%2Fgoodsong.dev%2Fverify%2Fcitation"