https://2s.io/api/paper/doi-lookupGET /api/paper/doi-lookup · x402 API by 2s.io
Resolve a DOI to authoritative bibliographic metadata via Crossref. Accepts bare DOI (10.1038/nature12373) or full DOI URL (https://doi.org/10.1038/nature12373). Returns work type, title, container (journal/conference), publisher, issued/published dates, abstract, authors (with ORCID + affiliations), page range, volume/issue, ISBN + ISSN lists, canonical URL, reference + citation counts, license blocks, and subject classifications. ~160M works in Crossref. Best authoritative DOI → bibliographic resolver. Metadata is CC0.
What does this x402 API do?
https://2s.io/api/paper/doi-lookup. This is an x402-gated GET API resource from 2s.io. TOLL·402 confirmed a protocol-valid HTTP 402 quote on 2026-07-21. No normalized USD price is recorded; the listing names Base and Solana. No settled paid call has been verified.
- Published price
- No normalized USD price is recorded
- Networks
- Base · Solana
- Latest evidence
- TOLL·402 confirmed a protocol-valid HTTP 402 quote on 2026-07-21
- Resource ID
- 012fb768e9a3181f5c31c09c
Start with a quote-only recipe. Payment signing stays in your project.
const response = await fetch("https://2s.io/api/paper/doi-lookup", {
method: "GET",
});
console.log(response.status);
console.log(Object.fromEntries(response.headers));
console.log((await response.text()).slice(0, 1000));
// A valid 402 is a quote, not a completed paid call.This sends no payment. Inspect the 402 response before adding a wallet-enabled client.
- Live 402 quote confirmed
GET returned a protocol-valid 402 quote (402). No payment was made.
- Origin reachable
HEAD https://2s.io/ returned 200.
- Observed in cdp-bazaar
The registry record was observed and retained with provenance.
- Observed in 402-index
Discovered through bazaar.
- Registry record checked
Registry health: healthy.
What evidence supports this listing?
Each record has an exact-route quote outcome. Unresolved templates and potentially mutating methods are labeled instead of being invoked without provider-specific test input. A quote is still separate from a settled paid call. Read the discovery and verification methodology →
Which networks and payment options does it accept?
The normalized listing price is No normalized USD price is recorded. Raw protocol requirements remain visible below for implementation and audit use.