Look up scholarly metadata for any DOI via CrossRef
Look up scholarly metadata for any DOI via CrossRef. Returns title, authors, journal, publication date, abstract, citation count, references, license, URL. Use ?doi=10.1038/nature12373. Built for AI research agents doing literature review and citation graph traversal. Accepts payment on Base or Solana — either network works.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
474 msmedian answer time
$0.008listed price per call
$0.008price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://api.x402node.dev/citation/doi
| Category | Market data |
|---|---|
| Provider host | api.x402node.dev |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.008 | 474 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"doi": "string"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"doi": {
"description": "DOI string (required)",
"type": "string"
}
},
"required": [
"doi"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}