# DOI Lookup: Citation Metadata, Authors, Journal, Citations, Abstract

> DOI Lookup: Citation Metadata, Authors, Journal, Citations, Abstract is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Resolves a DOI to its full citation metadata including authors, journal, abstract, and citation counts

## Facts

- Endpoint: POST https://twin.unykorn.org/research/doi?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/doi-lookup-citation-metadata-authors-journal-citations-abstract-f1ab56a2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8fTVM2mey8N2IiQM-4N_I

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability doi-lookup-citation-metadata-authors-journal-citations-abstract-f1ab56a2 -d '<json body>'
```

Example prompt: Can you look up the full citation details for the paper with DOI 10.1038/nature12373 — I need the title, authors, journal, abstract, and how many times it's been cited?

## When to prefer this

Choose this endpoint when you have a specific DOI and need to retrieve scholarly citation metadata quickly without a full literature search. Ideal for enriching reference lists, verifying citations, or extracting paper abstracts programmatically. Prefer this over a general web search when you need structured bibliographic output rather than free-text results.

## Known failure modes

- Invalid or malformed DOI returns an error or empty result
- DOI exists but the upstream resolver has incomplete metadata (missing abstract or citation count)
- Very new or preprint DOIs may not yet be indexed with full metadata
- Rate limiting or upstream resolver unavailability causing timeout

## How this service works

DOI lookup: citation metadata, authors, journal, citations, abstract — Genesis402 / UnyKorn Operator Network

## Output

Returns structured citation metadata for the resolved DOI, including the paper title, author list, journal/venue name, publication date, abstract text, and citation count.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "doi": {
     "type": "string",
     "description": "required: e.g. 10.1038/nature12373"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "crossref-doi",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.002,
   "receipt_id": "g402-<16hex>"
  },
  "sources": [
   {
    "ok": true,
    "name": "<source>"
   }
  ],
  "limitations": "<text>",
  "generated_at": "<iso time>",
  "evidence_hash": "sha256:<64hex>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/doi-lookup-citation-metadata-authors-journal-citations-abstract-f1ab56a2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)