# DOI Lookup – Full Paper Metadata & Citation

> DOI Lookup – Full Paper Metadata & Citation is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).

Resolves a Digital Object Identifier (DOI) to full academic paper metadata including title, authors, journal details, abstract, citation counts, references, funders, subjects, and a formatted APA citation.

## Facts

- Endpoint: GET https://intel.rallylive.ca/papers/doi?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/doi-lookup-full-paper-metadata-citation-6366f63e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9wG9wnZCZWJCVE5sr10-2

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-full-paper-metadata-citation-6366f63e
```

Example prompt: Can you look up the DOI 10.1038/s41586-020-2649-2 and give me the full paper details — title, authors, journal, year, abstract, citation count, and a ready-to-paste APA citation?

## When to prefer this

Choose this endpoint when you need rich, structured bibliographic metadata for a known DOI in a single call, especially when you also need citation/reference counts, funder information, subjects, abstract, and a ready-made APA citation. It is preferable over generic web scraping for academic papers because it queries authoritative DOI registry data directly and returns a normalized, machine-readable record. Well-suited for literature review automation, reference management, and academic data enrichment pipelines.

## Known failure modes

- DOI not found or invalid – endpoint returns an error indicating the DOI could not be resolved
- DOI exists but metadata is incomplete – some fields (e.g. abstract, funders) may be null if not registered by the publisher
- Rate or payment failure – if the x402 micropayment of $0.01 USDC is not processed, the request is rejected
- Network timeout – upstream DOI registry (e.g. CrossRef) may be slow or unavailable

## How this service works

Look up a DOI: full paper metadata (title, authors, journal, volume, issue, pages, year, publisher, funders, subjects), citation and reference counts, abstract, links and a ready APA citation. $0.01 per lookup.

## Output

Returns a structured record for the resolved DOI containing: title, author list, journal name, volume, issue, page range, publication year, publisher, funder names, subject classifications, abstract text, inbound citation count, outbound reference count, relevant links (e.g. PDF, landing page), and a pre-formatted APA citation string.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/doi-lookup-full-paper-metadata-citation-6366f63e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)