# Academic Paper Lookup

> Academic Paper Lookup is a paid API for AI agents from papers.use.x402atlas.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-11-03).

Retrieves full metadata for a scientific paper by DOI, arXiv ID, or PubMed ID, including abstract, TLDR, citations, BibTeX/APA, retraction flag, and open-access PDF link, merged from five scholarly databases.

## Facts

- Endpoint: GET https://papers.use.x402atlas.com/paper?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-03
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/academic-paper-lookup-f717327f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zrBxL9k6zmzEC0bdoNEf7

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 academic-paper-lookup-f717327f
```

Example prompt: Can you pull up the full details for the paper with DOI 10.1038/nature12373 — I need the abstract, a BibTeX citation, how many times it's been cited, and whether it's been retracted?

## When to prefer this

Use this endpoint when you already know the paper identifier (DOI, arXiv ID, or PMID) and need rich, merged metadata from multiple authoritative databases in one call — especially when you need citation-ready BibTeX/APA, retraction checks, or open-access PDF links. Prefer this over general web search when precision, citation formatting, and multi-source aggregation matter. Pair with the sibling Academic Paper Search endpoint when you need to discover papers first before fetching full details.

## Known failure modes

- Unknown or invalid ID returns a note field indicating no source matched, with empty fields
- Semantic Scholar TLDR may be empty if the paper is not indexed there
- PDF URL is null if the paper is not truly open access
- Temporary source failure sets coverage.retry=true, indicating partial data
- Malformed DOI or arXiv ID format returns an error or empty result

## How this service works

Scientific paper lookup by DOI, arXiv id or PMID: full abstract, Semantic Scholar TLDR, ready-to-paste BibTeX and APA citations, citation counts, retraction flag, paper type, open-access PDF link. Merged from OpenAlex, Crossref, arXiv, PubMed and Semantic Scholar. Use to cite a known paper or expand a search hit.

## Output

Returns a structured object containing the paper's title, authors, year, venue, full abstract, Semantic Scholar TLDR, DOI, citation count, citations per year, retraction flag, paper type (journal-article/preprint/review/book-chapter/other), open-access status, PDF URL if available, landing page URL, and ready-to-paste BibTeX and APA citations. Also includes a coverage object indicating which sources contributed data and whether any source failed temporarily.

## 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",
     "required": [
      "id"
     ],
     "properties": {
      "id": {
       "type": "string",
       "description": "id from /search: a DOI, arxiv:<id> or pmid:<id>"
      },
      "doi": {
       "type": "string",
       "description": "Alias of id"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "id",
      "title",
      "authors",
      "year",
      "venue",
      "abstract",
      "tldr",
      "doi",
      "citationCount",
      "citationsPerYear",
      "is_retracted",
      "type",
      "oa_status",
      "pdfUrl",
      "url",
      "citation",
      "coverage"
     ],
     "properties": {
      "id": {
       "type": "string",
       "description": "DOI, or arxiv:<id> / pmid:<id> when the paper has no DOI"
      },
      "doi": {
       "type": "string",
       "description": "Lowercase, no doi.org prefix; empty if none"
      },
      "url": {
       "type": "string",
       "description": "doi.org, arxiv.org or pubmed landing page"
      },
      "note": {
       "type": "string",
       "description": "Present only when no source matched"
      },
      "tldr": {
       "type": "string",
       "description": "Semantic Scholar TLDR; empty if unavailable"
      },
      "type": {
       "enum": [
        "journal-article",
        "preprint",
        "review",
        "book-chapter",
        "other"
       ],
       "type": "string"
      },
      "year": {
       "type": "integer",
       "description": "0 if unknown"
      },
      "title": {
       "type": "string"
      },
      "venue": {
       "type": "string",
       "description": "Empty if unknown"
      },
      "pdfUrl": {
       "type": [
        "string",
        "null"
       ],
       "description": "Only when the full text is really open"
      },
      "authors": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
    
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/academic-paper-lookup-f717327f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from papers.use.x402atlas.com](https://www.zero.xyz/host/papers.use.x402atlas.com/llms.txt)