# API Acre Crossref DOI Metadata Resolver

> API Acre Crossref DOI Metadata Resolver is a paid API for AI agents from apiacre.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Resolves a single DOI into normalized Crossref bibliographic metadata including authors, container, citation count, license, identifiers, and retraction links.

## Facts

- Endpoint: POST https://apiacre.com/v1/research/crossref-doi-metadata
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-acre-crossref-doi-metadata-resolver-e58a7073
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QHp5_s0wTJH3_XBCnwORX

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 api-acre-crossref-doi-metadata-resolver-e58a7073 -d '<json body>'
```

Example prompt: Can you look up the bibliographic metadata for this DOI — 10.1038/s41586-021-03819-2 — and tell me who the authors are, what journal it was published in, how many citations it has, and whether it has any retractions or corrections?

## When to prefer this

Choose this endpoint when you need fast, normalized Crossref metadata for a single DOI without needing abstracts or full text. Ideal for citation verification, retraction checking, license auditing, author disambiguation, and bibliographic enrichment pipelines. Prefer this over raw Crossref API calls when you need structured, agent-ready output without parsing Crossref's raw JSON format yourself.

## Known failure modes

- DOI not registered in Crossref — returns empty or not-found response
- Malformed or non-standard DOI string — validation error
- DOI exists but Crossref record is incomplete — some fields may be null or missing
- Crossref API rate limit or downstream timeout — transient error
- DOI resolves to a non-journal item type (e.g. dataset, book chapter) — metadata schema may differ

## How this service works

Resolve one DOI into normalized open Crossref bibliographic, author, container, citation-count, license, identifier, and correction or retraction-link metadata without abstracts or full text.

## Output

Returns a normalized JSON object containing bibliographic fields (title, publication date, DOI, type), author list with affiliations, container/journal name and ISSN, citation count, license details, related identifiers, and links to any correction or retraction notices. Abstracts and full text are not included.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "doi": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "doi": "10.1038/s41586-021-03819-2",
   "work": {
    "doi": "10.1038/s41586-021-03819-2",
    "type": "journal-article",
    "title": "Example normalized DOI record",
    "authors": [],
    "publishedDate": "2021-08-25"
   },
   "source": "https://api.crossref.org/works/10.1038%2Fs41586-021-03819-2",
   "status": "matched",
   "limitations": [
    "Demonstration metadata only; paid calls return the current DOI record.",
    "Abstracts and full text are deliberately excluded."
   ],
   "retrievedAt": "2026-08-20T12:00:00+00:00",
   "documentation": "https://www.crossref.org/documentation/retrieve-metadata/rest-api/",
   "metadataLicense": {
    "url": "https://www.crossref.org/documentation/retrieve-metadata/",
    "name": "Open bibliographic metadata / Crossref-generated data CC0",
    "abstractsReturned": false
   }
  },
  "meta": {
   "cached": false,
   "sources": [],
   "warnings": [],
   "duration_ms": 42,
   "next_actions": []
  },
  "service": "research.crossref-doi-metadata",
  "version": "1",
  "request_id": "018f1f54-7f38-7ba2-8dc3-5f90272d9f1a"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-acre-crossref-doi-metadata-resolver-e58a7073/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from apiacre.com](https://www.zero.xyz/host/apiacre.com/llms.txt)