Resolve one research paper and fuse its metadata across OpenAlex, Crossref, Unpaywall a…

What it does

Resolve one research paper and fuse its metadata across OpenAlex, Crossref, Unpaywall and Semantic Scholar into a single cited JSON. Give a doi, arxiv, pmid, pmcid, openalex_id or title and get canonical metadata, authors with ORCID and affiliations, venue, citation counts, an open-access PDF link and a full id crosswalk.

Tags: scholar · research · paper · doi · citation · bazaar

Call contract

Method

GET

Input

query parameters

Output

json

Last paid call

2026-10-08

{
  "doi": "10.1038/nature14539"
}

{
  "attribution": [
    "OpenAlex (openalex.org), CC0"
  ],
  "authors": [
    {
      "affiliations": [],
      "name": "Yann LeCun",
      "orcid": "0000-0002-1825-0097"
    }
  ],
  "counts": {
    "cited_by": {
      "crossref": 58000,
      "openalex": 60000
    },
    "influential_citations": 4200
  },
  "found": true,
  "ids": {
    "doi": "10.1038/nature14539",
    "openalex": "W2743563197",
    "pmid": "26017442"
  },
  "open_access": {
    "is_oa": true,
    "license": "cc-by",
    "pdf_url": "https://example.org/paper.pdf",
    "version": "publishedVersion"
  },
  "provenance": {
    "id.doi": "openalex",
    "open_access": "unpaywall",
    "title": "openalex"
  },
  "query": {
    "type": "doi",
    "value": "10.1038/nature14539"
  },
  "sources": {
    "partial": false,
    "used": [
      "openalex",
      "crossref",
      "unpaywall"
    ]
  },
  "title": "Deep learning",
  "type": "article",
  "venue": {
    "issn": "0028-0836",
    "name": "Nature"
  },
  "year": 2015
}

Use with an agent

1. Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
2. Inspect. Fetch /resources/29267.json for the price and payment options.
3. Pay. Call GET https://api.agentstools.dev/scholar/paper. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
4. Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price

$0.02 / request

Protocol

x402 v2

Auth

No account or API key. Pay per request.

Networks

Base

Demand

2 calls · 2 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xF22e558a00D91Ee12A1F50C52186FecB8dDFf493",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "amountUsd": 0.02,
    "maxTimeoutSeconds": 300
  }
]

Schemas

{
  "properties": {
    "example": {
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

{
  "example": {},
  "type": "string"
}

Examples

curl "https://api.agentstools.dev/scholar/paper"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://api.agentstools.dev/scholar/paper");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://api.agentstools.dev/scholar/paper")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider

api.agentstools.dev

Endpoint

https://api.agentstools.dev/scholar/paper

Machine-readable

/resources/29267.json