# Academic & Scientific Paper Search API

> Academic & Scientific Paper Search API is a paid API for AI agents from api.kadec0.xyz, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-13).

Searches academic and scientific papers across arXiv, PubMed, OpenAlex, Crossref, and Semantic Scholar in a single deduplicated, ranked call

## Facts

- Endpoint: GET https://api.kadec0.xyz/v1/papers?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/academic-scientific-paper-search-api-fb7d04ce
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NYuh26GWpGfVkr-NV5sGH

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-scientific-paper-search-api-fb7d04ce
```

Example prompt: Search for papers about 'transformer attention mechanisms' published between 2020 and 2024, sorted by citations, across all sources — give me up to 20 results with abstracts, DOIs, and PDF links.

## When to prefer this

Prefer this endpoint when you need a single call to search across multiple major academic databases simultaneously with deduplication and ranking. Ideal when you don't know which source a paper is in, want cross-source coverage, or need citation counts and PDF links alongside metadata. Better than calling each source API individually.

## Known failure modes

- Missing required query parameter 'q' returns a 400 error
- Invalid enum value for 'source' or 'sort' returns a validation error
- No matching papers found returns an empty result set
- Upstream source unavailable may reduce result coverage without a full failure
- Payment not provided or invalid returns a 402 Payment Required error

## How this service works

Academic and scientific paper search API. Search research papers and scholarly literature across arXiv, PubMed, OpenAlex, Crossref, and Semantic Scholar in one call, deduplicated into a ranked result set: title, authors, year, venue, abstract, citation count, DOI, and direct PDF link. Query by keyword or restrict to one source; filter by year range; sort by relevance, recency, or citations. Keyless.

## Output

A deduplicated, ranked list of up to 50 papers, each with title, authors, year, venue/journal, abstract, citation count, DOI, and direct PDF link — aggregated from arXiv, PubMed, OpenAlex, Crossref, and Semantic Scholar.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "q"
     ],
     "properties": {
      "q": {
       "type": "string",
       "description": "search query / keywords"
      },
      "sort": {
       "enum": [
        "relevance",
        "recency",
        "citations"
       ],
       "type": "string",
       "default": "relevance"
      },
      "source": {
       "enum": [
        "all",
        "arxiv",
        "pubmed",
        "openalex",
        "crossref",
        "semanticscholar"
       ],
       "type": "string",
       "default": "all"
      },
      "year_to": {
       "type": "string",
       "description": "latest publication year (inclusive)"
      },
      "maxItems": {
       "type": "string",
       "default": "20",
       "description": "1-50"
      },
      "year_from": {
       "type": "string",
       "description": "earliest publication year (inclusive)"
      }
     }
    }
   },
   "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/academic-scientific-paper-search-api-fb7d04ce/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.kadec0.xyz](https://www.zero.xyz/host/api.kadec0.xyz/llms.txt)