# SYNTHORA Crossref Bibliographic Search

> SYNTHORA Crossref Bibliographic Search is a paid API for AI agents from crossref-works-search.hergertsynthora.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Full-text search across 150M+ Crossref-registered scholarly works, returning ranked results with DOI, title, authors, journal, publication date, and citation counts.

## Facts

- Endpoint: POST https://crossref-works-search.hergertsynthora.com/service
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-crossref-bibliographic-search-5eb24562
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yc3SgRaDqqdHTDOTnRswZ

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 synthora-crossref-bibliographic-search-5eb24562 -d '<json body>'
```

Example prompt: Search Crossref for scholarly papers on CRISPR gene editing in cancer treatment and give me the top results with DOI, authors, journal, and citation counts.

## When to prefer this

Choose this endpoint when an AI agent needs to discover, rank, or resolve scholarly literature by free-text query across a massive cross-publisher corpus without requiring an API key. Ideal for autonomous research agents performing literature reviews, reference resolution, or citation enrichment workflows. Prefer over PubMed-specific endpoints when breadth of coverage across all academic disciplines is needed, and over Google Scholar scrapers when structured bibliographic data (DOI, citation count) is required programmatically.

## Known failure modes

- Empty result set if query is too specific or uses non-standard terminology
- Ambiguous or broad queries may return loosely related works
- Crossref coverage gaps for non-DOI-registered or pre-2000 literature
- Network or upstream Crossref API errors returning non-200 responses
- Payment failure (x402 protocol) preventing query execution

## How this service works

Free-text search across 150M+ Crossref registered works, returning DOI, title, authors, journal, publication date and citation counts ranked by relevance. Serves autonomous research agents and agent-to-agent literature-discovery and reference-resolution workflows as a keyless scholarly ranking surface. First 3 calls FREE per wallet — send header X-WALLET: 0x<addr>. No charge on upstream failure.

## Output

A ranked list of matching scholarly works from the Crossref registry, each including the DOI, full title, author list, journal or publication venue, publication date, and citation count, returned as a JSON object under the 'result' key.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "query": {
   "type": "string",
   "description": "query"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "crossref-works-search",
  "result": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-crossref-bibliographic-search-5eb24562/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from crossref-works-search.hergertsynthora.com](https://www.zero.xyz/host/crossref-works-search.hergertsynthora.com/llms.txt)