# Open Search – Multi-Source Search (Wikipedia + Hacker News + Crossref + Wikidata)

> Open Search – Multi-Source Search (Wikipedia + Hacker News + Crossref + Wikidata) is a paid API for AI agents from open-search.x402tookit.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-11-02).

Runs a single query across Wikipedia, Hacker News, Crossref academic papers, and Wikidata simultaneously, returning top hits from each source interleaved and labelled.

## Facts

- Endpoint: GET https://open-search.x402tookit.com/search-all?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/open-search-multi-source-search-wikipedia-hacker-news-crossref-wikidata-00d8f29a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sVl6JKj7Rl1FRysFTmz1M

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 open-search-multi-source-search-wikipedia-hacker-news-crossref-wikidata-00d8f29a
```

Example prompt: Search across Wikipedia, Hacker News, Crossref papers, and Wikidata for 'transformer neural networks' and give me the top 3 hits from each source.

## When to prefer this

Choose this endpoint when you need a quick, broad survey of a topic from multiple authoritative and community sources in a single call, avoiding the overhead of querying Wikipedia, Hacker News, Crossref, and Wikidata APIs separately. It is ideal for research summaries, fact-finding, or topic overviews where both encyclopedic knowledge and academic and community context are all relevant. Prefer individual sibling endpoints if you only need results from one specific source.

## Known failure modes

- One or more upstream sources (Wikipedia, HN, Crossref, Wikidata) may be unreachable, causing a degraded response with partial results and a 'notChecked' list
- Query string exceeds 200 characters returns a validation error
- perSource outside 1–5 range is rejected
- Empty or overly vague queries may return zero results from some sources
- Rate-limited or network-timeout from upstream APIs may reduce result counts

## How this service works

One query across Wikipedia, Hacker News, Crossref papers and Wikidata: top hits from each, source-labelled and interleaved.

## Output

A structured response containing interleaved, source-labelled results from up to four sources (Wikipedia, Hacker News, Crossref, Wikidata). Each result includes title, URL, source label, and source-specific fields: Wikipedia entries include snippet and word count; Hacker News entries include points and comment count with discussion link; Crossref entries include DOI, year, venue, and citation count; Wikidata entries include Q-id, label, and description. The response also reports which sources answered, a degraded flag if any source failed, and per-source hit counts.

## 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": [
      "q"
     ],
     "properties": {
      "q": {
       "type": "string",
       "description": "Search words, up to 200 characters"
      },
      "perSource": {
       "type": "integer",
       "description": "Hits kept per source, 1 to 5 (default 3)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "query": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ]
      },
      "results": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "id": {
          "type": [
           "null",
           "string"
          ]
         },
         "doi": {
          "type": [
           "null",
           "string"
          ]
         },
         "url": {
          "type": [
           "null",
           "string"
          ]
         },
         "date": {
          "type": [
           "null",
           "string"
          ]
         },
         "type": {
          "type": [
           "null",
           "string"
          ]
         },
         "year": {
          "type": [
           "null",
           "number"
          ]
         },
         "title": {
          "type": [
           "null",
           "string"
          ]
         },
         "venue": {
          "type": [
           "null",
           "string"
          ]
         },
         "words": {
          "type": [
           "null",
           "number"
          ]
         },
         "points": {
          "type": [
           "null",
           "number"
          ]
         },
         "source": {
          "type": [
 
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/open-search-multi-source-search-wikipedia-hacker-news-crossref-wikidata-00d8f29a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from open-search.x402tookit.com](https://www.zero.xyz/host/open-search.x402tookit.com/llms.txt)