# Wikipedia Fact Lookup API

> Wikipedia Fact Lookup API is a paid API for AI agents from freetier-agent-api.pages.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-11-01).

Returns the best-matching Wikipedia article summary, description, URL, and structured Wikidata facts for a given entity or topic query.

## Facts

- Endpoint: GET https://freetier-agent-api.pages.dev/api/wiki-fact?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/wikipedia-fact-lookup-api-478ffb3d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oKGsWwxBxSJSwZadvsSK4

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 wikipedia-fact-lookup-api-478ffb3d
```

Example prompt: Can you look up Wikipedia facts about Tesla — I want to know when it was founded, who the founders are, the current CEO, the stock ticker, and their official website?

## When to prefer this

Use this endpoint when you need structured, encyclopedic facts about a real-world entity — companies, cities, people, or organizations — and want both a human-readable Wikipedia summary and machine-readable Wikidata fields in a single call. Prefer this over raw Wikipedia scraping when you need structured fields like founder, CEO, ticker, or coordinates without parsing. Prefer over general web search when authoritative, structured reference data is needed rather than recent news or opinions.

## Known failure modes

- No matching Wikipedia article found for the query — returns empty or error response
- Ambiguous query matches unintended article — result may be off-topic
- Wikidata facts may be incomplete if the entity has sparse structured data
- Non-English language codes may have less structured Wikidata coverage
- Rate limiting or payment failure (x402) blocks the request

## How this service works

Invoice-to-JSON, on-chain tools (transaction explainer + payment check, wallet profile, contract ABI, ERC-20 token risk), company contacts and web-to-RAG for AI agents. Pay per call with x402 (USDC on Base). No signup, no API key.

## Output

A JSON object containing the best-matching Wikipedia article title, a short description, the article URL, and a structured facts object with available Wikidata properties such as founder(s), inception date, official website, headquarters, CEO, industry, employee count, stock ticker, population, and geographic coordinates.

## 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": "entity or topic"
      },
      "lang": {
       "type": "string",
       "description": "Wikipedia language code, default en"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://en.wikipedia.org/wiki/Coinbase",
  "facts": {
   "founder": [
    "Brian Armstrong",
    "Fred Ehrsam"
   ],
   "inception": "2012-06-20",
   "officialWebsite": "https://www.coinbase.com"
  },
  "title": "Coinbase",
  "description": "American cryptocurrency exchange"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/wikipedia-fact-lookup-api-478ffb3d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from freetier-agent-api.pages.dev](https://www.zero.xyz/host/freetier-agent-api.pages.dev/llms.txt)