# P0 Agent Economy Index – Wikipedia Knowledge Search > P0 Agent Economy Index – Wikipedia Knowledge Search is a paid API for AI agents from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-18). Searches Wikipedia articles by query and returns ranked encyclopedic extracts with metadata and attribution ## Facts - Endpoint: GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/knowledge/search?utm_source=zero.xyz - Price: $0.001/call - Payment: x402 - Status: unknown - Last checked: 2026-10-18 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/p0-agent-economy-index-wikipedia-knowledge-search-b70e2d16 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_x2v3W-cWhIjyqvvV8AP_n 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 p0-agent-economy-index-wikipedia-knowledge-search-b70e2d16 ``` Example prompt: Search Wikipedia for 'quantum entanglement' and give me the top 3 results in English with their summaries. ## When to prefer this Choose this endpoint when you need structured, attributed encyclopedic information from Wikipedia with Wikidata linkage, multilingual support, and machine-readable license metadata — especially when downstream reuse compliance (CC BY-SA 4.0) is required. Prefer over general web search when encyclopedic sourcing and stable article references matter. ## Known failure modes - No results found for obscure or misspelled queries - Query too short (under 2 characters) returns validation error - Unsupported language code returns error - Wikipedia API unavailable causes upstream failure - Rate limiting or payment failure at $0.001 USDC per call ## How this service works An open index of the machine-to-machine (agent) economy. x402 routes: ranked discovery over the live x402 service market, every indexed service scored by real 30-day calls and paying-wallet bounds, with a receipt naming the snapshot hash and scoring revision. /economy routes, for Tempo MPP, Virtuals ACP, Olas, Masumi, ERC-8004 agent registries, Solana agent registries, Base agent contracts and MCP servers (Official MCP Registry): each protocol's published figures (agent or server counts, transactions or payment events; payers and USD volume only where the source publishes them: payers for x402 and Tempo MPP, USD volume for x402 and Virtuals ACP), each with its unit, window and source; units differ, so totals are not summed. L402 and per-service MPP listings are not covered. ## Output A JSON object containing the search query, language, result count, source metadata (API endpoint, cache status, fetch timestamp), an array of ranked Wikipedia articles each with title, URL, page ID, plain-text extract (up to 1200 chars), Wikidata ID and URL, license, last revision ID and date, and attribution text for reuse compliance. ## Request schema (JSON Schema) ```json { "type": "object", "$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" ], "type": "string" }, "queryParams": { "type": "object", "required": [ "q" ], "properties": { "q": { "type": "string", "maxLength": 200, "minLength": 2, "description": "search query: a topic, name or question" }, "lang": { "enum": [ "en", "de", "fr", "es", "it", "pt", "ru", "ja", "zh", "pl", "nl", "uk", "ar", "fa", "sv", "ko", "id", "tr", "vi", "he", "cs", "fi", "no", "hu", "ro" ], "type": "string", "default": "en", "description": "Wikipedia language edition" }, "limit": { "type": "integer", "default": 5, "maximum": 10, "minimum": 1, "description": "number of articles" } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "required": [ "query", "lang", "count", "results", "attribution", "note" ], "properties": { "lang": { "type": "string" }, "note": { "type": "string" }, "count": { "type": "integer" }, "query": { "type": "string" }, "source": { "type": "object", "properties": { "api": { "type": "string" }, "name": { "type": "string" }, "cached": { "type": "boolean" }, "fetchedAt": { "type": "string" } } }, "results": { "type": "array", "items": { "type": "object", "required": [ "rank", "title", "url", "license", "licenseUrl" ], "properties": { "url": { "type": "string" }, "rank": { … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "lang": "en", "note": "Encyclopedic search over Wikipedia articles (not a general web search engine). Results are ranked by Wikipedia's own search. Check the linked article for current details.", "count": 1, "query": "bitcoin", "source": { "api": "https://en.wikipedia.org/w/api.php", "name": "Wikipedia (en)", "cached": false, "fetchedAt": "2026-10-06T10:12:30.000Z" }, "results": [ { "url": "https://en.wikipedia.org/wiki/Bitcoin", "rank": 1, "title": "Bitcoin", "pageId": 28249265, "extract": "Bitcoin (abbreviation: BTC; sign: ₿) is the first decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown person published a white paper under the pseudonym of Satoshi Nakamoto.", "license": "CC BY-SA 4.0", "historyUrl": "https://en.wikipedia.org/w/index.php?curid=28249265&action=history", "licenseUrl": "https://creativecommons.org/licenses/by-sa/4.0/", "wikidataId": "Q131723", "attribution": "\"Bitcoin\" from Wikipedia (en), https://en.wikipedia.org/wiki/Bitcoin, by its contributors, CC BY-SA 4.0", "description": "Decentralized digital cryptocurrency", "lastTouched": "2026-10-05T18:54:53Z", "wikidataUrl": "https://www.wikidata.org/wiki/Q131723", "lastRevisionId": 1378636617, "descriptionSource": "wikipedia" } ], "attribution": { "text": "Text from Wikipedia, the free encyclopedia, by its contributors (authors: see each result's historyUrl), licensed under CC BY-SA 4.0; reuse of these extracts must keep the same licence and credit. Wikidata IDs are CC0. P0 is not affiliated with or endorsed by the Wikimedia Foundation.", "changes": "Plain-text extract of the lead section (first 3 sentences, at most 1200 characters); formatting, links and references removed.", "license": "CC BY-SA 4.0", "licenseUrl": "https://creativecommons.org/licenses/by-sa/4.0/", "wikidataLicense": "CC0 1.0", "wikidataLicenseUrl": "https://creativecommons.org/publicdomain/zero/1.0/" } } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/p0-agent-economy-index-wikipedia-knowledge-search-b70e2d16/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev](https://www.zero.xyz/host/x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/llms.txt)