# srch.best Knowledge Search

> srch.best Knowledge Search is a paid API for AI agents from x402.srch.best, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns structured knowledge data (encyclopedia-style facts and entities) for a given query, billed per request via x402 micropayment

## Facts

- Endpoint: POST https://x402.srch.best/knowledge
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/srch-best-knowledge-search-4db734d9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Cakm1c6OoZ_Ra2UJsal3R

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 srch-best-knowledge-search-4db734d9 -d '<json body>'
```

Example prompt: Can you look up structured knowledge about the Roman Colosseum — give me up to 5 results in English?

## When to prefer this

Choose this endpoint when you need structured, entity-level factual knowledge data rather than raw web search results. It is ideal when an agent requires clean, machine-readable knowledge records (similar to a knowledge graph or encyclopedia) rather than scraped web pages. Prefer it over the sibling live web search endpoint when you want normalized, structured facts rather than ranked URLs or snippets. Best for enrichment, reasoning, and fact-checking tasks where structured output is more useful than prose.

## Known failure modes

- Query too short (< 2 chars) or too long (> 300 chars) returns validation error
- Limit exceeds maximum of 25 returns parameter error
- Invalid or expired cursor returns pagination error
- Payment failure via x402 prevents request from being fulfilled
- No matching knowledge records returns empty results array
- Unsupported language code may return fallback or empty results

## How this service works

Structured knowledge data for agents, paid per request with x402 v2

## Output

An array of structured knowledge records matching the query, each containing factual entity-level data (names, descriptions, attributes, relationships). Results are paginated using an opaque cursor for continuation, returned in the specified language (default English), with up to 25 records per call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer",
   "default": 10,
   "maximum": 25,
   "minimum": 1
  },
  "query": {
   "type": "string",
   "maxLength": 300,
   "minLength": 2
  },
  "cursor": {
   "type": "string",
   "maxLength": 128,
   "minLength": 1,
   "description": "Opaque continuation cursor returned by the previous response."
  },
  "language": {
   "type": "string",
   "default": "en"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/srch-best-knowledge-search-4db734d9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.srch.best](https://www.zero.xyz/host/x402.srch.best/llms.txt)