# serp402 Search Index

> serp402 Search Index is a paid API for AI agents from serp402.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-31).

Returns structured JSON search results for web, place, product, video, and publication queries without requiring a browser or API key, billed per call in USDC.

## Facts

- Endpoint: POST https://serp402.com/api/v1/search-index?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/serp402-search-index-e1aa4056
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MksgnrAomtZar6hU73pZe

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 serp402-search-index-e1aa4056 -d '<json body>'
```

Example prompt: Search for 'best electric vehicles 2024' and return the top 10 structured web results in English for the US market — I need clean JSON I can feed directly into my AI pipeline.

## When to prefer this

Choose this endpoint when you need structured, machine-readable JSON search results without setting up an account, API key, or subscription — ideal for AI grounding, search automation, and benchmarking workflows. It supports diverse result types (web, place, product, video, publication) in a single API, making it versatile for multi-domain pipelines. Pay-per-call USDC pricing suits low-volume or experimental use cases where committing to a subscription is undesirable.

## Known failure modes

- Invalid or missing query parameter returns an error
- Unsupported 'type' value causes a failed or empty response
- Location anchor 'll' missing when type=place is requested
- Payment not processed in USDC results in 402 rejection
- Invalid country or language code returns default or empty results
- Publication year range parameters ignored when type is not 'publication'
- Rate or quota limits on the underlying search index cause empty or partial results

## How this service works

Search Index: Fast, structured JSON for AI grounding, benchmarking, and search automation. No browser needed. Currently in preview. Structured JSON, USD 0.05 per call in USDC — no API key, no account, no subscription, no minimum. Not affiliated with, endorsed by or an official channel of any of the services the results come from. All trademarks and copyright remain the property of their respective owners.

## Output

A structured JSON object containing ranked search results matching the query, with result type varying by the 'type' parameter (web, place, product, video, or publication). Each result typically includes title, URL, snippet, and type-specific metadata such as ratings, prices, coordinates, or thumbnails. Pagination is supported via the 'start' offset parameter.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "q": {
   "type": "string"
  },
  "gl": {
   "type": "string",
   "description": "country as a two-letter country code (e.g., us for the United States, de for Germany). Web results are ranked with a preference for the country. Product…"
  },
  "hl": {
   "type": "string",
   "description": "language as a two or three-letter language code, optionally followed by a region code (e.g., en , fr , en-GB ). Web results are ranked with a preference for…"
  },
  "ll": {
   "type": "string",
   "description": "anchor point for place results. It accepts @lat,lng , @lat,lng,14z , @lat,lng,250m , or lat,lng , and is only supported with type=place ."
  },
  "num": {
   "type": "string",
   "description": "number of results to return. (default: 10 )."
  },
  "mode": {
   "type": "string",
   "description": "search mode. Set to deep for expanded recall via parallel sub-query fan-out. Returns more diverse results by decomposing the query into multiple aspects."
  },
  "safe": {
   "type": "string",
   "description": "level of filtering for adult content. It can be set to active (default) or off ."
  },
  "type": {
   "type": "string",
   "description": "result type. It can be set to web (default) to return organic results; typed results may also appear when typed mixing is enabled. Use place , product , video…"
  },
  "start": {
   "type": "string",
   "description": "result offset for pagination. (e.g., 0 (default) is the first page, 10 is the second page, etc.)."
  },
  "as_yhi": {
   "type": "string",
   "description": "inclusive upper publication year. It must be a 4-digit year and is only supported with type=publication ."
  },
  "as_ylo": {
   "type": "string",
   "description": "inclusive lower publication year. It must be a 4-digit year and is only supported with type=publication ."
  },
  "radius": {
   "type": "string",
   "description": "place search radius in kilometers. It must be greater than 0 and less than or equal to 20000 , and requires ll ."
  },
  "product_source": {
   "type": "string",
   "description": "Parameter restricts product results to one source. It is only supported with type=product ."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/serp402-search-index-e1aa4056/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from serp402.com](https://www.zero.xyz/host/serp402.com/llms.txt)