# Web Search Autocomplete API

> Web Search Autocomplete API is a paid API for AI agents from x402.openwebninja.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Returns real-time search query suggestions with Knowledge Graph entity enrichment for a given partial query string

## Facts

- Endpoint: GET https://x402.openwebninja.com/web-search-autocomplete/autocomplete
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/web-search-autocomplete-api-919cf73a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0lVaIKqF-Kg6dpkvQU-wa

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 web-search-autocomplete-api-919cf73a
```

Example prompt: Can you fetch autocomplete suggestions for the query 'eiffel' in the US region in English for a desktop user, including any Knowledge Graph entity titles and images?

## When to prefer this

Use this endpoint when you need real-time search query autocomplete suggestions with Knowledge Graph entity enrichment (images, titles, subtitles) for a given partial text input, particularly when building search UIs or agent search flows that need instant, per-keystroke query predictions with rich entity metadata. Prefer this over generic text completion or NLP APIs when the goal is specifically web-search-style typeahead behavior.

## Known failure modes

- Missing required 'query' parameter returns an error
- Invalid 'user_agent' enum value (not 'desktop' or 'mobile') causes rejection
- Unsupported region or language codes may return empty suggestions
- Payment not provided or insufficient USDC balance results in 402 Payment Required
- Rate limiting or quota exceeded may return 429 or error response
- Network timeout if upstream search provider is slow

## How this service works

40+ public web-data, SERP, e-commerce, real-estate, finance and AI-search APIs, payable per call over x402 (USDC on Base, Polygon, Arbitrum). No account or API key required. Most endpoints $0.003; AI-model endpoints $0.005.

## Output

An array of autocomplete suggestion objects, each containing the suggested query string, character highlight ranges (offset and length) for bolding matched text, and optional Knowledge Graph fields: entity title, subtitle, primary image URL, and additional image URLs. Also includes a status field.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "required": {
   "type": "string"
  },
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/web-search-autocomplete-api-919cf73a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.openwebninja.com](https://www.zero.xyz/host/x402.openwebninja.com/llms.txt)