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x402 Web Search API
x402
x402 Web Search API is a paid API for AI agents from call402.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).
Performs a live web search query and returns ranked results with titles, URLs, highlights, and publication dates, paid per-call via USDC on Base mainnet.
Price / call$0.01
Success—
StatusUnknown
How this service works
USDC pay-per-call APIs for AI agents via the x402 protocol (v2, exact, Base mainnet). Send a request, receive HTTP 402 with payment requirements, pay with @x402/fetch or any x402 client, retry with the PAYMENT-SIGNATURE header.
Output
A JSON object containing a meta block (source attribution, request ID, result count) and an array of result objects, each with a URL, relevance score, title, array of highlight passages extracted from the page, and a published date.
Example use cases
Real-time crypto ecosystem research
“Search the web for the latest announcements from the Base blockchain ecosystem this week and return the top 5 results with highlights.”
Competitive intelligence gathering
“Find the most recent news articles about OpenAI's new product launches — give me the top 3 results with titles, URLs, and the key passage from each page.”
Fact-checking a recent claim
“Search the web for information about whether the EU passed new AI regulations in 2025 and return up to 8 results so I can verify what's been published.”
Technical details
Endpoint
POSThttps://call402.com/api/web-search?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an AI agent needs live, up-to-date web search results and can pay per-call in USDC via the x402 protocol on Base mainnet. It is ideal for agents that need real-time information retrieval without a monthly subscription, or for workflows that require pay-as-you-go access. The Exa backend provides semantic relevance scoring and highlight extraction, making it preferable over raw search APIs when context snippets and publication dates matter.
Side effects
- Payment not included — returns HTTP 402 with payment requirements; agent must pay via x402 client and retry with PAYMENT-SIGNATURE header
- Query string missing — returns 400 bad request
- num_results out of range (must be 1-10) — returns 400 validation error
- No results found for obscure or malformed query — returns empty results array
- Upstream Exa provider timeout or outage — returns 502 or 503 error
- Insufficient USDC balance for payment — transaction fails before request is processed
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| query | string | Natural-language search query |
| num_results | integer | Results to return, 1-10 (default 5) |
Output
Schema · Response
{
"type": "json",
"example": {
"meta": {
"source": "exa",
"request_id": null,
"results_count": 1
},
"query": "latest Base ecosystem news",
"results": [
{
"url": "https://example.com",
"score": 0.9,
"title": "Example result",
"highlights": [
"Key passage from the page."
],
"published_date": "2026-10-01"
}
]
}
}Tags
x402
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