Exa neural web search
POST /api/exa-searchNeural (embedding-based) web search over Exa's curated index, which finds pages by meaning rather than keyword overlap. Send POST /api/exa-search with the required field query and pay $0.012 per call over x402 or MPP (there is no free tier). It returns a JSON object with source, fetchedAt, query, searchType, count and 1 more.
Use it when a keyword engine returns the wrong thing: conceptual questions, 'pages like this one', or niche technical writing. Returns up to 10 results with title, URL, published date and author. Complements the Brave-backed web search rather than replacing it.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
query | string | yes | What to search for, in natural language (max 1000 chars). Also accepted as q, search, term, keyword, question. |
numResults | number | no | Results to return, 1 to 10 (default 10). |
type | string | no | auto (default), neural, keyword, fast, or instant (lowest latency, some depth traded for speed). |
category | string | no | Optional Exa category filter: company, publication, news, personal site, financial report, people ("research paper" is accepted as an alias of "publication"; Exa retired pdf, github and tweet on 2026-07-23 and they are refused with this list). |
includeDomains | array | no | Only return results from these domains. |
excludeDomains | array | no | Never return results from these domains. |
startPublishedDate | string | no | ISO date; only pages published on or after it. |
endPublishedDate | string | no | ISO date; only pages published on or before it. |
Example request
curl -i -X POST https://agent402.tools/api/exa-search \
-H "Content-Type: application/json" \
-d '{"query":"how agent-to-agent micropayment protocols settle onchain","numResults":5}'
Without payment this returns HTTP 402 Payment Required with the exact price for exa-search; any x402 v2 or MPP client pays it and retries.
Example response
{
"source": "exa",
"fetchedAt": "2026-09-13T20:00:00.000Z",
"query": "how agent-to-agent micropayment protocols settle onchain",
"searchType": "neural",
"count": 1,
"results": [
{
"title": "What is the x402 payment protocol?",
"url": "https://example.com/x402-explained",
"publishedDate": "2026-08-02T00:00:00.000Z",
"author": null,
"text": null
}
]
}
| Field | Type | Always present | In the example |
|---|---|---|---|
source | string | yes | exa |
fetchedAt | string | yes | 2026-09-13T20:00:00.000Z |
query | string | yes | how agent-to-agent micropayment protocols settle onchain |
searchType | string | yes | neural |
count | number | yes | 1 |
results | array of objects | yes | 1 item in the example |
From an MCP client
catalog.call {
"slug": "exa-search",
"params": {
"query": "how agent-to-agent micropayment protocols settle onchain",
"numResults": 5
}
}
The hosted connector at https://agent402.tools/mcp needs a payment for exa-search; the stdio package pays it from a wallet or from AGENT402_CREDITS_KEY. Local install: npx -y agent402-mcp.
Errors and behavior
queryis required. An input the tool rejects returns an HTTP 4xx whose body carrieserror,tool,expected,requiredandexample, so the caller can correct it.- A paid call that ends in any status of 400 or above is not charged over x402, MPP or a prepaid credits key: settlement is cancelled when the tool fails. The exception is a Tempo push credential, a transfer the buyer sent before the call: it settles before the tool runs, so if the tool then fails the payment is recorded as a refund owed to the paying wallet.
- Wallet-only: this tool reaches the network or stored state, so it has no proof-of-work tier. A prepaid card-credits key issued earlier (
Authorization: Bearer a402_...) also pays it. - A
GETorHEADto /api/exa-search returns the same 402 quote, so the price can be read without a body. - An
Idempotency-Keyheader makes a retried paid call replay the first 200 instead of charging again (an answer larger than 1 MB is not replayed).
Paid call (JavaScript agent)
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
const client = new x402Client();
client.setSpendControls?.(false); // keep your own spending ceiling in code
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);
const res = await payFetch("https://agent402.tools/api/exa-search", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({
"query": "how agent-to-agent micropayment protocols settle onchain",
"numResults": 5
}),
});
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