JSON query

Extract a value from JSON by dot/bracket path, e.g. "items[2].name".

Input

Field	Type	Description
json *	any	JSON value (or a JSON string of one)
path *	string	Path like "a.b[0].c"

Example output

{
  "found": true,
  "value": "b"
}

Try it — see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/json-query \
  -H "Content-Type: application/json" \
  -d '{"json":{"items":[{"name":"a"},{"name":"b"}]},"path":"items[1].name"}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

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();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/json-query", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "json": {
      "items": [
        {
          "name": "a"
        },
        {
          "name": "b"
        }
      ]
    },
    "path": "items[1].name"
  }),
});

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