AI answer from web pages with verified quotes API

AI question answering over 1 to 3 web page, PDF or DOCX URLs: grounded, cited RAG answers for research or fact checks. Pages are fetched with SSRF checks and read as Markdown (about the first 8k tokens each). Returns an answer of at most 150 words, claims with source URL and verbatim quote (checked in code against the page; unverified claims dropped) and confidence. 404, not charged, when the pages do not support an answer. AI-generated by Anthropic Claude.

$0.01 per call  USDC over x402 v2 on Base, Polygon, Arbitrum, Avalanche or Sei. No signup, no API key. Requests that fail or match nothing are not charged.

Endpoint

GET https://api.kit-rx.com/v1/web/answer

Parameters

Example request

https://api.kit-rx.com/v1/web/answer?q=What+did+the+Declaration+of+Independence+declare+about+the+colonies+and+Great+Britain%3F&urls=https%3A%2F%2Fwww.archives.gov%2Ffounding-docs%2Fdeclaration-transcript

Without payment the server answers 402 Payment Required with the price (10000 atomic USDC) in the PAYMENT-REQUIRED header. Any x402 v2 client pays and retries automatically. A request with no parameters runs this example.

curl -i "https://api.kit-rx.com/v1/web/answer?q=What+did+the+Declaration+of+Independence+declare+about+the+colonies+and+Great+Britain%3F&urls=https%3A%2F%2Fwww.archives.gov%2Ffounding-docs%2Fdeclaration-transcript"

Pay from an agent

AgentCash: fetch the URL. OpenDexter MCP: x402_fetch. Kit Rx MCP server: https://api.kit-rx.com/mcp. Code:

import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.BUYER_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
const res = await pay("https://api.kit-rx.com/v1/web/answer?q=What+did+the+Declaration+of+Independence+declare+about+the+colonies+and+Great+Britain%3F&urls=https%3A%2F%2Fwww.archives.gov%2Ffounding-docs%2Fdeclaration-transcript");
console.log(await res.json());

Example response

{
  "query": {
    "q": "What did the Declaration of Independence declare about the colonies and Great Britain?",
    "urls": [
      "https://www.archives.gov/founding-docs/declaration-transcript"
    ]
  },
  "result": {
    "question": "What did the Declaration of Independence declare about the colonies and Great Britain?",
    "answer": "The Declaration declared that the United Colonies are, and of Right ought to be, Free and Independent States, that they are absolved from all allegiance to the British Crown, and that all political connection between them and the State of Great Britain is and ought to be totally dissolved.",
    "confidence": "high",
    "claims": [
      {
        "text": "The Declaration declares that the United Colonies are, and of Right ought to be, Free and Independent States.",
        "url": "https://www.archives.gov/founding-docs/declaration-transcript",
        "quote": "solemnly publish and declare, That these United Colonies are, and of Right ought to be Free and Independent States"
      },
      {
        "text": "The Declaration states that the Colonies are absolved from all allegiance to the British Crown.",
        "url": "https://www.archives.gov/founding-docs/declaration-transcript",
        "quote": "that they are Absolved from all Allegiance to the British Crown"
      },
      {
        "text": "The Declaration states that all political connection between the Colonies and the State of Great Britain is and ought to be totally dissolved.",
        "url": "https://www.archives.gov/founding-docs/declaration-transcript",
        "quote": "that all political connection between them and the State of Great Britain, is and ought to be totally dissolved"
      }
    ],
    "claims_dropped": 0,
    "citations": [
      {
        "url": "https://www.archives.gov/founding-docs/declaration-transcript",
        "title": "Declaration of Independence: A Transcription | National Archives"
      }
    ],
    "pages": [
      {
        "url": "https://www.archives.gov/founding-docs/declaration-transcript",
        "final_url": "https://www.archives.gov/founding-docs/declaration-transcript",
        "title": "Declaration of Independence: A Transcription | National Archives",
        "format": "html",
        "chars": 9985,
        "truncated": false
      }
    ],
    "pages_failed": [],
    "model_family": "Claude",
    "ai_generated": true
  },
  "sources": [
    {
      "name": "Cloudflare DNS over HTTPS (JSON API)",
      "url": "https://developers.cloudflare.com/1.1.1.1/encryption/dns-over-https/make-api-requests/dns-json/"
    },
    {
      "name": "Cloudflare Workers AI toMarkdown",
      "url": "https://developers.cloudflare.com/workers-ai/features/markdown-conversion/"
    },
    {
      "name": "Anthropic Claude (AI-generated text)",
      "url": "https://www.anthropic.com/claude"
    },
    {
      "name": "Live HTTP(S) fetch of the URL",
      "url": "https://www.archives.gov/founding-docs/declaration-transcript"
    }
  ],
  "notes": [
    "AI-generated answer by Anthropic Claude under a fixed Kit Rx prompt, using only the fetched pages; it can misstate or omit details, so check important facts against the quoted sources.",
    "Each claim's quote was checked in code against the text of the page it cites (ignoring letter case, whitespace, typographic quote and dash styles, and Markdown formatting); claims whose quotes were not found were dropped. The answer text itself is not verified.",
    "Pages fetched live by the Kit Rx fetcher (User-Agent KitRx/1.0), main content converted with Cloudflare Workers AI toMarkdown; content belongs to its publishers."
  ],
  "attribution": [
    "DNS resolved via Cloudflare 1.1.1.1 DNS-over-HTTPS."
  ],
  "generated_at": "2026-11-15T05:52:42.941Z"
}

Kit Rx: Pay-per-call data and safety tools for AI agents, paid in USDC over x402. No signup, no API key. Machine-readable: OpenAPI, llms.txt, /.well-known/x402, agent skills.