Cache Control Explain

{
  "asOf": "2026-10-11T14:26:44.297Z",
  "browserFreshnessSeconds": 0,
  "degraded": false,
  "directives": [
    {
      "directive": "public",
      "meaning": "Any cache may store the response, even if it would normally not be cacheable (for example with Authorization).",
      "value": null
    },
    {
      "directive": "max-age",
      "meaning": "Seconds the response stays fresh (request: the oldest response the client will accept).",
      "value": "3600"
    }
  ],
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "flags": [
    {
      "directive": "no-cache",
      "fix": null,
      "message": "no-cache forces revalidation on every reuse even though max-age is set: the max-age only helps stale-if-error and conditional requests.",
      "severity": "INFO"
    }
  ],
  "highCount": 0,
  "kind": "response",
  "mediumCount": 0,
  "notChecked": [
    "Expires, Pragma, Vary, ETag and Last-Modified headers, which also affect caching",
    "the response status code (only some are cacheable by default) and the request method",
    "…2 more"
  ],
  "reasons": [],
  "sharedCacheFreshnessSeconds": 0,
  "source": "RFC 9111 (HTTP Caching), RFC 5861, RFC 8246, computed locally",
  "storage": "browser and shared caches may store it, per freshness rules",
  "summary": "browser and shared caches may store it, per freshness rules. Browser freshness: 0 s; shared cache freshness: 0 s.",
  "usageChecked": null,
  "verdict": "ALWAYS_REVALIDATE"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://dev-reference.x402tookit.com/cache-control-explain?kind=response&value=public%2C+max-age%3D3600%2C+no-cache'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://dev-reference.x402tookit.com/cache-control-explain?kind=response&value=public%2C+max-age%3D3600%2C+no-cache' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

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

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fdev-reference.x402tookit.com%2Fcache-control-explain
const res = await pay("https://dev-reference.x402tookit.com/cache-control-explain?kind=response&value=public%2C+max-age%3D3600%2C+no-cache");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://dev-reference.x402tookit.com/cache-control-explain?kind=response&value=public%2C+max-age%3D3600%2C+no-cache")
    print(res.status_code, res.text)