ToolVet
78trust / 100

Dev Jwt Decoder

by AgentTools in Onchain & crypto

x402 APIPassing, checked 2 h ago

Decode a JSON Web Token's header and payload to readable JSON. Pure decoding: signatures are NOT verified and no secret is needed. Accepts standard and URL-safe base64 with or without padding; claims like exp and iat are rendered as dates. Use this when an agent needs to decode header and payload — no verification.

GET https://agentstoolshub.com/api/v1/dev/jwt-decoder

Last 30 days

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Status and outage history · Atom feed

Uptime
94.1%
Response time
179 ms typical, 273 ms slowest 5%
Last check
2 h ago
Next check
any minute now

How to call it

GET https://agentstoolshub.com/api/v1/dev/jwt-decoder

Each call costs $0.003 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

GET https://agentstoolshub.com/api/v1/dev/jwt-decoder?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkphbmUgRG9lIiwiaWF0IjoxNzAwMDAwMDAwfQ.dummy_signature_part

Parameters

ParameterTypeRequiredDescription
tokenstringYesheader.payload.signature

Example response

The provider's example. We can't check it without paying.

Example response, 31 lines
{
  "result": {
    "answer": "{\n  \"sub\": \"1234567890\",\n  \"name\": \"Jane Doe\",\n  \"iat\": 1700000000\n}",
    "answerLabel": "Payload claims",
    "details": [
      {
        "label": "Algorithm",
        "value": "HS256"
      },
      {
        "label": "Type",
        "value": "JWT"
      },
      {
        "label": "Signature",
        "value": "present (20 chars) — NOT verified"
      },
      {
        "label": "Time claim",
        "value": "iat: 2023-11-14T22:13:20.000Z"
      }
    ],
    "steps": [
      "Split token on dots",
      "Base64url-decode header and payload",
      "Parse both as JSON (signature left untouched)"
    ],
    "value": null
  },
  "tool": "jwt-decoder"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.003.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://agentstoolshub.com/api/v1/dev/jwt-decoder?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkphbmUgRG9lIiwiaWF0IjoxNzAwMDAwMDAwfQ.dummy_signature_part'

# 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://agentstoolshub.com/api/v1/dev/jwt-decoder?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkphbmUgRG9lIiwiaWF0IjoxNzAwMDAwMDAwfQ.dummy_signature_part' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// 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 $0.003 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.003" });
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 $0.003 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagentstoolshub.com%2Fapi%2Fv1%2Fdev%2Fjwt-decoder
const res = await pay("https://agentstoolshub.com/api/v1/dev/jwt-decoder?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkphbmUgRG9lIiwiaWF0IjoxNzAwMDAwMDAwfQ.dummy_signature_part");
console.log(res.status, await res.text());
Python: pay and call
# 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 $0.003 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.003"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://agentstoolshub.com/api/v1/dev/jwt-decoder?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkphbmUgRG9lIiwiaWF0IjoxNzAwMDAwMDAwfQ.dummy_signature_part")
    print(res.status_code, res.text)

Security scan

  • No findings. We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

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