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cURL Converter, JSON/YAML & Offline JWT Debugger

Transform cURL commands into idiomatic code across Go, TypeScript, and Python. Format, minify, and convert JSON/YAML/Base64, and safely inspect JWT claims in 100% offline client mode.

Module A100% Client-Side • Zero Data Transmission

API & Payload Inspector

Method & URL:POST https://api.netfox.space/v1/telemetry
Headers detected:2
Payload length:86 chars
interface ApiResponse<T = unknown> {
  data?: T;
  status: number;
}

async function executeRequest(): Promise<void> {
  const url = 'https://api.netfox.space/v1/telemetry';
  
  try {
    const response = await fetch(url, {
  method: 'POST',
  headers: {
      "Authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
      "Content-Type": "application/json"
  },
  body: JSON.stringify({"event":"user_signup","user_id":"usr_99482","meta":{"plan":"pro","source":"organic"}})
    });

    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }

    const contentType = response.headers.get('content-type');
    const data = contentType?.includes('application/json') 
      ? await response.json() 
      : await response.text();

    console.log('Response status:', response.status);
    console.log('Response data:', data);
  } catch (error) {
    console.error('Request failed:', error);
  }
}

executeRequest();
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How cURL Parsing and Multi-Language Request Generation Works

cURL (Client for URLs) is the ubiquitous command-line tool for executing HTTP requests. However, translating a raw command-line invocation into idiomatic application code requires understanding POSIX argument tokenization, HTTP verb overrides (-X POST), multipart boundary handling, and header normalizations.

Netfox splits cURL command strings by identifying quote-bounded parameters, extracting target endpoints, request headers (-H "Authorization: Bearer ..."), and payload encodings. When targeting Go's net/http or Fiber/v2, the engine generates memory-efficient io.Reader payloads. For TypeScript, it constructs clean fetch() and axios instances with proper headers and JSON stringification.

Understanding RFC 7519: The Anatomy of a JWT

A JSON Web Token (JWT) is composed of three URL-safe Base64 strings concatenated with periods (Header.Payload.Signature):

  • Header: Declares the token type (JWT) and the cryptographic signing algorithm (e.g., HS256 or RS256).
  • Payload (Claims): Contains registered claims such as iss (issuer), sub (subject), exp (expiration time), and custom user roles.
  • Signature: Ensures the integrity of the token by hashing the encoded header and payload with a shared secret key or private key.

Security Pitfalls: Why Remote JWT Debuggers are Dangerous

Standard online token decoders transmit your authorization headers over third-party networks. If a developer pastes a production JWT containing active user scopes, database IDs, or admin session credentials into a server-backed website, those credentials risk being persisted in server access logs or proxy caches.

Netfox eliminates this vulnerability entirely by decoding tokens in your browser's local sandbox memory using native TextDecoder and crypto.subtle primitives without transmitting a single byte across the internet.

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Payload Inspector & Converter FAQ

Frequently asked questions on cURL syntax parsing, JWT token validation, and offline security.

How do I convert a cURL command to Go, TypeScript, or Python code?▼

Paste your raw cURL command or raw HTTP request string into the input editor. The parser automatically extracts the HTTP method (-X), target URL, headers (-H), basic authentication (-u), and request body (--data / --json). You can then toggle between Go (net/http & Fiber), TypeScript (Fetch & Axios), and Python (requests & httpx) to copy clean, production-ready code.

Is my JWT token or Authorization header sent to any server when using the JWT debugger?▼

No. The JWT debugger is completely offline and client-side. The JSON Web Token is split by dots into its Header, Payload, and Signature components and decoded locally using browser TextDecoder and Base64URL decoders. No network requests are initiated.

How does the offline signature verification work for HS256 tokens?▼

When you provide a secret key, the tool uses the Web Cryptography API (crypto.subtle) to calculate the HMAC-SHA256 digest of 'encodedHeader.encodedPayload' using your browser's local crypto engine. It then compares the resulting base64url hash against the signature token.

Does the JSON <-> YAML converter preserve nested data structures and data types?▼

Yes. The converter parses strings, booleans, floating-point numbers, integers, arrays, and nested maps with strict RFC syntax validation. You can also format with 2-space or 4-space indentation or minify for compact network payloads.