JWT & Base64 Decoder/Verifier vs Sandbox Relay

JWT Decoder, Encoder & Verifier is the JSON Web Token companion your phone has been missing. Paste a token and instantly see its header, payload, and claims decoded - then verify its signature, sign your own, or convert Base64 back and forth. Everything runs on the device. No accounts, no network calls, nothing stored. 100% OFFLINE, NOTHING LEAVES YOUR DEVICE Tokens often carry sensitive data, so this app never uploads them. All parsing, verification, signing, and Base64 work happens locally. There is no server, no logging, and no analytics on the content you paste. It is the safe way to inspect a production token on your phone. DECODE - Live decoding as you type or paste - no "decode" button needed - Pretty-printed JSON for both the header and the payload - Time claims (iat, nbf, exp) shown as readable UTC, with EXPIRED and "not yet valid" badges - Raw Base64URL signature segment displayed separately - Clear, specific errors for malformed tokens VERIFY SIGNATURES - HMAC: HS256, HS384, HS512 with a shared secret (raw or Base64 key) - RSA: RS256, RS384, RS512 (RSASSA-PKCS1-v1.5) with a PEM public key - RSA-PSS: PS256, PS384, PS512 with a PEM public key - ECDSA: ES256, ES384, ES512 with a PEM public key - The input automatically switches between secret and PEM based on the token's algorithm, and the result clearly states valid, invalid, or why it could not be checked SIGN AND GENERATE - Build and HMAC-sign a JWT from any JSON payload (HS256/384/512) - One-tap "Generate key pair" creates a throwaway RSA or EC key for testing, fills the private key, and shows the public key to copy straight into the Verify tab - a complete sign-then-verify loop, entirely on device BASE64 TOOLBOX - Encode and decode standard Base64 and URL-safe Base64URL - Optional padding control - Falls back to a hex view when decoded bytes are not valid UTF-8 text BUILT FOR ENGINEERS - Paste straight from the system clipboard with one tap - Load a built-in example to see how each tool works - Copy any result to the clipboard - Monospace, selectable output throughout POLISHED TO MATCH YOUR PHONE - Native Material Design 3 interface - Light and dark themes that follow the system setting - Localized in English, Traditional Chinese, Simplified Chinese, and Japanese WHO IT IS FOR - Backend and mobile developers debugging auth tokens - Security engineers inspecting and verifying JWTs - QA and support teams checking expiry and claims - Anyone who needs to decode a token without pasting it into a website A note on standards: this tool reads and verifies tokens; it is an inspection and testing utility, not a secrets manager. Keys you paste or generate stay on the device and are never transmitted. JWT Decoder, Encoder & Verifier is fast, private, and made for real debugging. Install it once and stop pasting tokens into random web decoders.

For developers who run Claude Code or Codex in Docker Sandbox, Sandbox Relay is the phone client for driving that agent. It is a companion, not a standalone app: it needs a broker you run, with an agent connected behind it. Kick off a task from the train, check on a long-running job from the couch, or steer the agent while you are away from your desk. Docker Sandbox runs each agent in its own isolated micro VM. A small broker you self-host sits in the middle: you send work from your phone, the broker passes it to the agent, and the streamed reply comes back. Your infrastructure, your agent. The app is just the remote. New to this setup? The app's support page explains how it works and what you need to run it. WHAT YOU CAN DO - Connect to your broker with a URL and a bearer token. Connections use HTTPS, with plain HTTP allowed only for local-network addresses. - See every connected agent at a glance, with live online/offline status. - Send the agent work and watch its reply stream in token by token. Stop a turn mid-stream, or start a fresh thread whenever you want. - When an agent goes offline, its thread stays readable as history. - See per-turn input and output token counts when the broker reports them. - Save reusable prompts as local notes, organised by hierarchical tags like #work/project/feature. Drill down by tag, copy a note straight into a thread, or link a note to the thread it came from. Notes live on your device only; they never touch the broker. WHAT YOU NEED - A broker you run, reachable from your phone (over your local network, or remotely through a tunnel or private network you control). - A coding agent, Claude Code or Codex, running in Docker Sandbox and connected to that broker. PRIVACY Sandbox Relay talks only to the broker you configure. Your access token is stored securely on your device and sent only to that broker, to authenticate you; it never goes to the developer or any third party. Your notes stay on your device and are never sent anywhere. No third-party analytics, no account to create. Note that the app streams whatever your agent outputs, verbatim.