SigilTTY vs ShellDiver

SigilTTY is a native AI terminal for iPhone, iPad, and Mac — an SSH client built for the era of coding agents. Attach to the agents already running on your own servers, see which ones are working and which are stuck, get pushed the moment one needs you, and answer out loud. Everything a terminal still has to do — shells, SFTP, tunnels, keys — is here too, synced across your devices through iCloud. To be clear about what this is: SigilTTY does not run the AI, and there is no chatbot inside it. Your machines run the agents, right where your code, your tools and your credentials already are. SigilTTY is the control room you carry. Built on a GPU-accelerated terminal (powered by Ghostty) and the battle-tested libssh2 engine, SigilTTY feels instant and looks sharp on every screen. YOUR AGENTS, WHEREVER YOU ARE • Attach to the AI coding agents that herdr manages on your servers — each one is an ordinary terminal tab with a live status dot • Agents mode gathers every agent on every server into one tree in the sidebar on iPad and Mac; on iPhone your agents get a tab of their own • Be told when an agent is blocked or done, even while SigilTTY is closed. Offline alerts are encrypted end-to-end on your own server; our open-source relay only ever sees ciphertext • Answer by voice in an agent session: bring your own transcription key — Volcengine, iFlytek, or any compatible speech-to-text endpoint. Audio goes only to the endpoint you configured, and the transcript is typed into the prompt for you to read — it never sends itself • Paste or drop files straight into the terminal — they upload over SFTP and the remote path is typed out for the agent to read • Agent features need the open-source herdr 0.8.0 or later on your server STILL A REAL TERMINAL • Native, GPU-accelerated rendering — smooth even under heavy output • Multiple sessions with tabs, plus full menu commands and shortcuts on Mac • Hundreds of Ghostty/iTerm2-compatible color themes, with dedicated CJK font selection • Command snippets you can send with a single tap CONNECT YOUR WAY • SSH with password or private-key authentication • Telnet for legacy devices and equipment • Serial console over USB on Mac • Jump hosts / bastion chains to reach private networks • Quick Connect for ad-hoc user@host sessions FILES & TUNNELS • Full SFTP file browser — upload, download, rename, delete • File preview: code with syntax highlighting, images, PDFs and documents with Quick Look • Transfers run in their own session and never block your terminal • ZMODEM: run sz or rz on the remote side, right in the terminal • Local (-L) and remote (-R) port forwarding • SSH agent forwarding — the app answers the agent protocol itself, with no extra setup SECURITY FIRST • Credentials live in the Keychain, never in plain text • Optional Face ID / Touch ID protection for private keys • Sign in with a hardware security key over USB-C or NFC — FIDO2/WebAuthn, tested with YubiKey. The private key never exists in software • Trust-on-first-use host key verification warns you the moment a server's identity changes • A remote host asking to read or write your clipboard has to ask you first • Key Handoff: hand a private key to another device over your local network, end-to-end encrypted and confirmed with a verification code — the key never leaves your LAN • No ads. No analytics. No tracking. SYNCS EVERYWHERE • Your servers, folders, snippets, keys, known hosts and agent records sync securely with iCloud • Start on your Mac, pick up on your iPhone • Interface in English and Simplified Chinese SigilTTY is free to download. Have feedback or a feature request? Reach us at support@sigiltty.com.

With software, free is usually a question rather than an answer. Here it is arithmetic: no server of ours, no accounts, no analytics — nothing for a subscription to pay for. Sync, startup commands, port forwarding: all of it is in the app. WHERE YOUR KEYS LIVE In your device's keychain. ShellDiver has no account and no sign-in — there is simply nowhere on our side for anything of yours to sit. An Ed25519 key either travels with you through iCloud Keychain, end-to-end encrypted, or stays on this device behind Face ID. A Secure Enclave key is created inside the security chip. It cannot be read out — not even by ShellDiver — never leaves the device, and will ask for Face ID on every sign-in if you want it to. THE VAULT Instead of iCloud you can take syncing into your own hands: an encrypted file in a place you choose. A USB stick, a cloud folder, or your own WebDAV server, so Nextcloud, ownCloud, a Synology, an Apache with mod_dav. It works across different Apple IDs and carries the secrets with it: saved server passwords and private keys. Only your devices encrypt and decrypt. Whoever runs the storage location sees nothing but unreadable files. You add a second device with a QR code, without typing your passphrase there. THE TERMINAL It does not hang up because you looked somewhere else for a minute: the connection belongs to the session, not to the screen. The running build and the half-typed line are still there when you come back. Up to 20 sessions as tabs, terminals and files mixed. Real xterm emulation: colour, UTF-8, resizing that works — htop, vim and colourful logs look the way you expect. Plus search through the scrollback, your choice of monospaced font including Nerd Fonts, and five colour schemes. On iPhone there is a row above the keyboard with esc, ctrl, tab, arrows and a paste key, because a phone has no ⌘V. When the link drops, ShellDiver notices through keepalives and rebuilds it by itself. This is SSH, not Mosh: the new shell starts fresh. SIGNING IN WITHOUT GUESSING ShellDiver asks the server which methods it offers and works through whatever it holds credentials for. That covers publickey followed by keyboard-interactive — 2FA after the key — and equally a server that only offers keyboard-interactive while the host is saved as "password". One-time codes are never pre-filled and never stored. You confirm a host key once, by its fingerprint. Every connection after that checks it, and a key that has changed is refused rather than waved through. THROUGH A JUMP HOST When a server is only open on the inside, you give it a jump host — OpenSSH's ProxyJump. The jump host then forwards nothing but encrypted bytes and cannot read along; both sign-ins are signed on this device. So your key does not have to sit on the machine in between, and a Secure Enclave key works here too. FILES AND TUNNELS The SFTP browser downloads and uploads, whole folders included, renames, and deletes recursively. Local port forwarding brings a database or an admin interface onto this device. It listens on 127.0.0.1 only and cannot be reached from outside; each rule holds its own connection, so a tunnel does not fall with a terminal. WHAT YOU ALREADY HAVE Your ~/.ssh/config is imported, with each IdentityFile matched against the keys you have and any ProxyJump resolved; so is known_hosts, hashed entries as far as they can be matched. Keys come in as Ed25519, RSA or ECDSA — from the OpenSSH container, from PuTTY's .ppk (v2 and v3), and from the PEM family. A passphrase on the file is used once during import and not kept. Snippets are also the buttons above the keyboard — global or bound to one host, with a confirmation step if you want one. One per host runs by itself as soon as the shell is open. The backup is a JSON file you can read — secrets sit inside an encrypted block under a passphrase you choose. Without it nobody gets at them, us included.