Introduction
What shellz records, how it protects the recordings, and where to start.
shellz records every terminal session on your Linux servers and in your containers, whether a person or an AI agent is typing. Recordings are encrypted on the server before they leave it, stream to the dashboard about a second behind, and are decrypted only in your browser.
What gets recorded
| Session | Recorded as |
|---|---|
| Interactive SSH logins | ssh |
Remote commands (ssh host cmd) | command |
| SFTP transfers | sftp |
Physical, serial and hypervisor consoles (tty1, ttyS0, hvc0, /dev/console) | console |
Other local logins, su -, desktop terminals | local |
docker exec, docker attach, docker run -it, docker compose exec on a Docker host | container |
kubectl exec, ECS Exec and dev-container terminals, with shellz in the image | container, or command for one-off commands without a terminal |
Each session is kept twice: as a full terminal replay and as a clean text transcript. Input typed at hidden prompts, such as sudo and passwd passwords or read -s, is never recorded. tmux and screen started inside a recorded session are captured by that session's recording.
shellz records agents that log in or start a shell: SSH, remote commands, SFTP, su -, docker exec and kubectl exec. A process running as a service on the host that never starts a login session isn't a session, so it isn't recorded.
How it's protected
- Every session gets its own AES-256-GCM key, which is wrapped to your org's X25519 key on the server. shellz stores ciphertext only.
- Every piece of a recording is signed by the server's own Ed25519 key and chained to the previous one, so missing or edited pieces show up as a gap or as tampering.
- Uploaded recordings are stored write-once with a 365-day retention lock.
- The recorder can't be stopped through systemd and restarts if it's killed. Changes made with root access are reverted and reported, and a server that goes silent raises an alert.
- With Perfect Secrecy turned on, the keys that open recordings exist only in your team's browsers, unlocked by their passkeys. shellz can't decrypt your recordings.
Where to start
- Getting started: sign up and record your first session in about two minutes.
- How it works: the path a keystroke takes from your server to your screen.
- Choose an install method: Linux servers, Docker hosts, Kubernetes, ECS, Cloud Run and dev containers.
- Security overview: the threat model, the encryption and what shellz can and can't see.
Docs for AI agents
These docs are available as plain Markdown and through an MCP server, so coding agents can read them directly. See Use the docs with AI.