Phosphor MCP server

Phosphor

A macOS terminal that also runs your servers.

Shell, Docker, metrics, keys and files — over one SSH connection per host. Unlocked with your fingerprint. Green on black, because that is how it should look.

SSH client · Docker manager · server monitor · SFTP · authorizedkeys editor · MCP server for Claude Code and Claude Desktop · macOS 26 · Swift 6 · MIT*

The problem

You keep four windows open to do one job. A terminal for the shell. A second terminal for docker logs -f. A third for htop. A browser tab for whatever dashboard someone installed on the box. Each of them logs in separately, each one asks for the key passphrase again, and none of them knows what the others are looking at.

Phosphor opens one SSH connection per host and multiplexes everything through it — the interactive shell, container logs, docker commands, /proc snapshots, SFTP transfers, port forwards. One login. One tunnel through your proxy. One place where the state lives.

And because that state is already in the app, it also exposes an MCP server: Claude Code and Claude Desktop can use your servers through your connections, your keys and your access policy — with every call written to an audit log.

What it does

Docker, without leaving the terminal

The container list is a sidebar, not a separate app. Inspect, stats, mounts, environment and live logs with --tail and a filter, streamed over the SSH connection you already have. Environment values whose name looks like a secret (PASS, KEY, TOKEN, SECRET) are masked in the UI and never copied into the audit log.

No Docker Engine API to expose, no socket to tunnel: it shells out to docker with JSON output, which works on every box where Docker already runs.

Metrics that cost one channel

Per-core load, memory with the cache broken out, disks, network, and per container CPU and memory — from /proc snapshots taken over a single long-lived channel. No agent to install on the server, no swarm of exec channels. Polling stops when the window is hidden, and every buffer has a ceiling.

Hosts, groups and tags

One group per host, as many tags as you like. The group carries the settings — how to reach it, which key, which theme, what MCP is allowed to do — and tags are just for finding things. Import ~/.ssh/config and keep going.

Unlock with a fingerprint

Phosphor has no account and no password of its own. There is a profile on this Mac, and your fingerprint opens it. Passwords, passphrases and TOTP seeds live in the Keychain behind biometrics; keys can live in the Secure Enclave, where they cannot be copied off the machine at all. Risky actions ask again.

A new server, set up by a recipe

Connect to a fresh box and Phosphor probes it: what is installed, what is listening, whether anyone has been here before. If it is empty, it offers a recipe — packages and unattended upgrades, Docker with log size caps, nginx, certbot, a firewall that only opens 22/80/443, and finally disabling password login. Every step is idempotent, every step shows the exact commands, and the lockout guard means password login is closed only after a second key-based connection has proved it works.

Keys you can actually see

authorized_keys as a table instead of a text file: fingerprints computed locally, weak RSA flagged, options shown, disabled entries kept as comments. The key you are currently connected with cannot be removed without an explicit confirmation, writes are atomic, and a backup stays on the server.

Files on both sides

Shortened. The full README is on GitHub.