ai agents shouldshow their work.

local models, sized to your mac

Open models through Ollama on your own hardware. /models reads your chip, its memory, and its bandwidth, then recommends the largest model that fits and still runs at a usable speed. No API key anywhere in the product.

your mac, through its own apps

Notes, Calendar, Mail, Contacts, Reminders, Messages, and Shortcuts, plus the page in your browser and the files selected in Finder. Everything goes through the app itself, so what Saturn does shows up where you'd look. Mail is drafted, never sent, and /tools off turns off any app you don't want it near.

pause, steer & think

One loop, every pass on screen. Press Esc to pause a running turn: continue, type a correction to steer it, or abort. On a multi-step errand the agent keeps a checklist you can watch in the rail. Saturn thinks before it calls a tool and never before a plain answer; the status bar times each thought, Esc stops it, and /think sets fast, auto, or deep.

tool approval gates

Every write, command, and send stops with the real diff, the full command, or the recipient and exact text on screen. Enter rejects. A text message asks every time, and a number the model made up is refused before you're asked.

answers you can check

An answer that used tools ends with the exact calls and documents behind it, and /trace source shows the full material. Failed and declined calls are listed under the answer. Arithmetic and dates are computed, never guessed.

egress ledger & air gap

Every byte that leaves is recorded by host and channel and printed under the answer; /policy airgap seals the boundary. Web pages, mail, and files are quarantined against prompt injection, and a web address the model composed after reading outside content waits for your OK.

files & documents

Saturn works in the folder you launch it from and reads PDF, Word, and Excel. Every write is snapshotted for /undo, and a delete goes to the Trash. Ask it to add a file to your local knowledge base and it asks first, every time. SATURN.md holds your standing instructions.

memory that only takes your word

Say "I'm vegetarian" and Saturn keeps it without a prompt, with one line after the answer and the command that undoes it. That happens only when the fact's words come from a sentence you typed and nothing from a web page, mail, or file has entered the conversation; anything else asks first. The first launch offers three quick questions so it knows who you are from the start. Secrets are refused, and a fact that may contradict an older one says so.

skills

Write a procedure once as a markdown file and run it by typing its name. Saturn can draft one for you, and it shows you every line before it saves. That prompt appears whatever your policy says.

mcp servers

Connect any Model Context Protocol server from config.yaml. Its tools face the same gate as everything else and never self-declare their risk tier.

replayable runs

Every run drills down to its model passes, tool I/O, and gate decisions. Export it as JSON and replay it anywhere with saturn --replay — no database needed.

headless & pipes

-p and -q run one turn for scripts and pipes; gated tools deny by default and a send is refused outright; --json for machines; the run auto-exports so the receipt names a command that replays it.