Anatomy of a perfect file rule: simulate, apply, undo

There’s a quiet reason so many people give up on automating their own files: fear. Fear that the rule will overreach, move the wrong file into the wrong folder, and turn a small mess into a huge, irreversible one. It’s a legitimate fear — bad automation has wiped photo collections and scrambled years of documents. But that fear has a cure, and it isn’t “just be brave.” It’s a trust cycle: every rule is born harmless, you see exactly what it would do before you let it act, and if something comes out crooked, one click puts everything back. This post dissects the anatomy of a perfect file rule — the five moments that turn “will this work?” into “I’ve already seen that it does.”

Why most automation is scary#

Traditional file automation works in the dark. You write the rule, hit a button, and pray. If you got it right, great. If you got it wrong, the damage is already done — the files have moved, and reconstructing by hand where each one came from is a nightmare. Older tools never had two obvious pieces: a preview before and an undo after. Without them, every rule is a gamble.

The trust cycle flips that logic. It starts from the idea that you shouldn’t have to trust anything blindly. You should be able to check. And the only thing that separates an experimental rule from a rule on autopilot is how much trust it has already earned — never a blind leap.

The five moments of a perfect rule#

1. Build it in the wizard — without a line of code

Every rule starts in the Automation manager, at the “+ New rule” button. The wizard has five steps, and none of them asks you to program anything:

1. Rule name — give it something you’ll recognize later, like Invoices to the right folder.
2. Monitored folders — click “+ Add folder” and point at where the mess is born (usually Downloads). The “Include subfolders” option is your call.
3. When to run — the trigger. Always start on “Only when I say (manual)”; more on that shortly.
4. Which files (conditions) — under “Match All (AND) of these conditions” you stack filters. You can combine Extension is, Name contains, Older than (days), Downloaded from site (domain), and even Content contains (PDF, DOCX, TXT), which reads the text inside the file, scanned PDFs included — with built-in OCR, 100% on your PC.
5. What to do (actions) — what happens to whatever matched. Add, for example, Move to, and in the “Destination or pattern” box, type Documents/Invoices/{year}/{month-name}. The placeholders become real values on the spot: a file from March of {year} lands in Documents/Invoices/{year}/March.

Notice: up to here, nothing has happened. You sketched an intention. Not a single file moved. That’s the first relief — building isn’t applying.

2. Simulate effect — the dress rehearsal, no risk

Before you save, click “Simulate effect”. This is the heart of the trust

cycle. The app runs the full rehearsal: it scans the folders, applies the conditions, computes every destination, resolves name conflicts, and builds **the exact list** of what would happen — line by line, file, action, and final destination. At the top of the scene sits the notice *"Preview — nothing is actually changed"*. And it's literal: not one byte is written to disk.

This is where mistakes surface while they’re still cheap. Typed the wrong destination? You see it. The condition grabbed too many files? You count them on screen — the counter tells you how many files match right now. The simulation also shows what it will preserve: protected files appear as “Protected (preserved)”, and nothing belonging to the system is touched. You read the list calmly, fix whatever needs fixing, and simulate again. As many times as you like. It costs nothing.

3. Save the rule — store the intention, still no action

Happy with the preview? Click “Save rule”. That files the rule in your list — but since it was born on the manual trigger, it just sits there, waiting for your say-so. Saving isn’t unleashing the rule on the world; it’s only recording the design you approved.

4. Run now — the first flight, supervised

With the rule saved and still on manual, you run it by clicking “Run now”. Now the actions happen — but you watch them happen: the applying scene shows “Applying for real — you can watch” and, at the end, a summary like “Organized 12 file(s) into 3 folder(s)”, along with an estimate of the minutes of manual tidying you just saved. Because you simulated first, there are no surprises: what’s happening is exactly what the preview showed.

Once the rule has run a few clean times and you trust it, that’s when it’s worth promoting it to real time — “Automatically, when a file arrives (real time)” — so the folder starts tidying itself. That journey from manual to autopilot deserves its own chapter, and we wrote one in from manual to autopilot.

5. Undo — the net under the trapeze

The fifth moment is the one that closes the cycle and kills the fear for good. Every run — manual or automatic — can be undone. When the autopilot acts on its own, a notice “🤖 Autopilot acted” appears with an “Undo” button beside it; one click returns each file to the exact place it came from. In the manager, the Run history keeps every run with its own “Undo” button, and each line tells you how many actions are reversible.

Undo works for move, copy, rename, organize by type, and compress to ZIP. And deletions are never permanent: the “Move to Recycle Bin” action sends the file to the Windows Recycle Bin, where you restore it by hand like any deleted file. At no point is there a real, no-going-back deletion.

The whole cycle, in one line#

Build → Simulate effect → Save rule → Run now → Undo. Five moments, and in four of them you’re in control before anything irreversible happens — because nothing here is irreversible. That chain is what turns automation from a gamble into a calm tool. The idea of rules that watch folders isn’t new (the Mac world has had Hazel for years, as our post on whether there’s a Hazel for Windows explains); what changed was gaining the preview and the undo around it.

An example built from scratch#

Let’s create the example rule, end to end:

1. “+ New rule” → name it Invoices to the right folder.
2. “+ Add folder” → your Downloads.
3. When to run → “Only when I say (manual)”.
4. Conditions, under All (AND): Extension is → pdf; and Content contains (PDF, DOCX, TXT) → invoice. That way only PDFs that truly talk about an invoice get in.
5. Action: Move to → Documents/Invoices/{year}/{month-name}.

Click “Simulate effect”. Check the list: each line carries the file, the action, and the final destination. Matches what you expected? “Save rule”, then “Run now”. If a destination came out wrong, you saw it in the simulation, not in the wreckage — fix it and simulate again. Once you trust it, edit the rule and switch the trigger to real time: Downloads starts tidying itself, and the “Undo” button stays right there, at your side, forever.