The Porthole

1. What it is

Your own desk, on your phone. Read only.

Compass runs on your computer and does all of its work there: it holds your ThetaData subscription, builds your map, and computes every number you look at. The Porthole is a window onto the screen that machine has already drawn. While Compass is open, it sends a picture of the room you are standing in to a small page you can open on a phone. The phone draws that picture and nothing else.

That distinction is the whole design, and it is worth understanding on the first page rather than the last.

It is a glance, not a second desk. You have it for the school run, the queue, the ten minutes between meetings. The work stays where the work is.

2. Setting it up, once

Step 1. Open the address on your phone. Type porthole.trtcompass.com into your phone's browser. There is nothing to download and no account to make.

Step 2. Paste your key. The page asks for the same key Compass uses on your desk. It stays on that phone and travels in a header, so it never appears in a web address, in a browser history, or in anything you might accidentally share.

Step 3. Add it to your home screen. The page offers this within a few seconds of the first screen loading. On iPhone: tap Share, then Add to Home Screen. On Android the page can do it for you with one tap.

Step 3 is the one people skip and then wish they had taken. Installed, it opens full screen with its own icon: no address bar, no tab counter, no menu eating the top of a display that has none to spare. That strip of browser furniture is the least premium thing on a phone screen, and this is the only way to be rid of it.

3. What it carries

The Map, which is the room most people keep open. The symbol, the live price and what it has done since the open, the reads strip, the ladder with every strike and the exposure sitting on it, the King, the flip, overnight builds and drains, and the day's conditions.

The Swing Book, which is the longer question underneath the day. One move and the band it implies, the flip, the balance point, the field, and then the levels either side of price with how often price has actually reached that far inside a week.

The Telescope, including your pose on the name and the Hypothetical when one is set.

Three Needles, drawn on its own because three boards is a different question from one.

Switch rooms on the desk and the phone follows within a few seconds. Stand somewhere the Porthole has no board for, the Chest or the Engine Room, and it says so and tells you which room to go back to.

4. Asking it a question

There is a question box at the foot of the page, and a bar at the bottom of the screen that jumps you to it from anywhere.

You type a question and nothing else travels. The server is already holding the screen your desk sent, so the answer is worked out against the board you were just looking at. Under the answer it tells you which screen that was: answered against your desk as of 40s ago.

It is the same Ask Compass that lives beside your map on the desk, with the same notice, the same limits and the same honesty. The first time you ask on a phone it shows you that notice once, because consent belongs to a text you actually read rather than one you read somewhere else.

5. Reading the freshness marks

This matters more on a phone than on a desk, because a phone is a thing you pick up hours later.

The age is computed on the server, never on the phone. A phone's clock can be minutes out, and the whole design rests on you being told the truth about how old a number is.

Your desk sends about every fifteen seconds and the phone looks about every ten, so twenty-odd seconds of age is ordinary and the page stays quiet about it.

6. Where it stops

The Porthole draws. Your desk computes. The phone holds no chain, no history and no map of its own, and it derives nothing from what it is given. If it ever started working out a market fact for itself, the phone and the desk could disagree, and you would have two answers and no way to choose.

It is read only. Poses, saved strikes, the read log and every setting stay on the desk, where a two-handed decision belongs.

One key, one desk at a time. If you run Compass on two machines under the same key, the most recent one wins and the page names the machine it is showing you, so a swap is something you can see rather than something that quietly happens.

7. If something looks wrong

The page is empty and Compass is open. Check which room the desk is standing in. The Map, the Telescope and Three Needles send boards; the other rooms send a note saying so.

The key came back refused. Check it against the one on your desk, in Settings. If you have changed it recently, the phone is still holding the old one, and Use a different key at the foot of the page clears it.

Everything reads a few minutes old. Your desk has gone to sleep, or Compass has closed. The Porthole is honest about this rather than showing you a fresh-looking screen that is quietly an hour behind.

You want it off this phone. Tap Use a different key and the key leaves that phone's storage.

8. The reason it looks like Compass

Everything on that screen carries the same palette, the same type and the same rules as the desk, because they were copied out of the app rather than approximated. Teal is live data. Violet amplifies, teal compresses. Amber is only ever the King. Panels are lifted rather than outlined, because a drawn grey line reads as a seam between two objects and a one percent lift of light reads as one surface with a change of height in it.

None of that is decoration. It is the same instrument, seen through a smaller opening, and it should feel like picking up the same tool rather than opening a different product.

Read only. This is your own desk, through the Porthole.