Installation guide

From the file to your first conversation.

Ten minutes, most of it waiting for a download. Below is every step in order, with each dialog named — including the two your operating system will throw at you and the one setting that differs between Windows and macOS.

Five steps

1 — Download the right file
Windows: one installer. macOS: Apple Silicon or Intel — Apple menu > “About This Mac” tells you which. Both stand on the download page.
2 — Get past the first-launch warning
Windows: “More info” > “Run anyway”. macOS: right-click the app > “Open” > “Open” again. Double-clicking will not offer that choice.
3 — Grant the permissions
Windows asks for the microphone. macOS asks twice: microphone, and separately audio capture. Both are needed — the second is what lets Thalassa hear the other party.
4 — Sign in
Create an account or use Google or Microsoft. The trial starts here, in the app, not on the website.
5 — Add your documents, then test it on yourself
Drop your files into the knowledge base, wait for the indexing bar, then start a conversation and talk to yourself for a minute. Better here than in a client call.

Run the installer and start the application. Windows SmartScreen will call it an unknown application, because the build is not signed yet: click “More info”, then “Run anyway”. On first start, allow the microphone. That is all — Windows exposes played-back audio as a recording source on its own, so the other party's voice needs no driver and no setup. Windows 10 version 2004 or newer, 64-bit.

Open the disk image and drag Thalassa into Applications. Then right-click the app and choose “Open”, and “Open” again in the dialog — a plain double-click gives you no such button, only a dead end, because the build carries no developer certificate yet. macOS then asks for two separate permissions: the microphone (that is you) and audio capture (that is the other party). From macOS 14.2 that second one is all it takes. On macOS 11 to 14.1 the interface behind it does not exist, and the app walks you through installing BlackHole, a free virtual audio device — about three minutes, once.

Sign in with an email address or through Google or Microsoft. The trial begins at that moment; no card is required to start it. If you bought a plan on the website first, sign in with the same address and it is already attached — you do not enter a licence key anywhere.

What is actually happening

Four things worth understanding rather than clicking through.

Thalassa listens to two things at once. The system audio — whatever your speakers are playing — is the other party. The microphone is you. It needs both, because knowing who asked is what makes an answer an answer and not a transcript. On Windows the system audio is available to any application; on macOS it is a protected resource, which is why the second permission exists.

Apple treats them as different things, and granting one does not grant the other. If Thalassa hears you but not the person you are talking to, it is almost always the audio-capture permission: System Settings > Privacy & Security > and grant it there. The application says which of the two is missing rather than reporting a generic audio error.

Until the application is signed with a developer certificate and notarised, Windows SmartScreen and macOS Gatekeeper will warn about it. There is a second, less obvious consequence on macOS: permissions are tied to the signature, and every new build is a new identity — so after an update, macOS may ask for the permissions again. That is not a fault; it disappears once the application is signed with a stable certificate. We would rather write that here than let you wonder.

No sound from the other party is almost always the audio permission on macOS or the wrong output device on Windows. No answer usually means no knowledge base has finished indexing yet. The window appearing in a screen share means the whole screen is being shared on macOS 15.4 or newer — share a single window instead. Sign-in failures are usually a corporate network blocking the callback. The help page walks through each one.

Installation questions

What people ask while they are doing this.

Do I need administrator rights?

On macOS, no — dragging the app into Applications is enough, and you can install it into your own user folder instead. On Windows the installer will ask for them; if your machine is locked down, the portable folder build works without them. Write to support@thalassa-consulting.com and we will send it.

My employer blocks unsigned applications.

Then it will not start, and no workaround from us would be a good idea on a managed machine. The signed and notarised build is what solves this; ask us about the timeline before you buy, not after.

Where do my documents end up after installation?

In your user folder, on your machine. They are indexed and searched there. Nothing is uploaded — except a scanned PDF, whose pages go once to our backend for text recognition, and that can be switched off in the settings.

Can I install it on two computers?

Yes. The licence follows the account, not the machine. Running two conversations at the same time on one account is what it will not do.

How do I remove it completely?

Windows: uninstall like any other application. macOS: drag it to the trash. Both leave the knowledge base in your user folder — delete that folder too if you want it gone. Deleting the account itself is a separate step in the application's settings.

Get the file

Both systems, both Mac builds, and the current version — on the download page.

Go to the download page Something not working?