What leaves your Mac, and when

When you talk to it

Nothing below happens until you start it: hold the key and speak, type a message, or switch on a hands-free session. Calsifer listens while you hold the key or while that session is on, and it never captures your screen continuously.

A hands-free session keeps the microphone on until you end it, and whatever it hears becomes a turn. End it when you are done talking.

There are two ways it can listen. Fast conversation is the default and uses OpenAI for live speech-to-text. In Classic conversation, Apple’s on-device dictation is the default, and it turns your voice into text on your Mac.

Your voice

In Fast conversation, your voice streams to OpenAI while you speak, and OpenAI turns it into text. That stream goes straight from your Mac to OpenAI, using a short-lived pass that Calsifer’s server hands out. The audio itself does not pass through our server.

Your words

The text of what you said or typed goes to Anthropic, whose Claude model does the thinking and the drafting. In Fast conversation it also goes to OpenAI, which helps Calsifer pick a quick first reaction while Claude thinks.

Your screen

Each time you speak, Calsifer takes one snapshot of every connected display and sends it with your words to Anthropic and, in Fast conversation, to OpenAI. That is how “look at this” works. It also takes a snapshot when you ask for a screenshot yourself.

• It does not take one when you type, unless you ask for a screenshot, or when the blob is just sitting there. It never captures continuously, and never while your Mac is locked.
• Calsifer’s own windows and known password managers are left out. Nothing else is blurred, so if a tab is on screen when you speak, Calsifer can see it.
• You can switch the automatic snapshot off in Settings, under Screen & Privacy, or say “don’t look at my screen” for one turn. A screenshot you ask for still works.
• The automatic snapshot is used for that turn and is not saved to your library. It only sticks around if you ask, for example by telling Calsifer to attach a crop to your post. What Calsifer wrote or said about it is saved like any other reply.

The things that help it sound like you

Photos you attach, sampled frames and the transcript of a video, the canvas you have open, and relevant excerpts from your library (notes, earlier drafts, your writing style) go to Anthropic along with the turn. If Calsifer looks something up on the web for you, that search runs through Anthropic too.

Its reply

The text of Calsifer’s reply goes to ElevenLabs, which reads it aloud.

Your posts

When you post to X, the text and pictures go through Calsifer’s server to X. That only happens after you click Post or give an explicit spoken command. For LinkedIn, Calsifer opens Google Chrome with the post ready, and you press Post yourself. An X post with a video is handed to Chrome the same way.

What our server does with it

Calsifer’s server sits between your Mac and the AI providers. It holds the keys, checks that it is you, counts usage and passes requests along.

It does not store your speech, your screen snapshots, your draft text or the AI’s replies. It does not log the contents of requests or responses.

What the AI providers do with it

We cannot promise on their behalf. Anthropic, OpenAI and ElevenLabs each handle what they receive under their own policies, and those policies apply to anything Calsifer sends them for you. Our server labels requests to Anthropic and OpenAI with a scrambled version of your account ID.

• Anthropic’s privacy policy (thinking and drafting)
• OpenAI’s privacy policy (live speech-to-text and the quick first reaction)
• ElevenLabs’ privacy policy (the voice)

Anything you publish to X or LinkedIn is public, and theirs to handle under their own terms.

What our server stores

Enough to know who you are and how much you have used. Specifically:

• Your email address and the invite you used. We sign you in with a six-digit code by email, so there is no password to keep.
• A record of each Mac you are signed in on, including its name. The sign-in token itself is kept only as a scrambled fingerprint.
• Usage counts: what kind of request you made, how big it was, what it cost us and when. Counts only, never content.
• If you connect X: your X access and refresh tokens, encrypted, plus your X account ID and handle.
• For each X post: a fingerprint of the text (not the text) and how it went, including the link to the post once it is up.

We also count product events, like sign-ins, turns and posts, to learn what is working. They are numbers and categories, never your words, your screen or your drafts. They go to PostHog, an analytics service, labelled with your account ID and plan. Calsifer has a switch that stops the app sending its own events. Our server still records a few itself, like sign-ins, turns and posts.

The server runs on Cloudflare.

If you only joined the waitlist

We store the email address you gave us, so there is somewhere to send an invite. That is all the form collects.

What stays on your Mac

Your library: conversations, drafts, canvases, post history and what Calsifer has learned about how you write. It lives in a database on your Mac. There is no cloud sync, and no archive of microphone recordings.

Photos and videos you attach are kept as private copies on your Mac, so a draft does not break when you move the original.

Deleting your account

You can delete your account. Deleting it deletes your account records on our server, revokes Calsifer’s access to your X account, deletes your profile from our analytics and signs out all your Macs.

Three things it cannot do. It cannot reach into what the AI providers already received, which is covered by their policies above. It does not take down posts you already published; those stay on X until you delete them there. And it does not touch your library, which is on your Mac and stays there until you delete it yourself.

Deleting is done from inside Calsifer, while you are signed in. The beta build is not out yet, so there is no button to point at today.

This website

This site sets no cookies and loads no trackers, no analytics, and no fonts or scripts from anyone else. The only thing it sends anywhere is your email address, to Calsifer’s server, when you press the waitlist button. It is hosted on Cloudflare, which sees the request your browser makes, as any host does.