Sadie is a personal AI that reads, researches, and ideates with you.

Sadie takes in what you already know: your old posts, your Notion and Obsidian exports, your saved articles, your voice notes, your half-written drafts. From that, Sadie builds a living model of how you think and write, reads the feeds and newsletters you track, researches the ideas you’re working on, surfaces the live conversations worth weighing in on, and drafts in your voice when you’re ready to ship.

You’ve probably tried ChatGPT for this. You paste in a rough idea, get back a draft, and wince. You don’t ship it, or you ship it and wince for a week. You know?

Sadie starts somewhere else. Not a generic model trying to guess your voice. A personal one that’s been learning you for weeks, from everything you’ve already written and read. Refreshingly personal, properly useful, and tuned continuously to you. Built for busy operators who have things to say and no time to type them.

Start the morning brief Read the philosophy

We’d be honored to have you

Brief Today · 07:14

Personal knowledge bases are quietly becoming the interface to agents

Why now

Three substantial posts this week treat the wiki-as-context pattern as settled, not speculative. The framing shifted.

Why you

Your notes on compound synthesis and the six entries you filed on retrieval posture make you positioned to name what changed.

Who’s talking

@swyx Wiki-as-context is infra.
@cursor_ai Projects > prompts.
@simonw The new memory story.

Angles you could take

01 The wiki is not a document; it is the shape of your attention, made legible.
02 Agents don't need more tools. They need a reader with taste.
03 What you file today is what the model has to work with tomorrow.

The difference

Here’s how Sadie is different.

Most AI writing tools have a text box and a system prompt. That’s the whole learning layer. Paste in a prompt, get out a draft, start over tomorrow.

Sadie has four systems tuning to you continuously. All of them are visible in the app. All of them are editable. None of them are magic.

Soul

A structured model of your audience, obsessions, allergies, and recurring themes.

Built from evidence: your sources, your edits, your saves and dismisses. Not a form you fill out. Every item has a confidence score and a pointer to the evidence that justified it.

Voice portrait

Your prose, modeled across eight specific dimensions.

Sentence rhythm, argument architecture, register range, characteristic moves, vocabulary fingerprint, avoidances, emotional texture, framing habits. Every time you rewrite a Sadie draft, the dimension responsible gets sharpened.

Preference engine

Every save, dismiss, and rewrite is a signal.

Signals that accumulate across distinct days get promoted. Signals that stop arriving decay on a half-life. Your Sadie tracks who you are now, not who you were a year ago.

Agent evolution

The prompts and weights Sadie uses to draft for you get tuned over time.

New versions get proposed to you with plain-English diffs: softer openings, less hedging in chat, shorter briefs. You approve. You roll back. The longer you spend with Sadie, the more Sadie feels like something that’s been paying attention.

Your Sadie after a month drafts differently than someone else’s. After a year, the distance is significant. That’s the whole point.

The walk-through

Let’s walk through it.

Step 01

Reads with you.

What’s being talked about today?
Who’s already in the conversation?
What could I plausibly say?

Every morning, Sadie’s Today surface shows three discourse opportunities. The conversations live right now where your specific knowledge would actually change something. Each card answers those three questions. Nothing more. No trending tab. No feed. No fifty cards begging for attention.

When the day doesn’t have three conversations worth entering, Sadie tells you so. Honest empty states over manufactured volume. Early bird gets the work.

Brief Today · 07:14

Behavioral inference is overtaking preference forms in consumer AI

Why now

Two launches this week shipped without onboarding questionnaires. The category is rethinking the contract.

Why you

You have been making this case in drafts since January. The wider discourse is finally catching up.

Who’s talking

@karpathy Let behavior be the signal.
@npew Forms leak specificity.

Angles you could take

01 Self-description is a lossy codec. Watching is higher fidelity.
02 A good model of you should be editable, not declarative.
03 The distillation loop is the user interface — the text box is the follow-through.

Step 02

Researches with you.

You think out loud. Sadie handles the rest. Leave a voice note. Paste a Slack fragment. Type a half-idea into the chat surface. Sadie pulls context from your wiki, cross-references the live discourse, surfaces the three or four sources worth citing, and drafts in your voice.

Structure, research, tone, all handled before you sit down. Review, adjust, ship. Every edit teaches Sadie something about how you actually want to sound, and the next draft lands closer to finished.

On the shape of a personal wiki

A wiki, done well, is a kind of posture toward your own attention. It is the shape of what you have decided is worth remembering, rendered in enough detail that future-you can pick up the thread without re-reading the source.

Most personal wikis fail in the same way: they are write-only. The capture ritual gets designed; the retrieval never does.

Step 03

Ideates with you.

Where did I read that thing about margins?
What do I actually know about this topic?
What’s connected to what?

Sadie’s Memory holds everything you’ve given her and everything she’s learned. Wiki entries compound every time new sources arrive. Briefs synthesize across clusters. A knowledge graph shows the shape of what you know.

Your Notion pages, PDFs, old drafts, and saved articles — all of it in one place, all of it actually used, instead of rotting across seven tabs.

The honest answer

“But won’t it sound like AI?”

Here’s the honest answer: for the first week, Sadie’s drafts will feel close but not quite right. That’s expected. You’ll rewrite the openings, tighten the conclusions, swap a few words.

Those rewrites are the product. Every edit feeds the voice portrait. By week three, the drafts need less editing. By month three, the drafts need edits for taste, not voice. Your team can’t tell which posts started as voice notes.

The AI writing tools that claim to sound like you on day one are lying. The ones that actually do it take a few weeks of learning first. Sadie’s tuning engine is designed for that slope, and the curve gets steeper the more you write.

The answer is YES!

Can a personal AI be specific, continuously tuned to you, and properly useful?

With Sadie, the answer is absolutely YES!

Can Sadie learn my voice from how I already write, not a profile I fill out?
Can Sadie draft a post from a voice note or a Slack fragment?
Can Sadie tell me why a topic is live and why I’m positioned to say something?
Can Sadie cite my own past writing back to me as evidence?
Can Sadie handle my Notion exports, Obsidian vaults, PDFs, and newsletter archives?
Can Sadie show me exactly what evidence justified every Soul item?
Can Sadie tell me when there’s nothing worth posting today?
Can Sadie evolve continuously, and let me roll back when I disagree?
Can Sadie run on my own Neon database and Cloudflare account if I self-host?

It’s time

You wouldn’t be here if the drafts you’ve been shipping were working. It’s time for Sadie.

Ideas piling up you never got around to? It’s time for Sadie.
Tired of drafts that sound like everyone else? It’s time for Sadie.
Watching the conversations you were built for pass by while you’re in back-to-backs? It’s time for Sadie.
Notes scattered across Notion, Obsidian, and three drafts folders? It’s time for Sadie.
Want to grow on social without the hours? It’s time for Sadie.
Want an AI that remembers you between sessions and tunes itself to you, instead of starting cold every prompt? It’s time for Sadie.

Start the morning brief

FAQ

I have questions about Sadie…

How is Sadie different from ChatGPT or Claude?

Those are general-purpose AIs. They don’t know you. Every session starts from zero context, and every output tends toward the average voice of the internet. Sadie is the opposite. A personal AI with a persistent, four-layer model of who you are, what you know, how you write, and what you care about. Each output compounds on the last.

Does Sadie actually write in my voice, or just claim to?

Sadie builds a voice portrait from your actual writing, across eight dimensions, and refines it every time you rewrite a draft. Month one, it sounds like a careful imitation. Month three, your co-workers can’t tell which drafts started as yours.

What sources can I feed Sadie?

Anything text. Notion and Obsidian exports, PDFs, past posts, newsletter archives, Substack backups, saved articles, private notes. Sadie extracts concepts, people, and themes from all of them into a compounding wiki.

Will Sadie post to X or LinkedIn for me?

Sadie drafts. You review and ship. Nothing leaves your hands without your sign-off.

Can I self-host Sadie?

Yes. Sadie runs as a SaaS by default, but the whole thing deploys to your own Neon database and Cloudflare Pages account. Same product, your infrastructure, your data. One user per deployment either way.

What’s the pricing?

Three tiers: Bird Brain, Second Brain, Galaxy Brain. See the pricing page.

Why is it called Sadie?

Sadie is an anagram of ideas. The name is a small nod to what the product is built around, but not all of it. Sadie also reads the discourse, compounds a wiki of your knowledge, and drafts in your voice. The ideas are where it starts.

My ideas. My voice. My Sadie.

No other mailings. I'll write when there is something worth saying.