The second brain for
Projects and teams.

Documents, emails and notes become knowledge that your department questions together. Locally on your Mac or Windows, at your own AI endpoint, without data leaving your home.

Download for macOS How safe is that?

Apple Silicon · processed locally · your own AI endpoint · no telemetry

SideBrain chat, empty state: 'Ask your brain — or attach a document'. Ask your Gbrain in natural language, attach documents, get answers with sources. — Ask a question in natural language.

SideBrain chat with an answered question “What can SideBrain do for a project team?” and three source chips: Project Kickoff — Meeting Notes, Client Proposal — Cloud Migration, Team Handbook — Knowledge Capture. — Get an answer with source chips — always traceable.

Free for everyone, for nowFull functionality, no license question — until version 1.0.

Private, permanently freeNon-commercial use via free private license.

Business: let's talkLicensing starts at version 1.0 — until then we discuss business needs directly: View license model.

Docking instead of moving

SideBrain fits in — into your AI, your system, your decisions

No new silo, no integration project: SideBrain makes knowledge available where you already work - and keeps you independent, regardless of which AI model you use tomorrow.

In your AI solutions

By MCP and included Skill Your brain becomes a source of knowledge in the assistants you already use — Claude Desktop, agentic tools, your own company copilots. Enter a local address and you're done: no API development, no project.

Into your operating system

absorb knowledge without technical hurdles: Right-click in Finder, share menu, print dialog, a shortcut, a watched folder — even from the iPhone. Capturing happens in the workflow, not in an extra program.

In your decisions

Answers with sources at the moment of decision: the question overlay on every app, the appointment preparation before the meeting, the scheduled report on Monday morning. Knowledge that is used - not just stored.

The architecture at a glance: Assistants dock via MCP, SideBrain connects to your brains - the AI model behind it remains interchangeable.

And without dependence on the AI provider: The model behind it can be interchanged at any time - Anthropic, Azure OpenAI, Google Vertex, your own gateway or completely local. Your knowledge is available as open Markdown. You change provider, not memory.

For projects & departments

A brain that your team shares

Connect to the same brain endpoint: Anyone with access questions and adds to the same knowledge. Offers, protocols and specifications are located where the entire project finds them, instead of scattered in individual mailboxes.

One brain per project

Everything about the process in one place

Set up a separate brain for each project or department. Anyone who works on it gets read or write rights according to scope, clearly separated from everything else.

Induction

Ask new colleagues instead of disturbing them

Instead of clicking through drives, the new colleague asks the department knowledge and gets the answer with the source. Training in hours instead of weeks.

continuity

Knowledge remains when people leave

Once fed in, the team stays with it. No treasure of experience disappears with a canceled mailbox or a cleared drive.

Casual

The brain grows in the flow of work

Right click in the Finder, share menu, watched folder: everyone feeds in where they work anyway. There is no additional maintenance effort.

Usage scenarios

How does that look for you?

The same tools, very different everyday lives. Four perspectives on how SideBrain is transforming collaboration — and one for everyone who puts confidentiality first.

Crafts

Every order stays in your head - even in three years

Construction site photos, voice memos from the van, offers from back then: the company answers customer questions in seconds, with receipts.

SideBrain in crafts → Small service providers

Customer knowledge that doesn't live in your inbox

Emails, briefings and commitments in one place for everyone at the customer - and notice periods are self-evident.

For agencies & service providers → Business consulting

Project knowledge that outlives the mandate

Each mandate has its own brain, workshops record themselves, and “who knows about X?” answers the expert search.

For advice → Project teams

A memory for your project

Decisions can be read with the source, the Monday report writes itself - and after the end there remains an archive that answers.

For projects → Maximum data protection

Air-gapped or with EU data residency

Completely offline on Mac — or with strict EU processing on your own endpoints. Verifiable, not just promised: including review summary for data protection officers.

Both operating models in detail →

Do you advise SMEs yourself and want to bring SideBrain into customer projects? Become a partner — with reselling margin, support behind you and a ready-made sales kit.

Data security

Confidential matters remain confidential

SideBrain is built for sensitive company data: processed locally, without account requirements, and the AI runs where your guidelines allow it. Nothing leaves the device or your network unnoticed.

Local processing: Text is extracted and indexed on the device. Your documents are on your Macs or your own Brain endpoint, not on third-party servers.
Your AI endpoint: SideBrain uses the model endpoint that you specify: Azure OpenAI, Google Vertex, a LiteLLM gateway in your own network or a locally running model. A prompt only goes there, and only if someone asks.
No telemetry: No home radio, no tracking, no mandatory account. What happens on your Macs stays there.
Data sovereignty: Your knowledge is available as Markdown and can be fully exported at any time. No proprietary format, no lock-in, no dependency on us.
Behind the firewall: SideBrain works behind the corporate proxy and with internal endpoints. For maximum isolation, models run completely locally, without any internet.

All data flows at a glance — the list is short enough to be complete.

Strict requirements? Air-gapped operation and EU data residency in detail — including review summary for data protection officers.

SideBrain is proprietary software. Use is free for everyone until version 1.0; after that, commercial use requires a license, private non-commercial use remains permanently free. Details: EULA, Terms and Conditions and Private license.

AI connection

The AI runs according to your rules

SideBrain does not come with its own AI model and does not tie you to any provider. You store the URL, deployment name and key of your existing access, whether cloud, internal gateway or local.

Anthropic Claude Azure OpenAI Google Vertex AI OpenAI LiteLLM Gateway OpenRouter llmgateway.io Local models

No AI access in the house yet? All you need to get started is a free key via llmgateway.io or OpenRouter, created directly from the setup.

This is how it works

In three steps to your own knowledge store

No folder maintenance, no copying. From document to questionable note — with a short confirmation in between.

Feed in

Right-click the file in Finder and select “push to Gbrain” — or drag it into the window. PDFs, slides, Office documents, images and emails are recognized.

Understand

SideBrain extracts the content, suggests the title, type and date and shows a preview. You check briefly and take over - or skip.

Question

Ask your question in natural language. The answer comes with specific sources from the exact documents you included.

A look inside

This is what it looks like in everyday life

Real views from the app — here with sample data. The overview reports what is coming up; each answer cites its sources.

SideBrain-Übersicht mit Kennzahlen, Privatsphäre-Status, anstehenden Terminen und fälligen Punkten — The overview: key figures, privacy status, upcoming appointments, points due.

Brain-Explorer mit geöffneter Angebots-Notiz samt Typ, Tags und Verknüpfungen — The Brain Explorer: every note with type, tags and links — maintainable without CLI.

Antwort mit Quellen-Chips und Wissenslücken-Hinweis — An answer as it should be: facts with source chips - and honestly named gaps in knowledge with a jump to closing them.

Verknüpfungs-Graph mit einer Person im Zentrum und ihrem Umfeld — The connection graph: who and what is connected, at a glance - every neighbor clickable.

Verlaufsansicht mit Pushes und Status-Filter — The history: every push traceable, searchable, filterable by status.

In everyday working life

Moments when SideBrain steps in

No more programs to remember. SideBrain appears where knowledge is created and disappears again.

After the appointment

Before you leave the room

The meeting view collects screenshots, attachments and participants and stores them linked - while the context is still fresh.

Offer by email

In with it, without storage

Drag the email to a watched folder or send it via the share menu. SideBrain recognizes the process - with amount, participants and date.

Question in between

Answer without searching

A shortcut opens a field above everything. Ask your own knowledge, get the answer with sources — without even opening the app.

Screenshot & Article

Capture what matters

Insert a screenshot or share a link - the text is read and stored as a citable source, discoverable like anything else.

structure

Files become linked knowledge

SideBrain doesn't just dump text. It recognizes what a document is, assigns a type and automatically connects people, companies and processes - this creates a connection instead of another folder.

person company Offer Appointment project concept note e-mail source

Offer from municipal utilities mentioned → Municipal utilities model city belongs to → Project North Star

Ask for a person and you'll get the linked information straight away - offers, appointments, notes, without having to link yourself.

Trust

Answers you can check

No made up facts. Each statement refers to the place in your own documents from which it comes.

What requirements does the GDPR place on order processing? ⌥ Space

Art. 28 GDPR requires a written contract for order processing that specifies the subject, duration, type and purpose of the processing. The processor may only act according to instructions and must provide evidence of suitable technical and organizational measures.

GDPR white paper.pdf · §3 Compliance-Checkliste.md · lines 42–58 Training.key · Slide 12

Answer from 5 notes · in 2.3 s

The sources are clickable: one click opens the underlying note so you can see the context for yourself.

Native

Deeply at home in macOS

SideBrain docks into the places you use anyway - with system conventions instead of your own operating logic.

Finder Quick Action

Right click on each file → “SideBrain”. No opening, no pulling necessary.

Quick note ⌥ N

A symbol in the menu bar and an abbreviation for the occasional thought - from every app.

Overlay over everything ⌥ Space

Question your knowledge without changing the context. Answer with sources, then leave again.

Accompany the appointment ⌥ T

One view for the meeting: collect screenshots, attachments and participants and store them linked.

Watched folders

Place files in a folder of your choice - they will go to the Brain automatically or after a short confirmation.

Share menu

Feed text and links directly from any app via macOS “Share”.

Print → SideBrain

Save as a PDF note from any app using the print dialog - even where there is no export.

Calendar context

Detects the current appointment and suggests it as a reference if you have something in mind.

Das ⌥Space-Overlay mit beantworteter Frage, Quellen und Wissenslücken — The `⌥Space`-Overlay in action: ask, read the answer with sources, continue working - without opening the app.

AI integration

Your brain in the AI tools you already have

SideBrain provides the company's knowledge of the Model Context Protocol (MCP) — the open standard that AI assistants and agents speak today. There is also an included skill that teaches you how to use the brain.

Instead of copying knowledge into every tool, your assistants integrate it directly:

Claude Desktop (one-click setup), Codex, agentic tools and your own company co-pilots

Enter a local address — http://127.0.0.1:8765/mcp — finished, no integration project

Filing, searching and asking as tools; Read/write permissions according to token scope

Optionally also available on the network — a Mac becomes a shared MCP endpoint for a whole project team or small business, with no server of its own (opt-in, localhost stays the default; see “Mac as a Brain server on the network”)

"mcpServers": {
  "sidebrain": {
    "url": "http://127.0.0.1:8765/mcp"
  }
}

installation

Ready to go in two minutes

SideBrain comes with its own runtime. No Python, no homebrew, no configuration required.

To double click

Load the disk image, drag SideBrain into the Applications folder, done. The guided first start sets up everything else.

Load SideBrain.dmg

In the terminal

One command loads and installs the current version - without a quarantine detour.

$ curl -fsSL https://dl.sidebrain.eu/install.sh | bash

The launch takes place without Apple notarization. With the terminal route, the gatekeeper detour is automatically eliminated; For the DMG, a short illustrated guide helps when you start it for the first time.

Questions

Frequently asked

Is our data leaving the network?

Extraction and indexing run locally on the device. Only when someone asks an AI question will the relevant context go to exactly the endpoint you have configured. This can be an internal service, a gateway in your own network or a locally running model. SideBrain also works behind the corporate proxy.

Can several colleagues use the same Brain?

Yes. Connects SideBrain to the same Brain endpoint (URL and token), and everyone with access questions and adds to the same knowledge. Read and write rights depend on the scope of the token. Alternatively, everyone keeps a purely local brain on their own device.

Which AI providers are supported?

Anthropic Claude, Azure OpenAI, Google Vertex AI, OpenAI, every LiteLLM gateway as well as OpenRouter and llmgateway.io. Locally running models are also possible. You enter the URL, deployment name and key and retain full control over providers and costs.

How much does SideBrain cost?

SideBrain is currently free for everyone. Binding license models start at version 1.0 — until then, anyone can try and use the app for free. For private, non-commercial use, SideBrain also remains permanently free via private license. Professional requirements from a business context are best discussed personally or via a classic business license — details in the EULA.

Which file formats are supported?

PDFs, Office documents, Markdown, plain text files, emails, slides (Keynote, PowerPoint) and images with text content. Web links can also be inserted.

Does it also run on Intel Macs, Windows or Linux?

Yes for Apple Silicon (macOS, arm64) and Windows (x86_64) — both ship as their own signed installer. Intel Macs and Linux are not currently scheduled.

How do I uninstall SideBrain?

SideBrain can be completely removed via the settings, including quick actions and settings. If you wish, your brain data will be retained and can be exported beforehand.

Bring your department’s knowledge into one place.

Feed in the first document and ask the first question in five minutes. Try it without registering.

Download for macOS

The second brain forProjects and teams.