CAPSI
Download Capsi

CAPSI · by CAPSICOM

Run it. Find the computers. Send.

Messages and files, device to device.

  • No cloud chat service in the middle.
  • No accounts — each computer is identified by its device name.
  • No internet service required for computers on the same local network.

Just run Capsi on each computer and connect.

Download Capsi Learn more

Windows (64-bit) · Installer downloads from the latest GitHub release · Same Wi-Fi or wired network

How it works

  1. Run

    Install Capsi on each Windows computer, open it, and give the device a name.

  2. Find

    Capsi announces each device on the local network, so nearby computers running Capsi show up nearby — no addresses to type.

  3. Send

    Accept a device once, then send messages and files directly between those computers.

Features

Small scope, on purpose. Each item below is a different part of how Capsi works.

Device Discovery

Computers running Capsi announce themselves on the local network and appear in the Nearby list.

Direct Messages

One-to-one text messages between accepted devices, kept in a per-device conversation.

File Transfer

Offer a file to an accepted device; the other side accepts or declines, then receives it. One file per offer, up to 100 MB.

Accept-Once Trust

New devices appear as pending. Messages and files only flow after you accept a device; ignored devices stay blocked.

No Cloud Service

Local communication does not go through a Capsi chat server — devices talk directly on the same network.

No Account

No signup or login. A device name (up to 32 characters) is the identity other computers see.

Your network. Your devices. Your data.

Capsi is designed for places where computers share the same Wi-Fi or wired network — offices, homes, labs, classrooms, workshops — and should talk to each other without a chat service in the middle.

No external chat server is required for basic device-to-device communication on that network. Downloads and release metadata still come from GitHub; your messages and files do not pass through a Capsi cloud.

Local networking is not the same as encryption or invisibility: anyone else on the same network can observe traffic patterns, and a network owner can inspect or block local traffic. [VERIFY ENCRYPTION MODEL BEFORE PUBLISHING — see section 6.]

Built for Windows.

Download the installer, run it on each computer, and pick a device name. [VERIFY: supported Windows versions, 64-bit-only status, WebView2/first-run firewall behavior.]

Get Capsi for Windows

Ready to connect?

Install Capsi on each Windows computer on the same network, accept the devices, and start sending messages and files.

Download Capsi

Windows (64-bit) installer · From the latest GitHub release · Free to download