How MeshCore works

MeshCore is an open-source (MIT-licensed) mesh firmware for LoRa radios. It separates radios into clear jobs: the radio you carry, the repeaters that carry traffic, and room servers that store messages.

The three kinds of node

Firmware	What it does
Companion radio	Your personal radio. Connects to the MeshCore app on your phone or computer over Bluetooth, USB or Wi-Fi. It never relays other people’s messages.
Repeater	Fixed infrastructure on a rooftop or hill. Forwards traffic for everyone.
Room server	A tiny message board (BBS). It stores posts and, when you log in, sends you up to the last 32 messages you missed. Can also repeat if set to.

There’s also a sensor firmware example for remote telemetry. The MeshCore FAQ suggests running a repeater and a room server on separate devices.

How messages travel

1. The first time you message someone, the message floods through the repeaters.
2. When it arrives, a delivery report travels back, listing the repeaters it went through.
3. Your radio remembers that path. Later messages carry it, and only repeaters on that path retransmit.
4. If the path breaks, the app retries and, by default, floods again on the last try.

Group channels always flood, because there’s no single destination. Repeater owners can cap how far floods travel. The firmware supports up to 64 hops.

Adverts

Radios find each other through adverts. Repeaters send one every 12 hours by default. Your companion only advertises when you tap “advert” in the app, which keeps the airwaves quiet.

US radio settings

MeshCore’s recommended US/Canada preset is 910.525 MHz, 62.5 kHz bandwidth, SF7, CR5. Presets are suggestions, so check what your local network uses.

Change the default passwords

Repeaters and room servers ship with the admin password password. Room servers also have the guest password hello. Change both before installing a node anywhere.

Apps and tools

• The MeshCore app for Android, iOS, Windows and Mac
• The web app at app.meshcore.nz
• The web flasher at flasher.meshcore.io, and config.meshcore.io for setting up repeaters and room servers over USB
• A live map at map.meshcore.io
• Python (meshcore-cli) and JavaScript (meshcore.js) libraries

Next: Frequencies and regions

Sources

Checked on October 18, 2026.

1. github.com/meshcore-dev/MeshCore
2. github.com/meshcore-dev/MeshCore/blob/main/docs/faq.md
3. docs.meshcore.io/cli_commands
4. docs.meshcore.io/radio_presets
5. meshcore.io