ChirpStack is an open source LoRaWAN network server, the central piece of software that receives radio messages picked up by gateways and turns them into data that applications can use. Its author, developer Orne Brocaar, releases it under the MIT licence, one of the most permissive available. The project was long known as LoRa Server and took its current name in November 2019 because LoRa is a trademark registered by Semtech, as the announcement on the official forum explains.
The current fourth generation merges into one program what used to be split between a separate network server and application server.
What ChirpStack is for
A LoRaWAN network is made of very low power sensors, radio gateways that listen to them over several kilometres, and a network server that sorts everything out. ChirpStack plays that last part. It drops duplicates when several gateways hear the same message, checks frame authenticity, manages session keys, picks the best gateway for a reply and tunes each sensor’s data rate through adaptive data rate logic that can be customised with JavaScript plugins. Decoded data then flows to applications through its integrations or its gRPC and REST APIs, the same APIs the web interface is built on.
On the gateway side, the project supplies several building blocks. Concentratord drives Semtech radio chips and exposes a ZeroMQ interface, the MQTT Forwarder running on the gateway sends frames as Protobuf or JSON, and the Gateway Bridge converts the Semtech UDP Packet Forwarder and Basics Station protocols to MQTT when nothing can be installed on the device. ChirpStack Gateway OS even provides a complete system for gateways built around a Raspberry Pi, and Gateway Mesh extends coverage with solar powered relays.
The server supports device classes A, B and C, multicast, firmware updates over the air following the FUOTA specifications, and several frequency plans at once, such as EU868, US915, AU915 or AS923. Each tenant has its own gateways and devices with per user permissions, so an integrator can serve several customers from one installation. A live viewer shows frames and events as they arrive, which helps a great deal when working out why a sensor has gone quiet.
This sets ChirpStack apart from the VoIP oriented tools in this Telecom category, such as HOMER or RTPEngine. It handles no calls or audio streams, only messages of a few bytes sent by meters, probes or trackers.
Who is it for?
It appeals to local authorities instrumenting buildings or water networks, farms, manufacturers tracking machinery and integrators who want to run their own LoRaWAN network rather than rely on an operator. Universities and schools also like it for setting up a test network around a single Raspberry Pi gateway.
Several components have to be mastered, though: a PostgreSQL database at version 13 or later, or the SQLite variant, a Redis 6.2 or Valkey server and an MQTT broker that speaks version 5 of the protocol, Mosquitto being the usual pick. LoRaWAN concepts such as device profiles, keys and frequency plans take genuine time to learn. ChirpStack does not sell sensors and offers no business dashboards, so displaying measurements requires another application. An organisation that would rather host nothing should look at a LoRaWAN network run by a third party.
Download ChirpStack safely
The downloads page on chirpstack.io offers an APT repository for Debian and Ubuntu, .deb and .rpm packages and .tar.gz archives for amd64, armv7 and arm64 processors, each in a PostgreSQL or SQLite flavour. Two official Docker images are published under the chirpstack account, and the documentation walks through installation on Debian, Ubuntu, Docker or a Raspberry Pi. Older releases remain available on artifacts.chirpstack.io, and the source code sits in the chirpstack organisation on GitHub.
Everything is free. The project is funded by sponsors through GitHub Sponsors, and Orne Brocaar offers commercial support on request. A network server holds the encryption keys of every sensor, so an image or package from an unofficial repository could expose them. Importing the signing key given in the documentation before adding the repository is the safe habit.
Frequently asked questions
Is ChirpStack really free for commercial use?
Yes. The MIT licence allows use, modification and resale without royalties, as long as the copyright notice is kept. Only optional professional support costs money.
What is the difference between ChirpStack and LoRa Server?
They are the same project. LoRa Server was renamed ChirpStack in November 2019 for trademark reasons, and the packages were renamed at the same time.
Can I migrate from ChirpStack v3?
Yes. An official tool moves tenants, users, applications, devices and gateways to version 4. It targets the version 4.11 schema, so that release must be installed before moving on to later ones.
