Scala · Lightning Network · maintained by ACINQ
Eclair: a Lightning Network node built for scale
Eclair is an open-source implementation of the Bitcoin Lightning Network, written in Scala and maintained by ACINQ. It follows the BOLT specifications and is designed to run large, reliable routing nodes.
- Language Scala
- Runtime JVM
- Spec BOLT-compliant
- License Apache 2.0
- Backend Bitcoin Core
This is an independent, community-maintained guide. It is not the official Eclair website. The project is developed by ACINQ — source, releases and authoritative docs live at github.com/ACINQ/eclair. All download links here point to ACINQ’s official GitHub releases.
Definition
What is Eclair?
Eclair is a full Lightning Network node implementation written in Scala and maintained by ACINQ. It runs on the Java Virtual Machine, connects to a Bitcoin Core backend, and implements the BOLT (Basis of Lightning Technology) specifications so it can open payment channels, route payments, and interoperate with other Lightning implementations such as LND and Core Lightning.
Eclair is aimed at operators who need a dependable, scalable routing node rather than a desktop wallet. The same engine underpins ACINQ’s own infrastructure and the technology behind the Phoenix wallet.
Why operators pick it
Key characteristics
01 Built for scale
Eclair’s design targets large routing nodes with many channels, favouring throughput and reliability over a bundled GUI.
02 BOLT-compliant
It follows the open Lightning specifications, so it interoperates cleanly with other spec-compliant nodes across the network.
03 API-first
A JSON-RPC API and the eclair-cli tool let you script node operations, integrate services, and automate channel management.
Ready to run a node?
Grab the latest signed release from ACINQ and follow the install guide.