Home / FAQ
Frequently asked questions
Short, direct answers to the questions people ask most about Eclair.
What is Eclair?
Eclair is an open-source implementation of the Bitcoin Lightning Network, written in Scala and maintained by ACINQ. It runs a full Lightning node that opens payment channels and routes payments, following the BOLT specifications.
Who develops Eclair?
What programming language is Eclair written in?
Eclair is written in Scala and runs on the Java Virtual Machine (JVM), so it works on Linux, macOS and Windows where a suitable JDK is available.
Is Eclair a wallet?
No. Eclair is a headless Lightning node daemon controlled through an API and the eclair-cli tool, aimed at server-side and routing use. It is not a consumer wallet with a graphical interface.
Does Eclair need Bitcoin Core?
Yes. Eclair uses a Bitcoin Core full node as its backend for its view of the blockchain and wallet operations, so you need a synced Bitcoin Core instance.
How does Eclair compare to LND and Core Lightning?
All three are BOLT-compliant and interoperate. Eclair is written in Scala by ACINQ, LND in Go by Lightning Labs, and Core Lightning in C by Blockstream. Eclair is often chosen for large, server-side routing nodes. See the comparison page.
What license is Eclair released under?
Eclair is released under the Apache License 2.0, a permissive open-source license.
Where can I download Eclair?
Download Eclair only from ACINQ’s official GitHub releases, and verify the download against the published checksums or signatures.
Is Eclair free to use?
Yes. Eclair is free and open-source software. You can run, inspect and modify it under the terms of the Apache 2.0 license.