Core Lightning (c-lightning)

Core Lightning (CLN), formerly c-lightning, is one of the major Lightning Network implementations. Developed by Blockstream, it's written in C and emphasizes modularity, minimal resource footprint, and a plugin architecture that lets developers extend functionality without forking the core daemon.

How it stacks up against the other main implementations:

• CLN - C, modular, plugin-first, built to be lightweight. Added experimental BOLT-12 offers support in January 2021 and turned it on by default in December 2024.
• LND (Lightning Labs) - Go, monolithic, REST/gRPC APIs. In a study of public-network data from March 2018 to January 2020, about 87% of public nodes ran LND.
• Eclair (ACINQ) - Scala, aimed at server deployments such as routing nodes. ACINQ's mobile wallet runs on a separate ACINQ implementation, lightning-kmp.
• LDK - Library, not a daemon. Embedded into apps like Cash App and Alby Hub.

CLN's plugin system is the differentiator. Common plugins handle things like channel rebalancing, advanced routing strategies, watchtowers, and accounting. The model is "small core, many plugins" rather than "big monolith with feature flags." Splicing ships with CLN itself. Its everyday commands, splicein and spliceout, come from spender, a plugin bundled with CLN, which calls lower-level splice commands built into the daemon. Splicing was an experimental option from August 2023 until version 26.04 (April 2026) switched it on by default.

For self-hosted Lightning operators, that design shows up in a few places:

• It runs on small machines. RaspiBlitz, a do-it-yourself node built on a Raspberry Pi, can run CLN alongside LND.
• Routing nodes can add rebalancing through plugins such as rebalance, circular and sling.
• BOLT-12 support is built in, with no add-on needed.

Node-in-a-box products such as RaspiBlitz and Umbrel offer both daemons. Umbrel has its own LND-based Lightning Node app, and Blockstream publishes a Core Lightning app for it. See Lightning Node for the broader landscape.