BOLT: The Standard for Lightning Network Protocol

BOLT, or Basis of Lightning Technology, is the formal specification of the Lightning Network.

It is a set of documents that describe the Lightning Network protocol for off-chain bitcoin transfer, relying on on-chain transactions for enforcement.

Unlike Bitcoin, which has a reference implementation that also serves as the protocol’s specification, the various Lightning Network implementations follow BOLT so they can work with one another to form the same network.

BOLTs provide a standardised framework for building and operating off-chain payment channels on the Lightning Network, enabling faster and more cost-effective transactions. These specifications ensure interoperability among various implementations of the Lightning Network, enhancing its scalability and usability.

BOLTs encompass a series of documents that outline the rules, messaging formats, and procedures required for Lightning Network nodes to communicate effectively and securely, making it a vital foundation for the broader adoption of the Lightning Network.

At the time of writing there are 12 of these documents that have been accepted as a part of the formal specification, starting from BOLT0 to BOLT11. You can access them on the Github repository dedicated specifically to BOLTs.