Definition
A Lightning Service Provider (LSP) is a business or node operator that helps users connect to and transact on the Lightning Network, primarily by solving the inbound-liquidity problem. A brand-new wallet has no channels and therefore cannot receive a single satoshi until someone opens a channel toward it. An LSP opens that channel, often automatically, so the user can begin receiving payments immediately.
Inbound liquidity and JIT channels
Receiving on Lightning requires inbound capacity, meaning bitcoin sitting on the remote side of a channel pointed at you. LSPs provision this capacity on demand. With a "just-in-time" (JIT) channel, the LSP opens a channel in direct response to an incoming payment and deducts the cost from that first payment, so a user with zero channels can still receive their first funds. Other models let a user purchase a channel of a chosen size up front.
Standardization through bLIPs
The LSP ecosystem is converging on open specifications published as Bitcoin Lightning Improvement Proposals (bLIPs). bLIP-51 (LSPS1) defines ordering a channel from an LSP; bLIP-52 (LSPS2) defines JIT channels; and bLIP-50 (LSPS0) defines the underlying JSON-RPC transport spoken over encrypted peer-to-peer messages. Standardizing these flows lets wallets work with many competing LSPs rather than being locked to one.
LSPs frequently use a Zero-conf Channel to make onboarding instant. For the sovereignty trade-offs of relying on third-party infrastructure, this is a recurring theme across the Lightning ecosystem.
In Simple Terms
A Lightning Service Provider (LSP) is a business or node operator that helps users connect to and transact on the Lightning Network, primarily by solving…