Atomic Multi-Path Payments (AMP)

Atomic multi-path payments, or AMP, split a single Lightning Network payment into multiple smaller parts that travel different routes to the recipient, with a guarantee that either every part settles or none do. A 1 million satoshi payment might arrive as four independent streams of 250,000 satoshis each.

Why it matters

Lightning payments are limited by the capacity of individual channels along a route. Without multi-path techniques, a payment larger than any single channel simply fails, and senders must keep their funds concentrated in one place. Splitting payments lets wallets combine liquidity scattered across several channels, raises the practical size limit of Lightning payments, improves success rates, and adds a measure of privacy, since no single routing node sees the full amount.

How it works

In the AMP construction, the sender derives the secrets for each partial payment from a single root secret, sharded so that the recipient can only reconstruct it, and therefore only claim any of the parts, once every share has arrived. That makes settlement genuinely atomic: partial delivery is impossible by design. A related and widely deployed variant, multi-part payments, splits payments across routes while reusing a standard invoice's single secret. Together these techniques turned Lightning from a network of isolated channel balances into something closer to a unified pool of spendable bitcoin.