I see the difference between L402 and x402 like this… L402 is a bearer token while x402 is a process. And you can use an L402 bearer token inside the x402 process! ...at least theoretically.
Any blockchain network does in a sense include intermediaries whether that’s nodes on the network, miners, staking nodes, Lightning routing nodes, etc.
The x402 process does generally involve more parties as there is the facilitator service which is not a thing when using L402 alone.
I LOVE macaroons! I wrote about how elegant they are here hannahmr.hashnode.dev/macaroons-are-beautiful-and…
Worth flagging the structural difference between L402 and x402, since you mention them side by side. L402 inherits Lightning's properties: Bitcoin-only, sub-second settlement, off-chain via channels, but routing requires a path through other nodes which is structurally an intermediary even if it's not a settlement counterparty. x402 keeps the HTTP-native flow but pushes settlement onto a base chain (USDC on Base in the original Coinbase implementation), so you trade Lightning's speed for flexibility on currency and on-chain auditability.
The macaroons piece is the most underrated bit of L402. Cookie-style bearer tokens with caveats baked in mean an agent can prove its access scope without the service re-authorizing every call. That's the part agent stacks reinventing auth from scratch usually skip.