It’s time for another round of “what’s the difference between L402 & x402”? I think of it like this… L402 is a bearer token while x402 is a process. Let’s look at the example of an agent paying for an API endpoint. L402 is an access token that includes proof of payment. An agent shows up to an API endpoint looking for some data. The service returns a bearer token with a Lightning invoice. The agent pays that invoice, receives the preimage as proof of payment and adds that preimage to the token, making an L402. The agent then returns to the server to access the data in that API endpoint presenting the L402 to get instant access. But wait, there’s more. As this is a bearer token, an agent can also attenuate that token and sell it, or pass it along to sub-agents, etc. Lots of options. No identity needed, no need for the server to hold on to user data. x402 is a process that focuses more on the broader crypto ecosystem. An agent shows up to that same API endpoint. The server responds with a 402 Payment Required. No bearer token, just payment requirements: how much, in what currency, on which network. The agent creates a payment payload (say, USDC on Base, or now Bitcoin Lightning too), and retries the exact same request with proof of payment attached. A facilitator verifies the proof and the server delivers the data. But the agent doesn't walk away with anything reusable. No token to pass to a sub-agent, no attenuation, no credential. Next time it needs that data, it pays again via the same process. L402 is a protocol that was created by Lightning Labs in 2020. x402 is a protocol that was created by Coinbase in 2025.