FAQ
L402 Launch Checker
What is L402?
L402 is a protocol for Lightning Network payments as HTTP authentication. Instead of API keys, clients pay a small amount of sats and use the proof of payment (an L402 credential) to authenticate requests.
What does the L402 Launch Checker do?
It probes your API endpoint and tells you whether it is ready to accept Lightning payments via the L402 protocol. It runs a series of automated checks and gives you a clear classification: supported, unsupported, or unclear.
What is the difference between the free preflight check and the paid full scan?
The preflight check is a lightweight probe that sends a single request and checks for L402 signals. It gives you an immediate classification and is free to run.
The full scan executes the complete L402 flow against your endpoint, including invoice parsing, payment verification, and full transcript capture. It gives you a detailed report with a prioritized fix list.
What if my endpoint is not L402-ready yet?
That is the most common outcome and exactly when the paid scan is most useful. It tells you exactly what is missing and how to fix it.
How is this different from reading the L402 spec?
The spec describes what L402 should do. The scan tells you what your implementation actually does and where it diverges from the spec.
How long does the scan take?
Usually under 10 seconds. You set a max spend cap so costs are controlled.
What does the paid scan give me that the free preflight does not?
Extended challenge-response testing, invoice parsing and verification, full transcript capture, and a prioritized fix list with exact guidance.
How is pricing structured?
Preflight check is free. Full scan is 49 sats per scan. Scans are capped — you set the maximum spend before running. If the scan exhausts your cap, you pay only what was actually spent.
Who built this?
The L402 Launch Checker is built by the team behind Alby and the L402 protocol spec.
Contact
For support questions, email support@maximumsats.com with your invoice ID and we will resolve it promptly.