Follow One Payment
Follow One PaymentLearning to read real code by following one RLUSD payment
Chapter 0 of 11 · all chapters
  1. 0The Big Pictureyou are here
  2. 1How to Read Codenext
  3. 2Build Itlater
  4. 3Byteslater
  5. 4Sign Itlater
  6. 5Send Itlater
  7. 6Agreelater
  8. 7Check Itlater
  9. 8Plan the Routelater
  10. 9Move the Moneylater
  11. 10The Receiptlater
  12. 11Put It All Togetherlater

Part 1 · Before the code · about 30 minutes

Chapter 0 · The Big Picture

One real payment of 60 RLUSD, taken from the XRP Ledger. Before we read any code, we get the whole map. Press Play to watch it like a video, or step through the scenes yourself. Then follow the same payment through the real code, line by line.

Alice's wallet To rLpDMH…6SscAP Destination tag 115717373 Amount 60 RLUSD Send seconds later Ledger 107,250,681 closed 26 Sep 2026 15:03:10 UTC Alice → Bob: 60 RLUSD tesSUCCESS final: it can't be undone
Scene 1 of 9

Alice presses Send

On the twenty-sixth of September, one account on the XRP Ledger sent sixty RLUSD to another. We'll call them Alice and Bob. A few seconds later, the payment was final, and nothing can ever undo it. This whole course follows that one payment, from the moment Alice's wallet built it, to the moment the ledger wrote it down. Before we read any code, let's get the whole map.

From the real ledger

Read from an XRP Ledger server on 26 September 2026.

Payment ID
11D28D227049580AA070DA88AE209FA314266469095FBA682F9E438B8065E50B
Ledger
107,250,681
Closed
26 Sep 2026, 15:03:10 UTC
Amount
60 RLUSD
Result
tesSUCCESSthe code for "it worked"

Space plays or pauses. The arrow keys move between scenes. Every scene's words are printed beside the picture, so it works with the sound off too.

A first look at the real code

Follow it through the code

This is the actual code our payment passes through, from your wallet SDK to the server to your validator, with the payment's real values at every step. You don't need to understand every line yet. Watch where the payment goes and what happens to its numbers. From Chapter 1 on, we'll learn to read each stop properly.

    Your turn

    Try it

    Put the nine stops in order

    Use the arrows to move each stop. When you think the order is right, press Check. Try it from memory before looking at scene 9 again.

      Check yourself

      Two questions for me

      Answer in your own words, then press Copy and paste your answers to me in our chat. I'll tell you right or wrong.

      Own it

      Draw it from memory

      Close this page. On paper, draw Alice, Ripple and Bob with their two trust lines, and write each line's balance before and after the payment. Then open scene 7 and check yourself.

      Next: Chapter 1 · How to Read Code, the toolkit for every chapter after it.