Why bother rehearsing
The first bill is the one you want to get right
A bill of exchange is unforgiving by design. Once your buyer accepts, the sum and the date are fixed; once you endorse it onward, you stay liable for it. That discipline is the reason the instrument works, and the reason nobody should be learning the buttons on a live shipment.
On Testnet the whole mechanism runs exactly as it does on mainnet, against coins that are worth nothing. Practise the sequence, agree the wording with your counterparty, see what the endorsement chain looks like on a phone, then go and do it for real.
The rehearsal
Five steps, then you have done it once
01
Get onto Testnet3
Two different moves, one for each app. In eCash, open Settings and switch the wallet from Mainnet to Testnet. For eBills there is a separate address, so open ebill-testnet.bit.cr (opens in a new tab) in your browser, and when it prompts you, use Share, then Add to Home Screen.
Nothing you do from there touches mainnet, and your live identity stays where it is.
02
Bring a counterparty
A bill needs two sides. Use a colleague, a second device, or better still the buyer you actually intend to sell to on terms.
03
Issue and accept a bill
Draw it for a sum and a maturity you would really use. Have the other side accept, and read what the acceptance commits them to.
04
Endorse it onward
Pass the accepted bill to a third identity in payment. This is where the endorsement chain becomes visible, and where liability stops being abstract.
05
Mint it, then settle
Split the bill into e-cash with a test mint, which is what puts spendable test coins in your wallet, so there is nothing to claim from a faucet first. Spend some, then pay at maturity and watch the chain close. On Testnet a bill under 5,000 sats mints automatically, so you see the whole sequence without waiting on anyone; on mainnet a real Wildcat quotes every bill.
What is different on Testnet
- The coins are worthless
- Test coins have no price and cannot be exchanged for anything. Nobody gets rich or poor in here. There is no faucet to find, either: minting your test bill is what puts e-cash in the wallet, so step 5 is where the coins come from.
- The bills are not enforceable
- A rehearsal bill creates no obligation on anyone. Do not use one to document a real shipment.
- The mints are test mints
- Their rates are for practice, not quotes, and anything under 5,000 sats mints automatically to keep the rehearsal moving. On mainnet every bill is quoted by a real Wildcat, and there is no automatic threshold.
- The slate can be wiped
- Test networks get reset. Treat anything you build here as a sketch, and keep your real identity separate.
- Everything else is identical
- Same app, same signatures, same endorsement rules. What you learn here transfers exactly.
Worth trying
Three rehearsals that teach you something
Each one is a shape that turns up constantly in real trade. Run the one closest to your own business.
The ordinary export
One bill, ninety days, paid at maturity
Issue for the amount and term you actually sell on. Then leave it alone until maturity and pay it. This is the base case, and it is the one to be fluent in.
The chain
Pay your own supplier with the same bill
Endorse the accepted bill onward instead of minting it. Watch each signature attach, and see that you are still liable after passing it on, which is the part people misread.
The cash squeeze
Mint it because Friday is payroll
Split the bill into e-cash and spend part of it. Compare what you receive today against the face value at maturity, and decide whether that trade is one you would make.
Rehearsed it? Then do it for real
Rehearse at ebill-testnet.bit.cr; when it counts, use ebill.bit.cr and switch the wallet back to Mainnet. If you would rather have someone on the call while you do it, say so.