Parse Client Input

Clients usually know a symbol and a decimal value, not an atomic integer.

That is why the compact string input format exists.

Recommended input

USDC|1250.00
v1:USDC|1250.00

Server-side parsing

amount = Amount.parse(params[:balance])

For example:

payload = { balance: "USDC|1250.00" }
balance = Amount.parse(payload[:balance])

balance.atomic
# => 1250000000

In Rails models

If you use has_amount, assignment parsing already happens through the model writer:

holding.amount = "USDC|1250.00"

What not to ask from the client

Do not require:

{ "atomic": "1250000000", "symbol": "USDC" }

unless the client is another trusted backend system and the object format is actually useful there.