Go Payment Processor

Simulates a secure implementation of internal wallets transfers and external payments operations in a Fintech system. It demonstrates the use atomic database transactions and idempotency keys to prevent race conditions, double processing, and handling concurrent requests properly.

• Wallet Funding: Simulates funding wallet from an external source e.g virtual account credit
• Internal Wallet Transfer: Simulates transfer between wallets, accounts for race conditions and idempotency.
• External Bank Transfer: Simulates USD/GRP/EUR transfers to external bank accounts.

Setup with Docker

1) Clone repo

git clone https://github.com/jesseinvent/go-payment-processor

2) Build with Docker and run migrations

make build-docker

Endpoints

Create user - Simulates user registration

curl -X POST http://localhost:5001/api/v1/users \
-H "Content-Type: application/json" \
-d '{
  "name": "James",
  "email": "james@example.com",
  "phoneNumber": "09037148367"
}'

Get user - Simulates fetching user details e.g during login

curl -X GET http://localhost:5001/api/v1/users/1

Create Currency - Simulates adding a new currency to the system

curl -X POST http://localhost:5001/api/v1/currencies \
-H "Content-Type: application/json" \
-d '{
  "name": "USD",
  "symbol": "USD",
  "baseUnitFactor": 100,
  "iconUrl": "https://usd-icon.png"
}'

Get Currencies - Simulates fetching all available currencies in the system

curl -X GET http://localhost:5001/api/v1/currencies

Create wallet for user - Simulates wallet creation for a user in a specific currency

curl -X POST http://localhost:5001/api/v1/wallets \
-H "Content-Type: application/json" \
-d '{
  "userId": 1,
  "currencyId": 1
}'

Get user wallet details - Simulates fetching a user's wallets details including balance and currency information

curl -X GET http://localhost:5001/api/v1/wallets/user/1

Fund wallet - Simulates funding a user's wallet from an external source

curl -X POST http://localhost:5001/api/v1/wallets/fund-wallet \
-H "Content-Type: application/json" \
-d '{
  "userId": 1,
  "walletId": 1,
  "amount": 1000
}'

Internal wallet transfer - Simulates transferring payments in a specific currency between two wallets within the system

curl -X POST http://localhost:5001/api/v1/wallets/internal-transfer \
-H "Content-Type: application/json" \
-H "Idempotency-Key: <unique-uuid-key>" \
-d '{
  "senderUserId": 2,
  "receiverUserId": 1,
  "currencyId": 1,
  "amount": 20.5
}'

External bank transfer - Simulates transferring payments in a specific currency from a user's wallet to an external bank account

curl -X POST http://localhost:5001/api/v1/wallets/external-transfer \
-H "Content-Type: application/json" \
-H "Idempotency-Key: <unique-uuid-key>" \
-d '{
  "senderUserId": 1,
  "currencyId": 1,
  "amount": 10.5,
  "beneficiaryName": "John Doe",
  "beneficiaryAccountNumber": "1234568951",
  "beneficiaryBankCode": "133",
  "swiftCode": "11111",
  "sortCode": "0000"
}'

Get transaction history - Simulates fetching a user's transaction history

curl -X GET "http://localhost:5001/api/v1/transactions/user/1"