src/models/payment.rs::QuoteRequest.amount and SendPaymentRequest.send_amount are plain Strings with no validation that they parse as a positive decimal number before being forwarded to Horizon's /paths/strict-send or used to build DB records.
A malformed or negative amount (e.g., \"-5\", \"abc\", empty string) will either produce a confusing downstream Horizon error or silently insert garbage into transactions.send_amount. Add explicit parsing/validation (positive, non-zero, correct decimal precision) in src/routes/payments.rs before calling into PaymentService.
src/models/payment.rs::QuoteRequest.amountandSendPaymentRequest.send_amountare plainStrings with no validation that they parse as a positive decimal number before being forwarded to Horizon's/paths/strict-sendor used to build DB records.A malformed or negative amount (e.g.,
\"-5\",\"abc\", empty string) will either produce a confusing downstream Horizon error or silently insert garbage intotransactions.send_amount. Add explicit parsing/validation (positive, non-zero, correct decimal precision) insrc/routes/payments.rsbefore calling intoPaymentService.