Rails & Transfers
Heron allows you to move funds between different payment "rails"—the underlying infrastructure for global money movement. This guide explains how to select the right rail and how transfers are validated.
Payment Rails
A Rail defines the network and rules for a transaction. Heron supports two primary types of rails:
1. Fiat Rails
Used for traditional bank transfers. When using a Fiat rail, you must specify:
- Country: The destination ISO country code (e.g.,
US,GB,AU). - Currency: The asset being moved (e.g.,
USD,GBP,AUD). - Method: The specific transfer protocol (e.g.,
ACH,SEPA,DOMESTIC).
2. Crypto Rails
Used for digital asset transfers across blockchains. When using a Crypto rail, you must specify:
- Blockchain: The network (e.g.,
ETHEREUM,POLYGON,BITCOIN). - Asset: The specific token or cryptocurrency (e.g.,
USDC,ETH,BTC).
The Transfer Lifecycle
Every transfer in Heron goes through a strictly tracked lifecycle to ensure compliance and reliability.
- Pending: The transfer has been created but not yet validated against funds or compliance rules.
- Ready for Execution: All requirements are met, and the transfer is awaiting the next processing window.
- Executing: The funds are currently being moved across the selected rail.
- Completed: The recipient has received the funds.
- Failed: The transfer was rejected (e.g., insufficient funds or invalid instruction details).
Validation Rules
To prevent accidental failures, Heron enforces strict validation on transfer instructions:
- Exact Amounts: Amounts must be provided as positive decimal strings (e.g.,
"150.00"). We reject invalid characters or ambiguous formats. - Decimal Alignment: Each rail has a specific decimal precision. For example, most Fiat rails use 2 decimals, while some Crypto assets use up to 18.
- Instruction Details:
- US Rails: Require a valid 9-digit Routing Number and Account Number.
- EU Rails: Require a valid IBAN and optionally a BIC/SWIFT code.
- CA/AU/GB Rails: Require regional identifiers like Transit Numbers or Sort Codes.
IMPORTANT
Always verify that your instruction details match the requirements of the selected rail to avoid delays or reversals.