Transaction Relay

Overview

Transaction relay defines how nodes move pending transactions between peers before consensus includes them. Relay policy commonly checks syntax, fees, conflicts, resource limits, standardness, and dependencies to protect nodes from abuse.

Policy is not the same as consensus. A miner or validator may include a consensus-valid transaction that ordinary nodes would not relay, and software versions can differ in package, replacement, or fee rules. Wallets should construct widely relayable transactions, query rejection reasons, and support fee adjustment or rebroadcast where appropriate. Protocol designers must account for adversaries exploiting policy differences, especially with dependent or time-sensitive transactions. Operators should update policy carefully because excessively strict rules fragment propagation, while permissive rules can expose memory, bandwidth, and CPU resources to denial-of-service attacks.

Submission, peer acceptance, block inclusion, execution, confirmation, and finality provide different evidence, and a transaction can advance, stall, be replaced, or disappear from the canonical chain between those stages. Transaction Relay should be represented as a sequence of observable states rather than one success flag. Implementations need idempotent processing keyed to stable transaction and business identifiers. Repeated callbacks, node disagreements, reorganization, and delayed receipts must not create duplicate credits or irreversible state transitions before the required network evidence is available.

These records allow a later rescan to reconstruct the result when an endpoint, webhook, or local index becomes unreliable. Operational records should retain the raw transaction, network identifier, sender and destination, asset and amount, block reference, execution status, and observed timestamps. Settlement consideration: Relay policy governs pre-confirmation distribution, and its differences from consensus can determine whether a valid transaction reaches producers.