Transaction Dependency

Overview

A transaction dependency links operations that cannot be processed independently. A transaction may spend an output created by another, require a preceding nonce, consume an object version, or assume state established by an earlier contract call. Dependencies constrain mempool admission, parallel execution, block ordering, and reorganization behavior. Some systems express them explicitly through inputs or account lists, while others discover conflicts during execution and retry or reject affected operations.

Wallets should broadcast parent transactions before children and monitor both rather than displaying the later transaction as independently settled. Block builders must avoid cycles and unavailable prerequisites. Developers can improve throughput by minimizing unnecessary shared state, but they cannot ignore true causal relationships. A dependency becomes safe only at the confirmation or finality level required by the application. 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. User-facing status should describe what is known without overstating settlement. Unknown, pending, included, failed, replaced, and finalized conditions need separate handling, together with a recovery procedure for transactions whose observed state conflicts across providers.

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 Dependency should be represented as a sequence of observable states rather than one success flag.

Implementation note: Transaction dependencies impose causal order, affecting propagation, parallelism, failure handling, and the finality required for downstream actions.