Account Subscription

Overview

Account Subscription is a standing API or RPC subscription that sends notifications when the observed state of an account changes. It is used to avoid repeated polling and deliver near-real-time updates to wallets, payment systems, or monitoring tools. It differs from an account query, which returns a point-in-time response and does not continue watching.

A typical implementation works as follows: The client opens a streaming or socket connection, registers the account and commitment, receives update messages, and reconnects or backfills after interruption. Replay of Account Subscription should preserve original identifiers and timestamps so historical processing cannot masquerade as a new event.

Common risks include dropped connections and duplicate or reordered notifications. Important failure modes include dropped connections, duplicate or reordered notifications, reorganization effects, provider limits, and missed updates during reconnect. These failures can create gaps.

Core controls require teams to use subscription IDs, heartbeats, checkpointed state, idempotent consumers, backfill queries, explicit commitment, and bounded reconnect logic. A receiver should treat transport acknowledgement and successful downstream processing as separate states for Account Subscription.

Operational evidence should include subscription ID, account, connection, commitment, sequence or slot, last event, reconnect count, and backfill result. Account Subscription should be documented alongside Account Query, Address Monitor, and Callback Event.

The Account Subscription path should preserve ordering and duplicate evidence so delayed delivery cannot silently overwrite a newer state. Recovery for Account Subscription should combine replay controls with an authoritative status check rather than trusting delivery history alone. A Account Subscription handler should acknowledge only after durable receipt when the provider’s retry contract depends on the response.