accountSubscribe

accountSubscribe registers a live watch on one account, identified by its base-58 public key. Whenever the runtime commits a change to that account — its lamport balance moves, its data bytes are rewritten, or its owner changes — the server pushes an accountNotification frame over the same WebSocket connection. Between changes the stream is silent, so a quiet account costs nothing beyond the open subscription.

The optional config object mirrors getAccountInfo: commitment decides how settled a change must be before you hear about it (processed for lowest latency, confirmed — the default — for the usual balance of speed and safety, finalized when rollbacks are unacceptable), and encoding controls the shape of value.data (base58, base64, base64+zstd, or jsonParsed for well-known programs such as SPL Token). The notification payload is the same context/value envelope getAccountInfo returns, so parsing code can be shared between the polling and streaming paths.

Typical uses: tracking a hot wallet's SOL balance without polling, watching a token account for incoming deposits, following a program-derived address (PDA) that a program mutates, or reacting to an oracle price account the moment it updates. One WebSocket connection can carry many account subscriptions side by side — route incoming frames by params.subscription.

Two lifecycle rules catch people out. First, a subscription lives only as long as the WebSocket session: if the socket drops and you reconnect, you must send accountSubscribe again — subscription ids are not portable across connections. Second, notifications fire once per committed change of state, not once per transaction: several writes landing in one slot can collapse into a single notification carrying the final state. Stop the stream with accountUnsubscribe, passing the integer id from the subscribe ack.