slotSubscribe

slotSubscribe opens a Solana PubSub subscription that pushes a small notification — { parent, root, slot } — every time the node processes a new slot. Solana advances a slot roughly every 400ms under Proof-of-History, so this is a steady, lightweight heartbeat of the chain's leading edge, useful on a network whose fees are paid in SOL. The matching JSON-RPC endpoint is https://solana.therpc.io/YOUR_API_KEY, and you stop the stream by passing the returned subscription id to slotUnsubscribe.

Use cases

• Drive a live slot or height ticker in a UI off the ~400ms heartbeat, without ever polling getSlot.
• Trigger per-slot work in a streaming pipeline — sampling state or batching tasks each time a new slot lands.
• Detect chain progress and watch the root field advance to see finalization keep pace with the leading slot.

Parameters

此方法不需要任何参数，传入空数组 [] 即可。

Response

Example request

1# Open a WebSocket connection (e.g. with wscat) and send the subscribe request:
2wscat -c wss://solana.therpc.io/YOUR_API_KEY
3# then send:
4> {"jsonrpc":"2.0","id":1,"method":"slotSubscribe","params":[]}

Errors & troubleshooting

Common pitfalls

• Notifications track processed slots, which are not yet finalized and can be skipped or rolled back — if you need a settled view, map slots to a commitment yourself or follow rootSubscribe instead.
• This is a WebSocket-only method — it streams over a wss PubSub connection, and you stop it by passing the subscription id to slotUnsubscribe.

Supported networks

• Mainnet
• Devnet

See also

• getSlot
• rootSubscribe
• blockSubscribe