RPC method

eth_subscribe on BOB

Not available on SwiftNodes

Everything below was measured on 2026-10-13 by calling eth_subscribe on BOB through the same endpoint customers use, and is re-measured weekly.

What eth_subscribe does

Opens a subscription over WebSocket: newHeads pushes each new block header, logs pushes matching events, and newPendingTransactions pushes mempool transaction hashes where the node exposes them. It replaces polling, and it only works over WebSocket, not HTTP.

On BOB

newHeads did not work on BOB in our probe. Poll eth_blockNumber instead.

Other methods on BOB

eth_subscribe on other chains

Frequently asked questions

Does BOB support eth_subscribe?

eth_subscribe did not work on our BOB endpoint in the latest probe (2026-10-13).

BOB endpoints, live block height and WebSocket status are on the BOB RPC page.

One key covers every chain we serve, and SwiftNodes has a free tier.