RPC method

eth_subscribe on Mode

Not available on SwiftNodes

Everything below was measured on 2026-10-13 by calling eth_subscribe on Mode 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 Mode

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

Other methods on Mode

eth_subscribe on other chains

Frequently asked questions

Does Mode support eth_subscribe?

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

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

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