eth_subscribe
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.
newHeads worked on 47 of 55 chains through our WebSocket endpoint; newPendingTransactions on 45.
eth_subscribe on 47 chains, measured
Measured 2026-10-13 by calling eth_subscribe through the SwiftNodes endpoint for each chain, re-measured weekly. Each chain links to its own page with the full response and code.
| Chain | newHeads | logs | newPendingTransactions |
|---|---|---|---|
| Abstract | yes | yes | yes |
| ApeChain | yes | yes | yes |
| Arbitrum | yes | yes | yes |
| Arbitrum Nova | yes | yes | yes |
| Avalanche | yes | yes | yes |
| Base | yes | yes | no |
| Berachain | yes | yes | yes |
| Blast | yes | yes | yes |
| BNB Smart Chain | yes | yes | yes |
| Boba Network | yes | yes | yes |
| Celo | yes | yes | yes |
| Chiliz | yes | yes | yes |
| Core | yes | yes | yes |
| Cronos | yes | yes | yes |
| Ethereum | yes | yes | yes |
| Fantom | yes | yes | yes |
| Flare | yes | yes | yes |
| Fraxtal | yes | yes | yes |
| Hemi | yes | yes | yes |
| Hyperliquid | yes | yes | yes |
| Ink | yes | yes | yes |
| Kaia | yes | yes | yes |
| Katana | yes | yes | yes |
| Linea | yes | yes | yes |
| Lisk | yes | yes | yes |
| Manta Pacific | yes | yes | yes |
| Mantle | yes | yes | yes |
| MegaETH | yes | yes | yes |
| Monad | yes | yes | yes |
| Morph | yes | yes | yes |
| opBNB | yes | yes | yes |
| Optimism | yes | yes | yes |
| Polygon | yes | yes | yes |
| PulseChain | yes | yes | yes |
| Scroll | yes | yes | yes |
| Sei | yes | yes | no |
| Shibarium | yes | yes | yes |
| Soneium | yes | yes | yes |
| Sonic | yes | yes | yes |
| Story | yes | yes | yes |
| Taiko | yes | yes | yes |
| Telos EVM | yes | yes | yes |
| Tempo | yes | yes | yes |
| Unichain | yes | yes | yes |
| World Chain | yes | yes | yes |
| X Layer | yes | yes | yes |
| zkSync Era | yes | yes | yes |
Not served through our endpoint when measured: Gnosis, Ethereum Classic, Plasma, Mode, Immutable zkEVM, Zora, BOB, Ronin.
Replace YOUR_API_KEY in the examples on each chain page with your SwiftNodes key (free tier available).