RPC method

eth_subscribe on ApeChain

Supported on SwiftNodes

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

eth_subscribe on ApeChain: what we measured

newHeadssupported
First header after subscribing2.0 s
Median gap between headers810 ms
Headers in 15 seconds16
logssupported
newPendingTransactionssupported

What this means on ApeChain

Headers pushed over WebSocket are not identical to eth_getBlockByNumber over HTTP on ApeChain. Only the HTTP block has l1BlockNumber, sendCount, sendRoot, size. Fetch the block over HTTP if you need those fields.

Subscriptions end when the connection drops. Reconnect with backoff and, after reconnecting, fetch the blocks you missed with eth_getBlockByNumber.

Example request

wscat -c "wss://rpc.swiftnodes.io/ws/apechain?key=YOUR_API_KEY"
> {"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["newHeads"]}
import { createPublicClient, webSocket } from "viem";

const client = createPublicClient({
  transport: webSocket("wss://rpc.swiftnodes.io/ws/apechain?key=YOUR_API_KEY", { reconnect: true }),
});

const unwatch = client.watchBlocks({
  onBlock: (block) => console.log(block.number, block.hash),
});

// Events from one contract, pushed as they are mined
client.watchContractEvent({ address: token, abi: erc20Abi, eventName: "Transfer", onLogs: (logs) => console.log(logs) });

Other methods on ApeChain

eth_subscribe on other chains

Frequently asked questions

Does ApeChain support eth_subscribe?

Yes. eth_subscribe answered on the SwiftNodes ApeChain endpoint when our weekly probe called it through the customer path (2026-10-13).

Does ApeChain support WebSocket subscriptions?

Yes. newHeads and logs worked through wss://rpc.swiftnodes.io/ws/apechain on 2026-10-13.

Can I watch the ApeChain mempool?

newPendingTransactions is supported.

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

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