Neon Zero

Neon Zero gates sendTransaction on its own URLs by each region's distance to the current slot leader. It is built for automated traders that send many attempts, such as arbitrage bots.

How the gate works

The Solana leader changes every four slots and moves between validators around the world. Each constant-k RPC region runs its own gate and measures its own distance to the current leader. The gate is open while the current leader is close to that region and its slot has just begun; otherwise it is closed.

While the gate is open, the transaction is sent. Up to 50 sends per second per API key per region go through the staked path; above that rate, sends go through the network path. While the gate is closed, the transaction is not sent to the network. If the gate cannot decide, for example while it restarts, it counts as closed: nothing is sent ungated.

Every send counts toward the API key's regular sendTransaction rate limit and request rate limit, whether the gate is open or closed, as on the other RPC URLs. Only sends that pass the gate use the 50 per second staked allowance.

Endpoints

Region	URL
New York	https://neon-rpc-newyork.constant-k.com/?api-key=YOUR_API_KEY
Frankfurt	https://neon-rpc-frankfurt.constant-k.com/?api-key=YOUR_API_KEY
Amsterdam	https://neon-rpc-amsterdam.constant-k.com/?api-key=YOUR_API_KEY

Authentication is the same as on the other RPC URLs: the api-key query parameter or the x-api-key header. Existing URLs are unchanged.

Plans

Responses

Version 1 transactions (SIMD-0385) cannot be decoded while the gate is closed. Every other RPC method behaves as it does on the staked RPC URL.

Sending with Neon Zero

1. Point the client at the region's Neon Zero URL.
2. Send as usual.
3. Check the transaction's status by signature.

import { Connection } from "@solana/web3.js";

const connection = new Connection(
  "https://neon-rpc-newyork.constant-k.com/?api-key=YOUR_API_KEY",
);

// signedTx: a signed transaction, serialized
// lastValidBlockHeight: from the blockhash signedTx was built with
const opts = { skipPreflight: true, maxRetries: 0 };
const signature = await connection.sendRawTransaction(signedTx, opts);

while (true) {
  await new Promise((r) => setTimeout(r, 400));
  const { value: [status] } = await connection.getSignatureStatuses([signature]);
  if (status?.confirmationStatus) break;
  if ((await connection.getBlockHeight()) > lastValidBlockHeight) throw new Error("blockhash expired");
  // optional, your client's choice: send it again while it is unconfirmed
  await connection.sendRawTransaction(signedTx, opts);
}

Measured landing rate

Measured in Frankfurt in October 2026, as the share of transactions that landed in the slot they were sent (slot+0). About 25% of sends pass the gate.

Related