Sei RPC Endpoint

Flat-rate Sei RPC provider and Sei RPC node access: free tier, no KYC, HTTP & WebSocket. Sei mainnet chain ID 1329.

Sei is a high-throughput Layer 1 whose EVM execution layer (chain ID 1329) offers a parallelized EVM built for trading and DeFi. It combines Cosmos-based consensus with full EVM bytecode compatibility, letting Ethereum contracts deploy without code changes.

About Sei

Sei's EVM (introduced with Sei v2) runs Geth-based execution behind a parallelized engine and uses Twin Turbo Consensus, derived from CometBFT/Tendermint, for fast block production and instant finality. Block times are around 400 milliseconds with single-block, BFT finality, and the EVM is fully bytecode-compatible so existing Solidity contracts and tooling work unchanged.

The native asset SEI pays for gas on the EVM and secures the network through proof-of-stake. Sei targets trading-heavy applications, and its ecosystem has concentrated around DeFi protocols and DEXes. On the EVM, SEI is represented with 18 decimals.

Common Use Cases on Sei

• On-chain trading and order-book DeFi
• DEXes and AMMs
• Lending and stablecoin markets
• EVM smart contract deployment
• High-frequency, low-latency applications

Sei Ecosystem

DeFi leaders include Yei Finance, DragonSwap, Sailor, and Takara Lend, alongside a growing set of EVM-native protocols.

Sei Mainnet RPC URL (HTTP)

Sei WebSocket RPC URL

Quick Start: Connect to Sei

cURL

curl -X POST https://rpc.swiftnodes.io/rpc/sei?key=YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

ethers.js

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider(
  "https://rpc.swiftnodes.io/rpc/sei?key=YOUR_API_KEY"
);

const blockNumber = await provider.getBlockNumber();
console.log("Sei block:", blockNumber);

viem

import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://rpc.swiftnodes.io/rpc/sei?key=YOUR_API_KEY"),
});

const blockNumber = await client.getBlockNumber();

web3.py

from web3 import Web3

w3 = Web3(Web3.HTTPProvider("https://rpc.swiftnodes.io/rpc/sei?key=YOUR_API_KEY"))
print("Sei block:", w3.eth.block_number)

Add Sei to MetaMask

Bridging to Sei

Assets bridge to Sei via providers such as Wormhole and Stargate (LayerZero), plus integrations through the Sei bridge interface.

Features of SwiftNodes for Sei

• Load-balanced across multiple upstream nodes wherever a chain has more than one, with automatic failover
• Health-checked every 2 minutes with automatic failover
• Free tier available — no credit card or KYC required
• Flat-rate monthly pricing with no per-request fees
• HTTP and WebSocket support
• One API key works across all 75+ supported chains, including Sei

Rate Limits

Frequently Asked Questions: Sei

Sei guides from the blog

• Sei RPC: Parallel EVM, Dual Addresses, and Instant FinalitySei speaks standard eth_* JSON-RPC, so viem and ethers just work — but three things surprise devs coming from Ethereum: a parallelized EVM, a dual Cosmos/EVM address world with pointer contracts, and single-block instant finality that makes reorg handling unnecessary. Here's what actually differs.

Related Cosmos chains

Explore RPC endpoints for other Cosmos networks on SwiftNodes: