Sei RPC — Free Endpoint & Developer Guide

Sei is a fast layer-1 optimized for trading, with full EVM support. This guide shows how to connect to a free Sei RPC endpoint on MoltNode — no API key and no signup required.

What is Sei

Sei is a layer-1 blockchain built with trading and exchange-style applications in mind, emphasizing fast finality and high throughput so order-driven and latency-sensitive apps feel responsive. Alongside its native execution, Sei offers full EVM support, which means Solidity contracts and Ethereum tooling run on it directly.

Because Sei exposes an EVM interface, it speaks the standard eth_* JSON-RPC method set, uses ordinary Ethereum-style addresses, and is identified by an EVM chain ID. The native token is SEI, used to pay for gas, and the EVM chain ID is 1329. If you have built on any other EVM chain, your mental model transfers directly: deploy with the same compilers, query with the same RPC calls, and connect the same wallets. That makes Sei approachable whether you are porting an existing app or starting fresh.

Sei RPC endpoint on MoltNode

MoltNode gives Sei one clean URL that is also a live RPC endpoint:

https://moltnode.ag/sei

There is no API key to provision and no account to create. The endpoint speaks JSON-RPC 2.0 over HTTP POST, and CORS is open so browser apps can call it directly. The URL is intentionally dual-purpose: open it with a GET request in a browser and you get a human-readable page describing the chain; send a POST with a JSON-RPC body and you get a machine response. Same address, two audiences.

To add it as a custom network in a wallet, point the network's RPC URL at https://moltnode.ag/sei, set the chain ID to 1329, and use SEI as the currency symbol.

Probe it with curl

The quickest way to confirm the Sei JSON-RPC endpoint is live is to ask for the latest block number:

curl -s https://moltnode.ag/sei \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'

You will get back a JSON object with a hex-encoded block height in the result field. Swap in any other eth_* method — eth_chainId, eth_getBalance, eth_call — to read whatever your app needs.

Use it from your app

Any JSON-RPC client works. Here is a minimal example with viem, pointing a custom transport at the free Sei RPC:

import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://moltnode.ag/sei"),
});

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

The same URL drops into ethers, web3.py, wagmi, or any other library that accepts an HTTP RPC URL — no special configuration beyond the endpoint itself.

Reliability & failover

Behind the single moltnode.ag/sei URL, MoltNode routes requests to a managed upstream provider and can fail over to an alternate path when the primary is unreachable or returns an error, so transient upstream hiccups do not break your app. The provider API keys live server-side and are never exposed to your client, so you get the benefit of a premium upstream without managing any credentials yourself.

There is no hard rate limit, but the endpoint is a shared, free resource. Please use it responsibly: cache results where you can, avoid tight polling loops, and if you are running heavy production workloads, treat the Sei RPC endpoint as a fast default and a failover rather than a single point of dependence.

For humans and agents

The dual GET/POST behavior makes the endpoint friendly to both people and software. A developer can paste https://moltnode.ag/sei into a browser to read about the chain; a script or wallet POSTs Sei JSON-RPC to the same place.

For automated discovery, MoltNode publishes a machine-readable catalog of every supported chain at https://moltnode.ag/api/chains and an agent-oriented summary at https://moltnode.ag/llms.txt. An AI agent can fetch the catalog, find the Sei entry and its endpoint, and start issuing eth_* calls without any human setup.

Closing

The free Sei RPC endpoint at https://moltnode.ag/sei gives you a no-key, JSON-RPC Sei node that works with viem, ethers, wallets, and AI agents alike — with automatic failover handled for you. Point your client at the URL and start building.