1inch APIs are live on Cronos, Monad and HyperEVM

1inch Business now supports Cronos, Monad and HyperEVM with full API coverage from day one: Classic and Gasless Swaps, cross-chain swaps, limit orders, Web3 RPC and Data APIs. Pass chain ID 25, 143 or 999 to get started.

Three networks join 1inch Business at once: Cronos (chain ID 25), Monad (chain ID 143) and HyperEVM (chain ID 999), Hyperliquid's EVM network. Each one ships with the same API coverage you get on Ethereum or Base, and your existing API key and subscription already cover them.

Network	Chain ID	Gas token	Block time	Web3 RPC
Cronos	`25`	CRO	~0.4 s	`https://api.1inch.com/web3/25`
Monad	`143`	MON	300 ms, final at 600 ms	`https://api.1inch.com/web3/143`
HyperEVM	`999`	HYPE	1 s small blocks, 1 min large blocks	`https://api.1inch.com/web3/999`

WebSocket subscriptions use the same paths on wss://. Per-chain JSON-RPC method references are in the docs for Cronos, Monad and HyperEVM.

Why these networks

On every network the native token pays for gas, has 18 decimals, and is addressed in the Swap, Spot Price and Balance APIs as 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee, the same placeholder you use for ETH on Ethereum. Users who self-execute need a small balance of it; Gasless Swap users do not.

Cronos

Native token: CRO. Pays for gas on Cronos EVM and secures the network through staking.
Highlight: an established EVM chain with sub-second blocks and regulated stablecoin rails, native USDC, EURC and CCTP, on one network.

A public EVM chain built on the Cosmos SDK and live since November 2021. The Cronos ecosystem runs three chains; chain ID 25 is Cronos EVM, the general-purpose one. A July 2025 upgrade cut block time from 5.6 seconds to under half a second and added parallel transaction execution, so confirmations feel instant and fees stay under a cent. Since June 2026 the network carries native USDC and EURC with Circle's CCTP, alongside the older bridged USDC.e, which is still in circulation while liquidity migrates. Treat them as two separate tokens in your integration.

Monad

Native token: MON. Pays for gas and is staked by the validators that run MonadBFT.
Highlight: the fastest finality of the three: a transaction is included and irreversible in 600 ms, with your Ethereum contracts and tooling unchanged.

One of the fastest EVM chains: blocks every 300 ms with deterministic finality at 600 ms, so a transaction is both included and irreversible in under a second. Monad is EVM bytecode-compatible through the Fusaka fork, so contracts and tooling from other chains work without changes, and the contract size limit is 128 kB instead of Ethereum's 24.5 kB. Cold storage and account access are priced higher than on Ethereum, so estimate gas on-chain rather than reusing Ethereum constants. Monad runs native USDC through Circle's CCTP and has had an active trading community since launch.

HyperEVM

Native token: HYPE. Pays for gas on HyperEVM and moves freely between HyperEVM and HyperCore; both base and priority fees are burned.
Highlight: the EVM home of the Hyperliquid ecosystem. Your users get HYPE and the ecosystem tokens, reachable from any chain you support in one cross-chain swap.

Hyperliquid's EVM network, secured by the same HyperBFT consensus as the Hyperliquid exchange, and one of the most active trading ecosystems in DeFi. Fees are sub-cent. HyperEVM uses a dual-block layout: small blocks every second for ordinary transactions, and large blocks every minute with a 30M gas limit for heavy contract deployments, which an address opts into on the HyperCore side. Contracts on HyperEVM can read HyperCore state (spot balances, oracle prices, positions) through read precompiles.

What you can do

Swap API

Classic Swap is available on all three networks through the usual /swap/v6.1/<chainId> quote and swap endpoints, for self-executed on-chain trades. Gasless Swap is available on all three as well and gives your users MEV-protected execution without holding CRO, MON or HYPE for gas. Gasless Cross-chain Swap covers all three in both directions: move assets from Ethereum, Arbitrum or any other supported chain onto Cronos, Monad or HyperEVM, or back out again, in a single order with no bridge step.

Orderbook API

Limit orders can be placed and taken on the new chains. Makers sign orders off-chain and post them through the Orderbook API; takers fill them on-chain in the same flow you already use elsewhere.

Web3 RPC API

JSON-RPC over HTTPS and WebSocket subscriptions, with both full-node and archive-node access, from the endpoints in the table above. One provider and one API key cover all three networks alongside your existing chains:

import { createPublicClient, http } from "viem";

const chains = { cronos: 25, monad: 143, hyperEvm: 999 };

const clientFor = (chainId: number) =>

createPublicClient({

transport: http(`https://api.1inch.com/web3/${chainId}`, {

fetchOptions: {

headers: { Authorization: `Bearer ${process.env.ONEINCH_API_KEY}` }

}

})

});

for (const [name, chainId] of Object.entries(chains)) {

const blockNumber = await clientFor(chainId).getBlockNumber();

console.log(name, chainId, blockNumber);

}

Data APIs

Balance, History, Portfolio, Spot Price, Gas Price, Token, Token Details, Traces and Transaction Gateway all cover the new chains. In practice that means you can show a user's Cronos balances, decode their Monad transaction history, price HYPE on chain 999 with the Spot Price API, and broadcast transactions through the Transaction Gateway on each network from day one.

1inch MCP

AI assistants connected through the 1inch MCP Server can quote, swap and read data on chain IDs 25, 143 and 999 the same way they already do on your other chains. Ask for a quote on Monad or a wallet's HyperEVM balances and the assistant routes the call for you.

Integration notes

Two USDC tokens on Cronos. Native USDC and bridged USDC.e both circulate. Use the Token API to resolve addresses and label them separately in your UI.
Monad timestamps repeat. With 300 ms blocks, three to four consecutive blocks share the same second-granularity block.timestamp. Order by block number, not timestamp.
HyperEVM large blocks are opt-in. Contract deployments that exceed the small-block gas limit need the deploying address flagged for large blocks on HyperCore. Ordinary swaps and transfers fit in small blocks and need no change.
Gas tokens differ. Self-executed transactions need CRO, MON or HYPE respectively. Gasless Swap and Gasless Cross-chain Swap remove that requirement for your users.

Get started

There is nothing to enable on your account: your API key already covers chain IDs 25, 143 and 999. Chain-level calls such as Web3 RPC, Gas Price and Balance work as soon as you pass the new chainId.
Swap, Orderbook and other token-based calls need per-chain setup on top of the chainId. Token addresses differ on every network, so resolve them through the Token API rather than reusing addresses from another chain, and grant token approvals on each chain: the /swap/v6.1/<chainId>/approve/transaction endpoint builds the approval for that network's router.
Point your RPC client at https://api.1inch.com/web3/<chainId> if you want to read chain state or broadcast transactions through 1inch nodes.
Check the supported chains table for per-product details, and the Cronos, Monad and HyperEVM chain pages for the live product list.

HyperEVM is the EVM layer of Hyperliquid. Everything on chain ID 999 (quotes, balances, RPC) is EVM only; HyperCore, the perpetuals exchange, is a separate system and is not part of this release.