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Documentation Index

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Use this file to discover all available pages before exploring further.

This page answers the most common questions about Fuse Network, building on Fuse, using the token bridge, and understanding network fundamentals. If you don’t find what you need here, join the community on Discord or Telegram.

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Fuse basics

Fuse Network is a decentralized platform for creating and deploying Web3 applications. It is an EVM-compatible Layer 1 blockchain that offers fast and inexpensive transactions, making it ideal for building decentralized applications. The native token of the Fuse Network is the FUSE token.
A Fuse Smart Wallet is a non-custodial smart contract wallet based on ERC-4337 that allows users to securely store, send, and receive cryptocurrency and tokens. It is built on the Fuse Network and supports gasless transactions, making it practical for use in dApps. Each smart wallet is an upgradable smart contract deployed on-chain with an owner who controls the wallet’s funds.
An Operator on Fuse is an intermediary that enables consumers to interact with the Fuse blockchain via their own solutions. Operators can be integrators, payment providers, financial institutions, apps, consumer clubs, sharing economies, startups, local communities, and retailers. A key feature of Operators is that they pay network fees on behalf of their users. Operators build their applications using the FuseBox Web SDK, Flutter SDK, or REST API endpoints.
A gasless transaction is a transaction where the user does not pay gas fees directly. On Fuse, gasless transactions are covered by paymasters—entities that are incentivized to provide this service to users. The paymaster model is part of the ERC-4337 account abstraction standard.
  • Fuse mainnet: Chain ID / Network ID 122, RPC URL https://rpc.fuse.io
  • Fuse Spark testnet: Chain ID / Network ID 123, RPC URL https://rpc.fusespark.io

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Building on Fuse

Follow the “Build on Fuse” guide and set the Network ID to 123 in your deployment configuration. You can get free testnet FUSE tokens from the ChainDrop faucet or the Stakely faucet.
Follow the “Build on Fuse” guide and set the Network ID to 122. Ensure your deploying account holds enough FUSE tokens to pay for gas.
The full API reference is available in the API reference section of this documentation. It covers the Smart Wallet API, Balances API, Trade API, Notification API, Explorer API, and Staking API.
The FuseBox SDK currently supports Dart (Flutter) and JavaScript/TypeScript (Web SDK). Support for additional languages is planned. The SDK simplifies Account Abstraction on Fuse and offers smart contract wallet creation, ERC20 and native FUSE transfers, staking, data services, and trading functions.
The FuseBox SDK is designed to work with Fuse Network and Fuse Sparknet. Support for additional blockchains is planned for the future.
Try these steps:
  1. Verify you followed the installation instructions correctly.
  2. Check that you have the latest SDK version (Web SDK on npm, Flutter SDK on pub.dev).
  3. Confirm your API key is valid and has the necessary permissions. Get an API key at console.fuse.io/build.
  4. Check the SDK documentation for known issues and solutions.
  5. Ask for help in the Discord developer channel.

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Fuse Token Bridge

The Fuse Token Bridge supports FUSE, USDC, and WETH tokens.
Tokens can be bridged between Fuse Network and Polygon, Optimism, and Arbitrum.
The Fuse Bridge uses bridge-specific token versions: USDC V2 and WETH V2. Their value is identical to standard USDC and WETH, but they are different contracts. You need to swap your standard USDC or WETH for the V2 versions first using Voltage Finance, then bridge the V2 tokens.
When you deposit via the bridge, you receive USDC V2 or WETH V2 tokens. Add them to your wallet manually:After adding them, you can swap to standard USDC or WETH on Voltage Finance.
The Fuse Token Bridge is powered by LayerZero technology. Its security is monitored by blockchain security experts at Ironblocks.
Currently there are zero bridge fees on the Fuse Token Bridge. However, you will still pay gas fees on the source and destination networks.
Liquidity on the bridge is currently limited. Avoid bridging large amounts until liquidity improves.
There are two FUSE token contracts on Polygon: a deprecated one and the current active one. Both are valid, but the deprecated one is no longer used by the bridge.Swap the deprecated tokens for the new ones using MetaMask’s built-in swap or any dApp that supports both contracts.
Yes. Watch the bridge walkthrough video for a step-by-step demonstration.

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Gas fees

Gas fees are calculated by multiplying the amount of gas used by the current gas price:
gas fee = gas used × gas price (in gwei)
Each operation—sending tokens, interacting with a contract, transferring assets—requires a measurable amount of computational work expressed in gas units. Fuse Network has significantly lower gas prices than Ethereum mainnet, making individual transactions much cheaper.

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