EVM networks

One EVM driver serves every chain below, with either library: ethers (v6, the default) or web3 (v4). ChainSafe sunset web3.js in 2025, and 4.16.0 is its last release, with no further fixes, so library: 'web3' is deprecated: crypto-aio keeps it working and tested through 1.x, warns once per process (a DeprecationWarning, code CRYPTO_AIO_WEB3), and removes it in 2.0. Use ethers. The Build guides cover EVM fees, replacements, token verdicts and proofs and scans; Keys, signers and secrets covers the ethers and web3 clients.

Chain	Networks (chain id)	Fees	Finality	Replace / cancel
ethereum	mainnet (1), sepolia (11155111), hoodi (560048)	evm-1559	finalized tag	yes
bsc	mainnet (56), testnet (97)	evm-legacy (the base fee is always 0)	finalized tag	yes
polygon	mainnet (137), amoy (80002)	evm-1559; mainnet tips at least 25 gwei	finalized tag	yes
avalanche	mainnet (43114), fuji (43113)	evm-1559	the latest block is final	yes
arbitrum	mainnet (42161), sepolia (421614)	evm-1559	finalized tag	no: there is no mempool
optimism, base	mainnet (10, 8453), sepolia (11155420, 84532)	evm-1559 plus l1-data and operator charges	finalized tag	yes

• Tokens. ERC-20 only. USDT (Ethereum, Avalanche) and USDC (every built-in mainnet but BNB Smart Chain) resolve by alias on mainnet, where their issuers deploy them natively. Any other token resolves by contract, with its symbol and decimals read from the chain under the proof quorum, so one endpoint cannot mis-scale amounts. A contract whose decimals() or symbol() reverts or answers nothing usable, or an address with no contract yet, stays unresolvable (ASSET_RESOLUTION) until the container restarts; any other node error stays retryable.
• Deprecated tokens. Tether's USDT contract on Ethereum (TetherToken) can deprecate itself in favour of an upgraded contract (its upgradedAddress()). A transfer then still moves the money through the new contract, which emits the Transfer event, but the token verdict reads the event of the contract you sent to. So every token estimate first reads the contract's deprecated() (one eth_call from one endpoint), and a token that answers true is refused before signing with ASSET_RESOLUTION, whose message names no address. Send to the upgraded contract by contract, or register it as an asset, until a release moves the USDT alias there. A contract without the method (a revert, an empty answer, or anything but an ABI bool) is not deprecated, and a failed read stays retryable.
• OP Stack fees. On OP Mainnet, Base, their testnets and a custom network with params.l1DataFee: 'op-stack', every estimate, replacement and cancel also reads the GasPriceOracle predeploy, two calls side by side. l1-data is its getL1Fee for the unsigned bytes (details.l1Fee). operator, since the Isthmus upgrade, is its getOperatorFee for the whole gas limit (details.operatorFee): an upper bound, since the fee grows with the gas used, by the formula of the chain's fork (Jovian changed it). Both count in details.expected and the funds check, and the bound is expected: the L1 fee moves with L1 prices, the operator fee with the chain's operator settings. A chain before Isthmus (the call reverts or answers nothing) or a zero operator fee adds no operator charge; a failed or malformed answer stays retryable. A confirmed transaction's reported fee includes its receipt's L1 fee, not the operator fee.
• Presets. alchemy and infura serve every network above; ankr the Ethereum, BNB Smart Chain, Avalanche, Arbitrum and Base mainnets; public the networks whose chain documents a public endpoint (not Ethereum). The public Base, Arbitrum and OP Sepolia endpoints may refuse Node's fetch (a Cloudflare 403, seen as PROVIDER_UNAVAILABLE).
• Fee ceiling. No transfer, replacement or cancel signs a price per gas above the maxFeePerGas option, in wei as a bigint (chains.<id>.options or a handle's options; 1,000 gwei by default, DEFAULT_MAX_FEE_PER_GAS from crypto-aio/evm; a custom network may set params.maxFeePerGas). A node's suggestion is clamped to it, and an explicit fee or a cancel's least bump above it fails with INVALID_INTENT before signing (details.required, details.maxFeePerGas). If the base fee rises above the ceiling, transfers stall as FEE_TOO_LOW until it falls or you raise the option. Any key in the EVM options but maxFeePerGas and maxGasLimit fails with CONFIG_INVALID.
• Gas-limit bound. No transfer, replacement or cancel signs a gas limit above the maxGasLimit option, in gas as a bigint from 21,000 to 2^64 − 1 (set like maxFeePerGas; a custom network may set params.maxGasLimit). The default is 16,777,216 (2^24, DEFAULT_MAX_GAS_LIMIT), the per-transaction cap Ethereum enforces since Fusaka (EIP-7825): far above what a transfer needs, it stops an absurd estimate or override, not an expensive one, so set your own (with the fee ceiling it bounds the network charge at maxGasLimit × maxFeePerGas). The gas limit a transfer would sign, the node's eth_estimateGas plus its 20% headroom, an override's gasLimit, or the original's gas limit that a replacement keeps, fails above it with INVALID_INTENT before signing (details.required, details.maxGasLimit); it is never cut down, since a call given less gas than it needs runs out and still pays. An explicit gasLimit above it is refused before any request. Arbitrum's estimates count the L1 data fee in L2 gas, so they grow with L1 prices: leave that bound generous.
• Types. The declarations of crypto-aio/evm name both ethers' and web3's types, so with only one of them installed keep skipLibCheck: true (the tsc --init default), or install the other too.
• Not in this release: address history (it needs an indexer; history() throws UNSUPPORTED_CAPABILITY), contract calls other than ERC-20 transfer, and ext.evm beyond getNonce.