Concepts

Lib Coin and fees

Lib Coin is LibChain's native coin. On testnet it is tLIB. Fees follow EIP-1559: a base fee that is burned plus a priority tip.

Every transaction on LibChain pays gas in the native coin. On mainnet that will be Lib Coin (LIB); on Lib Testnet it's tLIB, with 18 decimals like ether.

#How fees work

LibChain uses the EIP-1559 fee market from Ethereum's London upgrade:

Base fee. Set by the protocol for each block and burned. It rises when blocks are more than half full (15 million gas) and falls when they are emptier.
Priority fee (tip). Optional, set by the sender, paid to the validator that seals the block.

The fee for a transaction is gasUsed × (baseFee + priorityFee), capped by the maxFeePerGas you sign.

#What it costs on testnet today

Base fee	7 wei per gas (the protocol minimum while blocks are nearly empty)
Suggested tip	1 wei per gas (`eth_maxPriorityFeePerGas`)
Minimum gas price	0: the validator accepts any tip
A plain transfer	21,000 gas × 8 wei = 168,000 wei, about 0.00000000000017 tLIB

In practice, fees on testnet are negligible. Wallets often set a higher tip by default; you'll still pay only what the block needs plus the tip you chose.

#Reading fees from the chain

Terminal

cast base-fee --rpc-url https://rpc-testnet.libchain.tech
cast gas-price --rpc-url https://rpc-testnet.libchain.tech
cast rpc eth_feeHistory 0x5 latest '[25,75]' --rpc-url https://rpc-testnet.libchain.tech

TypeScript

const { maxFeePerGas, maxPriorityFeePerGas } = await client.estimateFeesPerGas()
// a few wei each on a quiet testnet

#Legacy transactions

Type 0 (legacy) and type 2 (EIP-1559) transactions are both accepted. With a legacy transaction, the whole gasPrice above the base fee goes to the validator as the tip.

#No block rewards

LibChain doesn't mint new coins per block, and there is no mining. Validators earn only the tips in the blocks they seal; the base fee is burned. Mainnet economics, including any validator rewards, will be published before mainnet.

#Wrapped tLIB

Some contracts need an ERC-20 instead of the native coin. WtLIB wraps tLIB 1:1.