The Cheapest and Fastest Cross-chain Bridge — Narni’s Liquidity Provision Protocol

Umbria Network
3 min readApr 5, 2022


Umbria Network’s Narni bridge is a capital-efficient, multi-chain asset bridge, which enables the quick, cheap and easy migration of crypto assets between different blockchains. It currently facilitates the fastest and cheapest bidirectional bridging between the Ethereum Mainnet and Binance Smart Chain, Polygon, Avalanche (AVAX), Fantom (FTM), Optimism and Arbitrum (Solana is coming online soon with more Layer 2 networks and Ethereum scaling solutions in the pipeline).

Read on to discover what differentiates Umbria’s Narni bridge from other bridging solutions.

Liquidity-provision protocol

Narni uses a novel liquidity-provision protocol that greatly decreases the cost of transferring funds between chains in comparison to traditional validator-driven mint/burn, lock/unlock bridges. The protocol hosts liquidity pools of singular assets on distinct networks and significantly improves the cross-chain bridging experience by replacing slow and costly on-chain operations with a quick and cheap multi-chain decentralised oracle system.

Rewards for liquidity providers

The bridging protocol uses crowd-sourced liquidity and generates fee-based rewards for liquidity providers as an incentive for their liquidity provision. The fees are proportional to the amount of liquidity they lend to the protocol and are earned whenever someone uses the bridge to migrate assets between cryptocurrency networks.

There are two types of liquidity provision for the Umbria Network bridge:

  1. Lending a single asset to the bridge

Those lending a single asset to the bridge (such as ETH, USDC, USDT, MATIC WBTC) - on a single network — earn 40% of the bridging fee whenever someone bridges that asset to that network.

2) Lending $UMBR (Umbria’s native token) to the bridge

a) Those lending $UMBR on the Polygon Network earn 60% of the bridging fee whenever someone bridges any asset to the Polygon Network.

b) Those lending $UMBR on the Ethereum Network earn 60% of the bridging fee whenever someone bridges any asset to any network except the Polygon Network.

$UMBR stakers in the pool now earn 60% of all fees generated by the bridge, paid every minute in ETH, MATIC, USDC, USDT, GHST, WBTC and UMBR.

No impermanent loss, no lock in period

Liquidity providers earn fees in the asset they lend to the protocol and don’t incur impermanent loss unlike with other DeFi pools where pairs of assets are staked together. Liquidity providers are free to unstake their liquidity at any time. When a liquidity provider unstakes their assets they are automatically sent to their cryptocurrency wallet on the network to which they initially lent their assets.

Once per hour the fee rewards are automatically added to the liquidity providers’ staking balances. This causes staking balances to auto-compound and accrue a greater proportion of the total pool fee rewards over time. Compounding, compounding, compounding!

Umbria’s White paper

Find out more in our White paper:



Umbria Network

Umbria’s Narni Bridge is the fastest, cheapest cross-chain liquidity bridge Ethereum ↔️Polygon/AVAX/BSC. Migrate assets almost instantly for the LOWEST fees