Optimism

Optimism is an Ethereum Layer 2 scaling network and the origin of the OP Stack, an open-source codebase for building rollups. OP Mainnet was the first chain to run it, and the wider project now describes itself as the Superchain, a network of chains that share the same underlying software and, increasingly, common standards for communication between them.

How Optimism works

Optimism is an optimistic rollup. Transactions are executed off the Ethereum base layer and their results are posted back to Ethereum, where they are assumed valid unless challenged within a dispute window. This lets the network offer far lower fees than transacting directly on Ethereum while still settling to it. The chain is EVM-equivalent, meaning contracts and tooling written for Ethereum generally work without modification.

The OP Stack has become a widely used framework for launching Layer 2 chains. Chains built on it include Base from Coinbase, Unichain from Uniswap, Ink from Kraken, and World Chain from the Worldcoin project. The OP token has a maximum supply of 4,294,967,296, a figure chosen as two to the power of 32, with roughly 2.29 billion in circulation. OP is used for governance through the Optimism Collective, which splits decision-making between a Token House of token holders and a Citizens' House focused on funding public goods.

Role in the ecosystem

Optimism's significance extends beyond its own chain. Because so much Layer 2 activity runs on OP Stack software, decisions made in its codebase affect a large share of Ethereum scaling infrastructure. The project has also been prominent in retroactive public goods funding, a model where contributors are rewarded after their work has demonstrated value rather than through upfront grants.