Glossary · Infrastructure

What is the OP Stack?

The OP Stack is Optimism's open-source code for running an Ethereum rollup. OP Mainnet runs on it, and so do Unichain, Ink, Soneium and World Chain.

How does the OP Stack work?

The OP Stack is the software behind OP Mainnet, released as open source so other teams can launch chains from it. Optimism's docs describe it as a set of components that together produce a chain whose entire history is published to Ethereum. Out of the box that chain is an optimistic rollup: one sequencer orders transactions, batches go to Ethereum, and on OP Mainnet a withdrawal waits out a 7-day challenge period. OP Mainnet switched on permissionless fault proofs on June 10, 2024, and with them the stack reached Stage 1 on L2BEAT's scale.

Chains that run it and share revenue with the Optimism Collective form the Superchain. A member pays the greater of 2.5% of its gross fees or 15% of its onchain profit, meaning fees minus what it paid Ethereum, and OP Mainnet hands over all of its profit. On January 28, 2026, governance voted to spend half of the Collective's net Superchain sequencer revenue on OP buybacks, in a 12-month pilot starting in February.

Code and membership can part ways. Base launched on the OP Stack in 2023, and on February 18, 2026 it announced a move to a unified, Base-operated stack. It said the chain would stay compatible with the OP Stack specification and keep working with Optimism as a client of OP Enterprise. OP Labs' CEO, Jing Wang, said the new stack still shared 99% of its code with the OP Stack and related infrastructure.

Run the fee split on made-up numbers. A chain takes $100,000 in fees in a month and pays Ethereum $70,000 for data. 2.5% of the fees is $2,500 and 15% of the $30,000 profit is $4,500, so it owes the Collective $4,500. Halve the data bill to $35,000 and the share becomes $9,750.

Also called: Optimism OP Stack, OP Stack chain.

Where does the OP Stack show up in Cashboard?

The L2 scoreboard has no stack filter, and no cell says OP Stack. OP Mainnet and the other OP Stack chains growthepie tracks each get their own row, and in September 2026 those included Unichain, Ink, Soneium and World Chain. Sort by Fees for what users paid each chain on the day, the revenue figure the Superchain share starts from, or by Cost for the cheapest median transaction (growthepie data, CC BY 4.0). Hover a chain's L2BEAT stage tag and growthepie's label appears beside it, Optimistic Rollup for all five. OP Mainnet also has Chain status and watch-only portfolios.

L2 scoreboard

Frequently asked questions

Is Base still an OP Stack chain?

Partly. On February 18, 2026 Base announced a move to a unified, Base-operated stack that stays compatible with the OP Stack specification, with node operators switching to Base's own client releases. In September 2026 L2BEAT still listed it as built on the OP Stack, without the Superchain badge that OP Mainnet, Unichain and Ink carry.

What is the difference between the OP Stack and the Superchain?

The OP Stack is the code, and anyone can run it. The Superchain is the group of OP Stack chains that share revenue with the Optimism Collective, each paying the greater of 2.5% of gross fees or 15% of onchain profit. In January 2026 governance approved spending half of the Collective's net Superchain revenue on OP buybacks for 12 months from February.

Related terms

Last reviewed October 25, 2026. Market data in Cashboard comes from the providers named on each widget and may be delayed. Nothing here is financial advice.