OP Mainnet, a Layer 2 blockchain, has successfully implemented fault proofs, a crucial step towards achieving stage 1 rollup decentralization. This innovative solution enables users to withdraw ether and ERC-20 tokens without relying on trusted third parties, ensuring a more secure and decentralized experience. The fault proof system allows users to challenge and remove invalid withdrawals, promoting transparency and accountability within the network.

The introduction of fault proofs marks a significant milestone in OP Mainnet's journey towards decentralization. Previously, users had to trust operators to submit accurate state roots onto the mainnet. Now, with fault proofs in place, users can verify and contest potentially fraudulent or incorrect transactions, ensuring a more robust and resilient network.

The implementation of fault proofs was a collaborative effort, supported by multiple core development teams in the Optimism ecosystem, including OP Labs, Base, and Sunnyside Labs. This demonstrates the power of collective innovation and the commitment to advancing decentralization in the Layer 2 blockchain space.

OP Mainnet, developed by OP Labs, utilizes optimistic rollups as a scaling solution, aggregating Ethereum transactions off-chain for cheaper processing. The OP Stack, a development software stack, enables developers to launch their own Layer 2 blockchains, such as Coinbase's Base blockchain. As fault proofs are now operational on OP Mainnet, other OP Stack chains will follow suit, starting with Base, Metal, Mode, and Zora.

While open participation in the fault-proof system is live, the Optimism Security Council maintains an oversight role, ensuring a safe and responsible rollout. In case of system failures, the Security Council can intervene and revert the system to a permissioned state. Additional safeguards allow the Security Council to address system bugs and reset withdrawals if necessary.

OP Mainnet's roadmap is set towards a fully permissionless and decentralized "stage 2," managed solely via smart contracts. This ambitious goal is a testament to the project's commitment to decentralization and security. While most optimistic rollup blockchains have yet to incorporate fault proofs and decentralized contract upgrades, OP Mainnet's closest competitor, Arbitrum, also offers fault proofs, highlighting the importance of innovation and collaboration in the Layer 2 blockchain space.