Immutable X

The platform is built with environmental sustainability as a core principle. By leveraging the efficiency of ZK-Rollups, Immutable X drastically reduces the energy consumption per transaction. The protocol automatically purchases and retires carbon credits to offset the minimal remaining footprint of its infrastructure, making all NFTs minted and traded on the platform carbon-neutral by default. This addresses a major criticism of early NFT ecosystems built directly on proof-of-work blockchains.

A key innovation for NFT liquidity is Immutable X's shared global order book. This is a unified, protocol-level marketplace where any application built on the network can access and fulfill orders. Benefits include:

• Deep liquidity: Orders are not siloed within individual dApps or marketplaces.
• Composability: A user can list an NFT on one game's marketplace and have it purchased from another game's interface.
• Royalty enforcement: Creator royalties are enforced at the protocol level, ensuring they are paid on all secondary sales across any integrated marketplace.

Immutable X employs a hybrid data availability model to ensure security and liveness. While transaction validity is secured by Ethereum via ZK-proofs, the data needed to reconstruct the chain state is stored off-chain by Data Availability Committees (DACs). This model, known as Validium, provides:

• High throughput and low cost by not posting all data to L1.
• Robust security guarantees through a decentralized committee of reputable entities.
• Escape hatches that allow users to withdraw assets directly to L1 if the committee fails, ensuring capital is never permanently locked.

Mechanisms protect users if the Layer 2 operator becomes unresponsive.

• Withdrawal Guarantees: Users can initiate a withdrawal directly on Ethereum L1 if their request is ignored on L2, using a slow exit process.
• Forced Transactions: Users can force the inclusion of transactions (like transfers) directly on L1, bypassing the sequencer.
• These are safety nets but are slower and more expensive than standard L2 transactions.

Immutable X currently operates a single, permissioned sequencer to order transactions.

• This provides efficiency and prevents MEV extraction but introduces centralization risk.
• The sequencer could theoretically censor transactions. The forced transaction mechanism on L1 is the primary user recourse.
• Future roadmaps include plans to decentralize the sequencer role.

Like all complex systems, Immutable X's smart contracts carry inherent risk.

• Core contracts on Ethereum L1 are upgradeable via a multi-sig governance model.
• This allows for bug fixes and improvements but introduces governance risk.
• Users must trust the signers (Immutable and partners) to act honestly during upgrades. Contracts are regularly audited by firms like Certik.

ZK-Rollups are the core scaling technology powering Immutable X. They bundle thousands of transactions off-chain into a single cryptographic proof, which is then posted to the Ethereum mainnet. This provides:

• Massive scalability (9,000+ transactions per second).
• Inherited security from Ethereum's consensus.
• Instant trade confirmation and zero gas fees for users, with fees paid by the application in IMX tokens.

StarkEx is the specific validity-proof (STARK) engine developed by StarkWare that Immutable X uses to generate its ZK-Rollup proofs. It is a secure, production-ready scaling engine that enables:

• High throughput and low-cost transactions.
• Data availability guarantees, ensuring asset safety.
• Support for complex logic like conditional transfers and batch processing, essential for advanced NFT marketplaces and game mechanics.

Immutable X natively supports the dominant Ethereum NFT token standards, providing a seamless experience for developers and users.

• ERC-721: The standard for unique, non-fungible tokens, used for individual digital collectibles and assets.
• ERC-1155: A multi-token standard that allows for both fungible and non-fungible assets within a single contract, ideal for in-game items and resource bundles where efficiency is key.

A foundational feature of the Immutable X protocol is its Shared Global Order Book. This is a unified, open order book where any marketplace built on Immutable X can access and fulfill orders created on any other. This creates:

• Deep, aggregated liquidity across the entire ecosystem.
• Composability for developers, who can build applications without needing their own liquidity.
• A better user experience with best-price execution regardless of the marketplace interface.

Proof of Liquidity is a novel mechanism where the IMX token is staked by marketplaces to earn a proportional share of protocol fees. This aligns incentives across the ecosystem:

• Marketplaces stake IMX to prove commitment and share in 20% of all protocol fees (paid in ETH).
• Rewards are distributed weekly based on stake and trading volume.
• This creates a virtuous cycle where growth in ecosystem volume directly rewards its key contributors.