Summary: Cross-chain messaging enables ADI Chain to communicate with not only Ethereum, but other L2s and even L3s as well. One type of cross-chain messaging is bridging, or the process of transferring assets between blockchains. ADI Chain's bridge interface provides a simple way for users to transfer assets between ADI Chain and other blockchains, and the rapid generation time of validity proofs enables withdrawals from ADI Chain to be achieved in seconds rather than the week-long waiting period required by optimistic rollups.
The other primary type of cross-chain messaging is generic message passing, which essentially allows blockchains to “talk” to each other. Combined, bridging and generic message passing work together to create a seamlessly operating ecosystem. Users can easily transfer their tokens on all connected chains, and developers can offer more convenient access to applications by porting existing apps to all connected chains.
Overview
Cross-chain messaging refers to the mechanisms by which ADI Network communicates with Ethereum L1 and other chains (including potential L3s). This encompasses token transfers (bridging assets) as well as generic message passing (e.g., calling a function on L1 from L2 or vice versa). ADI Network’s approach to cross-chain messaging leverages its zkRollup foundations to ensure security and efficiency.
L1 ⇄ L2 Bridging: As a rollup, ADI Network uses an Inbox/Outbox model for messages to and from Ethereum. On Ethereum, the ADI Bridge contracts (discussed earlier) include an Inbox contract where L1-to-L2 messages (deposits or instructions) are posted, and an Outbox contract that holds L2-to-L1 messages until they can be executed on L1. When a user deposits an asset or calls a function on L2 via L1, they interact with the Inbox. The Sequencer will eventually include that message in an L2 block (the message is read by L2 and executed, such as minting tokens to the user’s L2 address). For L2 to L1, when the L2 transaction (say a withdrawal or a cross-chain function call) is executed on ADI, it produces a message that gets recorded in the L2’s state. Once that L2 block is proven on L1, the Outbox contract allows those messages to be executed on Ethereum (with the proof serving as authorization). Because ADI is a zkRollup, the moment the proof is accepted on L1, the messages are considered valid and can be processed – there is no additional delay. In optimistic systems, one had to wait through the challenge period before processing L2->L1 messages (often 7 days). Still, here, a withdrawal can be finalized as soon as the proof (covering that withdrawal) is on-chain and verified. This represents a significant UX improvement: users can withdraw funds or send information to L1 within minutes, making ADI’s bridge nearly instant and secure (only constrained by proof time and Ethereum block times).
For token transfers specifically, the ADI Bridge holds the locked tokens on L1, and the L2 ledger reflects the ownership on L2. A user withdrawing would burn their L2 tokens, the proof of that burn is verified on L1, and then the Bridge releases the L1 tokens to the user’s wallet. This design inherits the security of Ethereum for all asset movements – tokens can’t be fraudulently minted or stolen on L2 because any such attempt would fail the L1 verification. The ADI Bridge contract ensures that finality is only granted after valid proof, unifying security across the ADI ecosystem.
Portal Bridge UI
On the user-facing side, ADI will provide a Bridge interface (web portal) for users to easily deposit and withdraw assets. This UI (often referred to as a “portal”) will allow users to connect their wallet, choose an asset, and initiate a transfer from Ethereum to ADI or vice versa. Under the hood, it interacts with the portal bridge contracts. The emphasis for ADI’s portal is on security and simplicity, as it leverages the official ADI Bridge. Users are assured that the bridging is non-custodial and secured by Ethereum’s validation of proofs. The UI will likely display the status of transactions (e.g., “waiting for proof confirmation”) and abstract away the complexity of the ZK proof generation time, among other details, perhaps by showing an estimated time to finality.
In summary, cross-chain messaging on ADI Network is trust-minimized and fast. Token bridging benefits from near-immediate withdrawal capability thanks to validity proofs. General messaging ensures that contracts on different layers can interoperate with strong guarantees (the message will only be delivered if it was legitimately sent). This cross-chain communication framework is essential for ADI’s modular strategy – it means that whether an application is split across L1, L2, and L3, all parts can communicate securely and with provable consistency.