Crosschain System Overview

Architecture & Components

---

Lamina's Multilayered Infrastructure

This document is a high-level system overview of Lamina Finance's infrastructure components; and will briefly discuss each component's purpose, function, and usage.

Our proprietary infrastructure leverages a network of solvers that compete to fill intents across EVM, SVM, TONVM, MoveVM and BTC blockchains. Solvers in the Lamina network execute transactions on the destination chain from the signer's smart contract wallet, covering the execution, validation, and gas costs. Then the Lamina crosschain paymaster deterministically repays the solver from the signer's locked funds on their own escrow contract.

Through this system the execution is atomic and entirely P2P (user-solver).

Component: Crosschain API - Protocol interaction

Figure 1a Crosschain API and Protocol API interaction

Figure 1b Crosschain API - Protocol API callgraph

Figure 1a shows how our Lamina protocol (Protocol API) interacts with our Crosschain API and how other protocols could integrate with our Crosschain API. Protocols include actors such as bridges, liquidity aggregators, price matching aggregators, and multi-chain marketplaces. The components in this interaction can be generalized as the Crosschain API and the Protocol API.

The Protocol API composes transaction calldata to be executed as well as specifies the target, target chain, signer, and execution cost requirements. The Protocol API will have the user sign and submit data from Crosschain API.

Crosschain API runs a simulation on would-be transactions. The results of this simulation will estimate the cost for validation, execution, suggested bid, and base gas fee. Crosschain API will return, the sum total of these costs, a request for the signer to lock funds and a userop. Once signed and submitted to Crosschain API, the lock request and userop will be validated and added to the Crosschain Mempool.

---

Client Validation: Crosschain API - Client Interaction

Figure 2a Crosschain Client validates message to add to Crosschain Mempool

Figure 2b Crosschain Client callgraph

Figure 2a shows the process by which the Crosschain Client ensures funds are locked and the userop is signed. Similar to ERC4337 bundlers, the userop needs to be validated by the client before merging the message into the mempool. However, there are two key differences: (1) the lock request needs to be executed on an RPC for the origin chain and then validated; and (2) the transaction simulation is validated in an environment where the execution cost and paymaster calls are executed as pre-userop.

The Crosschain Client validates the userop in the context of a solver fronting the Hyperlane costs to the Crosschain Paymaster and to the SCW. After the Crosschain Client finishes validating the lock amount, lock deadline, and userop, the full message including lock info, calldata, and execution cost will be merged to the Crosschain Mempool.

---

Solver Execution: Crosschain Mempool - Solver Interaction

Figure 3a Solver finds a message on the Crosschain Mempool and executes it on-chain

Figure 3b Solver - Paymaster callgraph

Figure 3a shows how a Solver who joins the Lamina solver network executes a message from the Crosschain Mempool.

Note: validation for merging a message to the Crosschain Mempool does not ensure a successful userop bundle at execution time, therefore it is expected that the Solver re-validates the userop bundle before execution.

The Solver acts as liquidity provider directly for the signer. The operation is executed atomically as a three part bundle, in order : (1) overpaying Crosschain Paymaster to execute on Hyperlane; (2) add execution cost + validation gas + execution gas to the signer's smart contract wallet (SCW); and (3) the signer's signed userop.

Because the bundle is executed atomically, the Crosschain Paymaster call to Hyperlane is entirely deterministic.

---

Deterministic Crosschain: Crosschain Paymaster - Hyperlane Network

Figure 4a Crosschain Paymaster deterministically executes the solver payout across Hyperlane

Figure 4b Crosschain Paymaster - Hyperlane callgraph

Figure 4a shows the Crosschain Paymaster and how it utilizes Hyperlane. The preOp and postOp utilize the overpaid funds to ensure the Hyperlane message including userop and tx.origin data is successfully submitted to the Hyperlane Mailbox. At the end of the postOp the Crosschain Paymaster will redeposit stake used to the EntryPoint and send any residual ETH to the tx.origin.

Once the message is confirmed on the Hyperlane Network, a Hyperlane Validator will pickup and execute the message on the Hyperlane Mailbox to directly execute the handle function on the signer's Escrow contract.

---

Escrow Resolution: Hyperlane - Escrow Payout Validation

Figure 5a The user's escrow handles the Hyperlane message to payout the solver.

Figure 5b User Escrow - Solver payout callgraph

Figure 5a shows how Hyperlane Mailbox executes the handle function on the signer Escrow contract. The Escrow will validate the hashed data and payout funds to the solver. The payment includes the estimated user costs + the signer original bid.