AMBs or 'Arbitrary Message Bridges' are protocols that relay data between different blockchains. This 'arbitrary' data can be anything that a user wishes to send.

The originating contract on the source chain encodes data in the form of an arbitrary method call. This information, along with the target contract address, is passed to the AMB contracts. As soon as data are relayed from the source chain to the desintation by the Arbitrary Message Bridge oracles, the bridge contract on the destination chain passes the ABI-encoded method to the target contract.

The Superform Protocol currently supports three AMBs: LayerZero, Wormhole and Hyperlane.

AMBs allow the Superform Protocol to send executable data from a user's source chain to a user's destination chain to enable cross-chain deposits.

Example: A user on Optimism wants to deposit 100 USDC into a vault on Ethereum. On the source chain, the user's message is generated by the protocol which says "Once my 100 USDC arrive on Ethereum, deposit them into XYZ vault. Once complete, mint a SuperPosition back on the user's source chain."

The security of this message is paramount. If the message is corrupted, users funds could be sent to the wrong destination resulting in lost tokens. To prevent this, the Superform Protocol requires all messages to be sent through a primary AMB and a secondary AMB which validates the proof of the primary message. This ensures that no single AMB can compromise the Superform Protocol.