Terms used in Futaba

Src chain

The source chain requests data and receives the result.

Destination chain

The chain from where data is requested and the query is executed through the Relayer and returned to the Src chain.

User Contract

A contract is defined by the developer, which is the calling source of the Gateway API.

Gateway Contract

The contract endpoint requests data acquisition.

Light Client Contract

A contract that verifies data and can build its logic.


An intermediary between the src chain and the destination chain, which acquires proof for the destination chain and sends the data to the src chain.

Storage proof

A cryptographic commitment is used to prove that a storage value or transaction has been committed to the blockchain tree and that it is valid.


A module for retrieving the appropriate block header for each ecosystem. The default is Chainlink Oracle, with the possibility of using ZK Coprocessors such as Largange or Herodotus in the future.