MetaFab's convenience endpoints for contract interactions may not be flexible enough depending on your use case. For these situations, you can interact with contracts and create transactions directly.
Using this endpoint, you can execute a transaction for any writeable contract method as defined in the contract's ABI for the MetaFab contractId provided. Both Games and Player resources have authority to use this endpoint to execute transactions against any valid MetaFab contractId.
Additionally, MetaFab will automatically attempt to perform a gasless transaction for players interacting with a contract through this endpoint. Gasless transactions by players through this endpoint will only work if the target contract was deployed through MetaFab or supports MetaFab's ERC2771 trusted forwarder contract.