def METHOD_NAME(session: DbSession, content: Mapping[str, Any]) -> None:
    try:
        chain = Chain(content["chain"])
        height = content["main_height"]
    except KeyError:
        raise InvalidMessageFormat(
            "Missing field(s) chain and/or main_height for balance post"
        )
    dapp = content.get("dapp")
    LOGGER.info("Updating balances for %s (dapp: %s)", chain, dapp)
    balances: Dict[str, float] = content["balances"]
    update_balances_db(
        session=session,
        chain=chain,
        dapp=dapp,
        eth_height=height,
        balances=balances,
    )