# Service Billing

Each service call is recorded by Apron Node. When a fixed cycle is reached, Apron Node will aggregate the service call information and synchronize it to the chain through the OCW (off-chain worker) feature. The pricing information of the service is available on Apron service marketplace, and the service usage fee will be calculated based on the pricing information, service call times and service caller information. The developer will pay the usage fee to the service provider based on the billing information. Once the developer finds that there is a problem with the service or the billing information is false, the developer can file an arbitration application with the Dao's central arbitration court and ask the service provider to compensate for the losses caused.
