Contract State

The M3tering protocol uses the Arweave network to permanently log and archive all interaction data on the protocol, ensuring that a record of energy consumption and associated payments remain available and immutable for the foreseeable future. A novel smart contract standard know as SmartWeave, is used to compute the state of PPA contracts on the protocol.

SmartWeave contracts on Arweave are a type of smart contract specifically designed for use on the Arweave blockchain. Rather than executing code in real time (like on Ethereum), SmartWeave contracts rely on nodes to read the entire history of a contract’s interactions to compute its current state, an idea know as "Lazy Evaluation". This approach makes SmartWeave contracts scalable and ideal for decentralized, permanent storage applications, as it reduces computational demand on the network while prioritizing data availability and integrity. See more here

While payments still happen on a secure, deterministic EVM contract using DAI, SmartWeave contracts are be used to process metering data and manage interactions between users and the smart metering infrastructure.

Smartweave Contract Functions

The protocol defines three core functions within its Smartweave contracts to handle different types of interactions: register, topup, and meter.

The Register Function

The register function is used for retrieving a smart meter's public key information. This public key is essential for authenticating any data that the meter sends. To do this, it requires a JSON object that includes an EVM transaction hash.

Example input:

{
  "input": {
    "function": "register",
    "txHash": "0x5cfeb3b6e68c9cbdd96e6f7db033900514009db660adc3c81d98495e6600506b"
  }
}

During registration, the transaction emits a smart contract event that contains the token ID, public key, and address of the sender, along with a timestamp, following the ABI below:

event Register(uint256 indexed tokenId, bytes32 indexed publicKey, address from, uint256 timestamp)

The Topup Function

The topup function enables offtakers to add balance or credits to their accounts. Similar to the register function, it requires an Ethereum transaction hash to validate the top-up transaction. This transaction hash is used to retrieve the payment amount and the current electricity tariff from the Ethereum smart contract. The participant’s electricity balance is then updated accordingly.

Example input:

{
  "input": {
    "function": "topup",
    "txHash": "0x5cfeb3b6e68c9cbdd96e6f7db033900514009db660adc3c81d98495e6600506b"
  }
}

For the topup to be processed correctly, the transaction is expected to emit a smart contract event that provides details on the top-up, including the amount paid, the tariff rate, the source address, and the timestamp, with the following ABI:

event Revenue(uint256 indexed tokenId, uint256 indexed amount, uint256 indexed tariff, address from, uint256 timestamp)

The Meter Function

The meter function is the primary function that processes data collected from smart metering hardware. It expects the payload from the meter, containing the signed data, signature, and public key. This function would compute the offtaker electricity balances and deduct usage based on real-time electricity consumption data payload posted to Arweave. For more information about this payload see Meter Payload documentation

Example input:

{
  "input": {
    "function": "meter",
    "payload": [
      "[2,213.7,0.38,0.007420]",
      "9C7lPdznR9pymAIvjDPmm/mVX/uUTemapJRb8yzGKvG8or43u6V97oDPcW7ZP9HeHRZrGEf1iIkyLixAVdWsDg==",
      "JR2VNczJacY86eyyCBr1iTTT7vxKtYbfqegeTkXJD88="
    ]
  }
}