Specification

Introduction

In order to access verifiable high-performance compute resources available on Open Chain, OVM task contracts must conform to this specification.

Since OVM tasks are languague-agnostic, the runtime environment is not part of this specification, but specified in its git repository.

Specification

struct Specification {
    string name;
    string version;
    string description;
    string repository;
    string repoTag;
    string license;
    Requirement requirement;
    uint256 royalty;
    string apiABIs;
    Arch arch;
    ExecMode execMode;
}
 
enum ExecMode {
    JIT,
    PERSISTENT
}
 
enum Arch {
    AMD64,
    ARM64
}
 
enum GPUModel {
    T4
}
 
struct Requirement {
    string ram;
    string disk;
    uint256 timeout;
    uint256 cpu;
    uint256 gpu;
    GPUModel gpuModel;
}

Name

Name of the task.

Example: ovm-cal-pi

Version

Version of the specification schema.

Example: v1.0.0

Description

Description of the task.

Example: Calculate PI

Repository

Git repository of the task runtime.

Example: https://github.com/webisopen/ovm-cal-pi

RepoTag

Semver tag or git sha of the task runtime repository.

Example: v1.0.0

License

License of the task.

Example: WTFPL

Requirement

Resources required to compute the task.

Example:

{ ram: "256mb", disk: "5mb", timeout: 600, cpu: 1, gpu: false}

Royalty

Royalty fee rate to be collected by the task author, in basis points.

Example: 5 (equivalent to 0.05%)

ApiABIs

Declaration of the abis for request&response interfaces.

Example:

[
  {
    "request": {
      "type": "function",
      "name": "sendRequest",
      "inputs": [
        { "name": "numDigits", "type": "uint256", "internalType": "uint256" }
      ],
      "outputs": [
        { "name": "requestId", "type": "bytes32", "internalType": "bytes32" }
      ],
      "stateMutability": "payable"
    },
    "getResponse": {
      "type": "function",
      "name": "getResponse",
      "inputs": [
        { "name": "requestId", "type": "bytes32", "internalType": "bytes32" }
      ],
      "outputs": [{ "name": "", "type": "string", "internalType": "string" }],
      "stateMutability": "view"
    }
  }
]

ExecMode

Execution mode for the task runtime, JIT or PERSISTENT.

Example: JIT: tasks are compiled by the runtime before execution. PERSISTENT: tasks require preemptive compilation to be executed instantly by available environment.

Arch

Architecture of the task runtime.

Example: ARM64 or AMD64

The Specification defines the computation task and its requirement of external compute power. To ensure proper integration between your computation task and the contract, follow the following principles:

1. Input: You can pass any type of parameters to the computation task, as long as they are correctly formatted as a single bytes variable in your contract (the computation task will decode it as needed).
2. Output: The task must return a single bytes as output, which will be further processed and, if necessary, decoded within the contract.