Example — Subscription Contract

Deploy the 779-byte WASM subscription engine described in the foundation blog post. Three functions: subscribe, is_active, get_expiry. On-chain subscription state without a payment intermediary.

What the contract does

subscribe(address, plan_id, start_timestamp) → activates a subscription
is_active(address)                           → bool, is the subscription current?
get_expiry(address)                          → timestamp, when does it expire?

Total compiled size: 779 bytes of WASM (smaller than a typical favicon). Deployment cost: approximately 0.001 OMC.

The deployed reference contract

A reference instance lives on the Ignis devnet at:

contract_5e4b50f74b94f16cf857f69c8703f063ba712249

WASM SHA-256 hash:

17578a1010bcd948ec1855d461ce9597a6d910115d3f296016b0801d41bb2108

Verify on the explorer: omnescan.com/contract/contract_5e4b50f74b94f16cf857f69c8703f063ba712249

Call the reference contract

import { Wallet, OmneClient } from '@omne/sdk'
 
async function main() {
  const wallet = Wallet.generate()
  const account = wallet.getAccount(0)
 
  const client = new OmneClient('wss://rpc.ignis.omnechain.network')
  await client.rpcCall('faucet_request', [account.address])
  await new Promise((resolve) => setTimeout(resolve, 3500))
 
  const CONTRACT = 'contract_5e4b50f74b94f16cf857f69c8703f063ba712249'
 
  // Activate a subscription for this account
  const activation = await client.contractCall({
    contractAddress: CONTRACT,
    method: 'subscribe',
    args: [account.address, 'plan_premium', Math.floor(Date.now() / 1000)],
    from: account.address,
  })
  console.log('subscribe() tx:', activation.transactionId)
 
  // Wait for the commerce block
  await new Promise((resolve) => setTimeout(resolve, 3500))
 
  // Check it's active
  const isActive = await client.contractCall({
    contractAddress: CONTRACT,
    method: 'is_active',
    args: [account.address],
    from: account.address,
  })
  console.log('is_active():', isActive.result)
 
  // Check expiry
  const expiry = await client.contractCall({
    contractAddress: CONTRACT,
    method: 'get_expiry',
    args: [account.address],
    from: account.address,
  })
  console.log('get_expiry():', new Date(Number(expiry.result) * 1000).toISOString())
}
 
main().catch(console.error)

Deploy your own

The contract source is Rust compiled to WASM. The binary hash lets you verify any deployed copy against a known build.

Build and deploy the contract:

import fs from 'node:fs'
import { OmneClient, Wallet } from '@omne/sdk'
 
const wasm = fs.readFileSync('./subscription.wasm')
const wallet = Wallet.fromMnemonic(process.env.MNEMONIC!)
const deployer = wallet.getAccount(0)
 
const client = new OmneClient('wss://rpc.ignis.omnechain.network')
 
const result = await client.deployContract({
  bytecode: wasm,
  constructorArgs: [],
  from: deployer.address,
  gasLimit: 500000,
})
 
console.log('Your subscription contract:', result.contractAddress)
console.log('Verify:', `https://omnescan.com/contract/${result.contractAddress}`)

Why put subscriptions on-chain?

From the foundation post:

Provider	Cost per subscription
Stripe Billing	0.5–0.8% of revenue + 2.9% + $0.30 processing
Chargebee	$0.10 per subscription per month minimum
RevenueCat	1–2.5% of tracked revenue
On-chain (Omne)	~0.000002 OMC per transition

For high-volume low-ticket subscriptions ( $0.50–$ 5/month), the intermediary fee stack is the business model. On-chain state on Omne removes that stack from the critical path — at the cost of writing your own subscription logic.

Next step

Wire the contract into a UI with the event subscription example to show live activation status.

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