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Chainlink VRF

Chainlink VRF can be added as a plugin to any network. Once a network is running, please select "Plugins" and install Chainlink VRF.

Summary​

The Bloctopus VRF Plugin streamlines the integration of Chainlink's Verifiable Random Function into your smart contract development process. Whether you're building something like a lottery that relies on randomness, or any dApp needing unpredictable values, this plugin lets you use Chainlink's services exactly as you would on mainnet—no mocks required.

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Check out the official Chainlink VRF v2.5 documentation for more technical details.

Key Capabilities​

  • Shared Subscription Model Manage multiple consuming contracts through one LINK-funded subscription.

  • Flexible Subscription Handling Easily connect to your existing Chainlink subscription or spin up a new one.

  • Multi-Chain Ready Compatible with major chains including Ethereum, Arbitrum, Avalanche, BNB Chain, and Polygon.

Getting Started​

Step 1: Plugin Installation​

  • Sign in to your Bloctopus account.
  • Go to the Plugins tab of any existing network (or create a new network if none are running).
  • Search for "Chainlink VRF" and click Install.

Step 2: Confirm Installation​

  • Wait a few minutes for the plugin to be Installed. Click its card to open a details page with all the information you need to use Chainlink VRF and perform further operations with the running Chainlink nodes.

  • Details page: This page should display:

    • The Chainlink node Operator UI, where you can view node settings, VRF job runs, keys, and manage or run jobs as needed.
    • Contract addresses:
      • Coordinator Address: Use this address to interact with the main VRF Coordinator contract—create subscriptions, register consumers, and request random values.
      • Batch Coordinator Address: Use this address for batch operations, such as managing multiple requests or subscriptions in a single transaction. This is useful for advanced workflows or optimizing gas usage when dealing with many consumers or requests at once.

Using the Plugin​

  1. Call createSubscription() on the VRF Coordinator Contract inside your sandbox.
  2. Fund the subscription by calling transferAndCall() using LINK.
  3. Follow the provided script for an automated setup.
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Make sure your account has enough LINK. Use the faucet if needed.

Technical Notes:​
  • LINK amounts must be specified in Juel (1 LINK = 1e18 Juel).
  • The data parameter for transferAndCall() must include your Subscription ID, encoded using ABI format.

Final Steps​

  • Deploy your consumer contract.
  • Register it with the VRF Coordinator on your newly created Subscription.
  • Request random values as you would on the mainnet.