Chainlink VRF Integration

How Chainlink VRF ensures provably fair randomness in all VORTEX draws

Why Chainlink VRF?

Fairness is non-negotiable for a raffle-based protocol. Users must trust that:

• The team cannot influence draw outcomes

• No one can predict or manipulate the random number

• Every draw result is verifiable on-chain

Chainlink VRF (Verifiable Random Function) is the industry standard for on-chain randomness. It provides:

Feature	Benefit
Cryptographic proof	Every random number comes with a proof that it was generated fairly
On-chain verification	Anyone can verify the proof on-chain
Tamper-proof	Neither the oracle, the team, nor miners can manipulate the result
Battle-tested	Used by hundreds of protocols, billions in value secured

How It Works in VORTEX

Vortex Draws

1. Draw time arrives (e.g., Friday 20:00 UTC)
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2. Anyone calls triggerDraw() on the Vortex Contract
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3. Vortex Contract snapshots all valid Raffle Passes
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4. Vortex Contract calls VRF Consumer → requestRandomWinner()
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5. VRF Consumer sends request to Chainlink VRF Coordinator
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6. Chainlink node generates random number + cryptographic proof
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7. Chainlink calls fulfillRandomWords() on VRF Consumer
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8. VRF Consumer forwards random number to Vortex Contract
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9. Vortex Contract uses random number to select weighted winner
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10. Winner is announced, prize distributed, passes burned

Mystery Crates

Mystery Crate outcomes also use Chainlink VRF:

1. User calls claimDailyCrate() on Staking Contract
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2. Staking Contract requests random number from VRF Consumer
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3. Chainlink returns random number
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4. Random number determines crate rarity:
   │   0-59:    Common (60%)
   │   60-84:   Rare (25%)
   │   85-96:   Epic (12%)
   │   97-99.4: Legendary (2.5%)
   │   99.5+:   Mythic (0.5%)
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5. Reward distributed based on rarity

VRF Configuration

Parameter	Value	Rationale
VRF Version	V2.5	Latest version with improved gas efficiency
Key Hash	[CHAIN-specific]	Determines the Chainlink node used
Confirmations	3 blocks	Balance between speed and security
Callback Gas	500,000 (draws) / 200,000 (crates)	Sufficient for winner selection logic
Subscription	Funded by protocol	LINK tokens maintained by treasury

Verification

How Users Can Verify Fairness

1. Find the draw transaction on the block explorer

2. Locate the VRF request ID in the transaction logs

3. Find the fulfillment transaction from Chainlink

4. Verify the proof — the cryptographic proof confirms the random number was generated from the request, not chosen by anyone

5. Check the winner selection — the weighted random selection algorithm is open-source and deterministic given the random number

Verification Tools

• VORTEX will provide a "Verify Draw" page on the website

• Input any draw ID to see: VRF request, random number, proof, winner selection math

• All data sourced directly from on-chain events

Cost

Operation	Estimated VRF Cost
Daily Draw	~0.5 LINK
Mini Draw	~0.5 LINK
Monthly Mega Draw	~0.5 LINK
Daily Mystery Crates (per user)	~0.1 LINK

VRF costs are funded by the protocol's Chainlink subscription, maintained by the treasury.

For high-volume crate claims, the protocol may implement batch VRF requests — a single random number used to derive multiple crate outcomes, reducing cost significantly.

Fallback Mechanism

In the unlikely event of Chainlink VRF downtime:

1. Draws are postponed (not cancelled)

2. The pot continues to accumulate

3. Once VRF is restored, the draw executes with the accumulated pot

4. No manual intervention is possible — the contract waits for VRF

There is no backdoor for the team to execute draws without VRF. This is enforced at the smart contract level.