Configuration

Chainlink VRF allows you to integrate provably fair and verifiably random data in your smart contract.

For implementation details, read Introduction to Chainlink VRF.

Coordinator parameters

These parameters are configured in the coordinator contract. You can view these values by running getConfig on the coordinator or by viewing the coordinator contracts in a blockchain explorer.

• uint16 minimumRequestConfirmations: The minimum number of confirmation blocks on VRF requests before oracles respond
• uint32 maxGasLimit: The maximum gas limit supported for a fulfillRandomWords callback.
• uint32 stalenessSeconds: How long the coordinator waits until we consider the ETH/LINK price used for converting gas costs to LINK is stale and use fallbackWeiPerUnitLink
• uint32 gasAfterPaymentCalculation: How much gas is used outside of the payment calculation. This covers the additional operations required to decrement the subscription balance and increment the balance for the oracle that handled the request.

Fee parameters

Fee parameters are configured in the coordinator contract and specify the premium you pay per request in addition to the gas cost for the transaction. You can view them by running getFeeConfig on the coordinator. The uint32 fulfillmentFlatFeeLinkPPMTier1 parameter defines the fees per request specified in millionths of LINK. The details for calculating the total transaction cost can be found here.

Configurations

VRF v2 coordinators for subscription funding are available on several networks. To see a list of coordinators for direct funding, see the Direct Funding Configurations page.

:::caution[Understand Risks associated with Bridges] If you are using a cross-chain bridge to transfer your LINK tokens, read the Bridges and Associated Risks guide to understand what cross-chain bridges are and the risks associated with using them. :::

Ethereum mainnet

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | LINK Token | 0x514910771AF9Ca656af840dff83E8264EcF986CA | | VRF Coordinator | 0x271682DEB8C4E0901D1a1550aD2e64D568E69909 | | 200 gwei Key Hash | 0x8af398995b04c28e9951adb9721ef74c74f93e6a478f39e7e0777be13527e7ef | | 500 gwei Key Hash | 0xff8dedfbfa60af186cf3c830acbc32c05aae823045ae5ea7da1e45fbfaba4f92 | | 1000 gwei Key Hash | 0x9fe0eebf5e446e3c998ec9bb19951541aee00bb90ea201ae456421a2ded86805 | | Premium | 0.25 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Sepolia testnet

| Item | Value | | --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0x779877A7B0D9E8603169DdbD7836e478b4624789 | | VRF Coordinator | 0x8103B0A8A00be2DDC778e6e7eaa21791Cd364625 | | 30 gwei Key Hash | 0x474e34a077df58807dbe9c96d3c009b23b3c6d0cce433e59bbf5b34f823bc56c | | Premium | 0.25 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Goerli testnet

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0x326C977E6efc84E512bB9C30f76E30c160eD06FB | | VRF Coordinator | 0x2Ca8E0C643bDe4C2E08ab1fA0da3401AdAD7734D | | 150 gwei Key Hash | 0x79d3d8832d904592c0bf9818b621522c988bb8b0c05cdc3b15aea1b6e8db0c15 | | Premium | 0.25 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

BNB Chain

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | LINK Token | 0x404460C6A5EdE2D891e8297795264fDe62ADBB75 | | VRF Coordinator | 0xc587d9053cd1118f25F645F9E08BB98c9712A4EE | | 200 gwei Key Hash | 0x114f3da0a805b6a67d6e9cd2ec746f7028f1b7376365af575cfea3550dd1aa04 | | 500 gwei Key Hash | 0xba6e730de88d94a5510ae6613898bfb0c3de5d16e609c5b7da808747125506f7 | | 1000 gwei Key Hash | 0x17cd473250a9a479dc7f234c64332ed4bc8af9e8ded7556aa6e66d83da49f470 | | Premium | 0.005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

BNB Chain testnet

| Item | Value | | --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0x84b9B910527Ad5C03A9Ca831909E21e236EA7b06 | | VRF Coordinator | 0x6A2AAd07396B36Fe02a22b33cf443582f682c82f | | 50 gwei Key Hash | 0xd4bb89654db74673a187bd804519e65e3f71a52bc55f11da7601a13dcf505314 | | Premium | 0.005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Polygon (Matic) mainnet

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0xb0897686c545045aFc77CF20eC7A532E3120E0F1 | | VRF Coordinator | 0xAE975071Be8F8eE67addBC1A82488F1C24858067 | | 200 gwei Key Hash | 0x6e099d640cde6de9d40ac749b4b594126b0169747122711109c9985d47751f93 | | 500 gwei Key Hash | 0xcc294a196eeeb44da2888d17c0625cc88d70d9760a69d58d853ba6581a9ab0cd | | 1000 gwei Key Hash | 0xd729dc84e21ae57ffb6be0053bf2b0668aa2aaf300a2a7b2ddf7dc0bb6e875a8 | | Premium | 0.0005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Polygon (Matic) Mumbai testnet

| Item | Value | | --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0x326C977E6efc84E512bB9C30f76E30c160eD06FB | | VRF Coordinator | 0x7a1BaC17Ccc5b313516C5E16fb24f7659aA5ebed | | 500 gwei Key Hash | 0x4b09e658ed251bcafeebbc69400383d49f344ace09b9576fe248bb02c003fe9f | | Premium | 0.0005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 3 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Avalanche mainnet

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | LINK Token | 0x5947BB275c521040051D82396192181b413227A3 | | VRF Coordinator | 0xd5D517aBE5cF79B7e95eC98dB0f0277788aFF634 | | 200 gwei Key Hash | 0x83250c5584ffa93feb6ee082981c5ebe484c865196750b39835ad4f13780435d | | 500 gwei Key Hash | 0x89630569c9567e43c4fe7b1633258df9f2531b62f2352fa721cf3162ee4ecb46 | | 1000 gwei Key Hash | 0x06eb0e2ea7cca202fc7c8258397a36f33d88568d2522b37aaa3b14ff6ee1b696 | | Premium | 0.005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 1 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Avalanche Fuji testnet

| Item | Value | | --------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0x0b9d5D9136855f6FEc3c0993feE6E9CE8a297846 | | VRF Coordinator | 0x2eD832Ba664535e5886b75D64C46EB9a228C2610 | | 300 gwei Key Hash | 0x354d2f95da55398f44b7cff77da56283d9c6c829a4bdf1bbcaf2ad6a4d081f61 | | Premium | 0.005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 1 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Fantom mainnet

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | LINK Token | 0x6F43FF82CCA38001B6699a8AC47A2d0E66939407 | | VRF Coordinator | 0xd5D517aBE5cF79B7e95eC98dB0f0277788aFF634 | | 4000 gwei Key Hash | 0xb4797e686f9a1548b9a2e8c68988d74788e0c4af5899020fb0c47784af76ddfa | | 10000 gwei Key Hash | 0x5881eea62f9876043df723cf89f0c2bb6f950da25e9dfe66995c24f919c8f8ab | | 20000 gwei Key Hash | 0x64ae04e5dba58bc08ba2d53eb33fe95bf71f5002789692fe78fb3778f16121c9 | | Premium | 0.0005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 1 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |

Fantom testnet

| Item | Value | | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | LINK Token | 0xfaFedb041c0DD4fA2Dc0d87a6B0979Ee6FA7af5F | | VRF Coordinator | 0xbd13f08b8352A3635218ab9418E340c60d6Eb418 | | 3000 gwei Key Hash | 0x121a143066e0f2f08b620784af77cccb35c6242460b4a8ee251b4b416abaebd4 | | Premium | 0.0005 LINK | | Max Gas Limit | 2,500,000 | | Minimum Confirmations | 1 | | Maximum Confirmations | 200 | | Maximum Random Values | 500 |