Axion is a commit-reveal randomness oracle built for Robinhood Chain. Every feature is designed to give developers and agents entropy they can trust.
Unbiased
Two-party commit-reveal: user randomness combined with provider's hash chain reveal. Neither party can unilaterally bias the outcome.
- The user submits a sealed commitment before the provider reveals.
- The provider's reveal is drawn from a pre-generated hash chain.
- Final randomness is a Keccak256 hash of both inputs plus the provider preimage.
- As long as the provider seed remains private, no single actor controls the output.
Verifiable
Every reveal is checked onchain via Keccak256. Anyone can independently verify the randomness was computed correctly.
- The oracle contract recomputes the expected reveal and validates the hash chain link.
- Callbacks include the sequence number and final bytes32 random value.
- All historical requests and reveals are public on Blockscout.
- SDK helpers expose the same verification logic offchain for client-side checks.
Developer-first
TypeScript SDK, Solidity interfaces, and a simple callback pattern. Integrate in under 50 lines of code.
- Import IEntropy and IEntropyConsumer from the published SDK package.
- Implement entropyCallback() to receive the random value.
- requestV2() accepts a provider, user random, and callback gas limit.
- Docs include full Hardhat/Foundry examples and testnet deployment addresses.
Agent-friendly
x402 live: agents pay fixed $0.05 USDG on Robinhood via Primer, then receive verifiable randomness.
- Agents do not need ETH to request randomness — payment settles in USDG.
- Primer handles the x402 payment negotiation and onchain settlement.
- Direct requestV2 with the exact 0.000025 ETH fee remains available for non-agent callers.
- Designed for autonomous workflows that need entropy without wallet management.