Crate solana_randomness_service_lite

source ·
Expand description

The Solana Randomness Service uses a Switchboard SGX enabled oracle to provide randomness to any Solana program using a callback instruction.

Program ID: RANDMo5gFnqnXJW5Z52KNmd24sAo95KAd5VbiCtq5Rh

See the crate solana-randomness-service for the full CPI interface.

§Example Program

use anchor_lang::prelude::*;
use solana_randomness_service_lite::{SimpleRandomnessV1Request, ID as SolanaRandomnessServiceID};

#[program]
pub mod solana_randomness_consumer {
    use super::*;

    pub fn request_randomness(ctx: Context<RequestRandomness>) -> anchor_lang::prelude::Result<()> {
        msg!("Requesting randomness...");

        let request = SimpleRandomnessV1Request {
            request: ctx.accounts.randomness_request.to_account_info(),
            escrow: ctx.accounts.randomness_escrow.to_account_info(),
            state: ctx.accounts.randomness_state.to_account_info(),
            mint: ctx.accounts.randomness_mint.to_account_info(),
            payer: ctx.accounts.payer.to_account_info(),
            system_program: ctx.accounts.system_program.to_account_info(),
            token_program: ctx.accounts.token_program.to_account_info(),
            associated_token_program: ctx.accounts.associated_token_program.to_account_info(),
        };
        request.invoke(
            ctx.accounts.randomness_service.to_account_info(),
            8, // Request 8 bytes of randomness
            &solana_randomness_service_lite::Callback::new(
                ID,
                vec![
                    AccountMeta::new_readonly(ctx.accounts.randomness_state.key(), true).into(),
                    AccountMeta::new_readonly(ctx.accounts.randomness_request.key(), false).into(),
                ],
                [190, 217, 49, 162, 99, 26, 73, 234].to_vec(), // Our callback ixn discriminator. The oracle will append the randomness bytes to the end
            ),
            &Some(solana_randomness_service_lite::TransactionOptions {
                compute_units: Some(1_000_000),
                compute_unit_price: Some(100),
            }),
        )?;

        // Here we can emit some event to index our requests

        Ok(())
    }
}

#[derive(Accounts)]
pub struct RequestRandomness<'info> {
    /// CHECK: manually check programID and executable status
    #[account(
        constraint = randomness_service.key() == SolanaRandomnessServiceID,
        constraint = randomness_service.executable,
    )]
    pub randomness_service: AccountInfo<'info>,

    /// The account that will be created on-chain to hold the randomness request.
    /// Used by the off-chain oracle to pickup the request and fulfill it.
    /// CHECK: todo
    #[account(
        mut,
        signer,
        owner = system_program.key(),
        constraint = randomness_request.data_len() == 0 && randomness_request.lamports() == 0,
    )]
    pub randomness_request: AccountInfo<'info>,

    /// The TokenAccount that will store the funds for the randomness request.
    /// CHECK: todo
    #[account(
        mut,
        owner = system_program.key(),
        constraint = randomness_escrow.data_len() == 0 && randomness_escrow.lamports() == 0,
    )]
    pub randomness_escrow: AccountInfo<'info>,

    /// The randomness service's state account. Responsible for storing the
    /// reward escrow and the cost per random byte.
    #[account(
        seeds = [b"STATE"],
        bump = randomness_state.bump,
        seeds::program = randomness_service.key(),
    )]
    pub randomness_state: Box<Account<'info, solana_randomness_service::State>>,

    /// The token mint to use for paying for randomness requests.
    #[account(address = NativeMint::ID)]
    pub randomness_mint: Account<'info, Mint>,

    /// The account that will pay for the randomness request.
    #[account(mut)]
    pub payer: Signer<'info>,

    /// The Solana System program. Used to allocate space on-chain for the randomness_request account.
    pub system_program: Program<'info, System>,

    /// The Solana Token program. Used to transfer funds to the randomness escrow.
    pub token_program: Program<'info, Token>,

    /// The Solana Associated Token program. Used to create the TokenAccount for the randomness escrow.
    pub associated_token_program: Program<'info, AssociatedToken>,
}

Re-exports§

Modules§

Structs§

Enums§

Constants§

Functions§

  • check_id
    Returns true if given pubkey is the program ID.
  • id
    Returns the program ID.