Soroban / Rust

Smart Contracts

To use Relink Protocol from your Soroban contract, and let users request Chainlink data, make use of our consumer contract lib and call the public functions as shown below.

Note: to always get the most up to date information about the library, please see the README of the repo here: https://github.com/RelinkServices/relink-contracts-rust-soroban

Attention: The following code is for showcase purposes only and is not production ready.

use soroban_sdk::{contract, contractimpl, Address, BytesN, Env, Map, Vec};

use relink::{consumer, Error, RequestId, VrfDirectFundingConsumer};

mod events;
mod storage;
mod test;

#[contract]
pub struct VrfDirectFundingConsumerExample;

#[contractimpl]
impl VrfDirectFundingConsumerExample {
    /// Initialize contract by setting the proxy address and trusted oracles.
    pub fn initialize(env: Env, proxy: Address, threshold: u32, oracles: Vec<BytesN<32>>) {
        consumer::init(&env, &proxy, threshold, oracles);
    }

    /// Initiate a request for randomness.
    pub fn initiate_randomness_request(env: Env, origin: Address, value: i128) -> RequestId {
        let id = consumer::request_randomness(&env, origin, value, None, None);
        // store the request id until the response is processed
        storage::add_request_id(&env, id.clone());
        id
    }
}

#[contractimpl]
impl VrfDirectFundingConsumer for VrfDirectFundingConsumerExample {
    /// Process the response to a randomness request.
    fn verify_and_fulfill_randomness(
        env: Env,
        id: RequestId,
        request_origin: Address,
        random_words: Vec<BytesN<32>>,
        signatures: Map<BytesN<32>, BytesN<64>>,
    ) -> Result<(), Error> {
        // check if RequestId exists
        storage::has_request_id(&env, id.clone())?;
        // verify signatures
        consumer::verify_randomness(&env, &id, &request_origin, &random_words, &signatures)?;
        // remove request as it should only be handled once
        storage::remove_request_id(&env, id.clone());
        // emit event containing the provided random words
        events::randomness_provided(&env, id, random_words);
        Ok(())
    }
}