Reactive Bounties 2.0: Sprint #1 Cross-Chain Oracle

Reactive Network is kicking off Reactive Bounties 2.0: three two-week bounties to build production-grade, autonomous, cross-chain solutions using Reactive Contracts.

Reactive Bounties 2.0 is designed primarily for junior and mid-level developers who want to level up from tutorials to real systems. Across three back-to-back two-week sprints, you’ll be building production-ready pieces of automation on top of the Reactive Network stack, with clear specs and real constraints instead of toy problems.

See the full description of the program here: https://dorahacks.io/hackathon/reactive-bounties-2

Each sprint is a separate bounty with its own prize pool and winner selection. You can join any single sprint, or play the long game:

• Use the first bounty to get comfortable with Reactive Contracts and learn the stack.
• Apply what you’ve learned to ship a cleaner, safer, more complete solution in the next sprint.
• Compete in all three and aim to win more than one bounty as your understanding of Reactive deepens.

One developer can win one or multiple bounties. There is no limit: if you deliver the best implementation in Bounty #1 and come back even stronger for Bounty #2 or #3, you can take multiple prizes. The program is structured so that your knowledge compounds from one bounty to the next.

The first challenge: Cross-Chain Price Feed Oracle

This is the first challenge in a three-sprint series designed to showcase real reactivity in the wild — not examples, not demos, but fully functioning automation that proves what only Reactive can do.

Prize Pool for Sprint #1: $1,500 REACT (Winner) + $500 REACT (Runner-up)

Deadline: Nov 30, 2025

Bounty Description

Your task is to mirror an official Chainlink Price Feed from an origin chain to a destination chain. The destination chain exposes a read interface compatible with AggregatorV3Interface so applications can consume price data where a native Chainlink feed is not available. The deadline is November 30.

Origin chain behavior

• Read the canonical feed using AggregatorV3Interface functions, primarily latestRoundData() (optionally getRoundData(roundId) for audits). Capture roundId, answer, startedAt, updatedAt, and answeredInRound.
• Trigger cross-chain updates either by subscribing to the aggregator’s on-chain events (NewRound, AnswerUpdated) or by polling latestRoundData() at regular intervals using Cron events.

Message format and verification

• Send a signed cross-chain message containing: feed identifier (e.g., source proxy address), decimals, description, roundId, answer (int256), updatedAt, and a domain separator/version.

Target network contracts

• Deploy a minimal “FeedProxy” that stores (roundId, answer, startedAt, updatedAt, answeredInRound, decimals, description) and exposes a latestRoundData()-compatible getter for downstream apps.

Build the Cross-Chain Oracle → Submit → Win

Bounty #1 is live.
The spec is clear.
The challenge is real.
The best implementation wins.