Parametric Rainfall Derivatives · Smart Contracts · Product UX
Bruma Protocol
Price the rain. Transfer the risk.
Built for the Chainlink Convergence hackathon in Medellín, Bruma turns rainfall — the oldest unpriced risk in agriculture and outdoor business — into a structured financial position. Priced by Chainlink oracles against a decade of historical data, settled automatically, owned as an NFT. No counterparty negotiations, no intermediaries.
01 / The Challenge
Rainfall is the oldest risk nobody prices.
Farmers, event operators, and anyone running an outdoor business absorb weather risk every season with no structured way to hedge it. Institutional weather derivatives exist, but they were never built for an individual operator.
The idea came from a conversation with a woman in Medellín who checked the weather every morning — not as a ritual, but as a necessity.
The challenge wasn’t building another DeFi protocol. It was turning that daily act of reading the sky into a financial instrument — priced transparently, with no intermediary standing between the risk and the person carrying it.
02 / The Solution
An index, not an insurance claim.
Bruma structures rainfall as a bilateral index contract instead of a policy. A Call or Put settles purely on what a Chainlink oracle reports against a chosen strike — never on an assessment of actual loss.
A buyer may be hedging real exposure, or simply taking a financial position on rainfall. The protocol doesn’t distinguish between the two — it only reads the index.
Pricing, settlement, and payout all run through Chainlink Functions and Automation, so no one — including the protocol’s own builder — holds discretion over the outcome.
Live Walkthrough
An index priced, held, and settled on-chain.
DEPLOYED ON ETHEREUM SEPOLIA & AVALANCHE FUJI · CONNECT WALLET TO PRICE A POSITION.
03 / Product Architecture
Six layers. One verifiable settlement.
Pricing, automation, and custody are split across independent layers so no single party — oracle, vault, or builder — can move an outcome alone.
Chainlink Functions
Prices premiums and settles positions by fetching and computing rainfall data on-chain
Chainlink Automation
Keepers monitor option expiry and trigger settlement — no claims process, no manual step
Chainlink CRE
Vault Risk Guardian fetches 7-day forecasts and tightens utilization limits ahead of adverse rainfall
ERC-721 Position NFT
Every position is a transferable, self-custodied token — full ownership, no intermediary
ERC-4626 Vault
Standard vault with virtual share offset; 80% max utilization, 20% per-location cap
Pull Payment Pattern
CEI-pattern settlement with manual claim fallback if an auto-transfer fails
System Mechanics
Four steps from exposure to position
Fully automated via Chainlink Functions and Automation. Settlement is determined by oracle data, not by any assessment of actual loss.
Risk Framework
Two instruments, one liquidity pool.
Long Rainfall
Call Option
Pays out when oracle-reported rainfall exceeds the strike during the observation window, scaling linearly up to the spread cap. Built for exposure to excess rainfall — harvest operations, event venues, infrastructure.
Short Rainfall
Put Option
Pays out when oracle-reported rainfall falls below the strike, scaling down to the spread cap. Built for exposure to dry conditions — irrigated farms, seasonal tourism, water-dependent production.
Risk Counterparty
Liquidity Pool
Depositors act as the counterparty to option buyers and earn a share of every premium collected, governed by the same utilization and per-location caps that protect the vault.
Product Console
Every position, priced and monitored in one place.
The console covers the full lifecycle of a position — from choosing a location and strike, to watching the historical rainfall context behind a quote, to tracking vault health and the automation runs that settle it.
The machinery behind settlement, made visible.
A Pool view tracks vault TVL, utilization, and liquidity provider positions. A Workflow view surfaces the same three automation runs — settlement, vault risk guardian, reinsurance pool monitor — that operate the protocol on-chain, with a live execution log.
Full-Stack Execution
How We Built It
Technologies Used
Recognition
Built for the Chainlink Convergence.
Bruma Protocol was conceived, designed, and built solo over an intense sprint for the Chainlink Convergence hackathon in Medellín — with a little help from AI companions across architecture, interface, and code.
The protocol is designed to be autonomous: admin keys move to a timelock before any mainnet deployment, so the builder retains no ongoing discretion over settlement, pricing, or payouts — only the oracle and the vault parameters govern outcomes.