Free · Public · Cryptographically verified

Pick a winner.
Prove it publicly.

Results are permanently stored on a tamper-proof ledger and verified by the drand randomness beacon. Anyone can recompute the exact winner — no trust required.

How the cryptography works →

Draw title (optional)

Contestants ↑ Import

Columns Up to 3 columns on Free

First column is the draw identity. Import a CSV to auto-detect headers. Separate values with commas in the list below.

0 entries

Prizes

Algorithm

Unique winners only Each entrant wins at most once

Permanent · public · verified by drand beacon

How it works

Cryptographic proof, not promises

Every draw produces a public, immutable certificate that anyone can independently verify.

🔒

Commit–reveal scheme

A server seed hash is published before entries close. The seed is only revealed after the draw — so no one, including us, could have rigged it.

🎲

drand public randomness

The draw uses a future round of the drand randomness beacon — a distributed network nobody controls. Unpredictable and independently verifiable.

🔍

Anyone can verify

Every winner certificate shows the full inputs. Hit "Verify" to recompute the result in your own browser using SHA-256 — no downloads, no trust.

Stack pricing

Contests · RFWIN · RankFuel

One Rewards Fuel subscription — same plans on rewardsfuel.com and rnkfl.com. Every tier includes all three products.

Get two months free when you pay annually (10 months billed for 12 months of service).

Free

$0/mo

Try contests, verified draws, and leaderboards together.

Contests: core entry methods · unlimited contests
RFWIN: 100 entries/draw · 3 draws/month · verification
RankFuel: 3 leaderboards · 10k writes/mo · public proofs

Start now

Use RFWIN from Claude or Cursor

Run verifiable draws directly inside your AI assistant. No copy-paste, no browser tabs.

MCP Tool

rfwin_instant_draw

Pass a list of entrants and prizes. RFWIN runs the draw in one step, commits to drand randomness, and returns a verified draw ID you can share publicly.

MCP Tool

rfwin_get_draw

Retrieve the full verification bundle for any draw ID — winners, entrant hashes, drand round, draw digest, and server seed — for auditing or display.

Connect in 30 seconds

Add the Rewards Fuel MCP server to Claude Desktop, Cursor, or any MCP-compatible client. Sign in with your Rewards Fuel account to authenticate.

Claude Desktop — claude_desktop_config.json

// ~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "rewards-fuel": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://rewards-fuel-api.rewardsfuel.workers.dev/api/mcp"]
    }
  }
}

Available draw tools

rfwin_instant_draw Run a complete draw in one call.
title contestants[] prizes[] algorithm? uniqueWinners? → returns drawId + verification URL
rfwin_get_draw Fetch results and full proof chain for any draw.
drawId → returns winners, entrants, drand values, server seed

Example prompts

Pick 3 winners from my contest — here are 200 email addresses: …

Run a weighted draw where premium members get 3 tickets each

Show me the verification proof for draw k8m2x9p4q1

Full technical details: commit-reveal, drand, REST API, MCP spec →