What Is RankFuel? Leaderboards Anyone Can Verify

Most leaderboards ask you to trust them. That is fine for bragging rights, but not when money, prizes or reputation ride on the final standings. RankFuel is a leaderboard API built for that second case: every competition period ends with a proof bundle that you, your players, sponsors or auditors can download and re-run.

How it works: open, compete, settle

1. Open. When you create a leaderboard, RankFuel opens its first period and records a commitment: the SHA-256 hash of a secret it generated, the leaderboard id and the period label. The secret stays hidden; the hash is fixed from the start.
2. Compete. Scores arrive through the REST API or MCP. Each leaderboard runs in its own Durable Object on Cloudflare's edge, which keeps rankings consistent as writes come in. Writes are idempotent: send an Idempotency-Key and a retry never double-counts.
3. Settle. Closing a period locks it to a future round of drand, the public randomness beacon run by the League of Entropy. Once that round is published, settling reveals the secret, combines it with the drand value into a seed for tie-breaks, and writes the proof bundle.

Because the commitment is fixed before the drand value exists, nobody, including the leaderboard owner, can choose a seed that favours a particular result. Publish the commitment hash when the competition starts and anyone can hold you to it.

What the proof lets you check

The verify endpoint and the verify_ranking MCP tool recompute two things from the bundle: that the revealed secret matches the commitment published when the period opened, and that the seed equals the hash of the secret and the drand randomness. If either fails, the standings should not be trusted.

Cryptographic verification supports auditability. It does not replace your competition rules or legal obligations.

Built for agents too

RankFuel exposes the same operations as MCP tools: create_leaderboard, submit_score, get_leaderboard, get_rank, settle_period, verify_ranking and get_proof, plus appearance tools. An agent that is about to pay out a prize can read the standings and verify them in two calls instead of scraping a web page. See verify before you pay out.

What you can build

• Game and app leaderboards with themed embeds (sports, gaming, minimal, dark and more).
• Sports and golf boards: long drive, closest to the pin, skins, stroke play, Stableford, scramble and match play templates. Browse the live demos.
• Community and sales competitions where people want to see the standings were not edited.
• Agent competitions, where autonomous agents submit results and a settlement agent pays out.

Part of the Rewards Fuel stack

RankFuel decides who is winning, Rewards Fuel runs the contest and the prizes, and RFWIN picks random winners with a public proof. One subscription covers all three. The free plan includes 3 leaderboards, 10,000 score writes a month and public proofs; paid plans add more boards and writes, and the MCP server starts on Promoter. See pricing.

Ready to build? Read how to add a verifiable leaderboard with the API.