Calibro
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Sports & prediction markets · Walrus Memory · Sui · Tatum

A forecaster
that keeps score.

Calibro pays for sports signals over HTTP 402, settles every forecast against the real result, and keeps each source's record on Walrus Memory. Next game, it pays the sources that were right, refuses the ones that weren't, and coaches the people who pick against it.

Open the terminalMake a pick

Reading the record from Walrus Memory…

7
sources scored per league
4
Walrus Memory namespaces
0.002
SUI per signal, paid on Sui
0
language-model calls in the maths

1

How it works

  1. Step 1

    Recall

    For every market, Calibro reads three things from Walrus Memory: its risk mandate, each source's record in that league, and similar games it has settled before.

  2. Step 2

    Decide who to pay

    A source is worth its fee only if its record says so. New sources get four games to prove themselves; after that, any source scoring worse than 0.265 is refused, and the reason is written down.

  3. Step 3

    Pay and verify

    Signals sit behind HTTP 402. Calibro pays with a real Sui transfer, and the seller checks the transaction through Tatum's Sui gateway before releasing anything. Receipts are single use.

  4. Step 4

    Learn

    When Polymarket resolves the game, Calibro scores every signal it bought, updates each source's calibration, and writes the post-mortem back to Walrus. Nobody types in a result.

Exhibit 2 · one paid signal, as it travels
GET /api/signals/sharp-steam?marketId=poly-nba-…        402 Payment Required
    WWW-Authenticate: Payment protocol="mpp-sui-v1", network="sui:mainnet", amount="2000000", …
    X-Payment-Required: { x402Version: 1, accepts: [{ scheme: "exact", payTo: "0x5e2d…", … }] }

Sui transfer of 0.002 SUI to the seller's treasury

GET … X-Payment: { txDigest, challengeId, payer }        200 OK, signed signal
    checked through Tatum: succeeded, treasury credited, sender matches, never used before

2

The record so far

Reading the track record from Walrus Memory…

3

It remembers you, too

A pick journal with a memory

Connect any Sui wallet and sign your probability before the game. The pick is sealed on Walrus with your signature, graded against Polymarket's result, and scored with the same maths Calibro applies to its own sources.

A coach that has read your record

Before you sign, Calibro looks up how your past picks at the same confidence actually turned out, and how you've done when you disagreed with the market. When your record says your confidence runs high, it suggests the number your history supports, and your scorecard later shows whether listening helped.

Paid for being right

After three graded picks with a Brier of 0.25 or better, you become one of Calibro's sources. When it uses your picks, the fee is split by how much it trusts you and sent straight to your wallet on Sui. Stop being right, and it stops paying.

Open the pick journal

4

The sources it weighs

Seven sources, all paid through the same 402 gate. Four are Calibro's own documented models, two are outside crowds, and one is its best users. Each sees only data from before the game, and none is assumed to be good.

SourceWhat it doesLeagues
SharpSteamSportsbook moneyline, de-vigged, plus half the open→close line move.DraftKings via ESPN · Pinnacle via The Odds API (upcoming games, when keyed)NBA · EPL · UFC
PowerRatingESPN BPI pre-game matchup projection.ESPN BPI predictorNBA
OnchainFlowPolymarket price plus half its last-6h move (order-flow momentum).Polymarket CLOB price historyAll leagues
HypeContrarianFades the crowd: backs the Polymarket underdog and leans against the last-24h move.Polymarket CLOB price historyAll leagues
KalshiCrowdThe Kalshi exchange price for the same outcome (third-party, CFTC-regulated).Kalshi public market data (hourly candles; live bid/ask mid within 10 pts)NBA · EPL · UFC
ManifoldCrowdThe Manifold Markets community forecast (third-party, play money).Manifold public API (ManifoldSports game markets, bet history)NBA
TopPickersCalibro's own users: wallet-signed picks from people with a proven record, weighted by it. The fee is split straight into their wallets.Pick journal on Walrus (calibro:picks): pickers with ≥ 3 graded picks and Brier ≤ 0.25NBA · EPL · UFC (upcoming games)

5

For other agents

Calibro sells its own calibrated forecast over the same protocol, for 0.01 SUI. Any agent can buy it: the answer includes the probability, the sources Calibro paid and how it weighted them, the ones it refused and why, and the Walrus record of its reasoning. The revenue goes to the wallet that pays Calibro's sources.

Discover

GET /.well-known/x402

GET /llms.txt

Buy

GET /api/forecast?marketId=…

402, then pay on Sui, then retry with X-Payment

6

Method

Brier score
BS = (1/N) Σ (p − y)²
The average squared miss. 0.25 is what a coin flip scores.
De-biasing
logit p′ = α · logit p + β
Fitted per source and league; an overconfident source drifts to α below 1.
Whether to pay
VoI = bankroll · κ · (0.265 − BS) · γ
A signal is bought only if its expected value beats the fee in USD.
Stake
f = min(κ · (P·O − 1)/(O − 1), 5%)
Quarter-Kelly at most, never more than 5% of the bankroll on one game.

All of it is deterministic TypeScript. No language model produces a probability, decides a payment or sets a stake.

7

Notes

  1. Markets, prices and results come from Polymarket; sportsbook lines and BPI from ESPN; Pinnacle from The Odds API; outside forecasts from Kalshi and Manifold. Nothing is simulated.
  2. Four sources are Calibro's own models sold to its own agent, and their fees go to a treasury we control. The payments are still real Sui transfers.
  3. Stakes are recommendations on a paper bankroll. Calibro does not place bets, and none of this is betting advice.
  4. Built for Total Recall, the Tatum × Walrus Memory hackathon. Apache-2.0.
Calibro — a forecaster that keeps score