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Calibri is a prediction-market exchange. You trade on the outcome of real events — an election, a match, where Bitcoin closes — against other people, using real money, on a public order book. Calibri is non custodial, we never holds your funds. They stay in a wallet only you control, on-chain, the entire time.

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What a prediction market is

Every market asks one question with exactly two answers: YES or NO. You buy shares in whichever side you think is right. When the question is answered, each winning share pays 1.00 USDC and each losing share pays 0. Prices sit between 0.01 and 0.99 and read directly as probability: Cheap shares are the ones the market thinks are unlikely — they pay the most if you are right. YES and NO always sum to 1.00, so buying NO at 0.35 is exactly the mirror of selling YES at 0.65. Prices move as opinion moves, so the odds you see change right up until the market closes. You buy the outcome you think is right and are paid 1.00 per share if it happens, or sell your contracts before then at the price the market will pay.

How prediction markets work

The intuition and economics, in more depth.

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How Calibri approaches it

One order book, self-custody throughout. Everyone trades the same book, and every order is a signature you produce. There is no custodial Calibri balance (you don’t deposit into our custody or hot wallet as you might on a CEX).
  • Settled in USDC — a US-dollar stablecoin. Stakes, fees, winnings, rewards, all in USDC.
  • One fee, once — a taker fee when your order fills. Nothing at settlement, nothing at redemption. A winning share always pays the full 1.00. See Fees.
  • Resolution is published before you trade — the exact source that decides each market is on the market page. Crypto markets read Coinbase’s own data directly. See How markets are resolved.
  • Settlement is on-chain and enforced by public contracts, not by our word.

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Your money is yours

Your USDC lives in a Gnosis Safe — a smart-contract wallet on the blockchain that only your own keys can authorise. Calibri deploys it for you and pays the gas, but the operator is never an owner and has no ability to move anything out of it — with one narrow exception: the bridge module can move USDC you sent to your address on another supported network, and only to your own Safe on Polygon. See Deposits from other networks. That means:
  • You can withdraw even if Calibri is offline, because withdrawing is a transaction against your own wallet, not a request to a company.
  • If we vanished tomorrow, on-chain fallbacks still settle open markets or refund them. See Market resolution.
  • Your Safe and its transactions are public on the blockchain. Anyone can verify the funds are where we say they are — including you.
We hold no keys, and we cannot recover your account. There is no password reset for a wallet. If you lose the passkey or the wallet that owns your Safe, and you have no backup, your funds are unreachable — by you and by us. That is not a policy we could change; it is the same property that stops us from touching your money. Read Your wallet options before you fund anything.

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Two ways to hold it

Both end at the same place — your own Safe, holding your own USDC. They differ only in what owns the Safe.

A passkey wallet

Face ID, Touch ID, or your device PIN. No app, no browser extension, no seed phrase to write down. Best if you have never used a crypto wallet.

Your own wallet

MetaMask, Coinbase Wallet, Rainbow, or anything on WalletConnect. Keep the signing habits you already have, and sign in with your wallet too.

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How a passkey wallet works

A passkey is the same technology that lets you sign in to a website with Face ID instead of a password — used here to own a wallet.
  • There is no private key we could ever hold. Your device generates a credential in its secure hardware and gives Calibri only the public half. The private half cannot be exported, by you or by anyone.
  • Your Safe is owned by a signer contract derived from that public key, so approving with your face or fingerprint is what authorises a trade.
  • Your address exists the moment you enrol — it is computed from the public key, before anything is deployed on-chain.
Whether your passkey survives losing your device depends entirely on where your platform stores it — iPhone and Android sync it to your account, Windows Hello does not. That difference is the single most important thing to understand before funding an account, and it is laid out per-platform in Your wallet options.

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How signing works, briefly

You never send a blockchain transaction and you never need gas. What you do is approve, and here is what that approval actually is:
1

You build an order

Pick a market, a side, a price, and a size. Nothing has left your browser yet.
2

Your device signs it

The order’s exact terms — market, outcome token, amount, price, expiry — are turned into a structured message and signed by your passkey or wallet. The signature covers those terms specifically, so it cannot be reused for a different order.
3

Calibri checks the signature and places it

We verify the signature really came from your wallet before the order reaches the book. An order we cannot verify is rejected, not placed.
4

A match settles on-chain

When your order matches, the contracts pull the collateral from your Safe and mint the outcome tokens. Calibri submits the transaction and pays the gas — but it can only ever submit orders both sides have signed.
5

You claim your winnings

Resolution makes your winning shares redeemable. You sign the claim; we relay it and pay the gas. Nothing is pushed to you automatically.
If you use a passkey, approving every single order gets tiring — so you can authorise a session key once and trade without a prompt per order. It can place orders and nothing else: it provably cannot withdraw.

Signed orders — the technical detail

The EIP-712 domain, the order struct, the unit rules, and what the server validates.

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The contracts, in public

Everything above is enforced by contracts you can read yourself. Nothing about custody depends on trusting a claim on this page.

Deployed addresses

The live addresses, how to pull them from the API, and how to verify each one on the block explorer.

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Start here

Getting Started

Zero to your first trade: account, wallet, funding, order, settlement.

Your wallet options

Passkey or your own wallet — and what each means if you lose a device.

Core concepts

Binary markets, prices as probabilities, the combined book, and settlement.

Placing orders

Placing an order, and how a fill becomes a position.

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Understand the details

Fees

One taker fee, at the trade, never at settlement.

How markets are resolved

The exact source behind every market, and why a settlement is never revised.

Self-custody

Your Safe, signed orders, and the Conditional Token Framework end to end.

Rewards

Maker rebates for providing liquidity, referral rewards for bringing traders.

Terms of use

The rules you accept by trading.

Privacy policy

What we collect, and what the blockchain makes public regardless.

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Build on the API

Calibri exposes a REST and WebSocket API for browsing markets, placing signed orders, and reading account data. The API Overview covers base paths, authentication (a validated session or an HMAC-signed API key — not bearer tokens), and response format. The full endpoint-by-endpoint specification is the API Reference.