Tāhuna

Tāhuna is a decentralized prediction-market protocol in development on Radix mainnet. Anyone can list a market by posting a bond and writing the question; the listed creator then earns a share of every taker fee that market generates, creditable on the spot rather than at resolution. Markets are quoted in xUSDC and priced on an on-chain limit order book. Resolution is not performed by Tāhuna itself but handed to OTER, the optimistic oracle on Radix, for which Tāhuna is the founding integration.

The name is te reo Māori: tāhuna (TAH-hoo-nah) is a sandbank, beach or sandy shore – and the calm shallow water between the sand and the open sea.

Market mechanics

Tāhuna's stated design point is that the whole order book lives on the ledger. Every limit order, fill and cancellation is a Radix transaction and the matching engine runs in the contract, so there is no off-chain matching server, no custodial bridge and no settlement layer above the ledger – a design that leans on Radix's throughput and on the asset-oriented execution described in Scrypto fundamentals. Each market carries a price grid of 99 or 999 levels. An in-house indexing layer reads the on-chain state and republishes it live to the trading interface and over a public API, so integrators read the same feed as the frontend.

Fees run in one direction: the taker pays and the maker is paid back through an on-chain rebate credited per fill, with the fee peaking at 1.80% at 50¢ and tapering toward the ends of the price range. Listing a market is permissionless and free, or revenue-generating in exchange for a 10 xUSDC bond; a curator – human or automated – verifies the wording before a market goes live, after which the listed creator stays attached to it for its lifetime. Creators register once and can list any number of markets under one identity, accruing a share of taker fees across all of them. Beyond the per-fill rebate the project describes a planned off-chain liquidity-rewards programme modelled on Polymarket's, scoring depth and time-on-touch each minute against the same indexed data, on the reasoning that cranking the book on-chain once a minute is not feasible.

The protocol has no token, and the project states there is no presale and no airdrop.

Resolution

Tāhuna describes itself as the markets layer only; confirming an outcome is delegated to OTER, a separate project it depends on. When a market reaches its deadline a proposer submits a candidate outcome and posts a proposer bond, opening a four-hour challenge window – the default in OTER's own protocol specification, which marks it configurable per question. If nobody disputes it, the outcome finalizes, the market settles and the bond is returned – the path the project expects most markets with clear evidence to take, with no vote and no jury.

A challenger who posts a counter-bond escalates the question to OTER, where staked participants cast timelock-encrypted ballots. No ballot can be decrypted by anyone – including the juror who cast it – until the round closes and drand releases the decryption key, at which point every ballot is decrypted at once. Tāhuna contrasts this with UMA's commit–reveal cycle, which it says takes an extra round, and frames its own relationship to OTER as mirroring Polymarket's to UMA. The market creator posts a resolver reward when escalating, so jurors are paid by the market they are resolving.

Two details of that vote are documented by OTER rather than by Tāhuna, and neither is visible from the markets side. The jury is not simply whoever staked: seats are drawn from OTER's own BLS randomness beacon after ballots lock, seating roughly 97 of every 100 revealed votes, so no stake buys a guaranteed seat. And voting power grows with the square root of stake rather than linearly with it, which the oracle publishes as cutting the top holder's share of voting weight from 24.1% to 3.6%.

Where the two specifications disagree

Both projects are pre-launch and both descriptions are their own documentation, so nothing below has been observed on-ledger. Where the two disagree about the same mechanism, this page records the disagreement rather than choosing between them.

The deadlock row is the one that matters beyond wording. Tāhuna's page tells a trader that an ambiguous market ends in an administrator's decision; OTER's specification says an administrator can hurry a stuck question along but can never decide one, and that a question which cannot converge is closed as invalid instead. A market settling by admin call and a market voiding are different outcomes for whoever holds the position, and the two published documents do not agree on which one happens.

Status and roadmap

As of 29 August 2026 Tāhuna is pre-launch. Its published timeline targets a testnet in Q3 2026 and mainnet in Q4 2026, and the site offers a waitlist rather than a live application. The Tahuna-Labs GitHub organisation is registered but still publishes no public repositories – re-checked through the GitHub API on 29 August 2026, one month before the targeted testnet quarter closes – so the contracts are not open to inspection. The project states it is not available to residents of jurisdictions where prediction markets are prohibited.

Tāhuna's dependency on OTER means the two ship on linked timelines: OTER is likewise pre-launch, with its randomness beacon already live in production but the oracle itself not yet on mainnet.

External Links

• tahuna.org – official site and protocol specification
• How resolution works – Tāhuna
• Tāhuna on X (@tahuna_org)
• Tahuna-Labs on GitHub

Related pages

• OTER – the optimistic oracle that settles Tāhuna's disputed markets
• Religant – the earlier oracle effort on Radix
• Oracle Integration – consuming an oracle from a Scrypto blueprint
• Ociswap – order-book and AMM trading venue on Radix