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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 project expects most markets with clear evidence to take this path, with no vote at all.

A challenger who posts a counter-bond escalates the question to OTER, where every OTER staker may cast one timelock-encrypted ballot, weighted by the OTER staked behind it. No ballot can be decrypted by anyone, including the staker who cast it, until the round closes and drand releases the decryption key, at which point every ballot is decrypted at once. The leading outcome settles the market once it holds at least 70% of the revealed stake; short of that, the question goes to another round. Tāhuna contrasts this with UMA's commit–reveal cycle, where a voter has to return for a second reveal phase, and frames its own relationship to OTER as mirroring Polymarket's to UMA. Stakers who vote with the settled outcome earn OTER and a share of the losing bond, stakers on the wrong side are slashed, and the market creator funds a requester reward when the question is posted, paid to whichever side's bond wins the dispute.

Until September both projects described a narrower vote: a jury seated by a draw from OTER's randomness beacon, with voting power growing as the square root of stake. OTER's specification rev. 2026-09, on oter.io by 30 September 2026, drops both, and Tāhuna's page was revised to match.

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. The September revisions brought the two into line on who votes, on the 70% bar and on how correct stakers are paid. They still disagree on what happens to a question no round can settle.

Tāhuna, "How resolution works"OTER, protocol specification rev. 2026-09
After three failed roundsthe question reopens on a cooldown and "is never voided"; both bonds are refunded after each round without a verdictbonds refund and nobody is slashed; then a two-day window in which the admin may close the question as invalid, after which anyone can
Retry timingsix hours before the next attempt, doubling each time up to thirty daysan escalated question re-enters the next 48-hour vote cycle

The difference decides what a trader holds when a market cannot be settled. Under Tāhuna's description the position stays open, and its collateral locked, for as long as the retries run. Under OTER's the question can end as invalid, which OTER's own example settlement contract redeems at half the collateral on each side. Tāhuna's page previously said the opposite of both: that after five failed attempts resolution could be lifted to an admin call. Its September text drops that and states that OTER "does not hand the outcome to an admin".

Status and roadmap

Tāhuna is pre-launch. On 30 September 2026, the last day of the quarter its timeline gives for a testnet, tahuna.org still read "Now · Pre-launch", "Q3 2026 · Testnet" and "Q4 2026 · Mainnet", offered a waitlist rather than a live application, and had not changed since 3 September. The Tahuna-Labs GitHub organisation, registered in May 2026, still publishes no public repositories when re-checked through the GitHub API the same day, 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 live in production but the oracle itself not yet on mainnet.

  • 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
HydrateLast updated Sep 30, 2026v1.2.05 revisionsVerified Sep 30, 2026