Polymarket Protocol V2 opens canary markets, full switchover set for November 2

Polymarket opened canary markets for Protocol V2 on October 5, 2026 and will complete the full switchover — all new markets created on V2 — on November 2, 2026, Crypto Briefing reports. The upgrade retires the Gnosis Conditional Tokens Framework that Polymarket has used since 2019, consolidates outcome shares into a single ERC-1155 positions contract, and makes pUSD the sole accepted collateral.

What changes

Positions contract. V1 relied on the Gnosis Conditional Tokens Framework (CTF), where every market minted its own ERC-20 complementary-outcome tokens. V2 moves all outcome shares into one ERC-1155 positions contract, with per-market exchanges fronting a shared routing layer. The practical effect for integrators: fewer contract deployments, uniform event signatures, and a cleaner path for secondary venues to quote Polymarket outcomes.

Collateral. V1 accepted multiple USD-pegged stablecoins. V2 is pUSD-only — Polymarket's own stablecoin, bridged on Polygon — for new markets. Existing V1 markets keep their collateral mix and remain tradable until they resolve; there is no forced migration of open positions.

Oracles. V2 ships an OracleAggregator supporting both UMA's Optimistic Oracle and Chainlink data feeds on a per-market basis. Market creators pick the resolution source at listing time, rather than UMA being the only option. For data-feed-style markets (equity closes, sports scores, protocol metrics) this is a meaningful change — Chainlink's pull architecture is cheaper and faster than UMA's dispute window for high-frequency resolutions.

Data layer. A new Data API v2 with standardized response envelopes and cursor-based pagination replaces the V1 REST surface. Polymarket now runs its own on-chain indexer rather than depending on external services, which is the kind of change that reads boring in a release note but changes the latency and reliability floor for every downstream analytics product.

Audits and bounty

Six firms audited the V2 contracts, including Certora (formal verification). A bug-bounty program is live with payouts of up to $5 million for critical findings. The specific audit reports have not been linked at the time of writing.

Timeline

• October 5, 2026 — canary markets open on V2. Limited scope, used to shake out integrations.
• October 5–30, 2026 — canary window.
• November 2, 2026 — full switchover. From this date all new markets launch on V2; V1 remains live for existing markets until they resolve.

Context

The V2 refactor is the most invasive protocol change Polymarket has shipped. The CTF-to-ERC-1155 move is driven by the cost of running what became a very large set of per-market ERC-20 pairs on Polygon; the pluggable oracle layer is a response to UMA's dispute-window latency being a poor fit for frequent-resolution markets. The pUSD-only rule concentrates settlement risk on Polymarket's own peg mechanism and bridge — a tradeoff the team is making for integration simplicity and vendor control.

What to watch

1. Peg behaviour of pUSD under launch load — issuance mechanics, bridge-backed reserves, redemption throughput. The protocol is now downstream of this stablecoin.
2. OracleAggregator contention — how markets split between UMA and Chainlink in practice. If 95% land back on UMA, the aggregator is a design cost without a payoff.
3. V1 wind-down — timeline, forced-resolution policy for stale V1 markets, final liquidity on CTF-era pairs.
4. ERC-1155 integrations — secondary venues and aggregators that quoted V1 pairs need to re-index on the single-contract model before any meaningful cross-venue liquidity returns.
5. Audit disclosures — the six reports, and whether Certora's formal verification scope covers the escrow and oracle paths or only the ERC-1155 bookkeeping.