Polymarket retires its old data API nine days before new markets tentatively move to V2
Polymarket will retire Data API V1 on Oct. 24, nine days before new markets tentatively move off its 2019 Gnosis contracts onto Protocol V2 on Nov. 2. Old positions stay where they are, so integrations must run both contract systems until legacy markets close.
The Investor · Invest desk

What happened
- Canary markets, a limited set of live V2 test markets, run in production from Oct. 5 through Oct. 30.
- V2 holds outcome shares in a single ERC-1155 position system, with token IDs that encode the module, condition and outcome.
- Resolution moves to an OracleAggregator that can combine UMA, Chainlink and EOA reporters under thresholds set for each market.
- The replacement Data API v2 runs on Polymarket's own on-chain indexer, with standardized data formats and cursor-based pagination.
Why it matters
- What it limits constraint The old data API shuts six days before canary testing ends, so builders have to finish rewriting data tooling before they know whether V2 starts on schedule.
- What doesn't add up contradiction Crypto Briefing reports Nov. 2 as a full switchover for all new markets while crypto.news quotes Polymarket's protocol head hedging it, so readers of one outlet would plan to a firmer date than Polymarket gave.
- Who's exposed exposure With pUSD backing every new V2 position, the code rule that the wrapper vault's USDC and USDC.e must cover outstanding pUSD supply becomes the reserve check for all new markets.
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As Polymarket added market formats to the Gnosis framework, it also added separate adapters and contracts for negative-risk markets, collateral handling and resolution, according to crypto.news [11]. V2 folds binary, negative-risk and combinatorial markets into modules under one PositionManager, and all of them are already deployed on Polygon mainnet [12]. The consolidation covers only newly created markets [2]. Existing CTF markets and positions will not migrate automatically [3], and Polymarket's migration guide tells developers to keep CTF support for older markets and holdings [5].
For a market maker, that means two inventories. V2 balances sit in the PositionManager, while splits, merges and redemptions go through a Router [14]. Approvals granted to the old CTF contracts do not carry over, so V2 needs its own permissions [15]. A desk quoting an old market and a new one will hold positions in two contract systems under two sets of approvals, for as long as the longest-dated legacy market stays open. Neither report includes a date for retiring CTF support.
The start date is hedged. Rajath Alex, Polymarket's protocol head, said on Oct. 5 that net-new markets would "tentatively" begin moving to Protocol V2 on Nov. 2, crypto.news reported [1]. If the date holds, V2 starts taking new markets nine days after the old data API shuts [18], and the second stack grows from then. If it slips, new markets presumably keep opening on CTF contracts. That adds to the legacy book Polymarket has chosen to leave in place.
The counter-case is that the extra work is small. V2 takes pUSD as its only collateral [7], but the token arrived with the April exchange upgrade, and integrations already using it do not have to replace their collateral setup to add V2 [8]. On that reading, supporting V2 means new approvals and new contract calls, done once. I think that understates the cost for anyone quoting both systems, since every day both stay live is a day of reconciling two sets of positions. The view is wrong if most legacy markets settle within a few weeks of Nov. 2, because the second stack would then retire on its own.
What to watch
- Whether Polymarket extends Data API V1 past Oct. 24 if the Nov. 2 start moves.
- Any fault reported in the binary, negative-risk or combinatorial modules before the canary run ends on Oct. 30.
- Any tool from Polymarket to convert CTF holdings into V2 positions.
Information, not investment advice. This story is general information about companies and markets, drawn from cited reporting. It is not a recommendation to buy, sell or hold any security; check the cited sources before acting.
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- [1]
Polymarket protocol head Rajath Alex said on Oct. 5 that canary markets would run in production through Oct. 30 before net-new markets "tentatively" begin moving to Protocol V2 on Nov. 2.
- [2]
Polymarket has begun production testing of Protocol V2 ahead of a tentative Nov. 2 switch for newly created markets, replacing its 2019-era Gnosis CTF market architecture.
- [3]
Existing CTF markets and positions will not automatically migrate to the new contracts.
- [4]
On November 2, all new markets move to V2; Crypto Briefing described it as a full switchover for new markets.
- [5]
Polymarket tells developers to keep CTF support for older markets and holdings; its migration documentation says existing CTF holdings are not converted when an integration adds Protocol V2.
- [6]
pUSD is an ERC-20 token wrapping USDC and USDC.e at a 1:1 ratio through an external vault, and the code requires the combined USDC and USDC.e held by the vault to equal or exceed outstanding pUSD supply.
- [7]
Under V2, pUSD becomes the only accepted form of collateral backing positions on the platform.
- [8]
pUSD arrived with Polymarket's April exchange upgrade earlier in 2026; existing integrations already using pUSD do not need to replace their collateral setup when adding V2 support.
- [9]
The OracleAggregator sits above pluggable reporter, dispute and arbitration modules; reporter contracts include UMA Optimistic Oracle, Chainlink and EOA reporters, which can be combined under thresholds set for individual markets.
- [10]
Canary markets, a limited set of live test markets, run from October 5 through October 30.
- [11]
As new market formats were introduced on the Gnosis-based system, separate adapters and contracts were added for functions including negative-risk markets, collateral handling and resolution.
- [12]
V2's initial modules cover binary, atomic negative-risk, incremental negative-risk and combinatorial markets under a common PositionManager and Router, and Polymarket's Polygon deployment list shows them already deployed on mainnet.
- [13]
V2 uses a single ERC-1155 position system, and position IDs encode the module, condition and outcome directly into the token identifier.
- [14]
V2 balances sit in the new PositionManager, while splits, merges and redemptions go through the Router.
- [15]
Existing CTF approvals do not carry over, so integrations need new permissions for V2 operations.
- [16]
Polymarket's Data API V1 retires October 24.
- [17]
Data API v2 runs on an in-house on-chain indexer and offers standardized data formats and cursor-based pagination.
- [18]
Data API V1 retires nine days before new markets are due to move to V2.
- [19]
Data API V1 retires six days before the canary test period ends.
Sources
4 independent publishers whose own reporting we read for this story.
- cointelegraph.comPolymarket overhauls smart contracts with new Protocol V2 rollout
1 article · October 6, 2026
- crypto.newsPolymarket V2 could change how users bet on events
1 article · October 5, 2026
- cryptobriefing.comPolymarket unveils Protocol V2, with full switchover for new markets on Nov 2
1 article · October 5, 2026
- news.bitcoin.comPolymarket Is Rebuilding the Engine Under Every Bet Before November 2
1 article · October 6, 2026
Topics and entities
Topics
- Prediction Markets
- Smart contract migrations
- Blockchain Oracles
Entities
- Polygon
- Polymarket Protocol V2
- Polymarket
- Gnosis Conditional Tokens Framework
- Kalshi
- Chainlink