- changelog/changelog.md: full re-scrape from live, add Apr 28 V2 live entry - v2-migration.md: post-cutover language update (V2 live as of Apr 28) - trading/matching-engine.md: new page on matching engine restarts/HTTP 425
25 KiB
Documentation Index
Fetch the complete documentation index at: https://docs.polymarket.com/llms.txt Use this file to discover all available pages before exploring further.
Migrating to CLOB V2
A complete guide to upgrading your integration to Polymarket's CLOB V2 — new contracts, new backend, new collateral token, and a simpler builder program.
Polymarket has shipped a coordinated upgrade of its entire trading infrastructure: new Exchange contracts, a rewritten CLOB backend, and a new collateral token (Polymarket USD, or pUSD). This guide walks you through everything you need to migrate from CLOB V1 to CLOB V2.
**CLOB V2 is live as of April 28, 2026.** Legacy V1 SDKs and V1-signed orders are no longer supported on production. Upgrade to the V2 SDK or update your raw order signing before submitting orders to `https://clob.polymarket.com`. **Production URL:** CLOB V2 now runs at `https://clob.polymarket.com`. The pre-cutover `https://clob-v2.polymarket.com` testing host is no longer the integration target for production clients.TL;DR
| What | Before (V1) | After (V2) |
|---|---|---|
| SDK package | @polymarket/clob-client / py-clob-client |
@polymarket/clob-client-v2 / py-clob-client-v2 |
| Constructor | Positional args | Options object, chainId → chain |
| Order fields | nonce, feeRateBps, taker |
timestamp (ms), metadata, builder |
| Fees | Embedded in the signed order | Operator-set at match time |
| Collateral | USDC.e | pUSD (standard ERC-20, backed by USDC) |
| Builder auth | POLY_BUILDER_* HMAC headers + builder-signing-sdk |
A single builderCode field on the order |
| EIP-712 domain version | "1" |
"2" (exchange only — API auth unchanged) |
Exchange verifyingContract (raw API signers) |
V1 addresses | V2 addresses — see Contracts |
| Raw API order signing | V1 Order type | Updated Order type — see API users section |
If you're on the latest SDK, most of this is handled automatically. If you're signing orders manually, update the EIP-712 domain, order fields, and contract addresses described below.
Before you start
Even if a section doesn't look relevant, skim it. V2 touches more surface area than any previous release. Install the V2 SDK: [`@polymarket/clob-client-v2`](https://www.npmjs.com/package/@polymarket/clob-client-v2) (TypeScript) or [`py-clob-client-v2`](https://pypi.org/project/py-clob-client-v2/) (Python). Don't keep using the old `clob-client` / `py-clob-client` packages — those only work against V1 and no longer function against production. Use a small funded wallet to test market discovery, order signing, posting, cancellation, and settlement behavior end-to-end on production. **Open orders from before the CLOB V2 cutover were wiped.** If you had resting V1-era orders, they did not migrate and must be re-created with V2 order signing.What's changing
1. New Exchange contracts
The onchain exchange has been rewritten from the ground up.
- Solidity upgraded from 0.8.15 → 0.8.30, with Solady replacing OpenZeppelin for gas savings.
- Order struct simplified:
nonce,feeRateBps, andtakerremoved;timestamp,metadata,builderadded. - EIP-712 exchange domain version bumped from
"1"to"2". - Fees collected onchain at match time (no longer embedded in the signed order).
- Onchain cancel replaced with operator-controlled
pauseUser/unpauseUser. - Batched mint/merge operations for gas efficiency.
See Contracts for V2 addresses.
2. Rewritten CLOB backend
The order manager, ledger, executor, balance checker, and tracker are all new services. From an integrator's perspective:
- Nonce system removed. Order uniqueness now comes from
timestamp(milliseconds). You no longer track nonces. - New fee model. Platform fees are dynamic per market and queryable via
getClobMarketInfo(). - Builder codes enable integrator attribution and revenue sharing, replacing the old HMAC-header flow.
3. New collateral token
Polymarket is migrating from USDC.e to pUSD (Polymarket USD), a standard ERC-20 on Polygon backed by USDC. Backing is enforced onchain by the smart contract.
- For users trading on polymarket.com, the frontend handles wrapping automatically with a one-time approval.
- Power users and API-only traders wrap their USDC.e into pUSD via the Collateral Onramp contract's
wrap()function.
For API users
If you sign and post orders directly (without the SDK), here's what changes in the wire protocol. SDK users can skip this section — the client handles it.
EIP-712 domain
The Exchange domain version bumps to "2" and the verifyingContract moves to the V2 Exchange.
{
name: "Polymarket CTF Exchange",
version: "1", // [!code --]
version: "2", // [!code ++]
chainId: 137,
verifyingContract: "0x4bFb41d5B3570DeFd03C39a9A4D8dE6Bd8B8982E", // [!code --]
verifyingContract: "0xE111180000d2663C0091e4f400237545B87B996B", // [!code ++]
}
For Neg Risk markets, the verifyingContract is different:
{
verifyingContract: "0xC5d563A36AE78145C45a50134d48A1215220f80a", // [!code --]
verifyingContract: "0xe2222d279d744050d28e00520010520000310F59", // [!code ++]
}
See Contracts for the canonical V2 addresses.
**Only the Exchange domain changes.** The `ClobAuthDomain` used for L1 API authentication stays at version `"1"` — L1/L2 auth is identical in V2.EIP-712 Order type
The signed struct drops taker, expiration, nonce, and feeRateBps, and adds timestamp, metadata, and builder.
Order(
uint256 salt,
address maker,
address signer,
address taker, // [!code --]
uint256 tokenId,
uint256 makerAmount,
uint256 takerAmount,
uint256 expiration, // [!code --]
uint256 nonce, // [!code --]
uint256 feeRateBps, // [!code --]
uint8 side,
uint8 signatureType // [!code --]
uint8 signatureType, // [!code ++]
uint256 timestamp, // [!code ++]
bytes32 metadata, // [!code ++]
bytes32 builder // [!code ++]
)
Order value to sign
{
salt: "12345",
maker: "0x...",
signer: "0x...",
taker: "0x0000000000000000000000000000000000000000", // [!code --]
tokenId: "102936...",
makerAmount: "1000000",
takerAmount: "2000000",
expiration: "0", // [!code --]
nonce: "0", // [!code --]
feeRateBps: "0", // [!code --]
side: 0,
signatureType: 1 // [!code --]
signatureType: 1, // [!code ++]
timestamp: "1713398400000", // [!code ++]
metadata: "0x0000000000000000000000000000000000000000000000000000000000000000", // [!code ++]
builder: "0x0000000000000000000000000000000000000000000000000000000000000000" // [!code ++]
}
timestamp— order creation time in milliseconds. Replacesnoncefor per-address uniqueness (not an expiration).metadata— bytes32.builder— bytes32. Zero unless you're attaching a builder code.
side is encoded as uint8 in the signing payload (0 = BUY, 1 = SELL), even though the wire body uses the string "BUY" / "SELL". No change from V1.
POST /order body
expiration is still present in the POST /order wire body for GTD/order-expiry handling, but it is not part of the V2 EIP-712 signed struct.
{
"order": {
"salt": "12345",
"maker": "0x...",
"signer": "0x...",
"taker": "0x0000000000000000000000000000000000000000", // [!code --]
"tokenId": "102936...",
"makerAmount": "1000000",
"takerAmount": "2000000",
"expiration": "0",
"nonce": "0", // [!code --]
"feeRateBps": "0", // [!code --]
"side": "BUY",
"signatureType": 1,
"timestamp": "1713398400000", // [!code ++]
"metadata": "0x0000000000000000000000000000000000000000000000000000000000000000", // [!code ++]
"builder": "0x0000000000000000000000000000000000000000000000000000000000000000", // [!code ++]
"signature": "0x..."
},
"owner": "<api-key>",
"orderType": "GTC"
}
Request headers
The API auth headers are unchanged. Builder attribution moves into the signed builder field on the order, so the POLY_BUILDER_* HMAC headers are gone.
POLY_ADDRESS: 0x...
POLY_SIGNATURE: 0x...
POLY_TIMESTAMP: 1713398400
POLY_API_KEY: ...
POLY_PASSPHRASE: ...
POLY_BUILDER_API_KEY: ... # [!code --]
POLY_BUILDER_SECRET: ... # [!code --]
POLY_BUILDER_PASSPHRASE: ... # [!code --]
POLY_BUILDER_SIGNATURE: 0x... # [!code --]
SDK Migration
Install
CLOB V2 ships under new package names. Install them directly — don't keep using the old clob-client / py-clob-client packages.
pip install py-clob-client-v2
Constructor: positional args → options object
The single most visible change. chainId is renamed to chain. tickSizeTtlMs is no longer configurable.
const client = new ClobClient({
host,
chain: chainId, // ← renamed from chainId
signer,
creds,
signatureType,
funderAddress,
useServerTime,
builderConfig, // shape changed — see Builder Program below
getSigner,
retryOnError,
throwOnError,
});
Order creation
Three fields are no longer user-settable: feeRateBps, nonce, taker. One new optional field: builderCode.
const order: UserOrderV2 = {
tokenID: "0x123...",
price: 0.55,
size: 100,
side: Side.BUY,
expiration: 1714000000,
builderCode: "0x...", // optional — your builder code
};
Market orders follow the same pattern and add an optional userUSDCBalance field so the SDK can calculate fee-adjusted fill amounts:
const marketOrder: UserMarketOrderV2 = {
tokenID: "0x123...",
amount: 500,
side: Side.BUY,
orderType: OrderType.FOK,
userUSDCBalance: 1000, // optional — enables fee-aware calculations
builderCode: "0x...", // optional
};
Fee model
Fees are now determined by the protocol at match time, not embedded in your signed order.
- Platform fees are dynamic per market:
fee = C × feeRate × p × (1 - p) - Makers are never charged fees — only takers pay.
- You no longer set
feeRateBpson orders. The SDK handles fee calculation automatically.
Querying fee parameters
V2 introduces getClobMarketInfo(), which returns all CLOB-level market parameters in one call:
info = client.get_clob_market_info(condition_id)
# info["mts"] — minimum tick size
# info["mos"] — minimum order size
# info["fd"] — fee details { "r", "e", "to" }
# info["t"] — tokens list
If you were calculating fees manually in your integration, you can now rely on the SDK. Pass userUSDCBalance on market buy orders to get accurate fill amounts after fees.
Builder Program
V2 replaces the old builder authentication flow (HMAC headers + separate signing SDK) with a native builder code attached directly to each order.
What's gone
@polymarket/builder-signing-sdk— no longer neededPOLY_BUILDER_API_KEY,POLY_BUILDER_SECRET,POLY_BUILDER_PASSPHRASE,POLY_BUILDER_SIGNATUREheaders- Remote vs. local signing distinction
What's new
- A single
builderCode(bytes32) from your Builder Profile - Attach it per-order via the
builderCodefield, or pass it once at construction so every order inherits it
const builderConfig = new BuilderConfig({ localBuilderCreds: new BuilderApiKeyCreds({ key: process.env.POLY_BUILDER_API_KEY, secret: process.env.POLY_BUILDER_SECRET, passphrase: process.env.POLY_BUILDER_PASSPHRASE, }), });
const client = new ClobClient( host, chainId, signer, creds, signatureType, funderAddress, undefined, false, builderConfig, );
```typescript After (V2) — per-order builder code theme={null}
const client = new ClobClient({
host,
chain: chainId,
signer,
creds,
signatureType,
funderAddress,
});
await client.createAndPostOrder(
{
tokenID: "0x...",
price: 0.55,
size: 100,
side: Side.BUY,
builderCode: process.env.POLY_BUILDER_CODE,
},
{ tickSize: "0.01", negRisk: false },
);
const client = new ClobClient({
host,
chain: chainId,
signer,
creds,
signatureType,
funderAddress,
builderConfig: { builderCode: process.env.POLY_BUILDER_CODE },
});
// Every order posted by this client now carries your builder code.
await client.createAndPostOrder(
{
tokenID: "0x...",
price: 0.55,
size: 100,
side: Side.BUY,
},
{ tickSize: "0.01", negRisk: false },
);
Collateral token: USDC.e → pUSD
Polymarket USD (pUSD) replaces USDC.e as the collateral token. pUSD is a standard ERC-20 on Polygon backed by USDC, with backing enforced onchain by the smart contract. The permissionless Collateral Onramp accepts USDC.e.
- For users on polymarket.com: the UI handles wrapping automatically.
- For API-only traders: wrap USDC.e into pUSD via the Collateral Onramp's
wrap()function. See the pUSD page for full examples and Contracts for addresses.
Test markets
The markets below were used for pre-cutover testing on clob-v2.polymarket.com and are retained for migration reference. For live testing, resolve current active markets into token IDs and metadata with gamma-api.polymarket.com/markets?condition_ids=<id>, then submit small orders to production CLOB V2 at https://clob.polymarket.com.
Markets with fees enabled
Use these to verify fee handling end-to-end.
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
Additional markets with liquidity
0xcf8a237df51a51511c4f96bb4390480ad72b898ca8ec7e9a3c16c47c8e5e468a0x242d251e7e804f79e1f237896b0f5e73caea72375dcb84e5a60d1cd0d2f80ef50x9c47ba9e666983bd8d82bfab790509153bf7756c43913f6ef269e33c8955939c0x221aaa62fed17db56fbc7983f88110a9c34861c3262154ee3315425378e3ae120x625d0091f4c647e5497bd9b03f8526bd486d6c339380b8046e4dd5b3373046b70xc9b9f89ac915385c8d77edb73872c49e5bf76e510b74b9609e74e7f8d0339df20xde9f827cb2d568db7801439693645a941a38fe6feaeb08b86087ad367d9917040xfd029ab3d6d27b6e1f3480dce858c97fb12e5bebd6fb50be7520102c56ba8ce10x894a61a2baa777adf1d03a263a4b2d8faa7e1ebc7bf6694a37701fae8add01d90xcd57f3ad3bbbdaa96aacabd35f50c2d6e30f777e4a33876a4ab2dcd9f0b8c1700xc4b07998e8f9bf6b95f079d6dc0529f3c6f59698d4e168817ad5f99304de6c570xe4f4b614a6c2b4ecd8eb700d19c0e6533d3fbd1bc28193b2255394ef74006e6f0xec181db4470b152493b58229862af3f6335b77cc719f5a0e7ed58c9f9848b9920x6ec4fec4885df7f3ac46e5d0051beb6d8ac75de6a8481f13f245ff26dcb4b6620x8f6e71601903224dc29c69b886a63f248c8051be259e7db299850708f1f86dd60xfa40b5612a905f16ee42a18979f23fa1bbfcfc365f11d168f2e22bd0159ada770x182390641d3b1b47cc64274b9da290efd04221c586651ba190880713da6347d9
Migration checklist
Work through this list as you update your integration:
* [ ] Install `@polymarket/clob-client-v2` / `py-clob-client-v2` (remove the legacy `clob-client` / `py-clob-client` packages) * [ ] Convert constructor calls from positional args to options object * [ ] Rename `chainId` parameter to `chain` * [ ] Remove `tickSizeTtlMs` and `geoBlockToken` from constructor config * [ ] Remove `feeRateBps`, `nonce`, `taker` from order creation calls * [ ] Add `builderCode` to orders if you're a builder * [ ] Pass `userUSDCBalance` on market buy orders for fee-adjusted fill amounts (optional) * [ ] Remove any manual fee calculation logic — fees are protocol-handled * [ ] Remove `@polymarket/builder-signing-sdk` from dependencies * [ ] Remove `POLY_BUILDER_*` environment variables * [ ] Copy your builder code from [your Builder Profile](https://polymarket.com/settings?tab=builder) * [ ] Store it as `POLY_BUILDER_CODE` (or any env var you prefer) * [ ] Attach `builderCode` on every order to get attribution * [ ] Update any code that inspects raw order structs (new fields: `timestamp`, `metadata`, `builder`) * [ ] Update manual EIP-712 signing code (Exchange domain version `"1"` → `"2"`) * [ ] Update onchain contract references to new V2 addresses * [ ] If you're API-only, plan for wrapping USDC.e into pUSD via the Collateral Onramp * [ ] Update any hardcoded references to the old USDC.e address * [ ] Test the full order lifecycle with small production orders * [ ] Verify builder attribution appears on the [Builder Leaderboard](https://builders.polymarket.com) * [ ] Re-create any pre-cutover resting orders with V2 signingCutover day
Go-live occurred on April 28, 2026 (~11:00 UTC). The migration involved approximately 1 hour of downtime during which trading was paused.
During the window:
- All open orders were wiped. Any pre-cutover resting orders must be re-placed with V2 signing.
- The SDK's hot-swap mechanism queried a version endpoint and auto-refreshed when V2 went live.
- Clients already on the latest V2 SDK did not require manual intervention during the cutover.
If your integration is still on the V1 SDK, it will not work against production CLOB V2. There is no backward compatibility.
Follow Discord, Telegram, and status.polymarket.com for operational updates and incident notices.