> ## 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.

# Polymarket USD

> pUSD — the collateral token used for all trading on Polymarket

**pUSD** (Polymarket USD) is the collateral token used for all trading on Polymarket. It's a standard ERC-20 token on Polygon, backed by USDC. The smart contract — which enables the withdrawal functionality — enforces the backing. No algorithmic peg, no fractional reserve.

> [!NOTE]
>
> **Day to day, nothing changes.** You load funds, see a balance, trade, and
> withdraw. pUSD is the technical settlement layer underneath the same
> experience you're used to.

***

## Why pUSD

The protocol settles all trading activity in native USDC, providing a more capital efficient, scalable, and institutionally aligned settlement standard as the platform continues to grow.

pUSD is a standard ERC-20 wrapper that represents a USDC claim. Wrapping and unwrapping are enforced onchain by the `CollateralOnramp` and `CollateralOfframp` contracts.

***

## Key facts

| | |
| - | - |
| Token standard | ERC-20 |
| Network | Polygon mainnet |
| Decimals | 6 |
| Backing | USDC (enforced onchain) |
| Transferable | Yes — standard ERC-20 |

pUSD is designed to function within Polymarket. There are no current plans to list it on external exchanges.

See the [Contracts](/resources/contracts) page for all collateral-related contract addresses.

***

## Wrapping — USDC.e → pUSD

Use the **CollateralOnramp** to wrap USDC.e into pUSD.

```solidity theme={null}
function wrap(address _asset, address _to, uint256 _amount) external
```

**Parameters**

* `_asset` — address of the asset being wrapped. Must be USDC.e.
* `_to` — recipient of the minted pUSD. Does not have to be `msg.sender`.
* `_amount` — amount to wrap, in USDC.e base units (6 decimals).

**Requirements**

* The caller must first approve the **CollateralOnramp** contract (not the pUSD token) to spend USDC.e.
* Reverts with `OnlyUnpaused()` if the admin has paused USDC.e.

### Example

```typescript TypeScript theme={null}
import {
  createWalletClient,
  createPublicClient,
  http,
  parseAbi,
  parseUnits,
} from "viem";
import { polygon } from "viem/chains";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);
const walletClient = createWalletClient({ account, chain: polygon, transport: http() });
const publicClient = createPublicClient({ chain: polygon, transport: http() });

const ONRAMP = "0x93070a847efEf7F70739046A929D47a521F5B8ee" as const;
const USDCE = "0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174" as const; // USDC.e on Polygon

const amount = parseUnits("100", 6); // 100 USDC.e

// 1. Approve the Onramp to spend your USDC.e
const approveHash = await walletClient.writeContract({
  address: USDCE,
  abi: parseAbi(["function approve(address spender, uint256 amount) returns (bool)"]),
  functionName: "approve",
  args: [ONRAMP, amount],
});
await publicClient.waitForTransactionReceipt({ hash: approveHash });

// 2. Wrap USDC.e → pUSD
const wrapHash = await walletClient.writeContract({
  address: ONRAMP,
  abi: parseAbi(["function wrap(address _asset, address _to, uint256 _amount)"]),
  functionName: "wrap",
  args: [USDCE, account.address, amount],
});
await publicClient.waitForTransactionReceipt({ hash: wrapHash });
```

```python Python theme={null}
from web3 import Web3

ONRAMP = "0x93070a847efEf7F70739046A929D47a521F5B8ee"
USDCE = "0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174"

amount = 100 * 10**6  # 100 USDC.e

# 1. Approve the Onramp to spend your USDC.e
usdce = w3.eth.contract(address=USDCE, abi=[{
    "name": "approve", "type": "function",
    "inputs": [{"name": "spender", "type": "address"},
               {"name": "amount", "type": "uint256"}],
    "outputs": [{"type": "bool"}],
}])
usdce.functions.approve(ONRAMP, amount).transact({"from": address})

# 2. Wrap USDC.e → pUSD
onramp = w3.eth.contract(address=ONRAMP, abi=[{
    "name": "wrap", "type": "function",
    "inputs": [{"name": "_asset", "type": "address"},
               {"name": "_to", "type": "address"},
               {"name": "_amount", "type": "uint256"}],
    "outputs": [],
}])
onramp.functions.wrap(USDCE, address, amount).transact({"from": address})
```

***

## Unwrapping — pUSD → USDC.e

Use the **CollateralOfframp** to unwrap pUSD back into USDC.e.

```solidity theme={null}
function unwrap(address _asset, address _to, uint256 _amount) external
```

**Parameters**

* `_asset` — asset you want to receive. Must be USDC.e.
* `_to` — recipient of the underlying asset.
* `_amount` — amount of pUSD to unwrap (6 decimals).

**Requirements**

* The caller must first approve the **CollateralOfframp** contract to spend their pUSD.
* Same pause gate as the Onramp.

***

## Next steps

> **[Contracts](/resources/contracts)**
>
> All Polymarket contract addresses and audits

> **[Bridge](/trading/bridge/deposit)**
>
> Deposit from other chains — auto-wraps to pUSD


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.