# Swapping through Permissioned Pools (/docs/trading/swapping-api/swapping-permissioned-pools)

Swap tokens that trade through permissioned pools on Uniswap v4 and gate them in your app using the Uniswap API check permissions endpoint.

Some tokens on Uniswap v4 trade through [permissioned pools](/docs/protocols/v4-hooks/permissioned-pools/overview), which restrict swaps and liquidity provisioning to allowlisted addresses. Before a wallet can swap one of these tokens, your app must confirm the wallet is allowlisted. The Uniswap API exposes a check permissions endpoint for this purpose. This check is a client-side safeguard for user experience: the swap endpoints reject transactions from wallets that are not allowlisted regardless, so a token never becomes tradable just because an app skips the check.

## Check Permissions Before Swapping
Send the connected wallet and the tokens it wants to trade to the check permissions endpoint. The request accepts up to two tokens.

```bash
POST https://trade-api.gateway.uniswap.org/v1/permissions
```

```json
{
  "walletAddress": "0xC9bebBA9f481b12cE6f3EA54c4B182c9636ec421",
  "tokens": ["0x1111111111111111111111111111111111111111"],
  "chainId": 1
}
```

<img alt="App gating flow: check permissions, then allow quote and swap when allowlisted, or block submit and redirect to the KYC URL when not" src={__img0} placeholder="blur" />

## Handle the Response
`isPermissioned` describes the token, meaning whether it trades through a permissioned pool. `isAllowlisted` describes the connected wallet, meaning whether that wallet may trade the token. Each token returns a result with one of three shapes:

```json
{
  "requestId": "e63f1e1e-b9e9-411a-bcc8-ff18ce4e77cf",
  "results": [
    {
      "token": "0x1111111111111111111111111111111111111111",
      "isPermissioned": true,
      "isAllowlisted": false,
      "adapterTokenAddress": "0x2222222222222222222222222222222222222222",
      "kycUrl": "https://your-kyc-provider.example/verify",
      "issuer": "Your Issuer Name"
    }
  ]
}
```

* **Not permissioned:** `isPermissioned` is `false`. No token in the request requires permission to trade, so proceed to quoting and swapping normally.
* **Permissioned and allowlisted:** `isPermissioned` and `isAllowlisted` are both `true`. Trade normally.
* **Permissioned and not allowlisted:** `isAllowlisted` is `false` and the result includes a `kycUrl`. Direct the user to complete verification. The result also includes `issuer`, the KYC provider display name, so you can tell the user who runs the verification.

## Gate Your Interface
For a wallet that is not allowlisted, let the user quote the token so they can see prices, but block transaction submission to avoid reverts and a confusing experience. Link the user to the `kycUrl` so they can complete verification.

> [!NOTE]
> Check permissions before submitting. The swap endpoints reject transactions from wallets that are not allowlisted, so a pre-check avoids failed requests and wasted gas.

## Set the Universal Router Version
Quotes and swaps that involve a permissioned token must use [Universal Router](/docs/trading/swapping-api/supported-chains#universal-router-version) 2.2.0 or higher. Send the version header when any token in the request is permissioned.

```bash
x-universal-router-version: 2.2.0
```

## Routing Behavior
Routing will not send a user through a permissioned pool they are not allowed to trade in. Permissioned tokens are matched only as the input or output of a trade, never as an intermediate hop, so a disallowed user is never routed through a restricted token. For example, a permissioned token to USDC to ETH route is supported for an allowlisted user, while an unrelated trade routed through a permissioned token is not.

## Providing Liquidity
This page covers the swap path through the API. Liquidity provision is gated by the same allowlist: the permissioned hook checks `LIQUIDITY_ALLOWED` on `beforeAddLiquidity`, and positions are minted through the Permissioned Position Manager, which enforces the allowlist and issues non-transferable position NFTs. For the contract details, see [Permissioned Pools Architecture](/docs/protocols/v4-hooks/permissioned-pools/architecture) and [Deploy a Permissioned Pool](/docs/protocols/v4-hooks/permissioned-pools/deploy-a-permissioned-pool).

## Where to Go Next
* Learn how the pools work in [Permissioned Pools Architecture](/docs/protocols/v4-hooks/permissioned-pools/architecture).
* Onboard a token in [Deploy a Permissioned Pool](/docs/protocols/v4-hooks/permissioned-pools/deploy-a-permissioned-pool).