> For the complete documentation index, see [llms.txt](/llms.txt).

# Connect to a Snap

Dapps can connect to Snaps designed to communicate with dapps. Dapps can use these Snaps to take advantage of new features enabled by Snaps. This is possible because Snaps can expose a [custom JSON-RPC API](/snaps/learn/about-snaps/apis/#custom-json-rpc-apis).

## Detect wallet[​](#detect-wallet "Direct link to Detect wallet")

To connect to a Snap, dapps must first detect MetaMask in the user's browser.

### Detect MetaMask Flask[​](#detect-metamask-flask "Direct link to Detect MetaMask Flask")

When developing your Snap, you might need to require [MetaMask Flask](/snaps/get-started/install-flask/) in your dapp. We recommend detecting MetaMask Flask using the multi-wallet detection mechanism specified by EIP-6963. Alternatively, you can use the `window.ethereum` injected provider, but this might fail if the user is running multiple wallet extensions simultaneously.

To detect MetaMask Flask, you can add the following to `window.onload`:

- EIP-6963 example
- Injected provider example

index.js

```
window.addEventListener('eip6963:announceProvider', event => {
  /* event.detail contains the discovered provider interface. */
  const providerDetail = event.detail

  /* providerDetail.info.rdns is the best way to distinguish a wallet extension. */
  if (providerDetail.info.rdns === 'io.metamask.flask') {
    console.log('MetaMask Flask successfully detected!')
    // Now you can use Snaps!
  } else {
    console.error('Please install MetaMask Flask!')
  }
})

window.dispatchEvent(new Event('eip6963:requestProvider'))

```

index.js

```
const provider = window.ethereum

const isFlask = (await provider?.request({ method: 'web3_clientVersion' }))?.includes('flask')

if (provider && isFlask) {
  console.log('MetaMask Flask successfully detected!')
  // Now you can use Snaps!
} else {
  console.error('Please install MetaMask Flask!', error)
}

```

## Connect to a Snap[​](#connect-to-a-snap-1 "Direct link to Connect to a Snap")

Connect to a Snap by calling the [wallet_requestSnaps](/snaps/reference/snaps-api/wallet%5Frequestsnaps/)method from your dapp. If a user doesn't have the Snap installed in their MetaMask wallet, MetaMask prompts the user to install the Snap.

note

A Snap can grant a dapp an [automatic connection](/snaps/how-to/allow-automatic-connections/), skipping the need for users to confirm a connection.

The following are different possible outcomes from calling `wallet_requestSnaps`.

### User rejects the installation request[​](#user-rejects-the-installation-request "Direct link to User rejects the installation request")

If the user rejects the installation request, the call to `wallet_requestSnaps` throws the following error:

```
{ "code": 4001, "message": "User rejected the request." }

```

### User approves the installation request[​](#user-approves-the-installation-request "Direct link to User approves the installation request")

If the user approves the installation request, the call to `wallet_requestSnaps` returns an object with the following shape:

```
{
  "SNAP_ID": {
    "blocked": false,
    "enabled": true,
    "id": "SNAP_ID",
    "initialPermissions": {
      // The permissions in the Snap's manifest file.
    },
    "version": "SNAP_VERSION"
  }
}

```

### Snap is already installed[​](#snap-is-already-installed "Direct link to Snap is already installed")

If the Snap is already installed, the call to `wallet_requestSnaps` returns the same object as for a new installation of the Snap, but the user won't see a confirmation pop-up asking them to install the Snap.

## Determine whether a Snap is installed[​](#determine-whether-a-snap-is-installed "Direct link to Determine whether a Snap is installed")

Determine whether a Snap is installed by calling the [wallet_getSnaps](/snaps/reference/snaps-api/wallet%5Fgetsnaps/) method from your dapp. This method returns a list of only those Snaps that are connected to your current dapp.

The response is in the form of an object keyed by the ID of the Snap. Each value is a nested object with additional information, such as the version of the Snap that is installed.

note

`wallet_getSnaps` only returns the Snaps that are connected to your dapp. The user may have other Snaps installed that your dapp is not aware of.

The following example verifies whether a Snap with ID `npm:super-snap` is installed:

index.ts

```
const snaps = await ethereum.request({
  method: 'wallet_getSnaps',
})

const isMySnapInstalled = Object.keys(snaps).includes('npm:super-snap')

```

If you need to work with a specific version of a Snap, you can instead iterate over `Object.values(snaps)`, and use the `id` and `version` properties inside each object to determine whether the Snap is installed with the required version.

note

A user cannot install multiple versions of a Snap into a single MetaMask instance. You should avoid requiring a specific version of a Snap unless you absolutely need to. In most cases, you should request the latest version of the Snap and architect your dapp to be able to work with that version.

## Reconnect to a Snap[​](#reconnect-to-a-snap "Direct link to Reconnect to a Snap")

At any time, a user can open their MetaMask Snaps settings menu and see all the dapps connected to a Snap. From that menu they can revoke a dapp connection. If your dapp loses the connection to a Snap, you can reconnect by calling [wallet_requestSnaps](/snaps/reference/snaps-api/wallet%5Frequestsnaps/). Since the Snap is already installed, this returns a success response without MetaMask showing a pop-up. However, if the user has disabled the Snap, the response has `enabled` set to `false` for your `SNAP_ID`:

```
{
  "SNAP_ID": {
    "blocked": false,
    "enabled": false,
    "id": "SNAP_ID",
    "initialPermissions": {
      // The permissions in the Snap's manifest file.
    },
    "version": "SNAP_VERSION"
  }
}

```