• Snap
• Restricted

snap_getEntropy

Description

Get a deterministic 256-bit entropy value, specific to the Snap and the user's account. You can use this entropy to generate a private key, or any other value that requires a high level of randomness. Other Snaps can't access this entropy, and it changes if the user's secret recovery phrase changes.

You can optionally specify a salt to generate different entropy for different purposes. Using a salt results in entropy unrelated to the entropy generated without a salt.

This value is deterministic: it's always the same for the same Snap, user account, and salt.

Parameters

version

1required

The version of the entropy to retrieve. This is reserved for future use, and as of now, only version 1 is supported.

salt

string | null

An arbitrary string to be used as a salt for the entropy. This can be used to generate different entropy for different purposes.

source

string | null

The ID of the entropy source to use. If not specified, the primary entropy source will be used. For a list of available entropy sources, see the snap_listEntropySources method.

Returns

`0x${string}`

The entropy as a hexadecimal string.

Example

• Manifest
• Usage

{
  "initialPermissions": {
    "snap_getEntropy": {}
  }
}

const entropy = await snap.request({
  method: "snap_getEntropy",
  params: {
    version: 1,
    salt: "foo", // Optional.
  },
});

// '0x...'
console.log(entropy);