• Snap
• Restricted

snap_getBip32Entropy

Description

Enables you to manage users' non-EVM accounts by deriving the SLIP-10 keys specified by the path and curve parameters. The keys are derived using the entropy from the user's Secret Recovery Phrase.

If the keys you want to derive conform to the BIP-44 structure, use snap_getBip44Entropy instead. Otherwise, use this method.

This method is designed to be used with the @metamask/key-tree module. @metamask/key-tree can help you get the extended private keys for user addresses, but it's your responsibility to know how to use those keys to, for example, derive an address for the relevant protocol or sign a transaction for the user.

Parameters

curve

"ed25519" | "ed25519Bip32" | "secp256k1"required

The curve to use for the derived key. This must be a curve supported by @metamask/key-tree.

path

string[]required

The derivation path to use for the derived key, represented as an array of path segments. For example, the path m/44'/1'/0'/0/0 would be represented as ['m', "44'", "1'", "0'", '0', '0'].

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

depth

number

The 0-indexed path depth of this node.

masterFingerprint

number | null

The fingerprint of the master node, i.e., the node at depth 0. May be undefined if this node was created from an extended key.

parentFingerprint

number

The fingerprint of the parent key, or 0 if this is a master node.

index

number

The index of the node, or 0 if this is a master node.

network

"mainnet" | "testnet" | null

The network for the node. This is only used for extended keys, and defaults to mainnet.

privateKey

string | null

The (optional) private key of this node.

publicKey

string

The public key of this node.

chainCode

string

The chain code of this node.

curve

"ed25519" | "ed25519Bip32" | "secp256k1"

The name of the curve used by the node.

Example

• Manifest
• Usage

{
  "initialPermissions": {
    "snap_getBip32Entropy": [
      {
        "path": ["m", "44'", "3'"],
        "curve": "secp256k1" // Or "ed25519", "ed25519Bip32"
      }
    ]
  }
}

import { SLIP10Node } from "@metamask/key-tree";

// This example uses Dogecoin, which has a derivation path starting with
// m/44'/3'.
const dogecoinNode = await snap.request({
  method: "snap_getBip32Entropy",
  params: {
    // The path and curve must be specified in the initial permissions.
    path: ["m", "44'", "3'"],
    curve: "secp256k1",
  },
});

// Next, create an instance of a SLIP-10 node for the Dogecoin node.
const dogecoinSlip10Node = await SLIP10Node.fromJSON(dogecoinNode);

// m/44'/3'/0'
const accountKey0 = await dogecoinSlip10Node.derive(["bip32:0'"]);

// m/44'/3'/1'
const accountKey1 = await dogecoinSlip10Node.derive(["bip32:1'"]);

// Now, you can ask the user to sign transactions, etc.