@exodus/bip39

JavaScript implementation of Bitcoin BIP39: Mnemonic code for generating deterministic keys

This library prefers native webcrypto, so all methods are async.

Prior art: https://github.com/bitcoinjs/bip39

Installation

npm install @exodus/bip39

Entropy Sizes

• 128 bits → 12 words
• 160 bits → 15 words
• 192 bits → 18 words
• 224 bits → 21 words
• 256 bits → 24 words

API Reference

generateMnemonic({ bitsize, wordlist = english })

Generate a random mnemonic with a given bitsize.

Parameters:

• bitsize (number): Entropy size in bits. Must be one of: 128, 160, 192, 224, or 256
• wordlist (array, optional): Word list to use. Defaults to English wordlist

Returns: Promise - The generated mnemonic phrase

mnemonicToSeed({ mnemonic, password, validate, wordlist, format })

Convert a mnemonic to a seed for key derivation.

Parameters:

• mnemonic (string): The mnemonic phrase
• password (string, optional): Optional passphrase. Defaults to empty string
• validate (boolean, optional): Whether to validate the mnemonic. Defaults to true
• wordlist (array, optional): Word list for validation. Defaults to English wordlist
• format (string, optional): Output format - 'uint8', 'buffer', or 'hex'. Defaults to 'uint8'

Returns: Promise<Uint8Array|Buffer|string> - The seed in the specified format

mnemonicToEntropy({ mnemonic, wordlist, format })

Convert a mnemonic back to its original entropy.

Parameters:

• mnemonic (string): The mnemonic phrase
• wordlist (array, optional): Word list to use. Defaults to English wordlist
• format (string, optional): Output format - 'uint8', 'buffer', 'hex', or 'null'. Defaults to 'uint8'

Returns: Promise<Uint8Array|Buffer|string|null> - The entropy in the specified format

entropyToMnemonic({ entropy, wordlist })

Convert entropy to a mnemonic phrase.

Parameters:

• entropy (Uint8Array): The entropy bytes. Must be 16, 20, 24, 28, or 32 bytes
• wordlist (array, optional): Word list to use. Defaults to English wordlist

Returns: Promise - The mnemonic phrase

mnemonicIsInvalid({ mnemonic, wordlist })

[!WARNING] Read carefully! This returns true if the mnemonic is invalid

Parameters:

• mnemonic (string): The mnemonic phrase to validate
• wordlist (array, optional): Word list to use. Defaults to English wordlist

Returns: Promise - true if invalid, false if valid

wordlistHasWord({ word, wordlist })

Check if a word exists in a wordlist.

Parameters:

• word (string): The word to check
• wordlist (array, optional): Word list to check. Defaults to English wordlist

Returns: boolean - true if word exists in wordlist

Wordlists

The library comes with an English wordlist by default. For other languages, you'll need to provide them yourself.