embit/docs/api

Overview

Basics

Almost all classes have .parse(bytes) and .serialize() functions to create class instances from bytearray and other way around. They can also read from / write to streams like files or ByteIO objects using read_from(stream) and write_to(stream) methods.

The only exception is Descriptor that is purely string-based and doesn't have any binary representation.

For example:

# parsing pubkey from bytes
from embit.ec import PublicKey
from binascii import unhexlify
pub = PublicKey.parse(b"\x02\x01\x8a\x76\x85\x41\xc9\x46...\x85")

# reading raw transaction from file
from embit.transaction import Transaction
with open("raw.tx", "rb") as f:
	tx = Transaction.read_from(f)

# serialize to bytes
sec = pub.serialize()
# write to binary file
with open("raw2.tx", "wb") as f:
	tx.write_to(f)

Some classes also have string representations. If they don't - we assume hex representation. You can use .from_string() and .to_string() methods for that, or just call str(something):

from embit.bip32 import HDKey
from embit.ec import PublicKey, PrivateKey

xpub = HDKey.from_string("xpub6BysnKqL9EKxKwWxrgwU97FBNybxNZKKfGQgqurJy3BYGSJZBk4biPTzJCCMZ5wsqfxskrrUiJYQexJFX7qkA4DYB2DiADY7Fcto4wxLva4")
prv = PrivateKey.from_string("L16MDExY5qQ6ABZCvRRD3v3rXV4R3y2THZu56eFLLnGjhbqX7Gq7")
# hex representation:
pub = PublicKey.from_string("02018a768541c946e907bd6961f403edd820e76cddb40cefb3c5cf3ae47cea6186")

Modules

Library is splitted into modules, list of modules sorted by topic:

Keys:

• ec - individual elliptic curve keys (PrivateKey, PublicKey) and signatures (Signature, SchnorrSig)
• bip39 - helper functions for mnemonics
• bip32 - extended private and public keys (HDKey)

Scripts:

• script - basic bitcoin scripts (Script) and helper functions
• descriptor - descriptors (Descriptor) and miniscript functions

Transactions:

• transaction - raw transactions (Transaction)
• psbt - psbt transactions (PSBT)
• psbtview - RAM-optimized pbst transaction for embedded devices, doesn't read the whole transaction to memory but only gets the part you need right now (PSBTView)

Helpers:

• networks - constants for different Bitcoin networks
• base58 encoding - used for WIFs and legacy addresses
• bech32 encoding - used for segwit and taproot addresses
• compact - often used for serializations
• hashes - common bitcoin hash functions like tagged_hash, double_sha256 etc

Extensions / experimental:

• liquid - support for confidential assets, liquid transactions, blinded descriptors and psets (elements version of psbt)
• slip39 - shamir secret sharing scheme