Recursive Length Prefix (RLP)

Overview

The Recursive Length Prefix algorithm is a serialization method used extensively in the Ethereum protocol. RLP is a standard that aims to define a space-efficient approach to packaging and transferring arbitrary data.

RLP is commonly used for use cases on Ethereum Applications such as:

• serializing Transaction Envelopes to be submitted to the network,
• serializing EIP-7702 Authorization tuples to be signed over,
• serializing components to derive a CREATE Contract Address.

Examples

Encoding

We can serialize arbitrary data into RLP-encoded format using the Rlp.fromHex or Rlp.fromBytes functions.

import { Hex, Rlp } from 'ox'
 
const rlp = Rlp.fromHex([
  Hex.fromString('hello'),
  Hex.fromNumber(1337),
  [Hex.fromString('foo'), Hex.fromString('bar')],
])
0xd28568656c6c6f820539c883666f6f83626172

Decoding

We can deserialize RLP-encoded data into its original format using the Rlp.toHex or Rlp.toBytes functions.

import { Hex, Rlp } from 'ox'
 
const rlp = Rlp.fromHex([
  Hex.fromString('hello'),
  Hex.fromNumber(1337),
  [Hex.fromString('foo'), Hex.fromString('bar')],
])
 
const values = Rlp.toHex(rlp)
[Hex.fromString('hello'), Hex.fromNumber(1337), [Hex.fromString('foo'), Hex.fromString('bar')]]

Related Modules