Recursive Length Prefix encoding for Node.js and the browser. |
---|
To obtain the latest version, simply require the project using npm
:
npm install @ethereumjs/rlp
Install with -g
if you want to use the CLI.
// ./examples/simple.ts
import { RLP } from '@ethereumjs/rlp'
import assert from 'assert'
const nestedList = [[], [[]], [[], [[]]]]
const encoded = RLP.encode(nestedList)
const decoded = RLP.decode(encoded)
assert.deepStrictEqual(decoded, nestedList, 'decoded output does not match original')
console.log('assert.deepStrictEqual would have thrown if the decoded output did not match')
We provide hybrid ESM/CJS builds for all our libraries. With the v10 breaking release round from Spring 2025, all libraries are "pure-JS" by default and we have eliminated all hard-wired WASM code. Additionally we have substantially lowered the bundle sizes, reduced the number of dependencies, and cut out all usages of Node.js-specific primitives (like the Node.js event emitter).
It is easily possible to run a browser build of one of the EthereumJS libraries within a modern browser using the provided ESM build. For a setup example see ./examples/browser.html.
RLP.encode(plain)
- RLP encodes an Array
, Uint8Array
or String
and returns a Uint8Array
.
RLP.decode(encoded, [stream=false])
- Decodes an RLP encoded Uint8Array
, Array
or String
and returns a Uint8Array
or NestedUint8Array
. If stream
is enabled, it will just decode the first rlp sequence in the Uint8Array. By default, it would throw an error if there are more bytes in Uint8Array than used by the rlp sequence.
rlp encode <JSON string>
rlp decode <0x-prefixed hex string>
-
rlp encode '5'
->0x05
-
rlp encode '[5]'
->0xc105
-
rlp encode '["cat", "dog"]'
->0xc88363617483646f67
-
rlp decode 0xc88363617483646f67
->["cat","dog"]
See our organizational documentation for an introduction to EthereumJS
as well as information on current standards and best practices. If you want to join for work or carry out improvements on the libraries, please review our contribution guidelines first.