Multibase

An Elixir implementation of the multibase specification — a self-describing base encoding protocol.

Multibase prefixes a single character to encoded data so that the base encoding used can be unambiguously identified when decoding. This library handles the prefixing, encoding, and decoding steps for a set of commonly used base encodings.

Supported Encodings

Usage

Encoding

Multibase.encode("hello world", :base32)
# => "bnbswy3dpeb3w64tmmq"

Multibase.encode("hello world", :base58btc)
# => "zStV1DL6CwTryKyV"

Decoding

Decoding automatically detects the encoding from the prefix character:

Multibase.decode!("bnbswy3dpeb3w64tmmq")
# => "hello world"

Multibase.decode("zStV1DL6CwTryKyV")
# => {:ok, "hello world"}

Using individual codecs directly

Each base encoding is also available as its own module if you want to encode or decode without the multibase prefix:

Multibase.Base58.encode("hello world")
# => "StV1DL6CwTryKyV"

Multibase.Base58.decode!("StV1DL6CwTryKyV")
# => "hello world"

Custom base encodings

The Multibase.Codec behaviour defines the contract that all base encoding modules implement. If you are building a custom base encoding, implementing this behaviour ensures your module follows the same interface as the built-in ones:

defmodule MyApp.Base45 do
  @behaviour Multibase.Codec

  @impl true
  def encode(data, _opts), do: # ...

  @impl true
  def decode(data, _opts), do: # ...

  @impl true
  def decode!(data, _opts), do: # ...
end

The Multibase.AnyBase module can also be used to generate a base encoding module from a custom alphabet at compile time. See its documentation for details.

Part of the multiformats ecosystem

This library is one component of a family of Elixir multiformats libraries. For runtime codec registration and cross-component composition, see the multicodec project.