Summary

Add serialization support to py-multicodec with built-in JSON and raw codecs, addressing a key gap identified in the py-multicodec comparison analysis.

Problem

Currently, py-multicodec only provides low-level prefix operations (add_prefix, remove_prefix, etc.). Users must manually serialize/deserialize data before using these functions:

import json
from multicodec import add_prefix, remove_prefix

# Current workflow (manual)
data = {"hello": "world"}
json_bytes = json.dumps(data).encode()
prefixed = add_prefix("json", json_bytes)

# Decoding
raw_bytes = remove_prefix(prefixed)
decoded = json.loads(raw_bytes)

Other multicodec implementations (rust-multicodec, js-multiformats) provide integrated serialization.

Proposed Solution

Add a serialization module with:

1. Codec base class - Abstract interface for implementing codecs
2. Built-in codecs - JSONCodec and RawCodec
3. Generic functions - encode() and decode() with auto-detection
4. Codec registry - For custom codec registration
5. Exception types - EncodeError, DecodeError, UnknownCodecError

Related

• Discussion: py-multicodec gap analysis #1063