pocketpy/docs/modules/msgpack.md

---

icon: package

label: msgpack

msgpack

Encode simple values in the MessagePack binary format.

!!!info Optional module Enable PK_BUILD_MODULE_MSGPACK=ON; see build configuration. !!!

Function	Result
dumps(obj)	Encoded bytes.
loads(data: bytes)	Decoded Python value.

import msgpack

state = {'level': 2, 'items': ['key', 'coin'], 'payload': b'\x00\x01'}
packed = msgpack.dumps(state)
assert msgpack.loads(packed) == state

The built-in conversion supports None, booleans, signed 64-bit integers, floats, strings, bytes, lists, and dictionaries. Use string or integer map keys. Arrays decode to lists; tuples and arbitrary class instances are not part of the default encoder.

Keep integer values within pocketpy's signed 64-bit range, including when receiving MessagePack unsigned integers. Extension values require host-provided conversion hooks; they are not automatically mapped to Python classes. The API has no CPython third-party msgpack keyword option set.

Implementation: bindings.c.