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Binary serialization API

Introduction

Godot has a serialization API based on Variant. It's used for converting data types to an array of bytes efficiently. This API is exposed via the global bytes_to_var() and var_to_bytes() functions, but it is also used in the get_var and store_var methods of FileAccess as well as the packet APIs for PacketPeer. This format is not used for binary scenes and resources.

Full Objects vs Object instance IDs

If a variable is serialized with full_objects = true, then any Objects contained in the variable will be serialized and included in the result. This is recursive.

If full_objects = false, then only the instance IDs will be serialized for any Objects contained in the variable.

Packet specification

The packet is designed to be always padded to 4 bytes. All values are little-endian-encoded. All packets have a 4-byte header representing an integer, specifying the type of data.

The lowest value two bytes are used to determine the type, while the highest value two bytes contain flags:

base_type = val & 0xFFFF;
flags = val >> 16;

Type	Value
0	null
1	bool
2	integer
3	float
4	string
5	vector2
6	rect2
7	vector3
8	transform2d
9	plane
10	quaternion
11	aabb
12	basis
13	transform3d
14	color
15	node path
16	rid
17	object
18	dictionary
19	array
20	raw array
21	int32 array
22	int64 array
23	float32 array
24	float64 array
25	string array
26	vector2 array
27	vector3 array
28	color array
29	max

Following this is the actual packet contents, which varies for each type of packet. Note that this assumes Godot is compiled with single-precision floats, which is the default. If Godot was compiled with double-precision floats, the length of "Float" fields within data structures should be 8, and the offset should be (offset - 4) * 2 + 4. The "float" type itself always uses double precision.

0: null

1: bool

Offset	Len	Type	Description
4	4	Integer	0 for False, 1 for True

2: int

If no flags are set (flags == 0), the integer is sent as a 32 bit integer:

<