Module gvas 

UE4/UE5 GVAS save-file binary parser.

The GVAS serialization format is defined by the public Unreal Engine 5 source code — the SaveGame system and its binary layout are part of the engine’s open API.

Ported from legacy/extract_save_name.py. Extracts SlotName and DisplayName properties via manual binary walking, plus corruption detection by cross-referencing metadata against the canonical filename convention (savegame_N.sav / savegame_N_M.bak).

Structs

FullMetadata

Full metadata from all known GVAS properties.

SaveMetadata

Extracted metadata from a GVAS save file. Extracted metadata from a Subnautica 2 GVAS save file.

Functions

corruption_check

Return a corruption reason, or None if the file looks clean.

derive_slot_from_filename

Derive the expected slot name from a filename.

extract_bool_property 🔒

Find a BoolProperty by name and return its value (true/false).

extract_double_property 🔒

Find an IntProperty by name and return its u32 value.

extract_full_metadata

Parse a .sav or .bak file and return all known GVAS metadata.

extract_int_property 🔒

Extract an integer property value from a key-value text pair.

extract_metadata

extract_metadata_from_bytes

Parse a .sav or .bak file and return its GVAS metadata. Parse GVAS metadata from an in-memory byte slice. Useful for fuzzing.

extract_str_property 🔒

Find the first StrProperty named prop_name and return its FString value.

read_fname 🔒

Read a length-prefixed, null-terminated FName string.

read_fstring 🔒

Read an FString: length-prefixed, possibly UTF-16.

read_i32 🔒

Read a little-endian i32 at offset, returning None if out of bounds.

read_u32 🔒

Read a little-endian u32 at offset, returning None if out of bounds.

scan_double_near 🔒

Scan for a double value near a marker byte sequence.