• Entry paths are normalized like the engine does it: \ is a separator, ASCII letters are lowercased, and ./.. are resolved. Invalid names are rejected.
• Package.Open, OpenEntryStream (read nested VPKs in place) and Verify (all checks in one call, with progress and cancellation).
• RemoveDirectory and RenameDirectory.
• Write back over the read file, including a _dir.vpk, or repack into new chunk files with Write(path, repack: true).
• Path helpers (TryParseEntryPath, NormalizeDirectoryPath, PathComparer) and chunk file helpers (GetChunkFilePath, TryParseChunkFilePath, OpenArchiveStream).
• Writing refuses to overwrite the package's own chunk files.
• FindEntry no longer allocates, the library no longer uses LINQ, and writing and verifying allocate less.

• Edit packages that were read, including ones with chunk files, and write them back over the original files. Either every file is replaced or none is.
• Add Write(path, repack: true), which rewrites chunk files without the data of removed files.
• Add RenameFile and IsSigned, and add progress reporting to VerifyHashes.
• Lowercase and normalize added paths, and normalize paths in FindEntry.
• Change the default chunk size to 100 MiB.
• Throw after Dispose and on malformed packages.

• Breaking: call SetFileName("pak01_dir.vpk") before AddFile(..., multiChunk: true). Multi-chunk files are now written to disk when added, so packages of any size can be created, and Write must go to that same path.
• Breaking: a package can only be read once.
• Breaking: streams from GetMemoryMappedStreamIfPossible only work while the package is open.
• Added AddFile(string, Stream, bool).
• Write(Stream) works with non-seekable streams and multi-chunk packages.
• Reading entries is thread-safe and much faster.
• Packages can be read and written at non-zero stream positions.
• Malformed packages throw InvalidDataException or EndOfStreamException instead of returning bad data.

• Breaking: namespace changed to ValvePak.
• Added support for writing split packages: AddFile(..., multiChunk: true) writes files into numbered chunk files next to the directory file. Chunk size is controlled by WriteChunkSize (200 MiB default).
• Write(Stream) now throws for packages containing multi-chunk files; use Write(string) instead.
• Write now throws if the directory file would exceed 2 GiB or a chunk file would exceed 4 GiB.

• Now targets .NET 10.
• Version is now settable to allow writing v1 vpks.
• Added support for the new VPK signature format (as used by CS2): new ESignatureType enum and Package.SignatureType property, with verification via RSA.VerifyData.
• Updated Blake3, which is now a fully managed implementation.
• Hardened VPK write hashing to use Stream.ReadExactly.

• Renamed ArchiveMD5Entries to AccessPackFileHashes
• Added support for Blake3 chunk hashes
• Added an overload FindEntry(ReadOnlySpan<char> filePath)
  • Unlike the FindEntry(string) version, this one does not normalize the directory path separator.

• Enabled IsAotCompatible and Nullable

Full Changelog: 2.0.0...2.0.1

• Do not require _dir suffix in chunked vpks
• Removed System.Security.Cryptography.Algorithms
• Added ContinuousIntegrationBuild

Full Changelog: 1.8.0...2.0.0

• .NET 8.0 is now required
• Removed FindEntry overloads
• Reduced allocations in FindEntry
• Updated logo

Full Changelog: 1.7.0...1.8.0

• GetMemoryMappedStreamIfPossible will read files smaller or equal to 4096 bytes into memory instead of memory mapping.
• GetMemoryMappedStreamIfPossible now supports memory mapping files in non-split packages if the package was read from a FileStream or when using Read(file path).
• CRC32 is now calculated with System.IO.Hashing