protobuf-net/protobuf-net
Protobuf Net
protobuf-net is a .NET library that serializes and deserializes objects using the Protocol Buffers binary format for efficient data exchange. It provides a code-first gRPC service framework, allowing developers to define service contracts directly from existing C# classes without writing separate .proto files. The library is nullable-aware, encoding null values in collections and nullable scalars using wrapper messages to distinguish null from default zero values, and includes an ahead-of-time serializer generator that compiles serializer code at build time to eliminate runtime code generation and improve cold-start performance.
Contracts can be defined using .NET custom attributes on classes and properties, or through a runtime type model that avoids source code annotations entirely. The library supports generating classes from .proto schema files for cross-system alignment, and allows polymorphic type registration so derived types are serialized and deserialized correctly. Pre-measurement serialization computes the payload size before writing, enabling forward-only serialization and support for size headers. Additional capabilities include configuration for data type serialization behavior, runtime type model rules, and serializer capability detection for backward-compatible feature negotiation.
Features
- Protocol Buffers - Serializes and deserializes .NET objects to compact binary format using Protocol Buffers for efficient data exchange.
- Polymorphic Type Serializers - Declares derived types on base contracts to encode and reconstruct full class hierarchies during serialization.
- Wrapper-Based Nulls - Wraps collections and nullable scalars in additional Protobuf messages to encode null, empty, and populated states distinctly.
- Code-First gRPC Service Definitions - Defines gRPC service contracts directly from existing C# classes without writing separate .proto files.
- Attribute-Based Mappings - Marks classes and properties with .NET attributes to define Protobuf field numbers and serialization behavior.
- Null-Aware Protocol Buffers Wrappers - Encodes null and empty collections distinctly using Protocol Buffers wrappers for accurate round‑tripping.
- Dual Source Contract Definitions - Provides multiple ways to define Protobuf contracts, including attribute-based, runtime model, and .proto file generation.
- Integer Key Encoders - Marks classes and members with integer keys to specify how objects are serialized into binary protocol buffers.
- Modern IO Primitive Serializers - Serializes data directly from modern IO primitives like Span and IBufferWriter without intermediate streams.
- Pre-Measurement Serializations - Computes serialized payload size before writing to enable forward-only serialization and length-prefix headers.
- Collection Element Null Support - Encodes null entries inside collections by wrapping each element in a message with field presence.
- Collection Null Differentiation - Uses an extra message wrapper around a collection to encode null, empty, or populated states differently.
- Nullable Scalar Serializers - Wraps nullable scalar fields in a message layer to distinguish null from default zero values.
- Runtime Serialization Model Configurations - Defines serialization rules programmatically at runtime through a type model without requiring code attributes.
- AOT-Safe Serialization Generators - Compiles serializer code at build time to eliminate runtime code generation and improve cold-start performance.
- Serializer Code Generators - Compiles serializer code at build time to eliminate runtime code generation and improve cold-start performance.
- Payload Size Precalculation - Computes the serialized payload size before writing to enable forward-only serialization and size headers.
- Protobuf Class Generators - Generates .NET classes from Protocol Buffers schema files for cross-system contract alignment.
- Runtime Serialization Model Configurations - Supports defining serialization rules through a runtime type model without requiring code attributes.
- Serialization - Implementation of Google's Protocol Buffers binary format.
