BareWire

High-performance async messaging library for .NET 10 / C# 14.

An alternative to MassTransit with a fundamentally different architecture: raw-first (no envelope by default), zero-copy pipeline, manual topology, and deterministic memory usage.

Key Design Principles

• Raw-first — default serializer produces raw JSON, no envelope. Envelope format is opt-in.
• Manual topology — ConfigureConsumeTopology = false by default. Auto-topology is opt-in.
• Zero-copy pipeline — IBufferWriter<byte> / ReadOnlySequence<byte> with ArrayPool. No byte[] allocation per-message in hot paths.
• Credit-based flow control — bounded channels, atomic inflight tracking, health alerts at 90% capacity.
• Familiar API — uses MassTransit naming conventions (IBus, IConsumer<T>, ConsumeContext<T>) for easy migration.

Packages

Package	Description
BareWire.Abstractions	Public interfaces, zero dependencies
BareWire	Core engine, pipeline, bus implementation
BareWire.Serialization.Json	JSON serializer (System.Text.Json)
BareWire.Transport.RabbitMQ	RabbitMQ transport
BareWire.Saga	SAGA state machine
BareWire.Outbox	Outbox/Inbox pattern
BareWire.Observability	OpenTelemetry integration
BareWire.Testing	In-memory test harness

Build & Test

# Build
dotnet build BareWire.slnx

# All tests
dotnet test BareWire.slnx

# Unit tests only
dotnet test tests/BareWire.UnitTests/

# Benchmarks
dotnet run --project tests/BareWire.Benchmarks/ -c Release -- --filter '*Publish*'

Performance Targets

• < 768 B/msg publish allocation, < 256 B/msg consume allocation
• > 500K msgs/s publish throughput
• > 300K msgs/s consume throughput (in-memory transport)

Allocation characteristics

• PublishRaw — constant 136 B regardless of payload size (100 B → 10 KB, no difference). Pre-serialized ReadOnlyMemory<byte> is passed through without copying.
• PublishTyped — ~544 B fixed overhead + serialized payload size. The serialization boundary copy (.ToArray() in MessagePipeline.ProcessOutboundAsync) is architecturally required — OutboundMessage must outlive the pooled writer scope.
• Serialization (raw) — constant 448 B regardless of payload size. PooledBufferWriter rents from ArrayPool<byte>.Shared, confirming ADR-003 zero-copy pipeline.

Full report: doc/benchmark-report.md

License

Proprietary. All rights reserved.