crates/bindings-csharp/Codegen/README.md
⚠️ Internal Project ⚠️
This project is intended for internal use only. It is not stable and may change without notice.
See the C# module library reference for stable, user-facing documentation.
This project contains Roslyn incremental source generators that augment tables and reducers with static methods for self-describing and registration.
SpacetimeDB modules are compiled to WebAssembly modules that expose a specific interface; see the module ABI reference. This interface is implemented in the generated FFI class; see ../Codegen.Tests/fixtures/server/snapshots/Module#FFI.verified.cs for an example of what this generated code looks like.
The source generators are implemented via several attributes usable in module code:
[SpacetimeDB.Table] - generates code to register this table in the FFI upon startup so that they can be enumerated by the __describe_module__ FFI API. It implies [SpacetimeDB.Type], so you must not specify both attributes on the same struct.
[SpacetimeDB.Reducer] - generates code to register a static function as a SpacetimeDB reducer in the FFI upon startup and creates a wrapper that will parse SATS binary blob into individual arguments and invoke the underlying function for the __call_reducer__ FFI API.