ULinkRPC Docs

2026-06-05

API Layers

ULinkRPC exposes several kinds of public APIs. public means the type can be referenced by C#, but it does not always mean the type is a normal application entry point.

Use this page to decide which APIs your project should depend on directly.

Stable User API

These APIs are intended for regular application projects. They are the safest APIs to build long-lived code on.

  • RPC contract attributes such as [RpcService], [RpcMethod], [RpcNotificationContract], and [RpcNotification].
  • Generated client facade and generated server binders.
  • RpcClientOptions.
  • RpcClientRuntime when used through the generated client flow.
  • RpcServerHostBuilder.
  • RpcServerHost.
  • RpcServerLimits.
  • Official transport constructors.
  • Official serializer constructors.
  • RpcKeepAliveOptions.
  • RpcException.
  • RpcStatus.

User-facing tutorials and starter projects should stay inside this layer whenever possible.

Stable Extension API

These APIs are intended for projects that need custom transports, serializers, or connection acceptors.

  • ITransport
  • IRpcSerializer
  • IRpcConnectionAcceptor
  • IRemoteEndPointProvider
  • RpcAcceptedConnection
  • TransportFrame

ULinkRPC supports this extension model because official transport and serializer packages cannot cover every project requirement.

Generated-Support API

These APIs primarily support source-generated glue. Users may see them, but their compatibility is tied to matching ULinkRPC.Analyzers and runtime package versions.

  • IRpcClient
  • RpcMethod<TArg, TResult>
  • RpcNotificationMethod<TArg>
  • RpcGeneratedServicesBinderAttribute
  • RpcGeneratedServiceBinder
  • RpcServiceRegistry, while generated server binding still depends on registry plumbing

If this layer changes, rebuild the project so the source generator emits fresh glue code.

Runtime Internal API

These APIs may appear in reference docs while the project is still before a hard freeze, but they are not normal application extension points.

  • RpcSession
  • RpcHandler
  • RpcSessionHandler
  • direct (serviceId, methodId) handler registration
  • low-level session notification sending

Server applications should not create RpcSession directly. Use RpcServerHostBuilder, generated service binders, service implementation classes, and notification contracts.

Protocol and Infrastructure API

These APIs support protocol tooling, tests, diagnostics, transport internals, and package cooperation. They are not business application entry points.

  • RpcEnvelopeCodec
  • RPC envelope and decoded frame DTOs
  • RpcFrameType
  • RpcProtocolLimits
  • LengthPrefix
  • TransportFrameCodec
  • TransformingTransport
  • TransportSecurityConfig
  • PooledFrameBufferWriter

Use this layer only when building tooling, diagnostics, or lower-level integrations. Application code should normally express behavior through contracts and DTOs instead.