[moetemp]

What changed?

This PR adds @nexus.definition, which names an SDK type that gives the type arguments of a generic resource. An operation that returns the resource takes the definition in place of its runtime types.

/// @nexus.type-parameter "body-t"
/// @nexus.definition python="temporal_support.StreamDefinition"
///   typescript="StreamDefinition" typescript-import="../../../support/temporal_model_converters"
///   dotnet="Nexgen.Support.StreamDefinition"
resource %stream { ... }

So Python's create_stream(Turns, id=...) returns a Stream[Turn], and the TypeScript and .NET Workflow creates take the definition first too. A resource method that binds the operation keeps the runtime types. No SDK has StreamDefinition yet, so the sample names a type of its own support code. nexgen refuses the directive on a resource with no @nexus.type-parameter.

The TypeScript and .NET client targets still take the type argument, and take the definition in a follow-up PR.

Why?

The proposal creates a Stream from a definition, as in client.create_stream(Turns, id=...). The form of a definition is an SDK idiom in each language, like a Workflow definition. So the SDK defines it, and nexgen only names it.

How did you test it?

Link to a test plan if any -

• Unit Tests
• Staging
• End to End Tests

Python and .NET tests create a typed Stream from a definition.

[moetemp]

Not needed anymore. temporalio/api#895 has no Stream definitions now, so a call takes the payload type.