[Timothee Guerin (timotheeguerin)]

The emitter shipped private forks of the framework's ClassDeclaration, Property and EnumDeclaration — copies made because the framework offered no way to adjust them, which then drifted. With declaration overrides and component props now available (#11597, #11598), the forks go away and the divergences are expressed as configuration:

• The property policy (nullability, virtual/override/new, error-model members, JSON attributes) becomes a registered ModelProperty declaration override.
• ServerClassDeclaration becomes EfClassDeclaration with an explicit properties list and the generated constructors passed as children.
• Enums renders through EfEnumDeclaration with an explicit members list, keeping the emitter's more permissive union-as-enum detection.

models.tsx drops from ~270 lines to ~125, and the whole change is a net -350 lines.

One structural note for reviewers: the framework's TypeExpression recurses into itself, not into a consumer's wrapper. Any type kind whose handling recurses into a contained type therefore has to stay in the emitter's wrapper or its divergences are silently lost for the nested type. Scalars are the exception — they go through component overrides, which apply at every level. This is now written down in a comment at the top of the wrapper, because it is not obvious and it caused a regression while writing this.

Generated output is unchanged.

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This is the tip of the series and is still blocked on #11598 and #11600, whose commits it currently carries. A PR can only declare one base, so this stays on main and will reduce to a single commit as they merge.

One of 7 PRs moving @typespec/http-server-csharp onto the emitter framework instead of its private forks. Merged: #11596, #11597, #11599. Remaining: #11598, #11600, #11601, #11602.

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commit: 33e11c2

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All changed packages have been documented.

• ✅ @typespec/emitter-framework
• ✅ @typespec/http-server-csharp

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@typespec/emitter-framework - feature ✏️

Let emitters author the C# declaration components instead of forking them,> ,> - ClassDeclaration accepts an explicit properties list and extra members as children.,> - Property accepts every Alloy property prop, plus name and csharpType overrides.,> - EnumDeclaration accepts an explicit members list and a jsonAttributes prop.,> - JsonConverter accepts doc, access modifiers, extra members, an explicit csharpType, and a readReturns override.,> ,> tsx,> <ClassDeclaration type={model} properties={model.properties.values().filter(isVisible)} partial>,> <Constructor />,> </ClassDeclaration>,>

@typespec/http-server-csharp - fix ✏️

Fix generated error model constructors and numeric constraint attributes using the wrong C# types,> ,> Error model constructors declared parameters such as DateOnly and Uri while the matching properties were DateTime and string, producing code that did not compile. NumericConstraintAttribute<T> had the same mismatch, which stopped the converter from binding.

@typespec/http-server-csharp - internal ✏️

Build model, property and enum generation on @typespec/emitter-framework components,> ,> The emitter carried private forks of the framework's ClassDeclaration, Property and EnumDeclaration. They are now consumed directly, with the emitter's own behavior expressed as a declaration override and component props. Generated output is unchanged.

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Hi @Timothee Guerin (@timotheeguerin). The PR will be closed since the PR has no update for 28 days. If this is still relevant please reopen.