feat: Add operation and type registry codegen by jbelkins · Pull Request #1033 · smithy-lang/smithy-swift

jbelkins · 2026-02-26T04:43:19Z

Description of changes

Primary changes:

Add an Operation type, and code generation for a service's operations
Add a type registry type, and code generation for a service's error types
Adds a ClientProtocol type, which will be used by the Orchestrator to serialize & deserialize requests & responses.

Also:

Remove code from the Smithy-based code generator that was previously used to generate schemas.
Added a model transformer to generate clients with only specific operations. Used to support internal service clients.
Change smithy-model-info.json to swift-settings.json, which includes the same params as the Smithy-based code generator.
Add support for service closure renames (used in RestJson1 protocol tests).

Scope

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

jbelkins · 2026-02-26T19:35:03Z

...en/src/main/kotlin/software/amazon/smithy/swift/codegen/endpoints/EndpointParamsGenerator.kt

    ) {
        writer.apply {
-            val paramsType = ctx.settings.sdkId.clientName() + "AuthSchemeResolverParameters"
+            val paramsType = ctx.settings.clientBaseNamePreservingService + "AuthSchemeResolverParameters"


Ensure the endpoint params name used currently is preserved after the previous sdkId refactor.

jbelkins · 2026-02-26T19:36:08Z

...e/amazon/smithy/swift/codegen/integration/httpResponse/HTTPResponseBindingOutputGenerator.kt

        httpBindingResolver: HttpBindingResolver,
        defaultTimestampFormat: TimestampFormatTrait.Format,
    ) {
+        if (SerdeUtils.useSchemaBased(ctx)) return


Don't generate any of the Codable, URLPathProvider, QueryStringProvider, etc. extensions if this is a schema-based service.

jbelkins · 2026-02-26T19:36:52Z

...software/amazon/smithy/swift/codegen/integration/middlewares/OperationInputBodyMiddleware.kt

 class OperationInputBodyMiddleware(
-    val model: Model,
-    val symbolProvider: SymbolProvider,
+    val ctx: ProtocolGenerator.GenerationContext,


Simplified interface by taking ctx instead of separate model & symbol provider.

jbelkins · 2026-02-26T19:38:03Z

...software/amazon/smithy/swift/codegen/integration/middlewares/OperationInputBodyMiddleware.kt

+        ctx: ProtocolGenerator.GenerationContext,
        writer: SwiftWriter,
        inputSymbol: Symbol,
        outputSymbol: Symbol,


The 4 files below were used to generate schemas using the Smithy-based code generator. Since those will be generated by the Swift-native code generator instead, they are deleted here.

jbelkins · 2026-02-26T19:40:12Z

...main/kotlin/software/amazon/smithy/swift/codegen/integration/HTTPBindingProtocolGenerator.kt

-    private fun usesSchemaBasedSerialization(ctx: ProtocolGenerator.GenerationContext): Boolean =
-        // This fun is temporary; it will be eliminated when all services/protocols are moved to schema-based
-        ctx.service.allTraits.keys
-            .any { it.name == "rpcv2Cbor" }


The function above was moved to SerdeUtils.

The functions below (generateSchemas() and various helpers) are no longer needed since schemas are generated in the native-Swift code generator.

jbelkins · 2026-02-26T19:43:13Z

...-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/utils/SchemaFileUtils.kt

Previously used in the generation of schemas.

jbelkins · 2026-02-26T19:44:26Z

...y-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/DirectedSwiftCodegen.kt

-            LOGGER.info("[${service.id}] Generating Smithy model file info")
-            SmithyModelFileInfoGenerator(ctx).writeSmithyModelFileInfo()
+            LOGGER.info("[${service.id}] Generating swift-settings.json")
+            SwiftSettingsJSONGenerator(ctx).render()


Renamed smithy-model-info.json to swift-settings.json and aligned its contents with this code generator's SwiftSettings type.

jbelkins · 2026-02-26T19:45:11Z

smithy-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/SwiftSettings.kt

@@ -77,6 +59,24 @@ class SwiftSettings(
    val modelPath: String,
 ) {
    companion object {


The strings below have been exposed so the swift-settings.json writer can access them.

jbelkins · 2026-02-26T19:46:33Z

...t-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/SwiftSettingsJSONGenerator.kt

+
+class SwiftSettingsJSONGenerator(
+    val ctx: ProtocolGenerator.GenerationContext,
+) {


Using Smithy's Node type to convert to JSON, this file writes the swift-settings.json file for the service.

jbelkins · 2026-02-26T19:47:23Z

Sources/Smithy/Schema/Prelude.swift


    public static var unitSchema: Schema {
-        Schema(id: .init("smithy.api", "Unit"), type: .structure)
+        Schema(id: .init("smithy.api", "Unit"), type: .structure, traits: [UnitTypeTrait()])


Add the UnitTypeTrait to the smithy.api#Unit schema.

jbelkins · 2026-02-26T19:48:01Z

Sources/Smithy/TraitLibrary/AllSupportedTraits.swift

    SensitiveTrait.id,
    SparseTrait.id,
+    TimestampFormatTrait.id,
+    UnitTypeTrait.id, // UnitTypeTrait will only ever appear in Prelude.unitSchema


Above, new trait types are added to the runtime "allow list".

jbelkins · 2026-02-26T19:51:24Z

Sources/SmithyCodegenCLI/SmithyCodegenCLI.swift

 import ArgumentParser
 import Foundation
 import struct SmithyCodegenCore.CodeGenerator
+import struct SmithyCodegenCore.SwiftSettings


This file adds new params to support various new code generator features, plus the operations & type registry Swift files.

jbelkins · 2026-02-26T19:53:03Z

Sources/SmithyCodegenCore/Model/Model+AST.swift

    /// along with other shape types, and all Shape IDs are fully-qualified
    /// (i.e. members have the enclosing shape's namespace & name, along with their own member name.)
-    /// - Parameter astModel: The JSON AST model to create a `Model` from.
+    /// - Parameter astModel: The JSON AST model to load into the `Model` being created.


In this file, we add support for the rename field on Service, and the collectionOperationIDs and resourceIDs fields on Resource, which are needed to support all AWS services & protocol tests.

jbelkins · 2026-02-26T19:53:59Z

Sources/SmithyCodegenCore/ModelTransformer/Model+Deprecated.swift

@@ -34,98 +34,7 @@ extension Model {
            return sinceDate > cutoff
        }



The code immediately below was moved to its own source file in Sources/SmithyCodegenCore/ModelTransformer/Model+TrimReferences.swift.

jbelkins · 2026-02-26T19:55:52Z

Sources/SmithyCodegenCore/ModelTransformer/Model+Operations.swift

+// SPDX-License-Identifier: Apache-2.0
+//
+
+extension Model {


This model transformer removes unspecified operations from the service. If no operations are specified, all operations are preserved.

This is used to support internal service clients.

jbelkins · 2026-02-26T19:58:04Z

Sources/SmithyCodegenCore/ModelTransformer/Model+TrimReferences.swift

+// SPDX-License-Identifier: Apache-2.0
+//
+
+extension Model {


This was previously a helper function in the Model+Deprecated transform, but has been separated out into its own reusable transform.

It's used to "clean up" a model after it has had shapes removed, by also removing any references or shapes that depended on the removed shapes.

jbelkins · 2026-02-26T19:59:07Z

Sources/SmithyCodegenCore/Operations/OperationsCodegen.swift

+// SPDX-License-Identifier: Apache-2.0
+//
+
+struct OperationsCodegen {


Here, we code-generate a service's operations as a set of internal-scoped static variables namespaced under the client.

jbelkins · 2026-02-26T19:59:52Z

Sources/SmithyCodegenCore/Serialize/SerializeCodegen.swift

+                            // serialize the error member
+                            if try shape.hasTrait(StreamingTrait.self) && member.target.hasTrait(ErrorTrait.self) {
+                                continue
+                            }


The above logic fixes an issue when serializing an event stream that contains error types.

jbelkins · 2026-02-26T20:02:35Z

Sources/SmithyCodegenCore/Shape/ResourceShape.swift

@@ -12,6 +12,8 @@ import struct Smithy.TraitCollection
 /// A ``Shape`` subclass specialized for Smithy resources.
 public class ResourceShape: Shape {
    let operationIDs: [ShapeID]


Here & below, added support for the collectionOperations and resources fields, which are used by some AWS services.

jbelkins · 2026-02-26T20:03:15Z

Sources/SmithyCodegenCore/Shape/ServiceShape.swift

    let operationIDs: [ShapeID]
    let resourceIDs: [ShapeID]
    let errorIDs: [ShapeID]
+    let renames: [ShapeID: String]


Added support here for service-closure renames, which are used by RestJson1 protocol tests.

jbelkins · 2026-02-26T20:03:59Z

Sources/SmithyCodegenCore/SymbolProvider/SymbolProvider.swift

-                .replacingOccurrences(of: "Service", with: "")
-        }
-    }
-


The logic above was incorrect, and has been moved (with corrections) to SwiftSettings.

jbelkins · 2026-02-26T20:04:38Z

Sources/SmithyCodegenCore/SymbolProvider/SymbolProvider.swift

        switch shape.type {
        case .structure, .union, .enum, .intEnum:
-            let base = shape.id.name
+            let baseName = (service.renames[shape.id] ?? shape.id.name).capitalized.escapingReservedWords


Here we check if a service-closure rename has been provided for this type, and if so, we use that as the base for the type name.

jbelkins · 2026-02-26T20:05:23Z

Sources/SmithyCodegenCore/SymbolProvider/SymbolProvider.swift

-                throw SymbolProviderError("Shape has type .service but is not a ServiceShape")
-            }
-            return try "\(serviceShape.clientBaseName)Client"
+            return "\(settings.serviceName)Client"


Service name is now provided by SwiftSettings.

jbelkins · 2026-02-26T20:06:40Z

Sources/SmithyCodegenCore/TypeRegistry/TypeRegistryCodegen.swift

+
+import struct Smithy.ErrorTrait
+
+struct TypeRegistryCodegen {


The (very simple!) code below generates a type registry containing all of this service's errors. Used for deserializing errored responses.

jbelkins · 2026-02-26T20:07:28Z

Sources/SmithyCodegenCore/GenerationContext.swift


        // Perform model transformations here
        let finalModel = try model
+            .withOperations(settings: settings)


Added this model transform to support internal clients.

jbelkins · 2026-02-26T20:08:51Z

Sources/SmithyCodegenCore/SwiftSettings.swift

+
+import struct Smithy.ShapeID
+
+public struct SwiftSettings: Sendable {


This type captures the values encoded in the swift-settings.json file.

jbelkins · 2026-02-26T20:10:55Z

Sources/SmithySerialization/ClientProtocol/ClientProtocol.swift

+import protocol Smithy.ResponseMessage
+import struct Smithy.ShapeID
+
+public protocol ClientProtocol<RequestType, ResponseType>: Sendable {


Each AWS protocol (and RPCv2CBOR) will provide an implementation of this protocol, which will be used by the Orchestrator to perform serde.

jbelkins · 2026-02-26T20:12:28Z

Sources/SmithySerialization/ClientProtocol/Operation.swift

+
+import struct Smithy.Schema
+
+public struct Operation<Input: SerializableStruct, Output: DeserializableStruct> {


The Operation structure contains references to input/output types, schemas, and the error type registry for a given operation.

An instance of this type is code-generated for every operation, and is used during request/response processing.

jbelkins · 2026-02-26T20:13:36Z

Sources/SmithySerialization/ClientProtocol/OperationProperties.swift

+
+import struct Smithy.Schema
+
+public protocol OperationProperties: Sendable {


This protocol allows type-erased access to the schemas & type registry in an Operation.

jbelkins · 2026-02-26T20:14:48Z

Sources/SmithySerialization/Serialization/ShapeSerializer.swift

@@ -96,36 +97,36 @@ public extension ShapeSerializer {
    func writeDocument(_ schema: Schema, _ value: any SmithyDocument) throws {
        switch value.type {
        case .blob:


Per the Smithy spec, documents & their components should be serialized & deserialized using prelude schemas.

The appropriate schemas are substituted below.

jbelkins · 2026-02-26T20:17:00Z

Sources/SmithySerialization/TypeRegistry/TypeRegistry.swift

+import struct Smithy.Schema
+import struct Smithy.ShapeID
+
+public struct TypeRegistry: Sendable {


The TypeRegistry allows for a Shape ID or other schema property to be used to lookup the corresponding Swift type.

For now this is used for error deserialization, but will be used more broadly later for future Smithy features.

jbelkins · 2026-02-26T20:18:23Z

Sources/SmithySerialization/Codec.swift

+
+import struct Foundation.Data
+
+public protocol Codec: Sendable {


This protocol is used for obtaining the correct ShapeSerializer or ShapeDeserializer for a given protocol.

jbelkins · 2026-02-26T20:19:01Z

Tests/SmithyCodegenCoreTests/SmithyCodegenCoreTests.swift

-            deserializeFileURL: tempDirURL.appendingPathComponent("Deserialize.swift")
+            deserializeFileURL: tempDirURL.appendingPathComponent("Deserialize.swift"),
+            typeRegistryFileURL: tempDirURL.appendingPathComponent("TypeRegistry.swift"),
+            operationsFileURL: tempDirURL.appendingPathComponent("Operations.swift")


Update this test for new Swift generated files, and to use Swift settings.

jbelkins added 4 commits February 25, 2026 22:41

feat: Add operation and type registry codegen

a4f284a

Fix SmithyCodegenCoreTests

52a642c

Add support for service closure renames

3eb8e82

Abolish CI timeout

2c80da4

jbelkins commented Feb 26, 2026

View reviewed changes

jbelkins mentioned this pull request Feb 26, 2026

feat: Add operation and type registry codegen awslabs/aws-sdk-swift#2113

Open

jbelkins marked this pull request as ready for review February 26, 2026 20:30

jbelkins requested review from dayaffe and sichanyoo February 26, 2026 20:46

		@@ -34,98 +34,7 @@ extension Model {
		return sinceDate > cutoff
		}


		import struct Smithy.ShapeID

		public struct SwiftSettings: Sendable {


		import struct Smithy.Schema

		public struct Operation<Input: SerializableStruct, Output: DeserializableStruct> {


		import struct Smithy.Schema

		public protocol OperationProperties: Sendable {


		import struct Foundation.Data

		public protocol Codec: Sendable {

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jbelkins commented Feb 26, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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jbelkins commented Feb 26, 2026 •

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