From edca6f9f4fe2a7d3b3cf6ea99c86562bef9488c3 Mon Sep 17 00:00:00 2001
From: Krzysztof Rodak <krodak.konta@gmail.com>
Date: Tue, 22 Sep 2026 15:48:17 +0200
Subject: [PATCH] BridgeJS: Support protocol refinement and constrained imports

---
 .../Sources/BridgeJSCore/ExportSwift.swift    |  52 +-
 .../BridgeJSCore/ExternalModuleIndex.swift    |  15 +-
 .../Sources/BridgeJSCore/ImportTS.swift       |  18 +-
 .../BridgeJSCore/SwiftToSkeleton.swift        | 157 +++++-
 .../Sources/BridgeJSLink/BridgeJSLink.swift   |  36 +-
 .../BridgeJSSkeleton/BridgeJSSkeleton.swift   |  70 ++-
 .../GenericImportDiagnosticsTests.swift       | 113 ++++-
 .../Inputs/MacroSwift/GenericImports.swift    |  22 +
 .../BridgeJSCodegenTests/Alias.swift          |   8 +-
 .../BridgeJSCodegenTests/DocComments.swift    |  18 +-
 .../BridgeJSCodegenTests/GenericImports.json  | 289 ++++++++++-
 .../BridgeJSCodegenTests/GenericImports.swift | 199 ++++++++
 .../BridgeJSCodegenTests/Protocol.swift       | 128 ++---
 .../ProtocolInClosure.swift                   |  18 +-
 .../BridgeJSLinkTests/GenericImports.d.ts     |  20 +
 .../BridgeJSLinkTests/GenericImports.js       | 101 ++++
 .../Exporting-Swift-Protocols.md              |  12 +-
 .../Importing-JS-Function.md                  |  12 +
 .../Generated/BridgeJS.swift                  | 476 +++++++++++++++---
 .../Generated/JavaScript/BridgeJS.json        | 366 +++++++++++++-
 .../ImportGenericAPIs.swift                   |  54 ++
 Tests/prelude.mjs                             |   9 +
 22 files changed, 1933 insertions(+), 260 deletions(-)

diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift
index 55e3b063c..6b5d3ef76 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift
@@ -1425,7 +1425,7 @@ struct ProtocolCodegen {
         for method in proto.methods {
             let builder = try ImportTS.CallJSEmission(
                 moduleName: moduleName,
-                abiName: "_extern_\(method.name)",
+                abiName: method.abiName,
                 effects: method.effects,
                 returnType: method.returnType,
                 context: .exportSwift
@@ -1450,7 +1450,7 @@ struct ProtocolCodegen {
                 printer: externDeclPrinter,
                 moduleName: moduleName,
                 abiName: method.abiName,
-                functionName: "_extern_\(method.name)",
+                functionName: method.abiName,
                 abiParameters: builder.abiParameterSignatures,
                 returnType: builder.abiReturnType
             )
@@ -1478,32 +1478,34 @@ struct ProtocolCodegen {
             externDecls.append(contentsOf: propertyExternDecls)
         }
 
-        let structDeclPrinter = CodeFragmentPrinter()
-        structDeclPrinter.write("struct \(wrapperName): \(protocolName), _BridgedSwiftProtocolWrapper {")
-        structDeclPrinter.indent {
-            structDeclPrinter.write("let jsObject: JSObject")
-            structDeclPrinter.nextLine()
-
-            for methodDecl in methodDecls {
-                structDeclPrinter.write(lines: methodDecl.lines)
-                structDeclPrinter.nextLine()
-            }
-
-            for decl in propertyDecls {
-                structDeclPrinter.write(lines: decl.lines)
-                structDeclPrinter.nextLine()
+        var decls: [DeclSyntax] = []
+        if !methodDecls.isEmpty || !propertyDecls.isEmpty {
+            let extensionPrinter = CodeFragmentPrinter()
+            extensionPrinter.write("extension \(protocolName) where Self: _BridgedSwiftProtocolWrapper {")
+            extensionPrinter.indent {
+                var first = true
+                for decl in methodDecls + propertyDecls {
+                    if !first { extensionPrinter.nextLine() }
+                    first = false
+                    extensionPrinter.write(lines: decl.lines)
+                }
             }
-            structDeclPrinter.write(
-                multilineString: """
-                    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
-                        return \(wrapperName)(jsObject: JSObject(id: UInt32(bitPattern: value)))
-                    }
-                    """
-            )
+            extensionPrinter.write("}")
+            decls.append("\(raw: extensionPrinter.lines.joined(separator: "\n"))")
         }
-        structDeclPrinter.write("}")
 
-        return ["\(raw: structDeclPrinter.lines.joined(separator: "\n"))"] + externDecls
+        decls.append(
+            """
+            struct \(raw: wrapperName): \(raw: protocolName), _BridgedSwiftProtocolWrapper {
+                let jsObject: JSObject
+
+                static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+                    return \(raw: wrapperName)(jsObject: JSObject(id: UInt32(bitPattern: value)))
+                }
+            }
+            """
+        )
+        return decls + externDecls
     }
 
     private func renderProtocolProperty(
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/ExternalModuleIndex.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/ExternalModuleIndex.swift
index 33a27d087..b07fada44 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/ExternalModuleIndex.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/ExternalModuleIndex.swift
@@ -7,6 +7,7 @@ public struct ExternalModuleIndex {
     public struct ExternalType: Equatable {
         public let moduleName: String
         public let bridgeType: BridgeType
+        public var isGenericBridgeableProtocol = false
     }
 
     public enum LookupResult: Equatable {
@@ -31,8 +32,12 @@ public struct ExternalModuleIndex {
             guard let exported = skeleton.exported else { continue }
             var moduleEntries = entriesByModule[moduleName] ?? [:]
 
-            func register(dotPath: String, bridgeType: BridgeType) {
-                let externalType = ExternalType(moduleName: moduleName, bridgeType: bridgeType)
+            func register(dotPath: String, bridgeType: BridgeType, isGenericBridgeableProtocol: Bool = false) {
+                let externalType = ExternalType(
+                    moduleName: moduleName,
+                    bridgeType: bridgeType,
+                    isGenericBridgeableProtocol: isGenericBridgeableProtocol
+                )
                 if moduleEntries[dotPath] == nil {
                     moduleEntries[dotPath] = externalType
                     entriesByDotPath[dotPath, default: []].append(externalType)
@@ -61,7 +66,11 @@ public struct ExternalModuleIndex {
                 register(dotPath: enumDef.swiftCallName, bridgeType: bridgeType)
             }
             for proto in exported.protocols {
-                register(dotPath: proto.name, bridgeType: .swiftProtocol(proto.name))
+                register(
+                    dotPath: proto.name,
+                    bridgeType: .swiftProtocol(proto.name),
+                    isGenericBridgeableProtocol: proto.isGenericBridgeable == true
+                )
             }
             for alias in exported.aliases {
                 register(
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift
index 0ec5457fa..378fe2012 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift
@@ -381,7 +381,7 @@ public struct ImportTS {
             parameters: [Parameter],
             returnType: BridgeType,
             effects: Effects,
-            genericParameters: [String] = []
+            genericParameters: [GenericParameter] = []
         ) -> DeclSyntax {
             let printer = CodeFragmentPrinter()
             let signature = SwiftSignatureBuilder.buildFunctionSignature(
@@ -393,7 +393,13 @@ public struct ImportTS {
             let genericClause =
                 genericParameters.isEmpty
                 ? ""
-                : "<" + genericParameters.map { "\($0): BridgedSwiftGenericBridgeable" }.joined(separator: ", ")
+                : "<"
+                    + genericParameters.map { genericParameter in
+                        let constraints =
+                            ["BridgedSwiftGenericBridgeable"]
+                            + (genericParameter.swiftConstraints ?? genericParameter.constraints)
+                        return "\(genericParameter.name): \(constraints.joined(separator: " & "))"
+                    }.joined(separator: ", ")
                     + ">"
             printer.write("func \(name.backtickIfNeeded())\(genericClause)\(signature) {")
             printer.indent {
@@ -465,7 +471,7 @@ public struct ImportTS {
                 parameters: function.parameters,
                 returnType: function.returnType,
                 effects: function.effects,
-                genericParameters: function.genericParameterNames
+                genericParameters: function.genericParameters ?? []
             )
             .with(\.leadingTrivia, Self.renderDocumentation(documentation: function.documentation))
         ]
@@ -496,7 +502,7 @@ public struct ImportTS {
                     parameters: [selfParameter] + method.parameters,
                     returnType: method.returnType,
                     effects: method.effects,
-                    genericParameters: method.genericParameterNames
+                    genericParameters: method.genericParameters ?? []
                 )
             ]
         }
@@ -522,7 +528,7 @@ public struct ImportTS {
                     parameters: method.parameters,
                     returnType: method.returnType,
                     effects: method.effects,
-                    genericParameters: method.genericParameterNames
+                    genericParameters: method.genericParameters ?? []
                 )
             ]
         }
@@ -548,7 +554,7 @@ public struct ImportTS {
                     parameters: constructor.parameters,
                     returnType: .jsObject(nil),
                     effects: effects,
-                    genericParameters: constructor.genericParameterNames
+                    genericParameters: constructor.genericParameters ?? []
                 )
             ]
         }
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
index 63ce68fe5..0f9f79c06 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
@@ -7,6 +7,11 @@ import BridgeJSUtilities
 import BridgeJSSkeleton
 #endif
 
+enum GenericConstraintParseResult {
+    case parsed(GenericParameter)
+    case failed(message: String)
+}
+
 /// Outcome of attempting to resolve a type as a reference to a generic parameter.
 enum GenericParameterResolution {
     case resolved(BridgeType)
@@ -762,6 +767,13 @@ public final class SwiftToSkeleton {
     }
 
     private func resolveExternal(for type: TypeSyntax, errors: inout [DiagnosticError]) -> BridgeType? {
+        resolveExternalType(for: type, errors: &errors)?.bridgeType
+    }
+
+    private func resolveExternalType(
+        for type: TypeSyntax,
+        errors: inout [DiagnosticError]
+    ) -> ExternalModuleIndex.ExternalType? {
         guard
             !externalModuleIndex.isEmpty,
             var components = type.qualifiedComponents
@@ -787,7 +799,7 @@ public final class SwiftToSkeleton {
         switch lookupResult {
         case .unique(let externalType):
             usedExternalModules.insert(externalType.moduleName)
-            return externalType.bridgeType
+            return externalType
         case .ambiguous(let candidates):
             let moduleNames = candidates.map(\.moduleName).sorted().joined(separator: ", ")
             errors.append(
@@ -981,11 +993,94 @@ public final class SwiftToSkeleton {
         return name.unicodeScalars.dropFirst().allSatisfy { isIdentifierPart($0, isStart: false) }
     }
 
-    fileprivate static func isBridgeableGenericConstraint(_ constraint: String?) -> Bool {
+    fileprivate static func isBridgeableGenericConstraint(_ constraint: String) -> Bool {
         constraint == "BridgedSwiftGenericBridgeable"
             || constraint == "JavaScriptKit.BridgedSwiftGenericBridgeable"
     }
 
+    fileprivate func inheritsGenericBridgeability(for type: TypeSyntax, visited: Set<SyntaxIdentifier> = []) -> Bool {
+        if Self.isBridgeableGenericConstraint(type.trimmedDescription) { return true }
+        if let proto = typeDeclResolver.resolve(type)?.as(ProtocolDeclSyntax.self) {
+            guard !visited.contains(proto.id) else { return false }
+            return (proto.inheritanceClause?.inheritedTypes ?? []).contains {
+                inheritsGenericBridgeability(for: $0.type, visited: visited.union([proto.id]))
+            }
+        }
+        var errors: [DiagnosticError] = []
+        return resolveExternalType(for: type, errors: &errors)?.isGenericBridgeableProtocol == true
+    }
+
+    fileprivate func resolveJSProtocolConstraint(for type: TypeSyntax) -> String? {
+        if let typeDecl = typeDeclResolver.resolve(type) {
+            guard let protocolDecl = typeDecl.as(ProtocolDeclSyntax.self),
+                protocolDecl.attributes.hasJSAttribute()
+            else {
+                return nil
+            }
+            return protocolDecl.name.text
+        }
+        var scratchErrors: [DiagnosticError] = []
+        if let externalType = resolveExternal(for: type, errors: &scratchErrors),
+            case .swiftProtocol(let name) = externalType
+        {
+            return name
+        }
+        return nil
+    }
+
+    fileprivate func parseGenericParameterConstraints(
+        _ genericParam: GenericParameterSyntax,
+        attributeName: String
+    ) -> GenericConstraintParseResult {
+        let paramName = genericParam.name.text
+        guard let inheritedType = genericParam.inheritedType else {
+            return .failed(
+                message:
+                    "Generic parameter '\(paramName)' must be constrained to 'BridgedSwiftGenericBridgeable' to be used with \(attributeName)."
+            )
+        }
+        let elements: [TypeSyntax]
+        if let composition = inheritedType.as(CompositionTypeSyntax.self) {
+            elements = composition.elements.map { TypeSyntax($0.type) }
+        } else {
+            elements = [inheritedType]
+        }
+        var hasBridgeableConstraint = false
+        var constraints: [String] = []
+        var swiftConstraints: [String] = []
+        for element in elements {
+            if SwiftToSkeleton.isBridgeableGenericConstraint(element.trimmedDescription) {
+                hasBridgeableConstraint = true
+                continue
+            }
+            guard let protocolName = resolveJSProtocolConstraint(for: element) else {
+                return .failed(
+                    message:
+                        "Generic parameter '\(paramName)' has unsupported constraint '\(element.trimmedDescription)'. "
+                        + "Constraints on generic \(attributeName) declarations must be 'BridgedSwiftGenericBridgeable', "
+                        + "optionally composed with '@JS' protocols (e.g. '\(paramName): BridgedSwiftGenericBridgeable & MyProtocol')."
+                )
+            }
+            hasBridgeableConstraint = hasBridgeableConstraint || inheritsGenericBridgeability(for: element)
+            if !constraints.contains(protocolName) {
+                constraints.append(protocolName)
+            }
+            let swiftConstraint = element.is(MemberTypeSyntax.self) ? element.trimmedDescription : protocolName
+            if !swiftConstraints.contains(swiftConstraint) {
+                swiftConstraints.append(swiftConstraint)
+            }
+        }
+        guard hasBridgeableConstraint else {
+            let suggested = (["BridgedSwiftGenericBridgeable"] + swiftConstraints).joined(separator: " & ")
+            return .failed(
+                message:
+                    "Generic parameter '\(paramName)' is missing the 'BridgedSwiftGenericBridgeable' constraint. "
+                    + "Write '\(paramName): \(suggested)' to combine it with '@JS' protocol constraints on \(attributeName) declarations."
+            )
+        }
+        return .parsed(GenericParameter(name: paramName, constraints: constraints, swiftConstraints: swiftConstraints))
+    }
+
 }
 
 private enum ExportSwiftConstants {
@@ -2321,6 +2416,23 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
 
         let protocolUniqueKey = makeKey(name: name, namespace: effectiveNamespace)
 
+        var inheritedJSProtocols: [String] = []
+        for inherited in node.inheritanceClause?.inheritedTypes ?? [] {
+            guard let baseName = parent.resolveJSProtocolConstraint(for: inherited.type) else { continue }
+            guard parent.typeDeclResolver.resolve(inherited.type)?.is(ProtocolDeclSyntax.self) == true else {
+                diagnose(
+                    node: inherited,
+                    message: "Refining @JS protocol '\(baseName)' from another module is not supported yet.",
+                    hint:
+                        "Declare the inherited requirements on '\(name)' directly, or move the base protocol into this module."
+                )
+                return .skipChildren
+            }
+            if !inheritedJSProtocols.contains(baseName) {
+                inheritedJSProtocols.append(baseName)
+            }
+        }
+
         exportedProtocolByName[protocolUniqueKey] = ExportedProtocol(
             name: name,
             jsName: jsName,
@@ -2355,7 +2467,11 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
             properties: exportedProtocolByName[protocolUniqueKey]?.properties ?? [],
             namespace: effectiveNamespace,
             jsNamespace: namespaceResult.jsNamespace,
-            documentation: extractDocumentation(from: node)
+            documentation: extractDocumentation(from: node),
+            inheritedJSProtocols: inheritedJSProtocols.isEmpty ? nil : inheritedJSProtocols,
+            isGenericBridgeable: (node.inheritanceClause?.inheritedTypes ?? []).contains {
+                parent.inheritsGenericBridgeability(for: $0.type)
+            } ? true : nil
         )
 
         exportedProtocolByName[protocolUniqueKey] = exportedProtocol
@@ -3453,27 +3569,21 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
     ///
     /// Returns `nil` when a diagnostic was emitted; an empty array when the
     /// declaration is not generic.
-    private func parseGenericParameterNames(
+    private func parseGenericParameters(
         genericParameterClause: GenericParameterClauseSyntax?,
         genericWhereClause: GenericWhereClauseSyntax?,
         node: Syntax
-    ) -> [String]? {
-        var genericParameterNames: [String] = []
+    ) -> [GenericParameter]? {
+        var genericParameters: [GenericParameter] = []
         if let genericParameterClause {
             for genericParam in genericParameterClause.parameters {
-                let paramName = genericParam.name.text
-                let constraintText = genericParam.inheritedType?.trimmedDescription
-                guard SwiftToSkeleton.isBridgeableGenericConstraint(constraintText) else {
-                    errors.append(
-                        DiagnosticError(
-                            node: Syntax(genericParam),
-                            message:
-                                "Generic parameter '\(paramName)' must be constrained to 'BridgedSwiftGenericBridgeable' to be used with @JSFunction."
-                        )
-                    )
+                switch parent.parseGenericParameterConstraints(genericParam, attributeName: "@JSFunction") {
+                case .failed(let message):
+                    errors.append(DiagnosticError(node: Syntax(genericParam), message: message))
                     return nil
+                case .parsed(let genericParameter):
+                    genericParameters.append(genericParameter)
                 }
-                genericParameterNames.append(paramName)
             }
         }
         if genericWhereClause != nil {
@@ -3485,7 +3595,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
             )
             return nil
         }
-        return genericParameterNames
+        return genericParameters
     }
 
     private func parseConstructor(
@@ -3502,7 +3612,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
             return nil
         }
         guard
-            let genericParameterNames = parseGenericParameterNames(
+            let genericParameters = parseGenericParameters(
                 genericParameterClause: initializer.genericParameterClause,
                 genericWhereClause: initializer.genericWhereClause,
                 node: Syntax(initializer)
@@ -3510,6 +3620,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
         else {
             return nil
         }
+        let genericParameterNames = genericParameters.map(\.name)
         if !genericParameterNames.isEmpty && effects.isAsync {
             errors.append(
                 DiagnosticError(
@@ -3542,7 +3653,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
         return ImportedConstructorSkeleton(
             parameters: parameters,
             accessLevel: accessLevel,
-            genericParameters: genericParameterNames.isEmpty ? nil : genericParameterNames
+            genericParameters: genericParameters.isEmpty ? nil : genericParameters
         )
     }
 
@@ -3561,7 +3672,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
         }
 
         guard
-            let genericParameterNames = parseGenericParameterNames(
+            let genericParameters = parseGenericParameters(
                 genericParameterClause: node.genericParameterClause,
                 genericWhereClause: node.genericWhereClause,
                 node: Syntax(node)
@@ -3570,6 +3681,8 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
             return nil
         }
 
+        let genericParameterNames = genericParameters.map(\.name)
+
         let baseName = SwiftToSkeleton.normalizeIdentifier(node.name.text)
         let extractedJSName = extractJSName(from: jsFunction)
         let from = extractJSImportFrom(from: jsFunction)
@@ -3632,7 +3745,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
             effects: effects,
             documentation: nil,
             accessLevel: accessLevel,
-            genericParameters: genericParameterNames.isEmpty ? nil : genericParameterNames
+            genericParameters: genericParameters.isEmpty ? nil : genericParameters
         )
     }
 
diff --git a/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift b/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift
index 5d41869f8..40b1c13c3 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift
@@ -1021,7 +1021,10 @@ public struct BridgeJSLink {
         for skeleton in exportedSkeletons {
             for proto in skeleton.protocols {
                 printer.write(lines: renderJSDoc(documentation: proto.documentation, parameters: []))
-                printer.write("export interface \(proto.resolvedJSName) {")
+                let extendsClause =
+                    inheritedProtocolTSNames(of: proto, in: exportedSkeletons)
+                    .map { " extends \($0.joined(separator: ", "))" } ?? ""
+                printer.write("export interface \(proto.resolvedJSName)\(extendsClause) {")
                 printer.indent {
                     for method in proto.methods {
                         printer.write(
@@ -1521,7 +1524,7 @@ public struct BridgeJSLink {
                     // Add methods
                     for method in type.methods {
                         let methodName = method.resolvedJSName
-                        let genericClause = renderGenericClause(method.genericParameterNames)
+                        let genericClause = renderGenericClause(method.genericParameters ?? [])
                         let methodSignature =
                             "\(renderTSPropertyName(methodName))\(genericClause)\(renderTSSignature(parameters: method.parameters, returnType: method.returnType, effects: method.effects));"
                         printer.write(methodSignature)
@@ -1681,6 +1684,18 @@ public struct BridgeJSLink {
         }
     }
 
+    private func inheritedProtocolTSNames(of proto: ExportedProtocol, in skeletons: [ExportedSkeleton]) -> [String]? {
+        guard let inherited = proto.inheritedJSProtocols, !inherited.isEmpty else { return nil }
+        return inherited.map { baseName in
+            for skeleton in skeletons {
+                if let base = skeleton.protocols.first(where: { $0.name == baseName }) {
+                    return base.resolvedJSName
+                }
+            }
+            return baseName
+        }
+    }
+
     /// Resolves public TypeScript names without changing the skeleton's Swift type identities.
     private func resolveTypeScriptType(_ type: BridgeType) -> String {
         return Self.resolveTypeScriptType(type, exportedSkeletons: skeletons.compactMap(\.exported))
@@ -1771,8 +1786,15 @@ public struct BridgeJSLink {
         return "(\(parameterSignatures.joined(separator: ", "))): \(returnTypeWithEffect)"
     }
 
-    private func renderGenericClause(_ genericParameterNames: [String]) -> String {
-        genericParameterNames.isEmpty ? "" : "<\(genericParameterNames.joined(separator: ", "))>"
+    private func renderGenericClause(_ genericParameters: [GenericParameter]) -> String {
+        guard !genericParameters.isEmpty else { return "" }
+        let renderedParameters = genericParameters.map { genericParameter in
+            let constraints = genericParameter.constraints.map { resolveTypeScriptType(.swiftProtocol($0)) }
+            return constraints.isEmpty
+                ? genericParameter.name
+                : "\(genericParameter.name) extends \(constraints.joined(separator: " & "))"
+        }
+        return "<\(renderedParameters.joined(separator: ", "))>"
     }
 
     private func renderTSPropertyName(_ name: String) -> String {
@@ -3767,7 +3789,7 @@ extension BridgeJSLink {
         try thunkBuilder.call(calleeExpr: calleeExpr)
         let funcLines = thunkBuilder.renderFunction(name: function.abiName(context: nil))
         if function.from == nil {
-            let genericClause = renderGenericClause(genericParameters)
+            let genericClause = renderGenericClause(function.genericParameters ?? [])
             importObjectBuilder.appendDts(
                 [
                     "\(renderTSPropertyName(jsName))\(genericClause)\(renderTSSignature(parameters: function.parameters, returnType: function.returnType, effects: function.effects));"
@@ -3861,14 +3883,14 @@ extension BridgeJSLink {
             dtsPrinter.indent {
                 if let constructor = type.constructor {
                     let returnType = BridgeType.jsObject(type.name)
-                    let genericClause = renderGenericClause(constructor.genericParameterNames)
+                    let genericClause = renderGenericClause(constructor.genericParameters ?? [])
                     dtsPrinter.write(
                         "new\(genericClause)\(renderTSSignature(parameters: constructor.parameters, returnType: returnType, effects: Effects(isAsync: false, isThrows: false)));"
                     )
                 }
                 for method in type.staticMethods {
                     let methodName = method.resolvedJSName
-                    let genericClause = renderGenericClause(method.genericParameterNames)
+                    let genericClause = renderGenericClause(method.genericParameters ?? [])
                     let signature =
                         "\(renderTSPropertyName(methodName))\(genericClause)\(renderTSSignature(parameters: method.parameters, returnType: method.returnType, effects: method.effects));"
                     dtsPrinter.write(signature)
diff --git a/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift b/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift
index ce85176cc..8da9f2e4e 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift
@@ -382,6 +382,14 @@ extension ExportedSkeleton {
             guard let bridgeType = enumDef.genericBridgeType else { continue }
             entries.append(GenericBridgeableTypeEntry(swiftName: enumDef.swiftCallName, bridgeType: bridgeType))
         }
+        for proto in protocols where proto.isGenericBridgeable == true {
+            entries.append(
+                GenericBridgeableTypeEntry(
+                    swiftName: "Any\(proto.name)",
+                    bridgeType: .swiftProtocol(proto.name)
+                )
+            )
+        }
         return entries
     }
 }
@@ -546,6 +554,44 @@ public struct Parameter: Codable, Equatable, Sendable {
     }
 }
 
+public struct GenericParameter: Codable, Equatable, Hashable, Sendable {
+    public let name: String
+    public let constraints: [String]
+    public let swiftConstraints: [String]?
+
+    public init(name: String, constraints: [String] = [], swiftConstraints: [String]? = nil) {
+        self.name = name
+        self.constraints = constraints
+        self.swiftConstraints = swiftConstraints == constraints ? nil : swiftConstraints
+    }
+
+    private enum CodingKeys: String, CodingKey {
+        case name, constraints, swiftConstraints
+    }
+
+    public init(from decoder: any Decoder) throws {
+        if let single = try? decoder.singleValueContainer(), let name = try? single.decode(String.self) {
+            self.name = name
+            self.constraints = []
+            self.swiftConstraints = nil
+            return
+        }
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        self.name = try container.decode(String.self, forKey: .name)
+        self.constraints = try container.decodeIfPresent([String].self, forKey: .constraints) ?? []
+        self.swiftConstraints = try container.decodeIfPresent([String].self, forKey: .swiftConstraints)
+    }
+
+    public func encode(to encoder: any Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encode(name, forKey: .name)
+        if !constraints.isEmpty {
+            try container.encode(constraints, forKey: .constraints)
+        }
+        try container.encodeIfPresent(swiftConstraints, forKey: .swiftConstraints)
+    }
+}
+
 // MARK: - BridgeSkeleton Visitor
 
 public protocol BridgeSkeletonVisitor {
@@ -973,6 +1019,8 @@ public struct ExportedProtocol: Codable, Equatable, NamespacedExportedType {
     public let namespace: [String]?
     public let jsNamespace: [String]?
     public var documentation: String?
+    public var inheritedJSProtocols: [String]?
+    public var isGenericBridgeable: Bool?
 
     public init(
         name: String,
@@ -981,7 +1029,9 @@ public struct ExportedProtocol: Codable, Equatable, NamespacedExportedType {
         properties: [ExportedProtocolProperty] = [],
         namespace: [String]? = nil,
         jsNamespace: [String]? = nil,
-        documentation: String? = nil
+        documentation: String? = nil,
+        inheritedJSProtocols: [String]? = nil,
+        isGenericBridgeable: Bool? = nil
     ) {
         self.name = name
         self.jsName = jsName
@@ -990,6 +1040,8 @@ public struct ExportedProtocol: Codable, Equatable, NamespacedExportedType {
         self.namespace = namespace
         self.jsNamespace = jsNamespace
         self.documentation = documentation
+        self.inheritedJSProtocols = inheritedJSProtocols
+        self.isGenericBridgeable = isGenericBridgeable
     }
 }
 
@@ -1397,8 +1449,8 @@ public struct ImportedFunctionSkeleton: Codable {
     /// determine the access level of bridge-generated helpers (e.g. typed
     /// closure inits) that surface through this function's signature.
     public let accessLevel: BridgeJSAccessLevel
-    public let genericParameters: [String]?
-    public var genericParameterNames: [String] { genericParameters ?? [] }
+    public let genericParameters: [GenericParameter]?
+    public var genericParameterNames: [String] { (genericParameters ?? []).map(\.name) }
     public var isGeneric: Bool { !genericParameterNames.isEmpty }
 
     public var resolvedJSName: String { jsName ?? name }
@@ -1412,7 +1464,7 @@ public struct ImportedFunctionSkeleton: Codable {
         effects: Effects = Effects(isAsync: false, isThrows: true),
         documentation: String? = nil,
         accessLevel: BridgeJSAccessLevel = .internal,
-        genericParameters: [String]? = nil
+        genericParameters: [GenericParameter]? = nil
     ) {
         self.name = name
         self.jsName = jsName
@@ -1439,7 +1491,7 @@ public struct ImportedFunctionSkeleton: Codable {
         self.effects = try container.decode(Effects.self, forKey: .effects)
         self.documentation = try container.decodeIfPresent(String.self, forKey: .documentation)
         self.accessLevel = try container.decodeIfPresent(BridgeJSAccessLevel.self, forKey: .accessLevel) ?? .internal
-        self.genericParameters = try container.decodeIfPresent([String].self, forKey: .genericParameters)
+        self.genericParameters = try container.decodeIfPresent([GenericParameter].self, forKey: .genericParameters)
     }
 
     public func abiName(context: ImportedTypeSkeleton?) -> String {
@@ -1460,14 +1512,14 @@ public struct ImportedConstructorSkeleton: Codable {
     /// Source access level of the originating Swift `init`. Inherits from the
     /// enclosing `@JSClass` type when not annotated explicitly.
     public let accessLevel: BridgeJSAccessLevel
-    public let genericParameters: [String]?
-    public var genericParameterNames: [String] { genericParameters ?? [] }
+    public let genericParameters: [GenericParameter]?
+    public var genericParameterNames: [String] { (genericParameters ?? []).map(\.name) }
     public var isGeneric: Bool { !genericParameterNames.isEmpty }
 
     public init(
         parameters: [Parameter],
         accessLevel: BridgeJSAccessLevel = .internal,
-        genericParameters: [String]? = nil
+        genericParameters: [GenericParameter]? = nil
     ) {
         self.parameters = parameters
         self.accessLevel = accessLevel
@@ -1482,7 +1534,7 @@ public struct ImportedConstructorSkeleton: Codable {
         let container = try decoder.container(keyedBy: CodingKeys.self)
         self.parameters = try container.decode([Parameter].self, forKey: .parameters)
         self.accessLevel = try container.decodeIfPresent(BridgeJSAccessLevel.self, forKey: .accessLevel) ?? .internal
-        self.genericParameters = try container.decodeIfPresent([String].self, forKey: .genericParameters)
+        self.genericParameters = try container.decodeIfPresent([GenericParameter].self, forKey: .genericParameters)
     }
 
     public func abiName(context: ImportedTypeSkeleton) -> String {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/GenericImportDiagnosticsTests.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/GenericImportDiagnosticsTests.swift
index 4a421b73b..f2ff5dc81 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/GenericImportDiagnosticsTests.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/GenericImportDiagnosticsTests.swift
@@ -1,9 +1,116 @@
+import Foundation
 import Testing
 
+@testable import BridgeJSCore
+@testable import BridgeJSLink
 @testable import BridgeJSSkeleton
 
 @Suite struct GenericImportDiagnosticsTests {
 
+    @Test(arguments: [
+        ("protocol P {}", "BridgedSwiftGenericBridgeable & P", "unsupported constraint 'P'"),
+        ("@JS protocol P {}", "P", "missing the 'BridgedSwiftGenericBridgeable' constraint"),
+    ])
+    func invalidProtocolConstraint(declaration: String, constraint: String, diagnostic: String) {
+        expectDiagnostic(
+            source: "\(declaration)\n@JSFunction func f<T: \(constraint)>(_ value: T) throws(JSException) -> T",
+            contains: diagnostic
+        )
+    }
+
+    @Test func qualifiedExternalProtocolConstraint() throws {
+        let dependency = try makeSkeleton(
+            "@JS public protocol Node: BridgedSwiftGenericBridgeable {}",
+            moduleName: "GraphKit"
+        )
+        let decoded = try JSONDecoder().decode(BridgeJSSkeleton.self, from: JSONEncoder().encode(dependency))
+        let skeleton = try makeSkeleton(
+            """
+            import GraphKit
+            protocol Node {}
+            @JSFunction func f<T: GraphKit.Node>(_ value: T) throws(JSException) -> T
+            """,
+            dependencies: [(moduleName: "GraphKit", skeleton: decoded)]
+        )
+        let roundTrip = try JSONDecoder().decode(BridgeJSSkeleton.self, from: JSONEncoder().encode(skeleton))
+        let imported = try #require(roundTrip.imported)
+        #expect(
+            imported.children.flatMap(\.functions).first?.genericParameters == [
+                GenericParameter(name: "T", constraints: ["Node"], swiftConstraints: ["GraphKit.Node"])
+            ]
+        )
+        let glue = try #require(
+            try ImportTS(progress: .silent, moduleName: skeleton.moduleName, skeleton: imported).finalize()
+        )
+        #expect(glue.contains("T: BridgedSwiftGenericBridgeable & GraphKit.Node"))
+        #expect(roundTrip.usedExternalModules == ["GraphKit"])
+    }
+
+    @Test func refinedProtocolRequirementsAndAdapter() throws {
+        let skeleton = try makeSkeleton(
+            """
+            @JS(namespace: "API") protocol Base: BridgedSwiftGenericBridgeable {
+                func read() -> Int
+                var value: Int { get set }
+            }
+            @JS protocol Middle: Base {}
+            @JS("PublicNode", namespace: "API") protocol Node: Middle {
+                var value: Int { get }
+            }
+            @JSFunction func f<T: Node>(_ value: T) throws(JSException) -> T
+            """
+        )
+        let exported = try #require(skeleton.exported)
+        let node = try #require(exported.protocols.first { $0.name == "Node" })
+        #expect(node.methods.isEmpty)
+        #expect(node.properties.map(\.name) == ["value"])
+        #expect(node.inheritedJSProtocols == ["Middle"])
+        #expect(node.jsName == "PublicNode")
+        #expect(
+            exported.genericBridgeableTypeEntries.contains {
+                $0.swiftName == "AnyNode" && $0.bridgeType == .swiftProtocol("Node")
+            }
+        )
+        let glue = try #require(
+            try ExportSwift(progress: .silent, moduleName: skeleton.moduleName, skeleton: exported).finalize()
+        )
+        #expect(glue.contains("extension Base where Self: _BridgedSwiftProtocolWrapper {"))
+        #expect(glue.contains("extension Node where Self: _BridgedSwiftProtocolWrapper {"))
+        #expect(!glue.contains("extension Middle where Self"))
+        #expect(glue.contains("struct AnyNode: Node, _BridgedSwiftProtocolWrapper {"))
+        #expect(glue.contains("name: \"bjs_Base_read\""))
+        #expect(!glue.contains("bjs_Node_read"))
+        let linked = try BridgeJSLink(skeletons: [skeleton]).link()
+        #expect(linked.outputDts.contains("f<T extends PublicNode>"))
+        #expect(linked.outputDts.contains("export interface PublicNode extends Middle {"))
+        #expect(linked.outputDts.contains("export interface Middle extends Base {"))
+    }
+
+    @Test func externalProtocolRefinementIsRejected() throws {
+        let dependency = try makeSkeleton("@JS public protocol Base {}", moduleName: "GraphKit")
+        do {
+            _ = try makeSkeleton(
+                "import GraphKit\n@JS protocol Child: GraphKit.Base {}",
+                dependencies: [(moduleName: "GraphKit", skeleton: dependency)]
+            )
+            Issue.record("Expected external refinement diagnostic")
+        } catch let error as BridgeJSCoreDiagnosticError {
+            #expect(
+                error.diagnostics.contains {
+                    $0.diagnostic.message.contains("from another module is not supported")
+                }
+            )
+        }
+    }
+
+    @Test func legacyGenericParameterDecoding() throws {
+        let constructor = try JSONDecoder().decode(
+            ImportedConstructorSkeleton.self,
+            from: Data(#"{"parameters":[],"genericParameters":["T"]}"#.utf8)
+        )
+        #expect(constructor.genericParameters == [GenericParameter(name: "T")])
+    }
+
     @Test
     func genericParameterRequiresBridgeableConstraint() {
         expectDiagnostic(
@@ -48,7 +155,7 @@ import Testing
         let types = imported.children.flatMap { $0.types }
         let box = try #require(types.first { $0.name == "Box" })
         let method = try #require(box.methods.first { $0.name == "member" })
-        #expect(method.genericParameters == ["T"])
+        #expect(method.genericParameters == [GenericParameter(name: "T")])
     }
 
     @Test
@@ -65,7 +172,7 @@ import Testing
         let types = imported.children.flatMap { $0.types }
         let box = try #require(types.first { $0.name == "Box" })
         let constructor = try #require(box.constructor)
-        #expect(constructor.genericParameters == ["T"])
+        #expect(constructor.genericParameters == [GenericParameter(name: "T")])
         #expect(constructor.parameters.map(\.type) == [.generic("T")])
     }
 
@@ -205,6 +312,6 @@ import Testing
         let imported = try #require(skeleton.imported)
         let functions = imported.children.flatMap { $0.functions }
         let function = try #require(functions.first { $0.name == "make" })
-        #expect(function.genericParameters == ["T"])
+        #expect(function.genericParameters == [GenericParameter(name: "T")])
     }
 }
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/GenericImports.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/GenericImports.swift
index 5fd3d0226..546207cd3 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/GenericImports.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/GenericImports.swift
@@ -72,3 +72,25 @@ struct GenericPoint {
     @JSFunction func identity<T: BridgedSwiftGenericBridgeable>(_ value: T) throws(JSException) -> T
     @JSFunction static func box<T: BridgedSwiftGenericBridgeable>(_ value: T) throws(JSException) -> T
 }
+
+@JS protocol GenericReadable: BridgedSwiftGenericBridgeable {
+    func read() -> Int
+}
+
+@JS protocol GenericWritable {
+    var value: Int { get set }
+}
+
+@JS protocol GenericNode: GenericReadable, GenericWritable {}
+
+@JSFunction func constrainedRoundTrip<T: GenericNode>(_ value: T) throws(JSException) -> T
+
+@JSFunction func constrainedComposition<T: BridgedSwiftGenericBridgeable & GenericWritable>(
+    _ value: T
+) throws(JSException) -> T
+
+@JSClass struct ConstrainedConsumer {
+    @JSFunction init<T: GenericNode>(_ value: T) throws(JSException)
+    @JSFunction func accept<T: GenericNode>(_ value: T) throws(JSException) -> T
+    @JSFunction static func identity<T: GenericNode>(_ value: T) throws(JSException) -> T
+}
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Alias.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Alias.swift
index af8a8a453..2529f22d3 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Alias.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Alias.swift
@@ -1,6 +1,4 @@
-struct AnyHasOptionalUserId: HasOptionalUserId, _BridgedSwiftProtocolWrapper {
-    let jsObject: JSObject
-
+extension HasOptionalUserId where Self: _BridgedSwiftProtocolWrapper {
     var userId: Optional<UserId> {
         get {
             let jsObjectValue = jsObject.bridgeJSLowerParameter()
@@ -8,6 +6,10 @@ struct AnyHasOptionalUserId: HasOptionalUserId, _BridgedSwiftProtocolWrapper {
             return Optional<UserId>.bridgeJSLiftReturnFromSideChannel()
         }
     }
+}
+
+struct AnyHasOptionalUserId: HasOptionalUserId, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyHasOptionalUserId(jsObject: JSObject(id: UInt32(bitPattern: value)))
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DocComments.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DocComments.swift
index b9c65e28f..05c575b73 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DocComments.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DocComments.swift
@@ -1,10 +1,8 @@
-struct AnyListener: Listener, _BridgedSwiftProtocolWrapper {
-    let jsObject: JSObject
-
+extension Listener where Self: _BridgedSwiftProtocolWrapper {
     func onEvent(id: Int) -> Void {
         let idValue = id.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_onEvent(jsObjectValue, idValue)
+        bjs_Listener_onEvent(jsObjectValue, idValue)
     }
 
     var name: String {
@@ -14,6 +12,10 @@ struct AnyListener: Listener, _BridgedSwiftProtocolWrapper {
             return String.bridgeJSLiftReturn(ret)
         }
     }
+}
+
+struct AnyListener: Listener, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyListener(jsObject: JSObject(id: UInt32(bitPattern: value)))
@@ -22,14 +24,14 @@ struct AnyListener: Listener, _BridgedSwiftProtocolWrapper {
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_Listener_onEvent")
-fileprivate func _extern_onEvent_extern(_ jsObject: Int32, _ id: Int32) -> Void
+fileprivate func bjs_Listener_onEvent_extern(_ jsObject: Int32, _ id: Int32) -> Void
 #else
-fileprivate func _extern_onEvent_extern(_ jsObject: Int32, _ id: Int32) -> Void {
+fileprivate func bjs_Listener_onEvent_extern(_ jsObject: Int32, _ id: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onEvent(_ jsObject: Int32, _ id: Int32) -> Void {
-    return _extern_onEvent_extern(jsObject, id)
+@inline(never) fileprivate func bjs_Listener_onEvent(_ jsObject: Int32, _ id: Int32) -> Void {
+    return bjs_Listener_onEvent_extern(jsObject, id)
 }
 
 #if arch(wasm32)
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.json
index c7f3e98ae..9f9f7a834 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.json
@@ -172,7 +172,69 @@
 
     ],
     "protocols" : [
+      {
+        "isGenericBridgeable" : true,
+        "methods" : [
+          {
+            "abiName" : "bjs_GenericReadable_read",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : false
+            },
+            "name" : "read",
+            "parameters" : [
 
+            ],
+            "returnType" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
+        ],
+        "name" : "GenericReadable",
+        "properties" : [
+
+        ]
+      },
+      {
+        "methods" : [
+
+        ],
+        "name" : "GenericWritable",
+        "properties" : [
+          {
+            "isReadonly" : false,
+            "name" : "value",
+            "type" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
+        ]
+      },
+      {
+        "inheritedJSProtocols" : [
+          "GenericReadable",
+          "GenericWritable"
+        ],
+        "isGenericBridgeable" : true,
+        "methods" : [
+
+        ],
+        "name" : "GenericNode",
+        "properties" : [
+
+        ]
+      }
     ],
     "structs" : [
       {
@@ -224,7 +286,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "genericRoundTrip",
             "parameters" : [
@@ -251,7 +315,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "genericParse",
             "parameters" : [
@@ -278,8 +344,12 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T",
-              "U"
+              {
+                "name" : "T"
+              },
+              {
+                "name" : "U"
+              }
             ],
             "name" : "importGenericCombine",
             "parameters" : [
@@ -314,8 +384,12 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T",
-              "t"
+              {
+                "name" : "T"
+              },
+              {
+                "name" : "t"
+              }
             ],
             "name" : "importGenericCaseDistinct",
             "parameters" : [
@@ -350,7 +424,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "importGenericArray",
             "parameters" : [
@@ -385,7 +461,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "importGenericOptional",
             "parameters" : [
@@ -422,7 +500,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "importGenericDictionary",
             "parameters" : [
@@ -457,7 +537,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "importGenericAfterOptionalArray",
             "parameters" : [
@@ -495,6 +577,70 @@
                 "_0" : "T"
               }
             }
+          },
+          {
+            "accessLevel" : "internal",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "genericParameters" : [
+              {
+                "constraints" : [
+                  "GenericNode"
+                ],
+                "name" : "T"
+              }
+            ],
+            "name" : "constrainedRoundTrip",
+            "parameters" : [
+              {
+                "name" : "value",
+                "type" : {
+                  "generic" : {
+                    "_0" : "T"
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "generic" : {
+                "_0" : "T"
+              }
+            }
+          },
+          {
+            "accessLevel" : "internal",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "genericParameters" : [
+              {
+                "constraints" : [
+                  "GenericWritable"
+                ],
+                "name" : "T"
+              }
+            ],
+            "name" : "constrainedComposition",
+            "parameters" : [
+              {
+                "name" : "value",
+                "type" : {
+                  "generic" : {
+                    "_0" : "T"
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "generic" : {
+                "_0" : "T"
+              }
+            }
           }
         ],
         "types" : [
@@ -503,8 +649,12 @@
             "constructor" : {
               "accessLevel" : "internal",
               "genericParameters" : [
-                "T",
-                "U"
+                {
+                  "name" : "T"
+                },
+                {
+                  "name" : "U"
+                }
               ],
               "parameters" : [
                 {
@@ -552,7 +702,9 @@
             "constructor" : {
               "accessLevel" : "internal",
               "genericParameters" : [
-                "T"
+                {
+                  "name" : "T"
+                }
               ],
               "parameters" : [
                 {
@@ -577,7 +729,9 @@
                   "isThrows" : true
                 },
                 "genericParameters" : [
-                  "T"
+                  {
+                    "name" : "T"
+                  }
                 ],
                 "name" : "accept",
                 "parameters" : [
@@ -604,7 +758,9 @@
                   "isThrows" : true
                 },
                 "genericParameters" : [
-                  "T"
+                  {
+                    "name" : "T"
+                  }
                 ],
                 "name" : "identity",
                 "parameters" : [
@@ -637,7 +793,9 @@
                   "isThrows" : true
                 },
                 "genericParameters" : [
-                  "T"
+                  {
+                    "name" : "T"
+                  }
                 ],
                 "name" : "box",
                 "parameters" : [
@@ -657,6 +815,105 @@
                 }
               }
             ]
+          },
+          {
+            "accessLevel" : "internal",
+            "constructor" : {
+              "accessLevel" : "internal",
+              "genericParameters" : [
+                {
+                  "constraints" : [
+                    "GenericNode"
+                  ],
+                  "name" : "T"
+                }
+              ],
+              "parameters" : [
+                {
+                  "name" : "value",
+                  "type" : {
+                    "generic" : {
+                      "_0" : "T"
+                    }
+                  }
+                }
+              ]
+            },
+            "getters" : [
+
+            ],
+            "methods" : [
+              {
+                "accessLevel" : "internal",
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
+                "genericParameters" : [
+                  {
+                    "constraints" : [
+                      "GenericNode"
+                    ],
+                    "name" : "T"
+                  }
+                ],
+                "name" : "accept",
+                "parameters" : [
+                  {
+                    "name" : "value",
+                    "type" : {
+                      "generic" : {
+                        "_0" : "T"
+                      }
+                    }
+                  }
+                ],
+                "returnType" : {
+                  "generic" : {
+                    "_0" : "T"
+                  }
+                }
+              }
+            ],
+            "name" : "ConstrainedConsumer",
+            "setters" : [
+
+            ],
+            "staticMethods" : [
+              {
+                "accessLevel" : "internal",
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
+                "genericParameters" : [
+                  {
+                    "constraints" : [
+                      "GenericNode"
+                    ],
+                    "name" : "T"
+                  }
+                ],
+                "name" : "identity",
+                "parameters" : [
+                  {
+                    "name" : "value",
+                    "type" : {
+                      "generic" : {
+                        "_0" : "T"
+                      }
+                    }
+                  }
+                ],
+                "returnType" : {
+                  "generic" : {
+                    "_0" : "T"
+                  }
+                }
+              }
+            ]
           }
         ]
       }
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.swift
index cf07236fc..ecb1512cf 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GenericImports.swift
@@ -1,3 +1,86 @@
+extension GenericReadable where Self: _BridgedSwiftProtocolWrapper {
+    func read() -> Int {
+        let jsObjectValue = jsObject.bridgeJSLowerParameter()
+        let ret = bjs_GenericReadable_read(jsObjectValue)
+        return Int.bridgeJSLiftReturn(ret)
+    }
+}
+
+struct AnyGenericReadable: GenericReadable, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyGenericReadable(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_GenericReadable_read")
+fileprivate func bjs_GenericReadable_read_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_GenericReadable_read_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_GenericReadable_read(_ jsObject: Int32) -> Int32 {
+    return bjs_GenericReadable_read_extern(jsObject)
+}
+
+extension GenericWritable where Self: _BridgedSwiftProtocolWrapper {
+    var value: Int {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_GenericWritable_value_get(jsObjectValue)
+            return Int.bridgeJSLiftReturn(ret)
+        }
+        set {
+            let newValueValue = newValue.bridgeJSLowerParameter()
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            bjs_GenericWritable_value_set(jsObjectValue, newValueValue)
+        }
+    }
+}
+
+struct AnyGenericWritable: GenericWritable, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyGenericWritable(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_GenericWritable_value_get")
+fileprivate func bjs_GenericWritable_value_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_GenericWritable_value_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_GenericWritable_value_get(_ jsObject: Int32) -> Int32 {
+    return bjs_GenericWritable_value_get_extern(jsObject)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_GenericWritable_value_set")
+fileprivate func bjs_GenericWritable_value_set_extern(_ jsObject: Int32, _ newValue: Int32) -> Void
+#else
+fileprivate func bjs_GenericWritable_value_set_extern(_ jsObject: Int32, _ newValue: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_GenericWritable_value_set(_ jsObject: Int32, _ newValue: Int32) -> Void {
+    return bjs_GenericWritable_value_set_extern(jsObject, newValue)
+}
+
+struct AnyGenericNode: GenericNode, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyGenericNode(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
 extension GenericColor: _BridgedSwiftCaseEnum {
     @_spi(BridgeJS) @_transparent public consuming func bridgeJSLowerParameter() -> Int32 {
         return bridgeJSRawValue
@@ -207,6 +290,14 @@ extension GenericTagged: BridgedSwiftGenericBridgeable {
     @_spi(BridgeJS) public static let bridgeJSTypeHandle = GenericTagged.bridgeJSMakeTypeHandle()
 }
 
+extension AnyGenericReadable: BridgedSwiftGenericBridgeable {
+    @_spi(BridgeJS) public static let bridgeJSTypeHandle = AnyGenericReadable.bridgeJSMakeTypeHandle()
+}
+
+extension AnyGenericNode: BridgedSwiftGenericBridgeable {
+    @_spi(BridgeJS) public static let bridgeJSTypeHandle = AnyGenericNode.bridgeJSMakeTypeHandle()
+}
+
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_genericRoundTrip")
 fileprivate func bjs_genericRoundTrip_extern(_ _generic0TypeId: Int32) -> Void
@@ -379,6 +470,48 @@ func _$importGenericAfterOptionalArray<T: BridgedSwiftGenericBridgeable>(_ value
     return T.bridgeJSStackPop()
 }
 
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_constrainedRoundTrip")
+fileprivate func bjs_constrainedRoundTrip_extern(_ _generic0TypeId: Int32) -> Void
+#else
+fileprivate func bjs_constrainedRoundTrip_extern(_ _generic0TypeId: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_constrainedRoundTrip(_ _generic0TypeId: Int32) -> Void {
+    return bjs_constrainedRoundTrip_extern(_generic0TypeId)
+}
+
+func _$constrainedRoundTrip<T: BridgedSwiftGenericBridgeable & GenericNode>(_ value: T) throws(JSException) -> T {
+    value.bridgeJSStackPush()
+    bjs_constrainedRoundTrip(T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return T.bridgeJSStackPop()
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_constrainedComposition")
+fileprivate func bjs_constrainedComposition_extern(_ _generic0TypeId: Int32) -> Void
+#else
+fileprivate func bjs_constrainedComposition_extern(_ _generic0TypeId: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_constrainedComposition(_ _generic0TypeId: Int32) -> Void {
+    return bjs_constrainedComposition_extern(_generic0TypeId)
+}
+
+func _$constrainedComposition<T: BridgedSwiftGenericBridgeable & GenericWritable>(_ value: T) throws(JSException) -> T {
+    value.bridgeJSStackPush()
+    bjs_constrainedComposition(T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return T.bridgeJSStackPop()
+}
+
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_GenericPairFactory_init")
 fileprivate func bjs_GenericPairFactory_init_extern(_ tagBytes: Int32, _ tagLength: Int32, _ _generic0TypeId: Int32, _ _generic1TypeId: Int32) -> Int32
@@ -490,6 +623,70 @@ func _$GenericConsumer_identity<T: BridgedSwiftGenericBridgeable>(_ self: JSObje
     return T.bridgeJSStackPop()
 }
 
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_ConstrainedConsumer_init")
+fileprivate func bjs_ConstrainedConsumer_init_extern(_ _generic0TypeId: Int32) -> Int32
+#else
+fileprivate func bjs_ConstrainedConsumer_init_extern(_ _generic0TypeId: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_ConstrainedConsumer_init(_ _generic0TypeId: Int32) -> Int32 {
+    return bjs_ConstrainedConsumer_init_extern(_generic0TypeId)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_ConstrainedConsumer_identity_static")
+fileprivate func bjs_ConstrainedConsumer_identity_static_extern(_ _generic0TypeId: Int32) -> Void
+#else
+fileprivate func bjs_ConstrainedConsumer_identity_static_extern(_ _generic0TypeId: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_ConstrainedConsumer_identity_static(_ _generic0TypeId: Int32) -> Void {
+    return bjs_ConstrainedConsumer_identity_static_extern(_generic0TypeId)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_ConstrainedConsumer_accept")
+fileprivate func bjs_ConstrainedConsumer_accept_extern(_ self: Int32, _ _generic0TypeId: Int32) -> Void
+#else
+fileprivate func bjs_ConstrainedConsumer_accept_extern(_ self: Int32, _ _generic0TypeId: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_ConstrainedConsumer_accept(_ self: Int32, _ _generic0TypeId: Int32) -> Void {
+    return bjs_ConstrainedConsumer_accept_extern(self, _generic0TypeId)
+}
+
+func _$ConstrainedConsumer_init<T: BridgedSwiftGenericBridgeable & GenericNode>(_ value: T) throws(JSException) -> JSObject {
+    value.bridgeJSStackPush()
+    let ret = bjs_ConstrainedConsumer_init(T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return JSObject.bridgeJSLiftReturn(ret)
+}
+
+func _$ConstrainedConsumer_identity<T: BridgedSwiftGenericBridgeable & GenericNode>(_ value: T) throws(JSException) -> T {
+    value.bridgeJSStackPush()
+    bjs_ConstrainedConsumer_identity_static(T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return T.bridgeJSStackPop()
+}
+
+func _$ConstrainedConsumer_accept<T: BridgedSwiftGenericBridgeable & GenericNode>(_ self: JSObject, _ value: T) throws(JSException) -> T {
+    value.bridgeJSStackPush()
+    let selfValue = self.bridgeJSLowerParameter()
+    bjs_ConstrainedConsumer_accept(selfValue, T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return T.bridgeJSStackPop()
+}
+
 #if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "bjs_TestModule_register_type_handles")
 fileprivate func _bjs_TestModule_register_type_handles_extern(_ base: UnsafePointer<Int32>?, _ count: Int32)
@@ -502,6 +699,8 @@ public func _bjs_TestModule_register_type_handles() {
         GenericColor.bridgeJSTypeID,
         GenericMode.bridgeJSTypeID,
         GenericTagged.bridgeJSTypeID,
+        AnyGenericReadable.bridgeJSTypeID,
+        AnyGenericNode.bridgeJSTypeID,
     ]
     typeIds.withUnsafeBufferPointer { buffer in
         _bjs_TestModule_register_type_handles_extern(buffer.baseAddress, Int32(buffer.count))
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Protocol.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Protocol.swift
index ef9beefac..ec3d2f65a 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Protocol.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Protocol.swift
@@ -1,22 +1,20 @@
-struct AnyMyViewControllerDelegate: MyViewControllerDelegate, _BridgedSwiftProtocolWrapper {
-    let jsObject: JSObject
-
+extension MyViewControllerDelegate where Self: _BridgedSwiftProtocolWrapper {
     func onSomethingHappened() -> Void {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_onSomethingHappened(jsObjectValue)
+        bjs_MyViewControllerDelegate_onSomethingHappened(jsObjectValue)
     }
 
     func onValueChanged(_ value: String) -> Void {
         value.bridgeJSWithLoweredParameter { (valueBytes, valueLength) in
             let jsObjectValue = jsObject.bridgeJSLowerParameter()
-            _extern_onValueChanged(jsObjectValue, valueBytes, valueLength)
+            bjs_MyViewControllerDelegate_onValueChanged(jsObjectValue, valueBytes, valueLength)
         }
     }
 
     func onCountUpdated(count: Int) -> Bool {
         let countValue = count.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_onCountUpdated(jsObjectValue, countValue)
+        let ret = bjs_MyViewControllerDelegate_onCountUpdated(jsObjectValue, countValue)
         return Bool.bridgeJSLiftReturn(ret)
     }
 
@@ -24,56 +22,56 @@ struct AnyMyViewControllerDelegate: MyViewControllerDelegate, _BridgedSwiftProto
         prefix.bridgeJSWithLoweredParameter { (prefixBytes, prefixLength) in
             suffix.bridgeJSWithLoweredParameter { (suffixBytes, suffixLength) in
                 let jsObjectValue = jsObject.bridgeJSLowerParameter()
-                _extern_onLabelUpdated(jsObjectValue, prefixBytes, prefixLength, suffixBytes, suffixLength)
+                bjs_MyViewControllerDelegate_onLabelUpdated(jsObjectValue, prefixBytes, prefixLength, suffixBytes, suffixLength)
             }
         }
     }
 
     func isCountEven() -> Bool {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_isCountEven(jsObjectValue)
+        let ret = bjs_MyViewControllerDelegate_isCountEven(jsObjectValue)
         return Bool.bridgeJSLiftReturn(ret)
     }
 
     func onHelperUpdated(_ helper: Helper) -> Void {
         let helperPointer = helper.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_onHelperUpdated(jsObjectValue, helperPointer)
+        bjs_MyViewControllerDelegate_onHelperUpdated(jsObjectValue, helperPointer)
     }
 
     func createHelper() -> Helper {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_createHelper(jsObjectValue)
+        let ret = bjs_MyViewControllerDelegate_createHelper(jsObjectValue)
         return Helper.bridgeJSLiftReturn(ret)
     }
 
     func onOptionalHelperUpdated(_ helper: Optional<Helper>) -> Void {
         let (helperIsSome, helperPointer) = helper.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_onOptionalHelperUpdated(jsObjectValue, helperIsSome, helperPointer)
+        bjs_MyViewControllerDelegate_onOptionalHelperUpdated(jsObjectValue, helperIsSome, helperPointer)
     }
 
     func createOptionalHelper() -> Optional<Helper> {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_createOptionalHelper(jsObjectValue)
+        let ret = bjs_MyViewControllerDelegate_createOptionalHelper(jsObjectValue)
         return Optional<Helper>.bridgeJSLiftReturn(ret)
     }
 
     func createEnum() -> ExampleEnum {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_createEnum(jsObjectValue)
+        let ret = bjs_MyViewControllerDelegate_createEnum(jsObjectValue)
         return ExampleEnum.bridgeJSLiftReturn(ret)
     }
 
     func handleResult(_ result: Result) -> Void {
         let resultCaseId = result.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_handleResult(jsObjectValue, resultCaseId)
+        bjs_MyViewControllerDelegate_handleResult(jsObjectValue, resultCaseId)
     }
 
     func getResult() -> Result {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_getResult(jsObjectValue)
+        let ret = bjs_MyViewControllerDelegate_getResult(jsObjectValue)
         return Result.bridgeJSLiftReturn(ret)
     }
 
@@ -217,6 +215,10 @@ struct AnyMyViewControllerDelegate: MyViewControllerDelegate, _BridgedSwiftProto
             bjs_MyViewControllerDelegate_priorityOptional_set(jsObjectValue, newValueIsSome, newValueValue)
         }
     }
+}
+
+struct AnyMyViewControllerDelegate: MyViewControllerDelegate, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyMyViewControllerDelegate(jsObject: JSObject(id: UInt32(bitPattern: value)))
@@ -225,146 +227,146 @@ struct AnyMyViewControllerDelegate: MyViewControllerDelegate, _BridgedSwiftProto
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_onSomethingHappened")
-fileprivate func _extern_onSomethingHappened_extern(_ jsObject: Int32) -> Void
+fileprivate func bjs_MyViewControllerDelegate_onSomethingHappened_extern(_ jsObject: Int32) -> Void
 #else
-fileprivate func _extern_onSomethingHappened_extern(_ jsObject: Int32) -> Void {
+fileprivate func bjs_MyViewControllerDelegate_onSomethingHappened_extern(_ jsObject: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onSomethingHappened(_ jsObject: Int32) -> Void {
-    return _extern_onSomethingHappened_extern(jsObject)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_onSomethingHappened(_ jsObject: Int32) -> Void {
+    return bjs_MyViewControllerDelegate_onSomethingHappened_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_onValueChanged")
-fileprivate func _extern_onValueChanged_extern(_ jsObject: Int32, _ valueBytes: Int32, _ valueLength: Int32) -> Void
+fileprivate func bjs_MyViewControllerDelegate_onValueChanged_extern(_ jsObject: Int32, _ valueBytes: Int32, _ valueLength: Int32) -> Void
 #else
-fileprivate func _extern_onValueChanged_extern(_ jsObject: Int32, _ valueBytes: Int32, _ valueLength: Int32) -> Void {
+fileprivate func bjs_MyViewControllerDelegate_onValueChanged_extern(_ jsObject: Int32, _ valueBytes: Int32, _ valueLength: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onValueChanged(_ jsObject: Int32, _ valueBytes: Int32, _ valueLength: Int32) -> Void {
-    return _extern_onValueChanged_extern(jsObject, valueBytes, valueLength)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_onValueChanged(_ jsObject: Int32, _ valueBytes: Int32, _ valueLength: Int32) -> Void {
+    return bjs_MyViewControllerDelegate_onValueChanged_extern(jsObject, valueBytes, valueLength)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_onCountUpdated")
-fileprivate func _extern_onCountUpdated_extern(_ jsObject: Int32, _ count: Int32) -> Int32
+fileprivate func bjs_MyViewControllerDelegate_onCountUpdated_extern(_ jsObject: Int32, _ count: Int32) -> Int32
 #else
-fileprivate func _extern_onCountUpdated_extern(_ jsObject: Int32, _ count: Int32) -> Int32 {
+fileprivate func bjs_MyViewControllerDelegate_onCountUpdated_extern(_ jsObject: Int32, _ count: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onCountUpdated(_ jsObject: Int32, _ count: Int32) -> Int32 {
-    return _extern_onCountUpdated_extern(jsObject, count)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_onCountUpdated(_ jsObject: Int32, _ count: Int32) -> Int32 {
+    return bjs_MyViewControllerDelegate_onCountUpdated_extern(jsObject, count)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_onLabelUpdated")
-fileprivate func _extern_onLabelUpdated_extern(_ jsObject: Int32, _ prefixBytes: Int32, _ prefixLength: Int32, _ suffixBytes: Int32, _ suffixLength: Int32) -> Void
+fileprivate func bjs_MyViewControllerDelegate_onLabelUpdated_extern(_ jsObject: Int32, _ prefixBytes: Int32, _ prefixLength: Int32, _ suffixBytes: Int32, _ suffixLength: Int32) -> Void
 #else
-fileprivate func _extern_onLabelUpdated_extern(_ jsObject: Int32, _ prefixBytes: Int32, _ prefixLength: Int32, _ suffixBytes: Int32, _ suffixLength: Int32) -> Void {
+fileprivate func bjs_MyViewControllerDelegate_onLabelUpdated_extern(_ jsObject: Int32, _ prefixBytes: Int32, _ prefixLength: Int32, _ suffixBytes: Int32, _ suffixLength: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onLabelUpdated(_ jsObject: Int32, _ prefixBytes: Int32, _ prefixLength: Int32, _ suffixBytes: Int32, _ suffixLength: Int32) -> Void {
-    return _extern_onLabelUpdated_extern(jsObject, prefixBytes, prefixLength, suffixBytes, suffixLength)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_onLabelUpdated(_ jsObject: Int32, _ prefixBytes: Int32, _ prefixLength: Int32, _ suffixBytes: Int32, _ suffixLength: Int32) -> Void {
+    return bjs_MyViewControllerDelegate_onLabelUpdated_extern(jsObject, prefixBytes, prefixLength, suffixBytes, suffixLength)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_isCountEven")
-fileprivate func _extern_isCountEven_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_MyViewControllerDelegate_isCountEven_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_isCountEven_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_MyViewControllerDelegate_isCountEven_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_isCountEven(_ jsObject: Int32) -> Int32 {
-    return _extern_isCountEven_extern(jsObject)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_isCountEven(_ jsObject: Int32) -> Int32 {
+    return bjs_MyViewControllerDelegate_isCountEven_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_onHelperUpdated")
-fileprivate func _extern_onHelperUpdated_extern(_ jsObject: Int32, _ helper: UnsafeMutableRawPointer) -> Void
+fileprivate func bjs_MyViewControllerDelegate_onHelperUpdated_extern(_ jsObject: Int32, _ helper: UnsafeMutableRawPointer) -> Void
 #else
-fileprivate func _extern_onHelperUpdated_extern(_ jsObject: Int32, _ helper: UnsafeMutableRawPointer) -> Void {
+fileprivate func bjs_MyViewControllerDelegate_onHelperUpdated_extern(_ jsObject: Int32, _ helper: UnsafeMutableRawPointer) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onHelperUpdated(_ jsObject: Int32, _ helper: UnsafeMutableRawPointer) -> Void {
-    return _extern_onHelperUpdated_extern(jsObject, helper)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_onHelperUpdated(_ jsObject: Int32, _ helper: UnsafeMutableRawPointer) -> Void {
+    return bjs_MyViewControllerDelegate_onHelperUpdated_extern(jsObject, helper)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_createHelper")
-fileprivate func _extern_createHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
+fileprivate func bjs_MyViewControllerDelegate_createHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
 #else
-fileprivate func _extern_createHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+fileprivate func bjs_MyViewControllerDelegate_createHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_createHelper(_ jsObject: Int32) -> UnsafeMutableRawPointer {
-    return _extern_createHelper_extern(jsObject)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_createHelper(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+    return bjs_MyViewControllerDelegate_createHelper_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_onOptionalHelperUpdated")
-fileprivate func _extern_onOptionalHelperUpdated_extern(_ jsObject: Int32, _ helperIsSome: Int32, _ helperPointer: UnsafeMutableRawPointer) -> Void
+fileprivate func bjs_MyViewControllerDelegate_onOptionalHelperUpdated_extern(_ jsObject: Int32, _ helperIsSome: Int32, _ helperPointer: UnsafeMutableRawPointer) -> Void
 #else
-fileprivate func _extern_onOptionalHelperUpdated_extern(_ jsObject: Int32, _ helperIsSome: Int32, _ helperPointer: UnsafeMutableRawPointer) -> Void {
+fileprivate func bjs_MyViewControllerDelegate_onOptionalHelperUpdated_extern(_ jsObject: Int32, _ helperIsSome: Int32, _ helperPointer: UnsafeMutableRawPointer) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_onOptionalHelperUpdated(_ jsObject: Int32, _ helperIsSome: Int32, _ helperPointer: UnsafeMutableRawPointer) -> Void {
-    return _extern_onOptionalHelperUpdated_extern(jsObject, helperIsSome, helperPointer)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_onOptionalHelperUpdated(_ jsObject: Int32, _ helperIsSome: Int32, _ helperPointer: UnsafeMutableRawPointer) -> Void {
+    return bjs_MyViewControllerDelegate_onOptionalHelperUpdated_extern(jsObject, helperIsSome, helperPointer)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_createOptionalHelper")
-fileprivate func _extern_createOptionalHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
+fileprivate func bjs_MyViewControllerDelegate_createOptionalHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
 #else
-fileprivate func _extern_createOptionalHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+fileprivate func bjs_MyViewControllerDelegate_createOptionalHelper_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_createOptionalHelper(_ jsObject: Int32) -> UnsafeMutableRawPointer {
-    return _extern_createOptionalHelper_extern(jsObject)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_createOptionalHelper(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+    return bjs_MyViewControllerDelegate_createOptionalHelper_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_createEnum")
-fileprivate func _extern_createEnum_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_MyViewControllerDelegate_createEnum_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_createEnum_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_MyViewControllerDelegate_createEnum_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_createEnum(_ jsObject: Int32) -> Int32 {
-    return _extern_createEnum_extern(jsObject)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_createEnum(_ jsObject: Int32) -> Int32 {
+    return bjs_MyViewControllerDelegate_createEnum_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_handleResult")
-fileprivate func _extern_handleResult_extern(_ jsObject: Int32, _ result: Int32) -> Void
+fileprivate func bjs_MyViewControllerDelegate_handleResult_extern(_ jsObject: Int32, _ result: Int32) -> Void
 #else
-fileprivate func _extern_handleResult_extern(_ jsObject: Int32, _ result: Int32) -> Void {
+fileprivate func bjs_MyViewControllerDelegate_handleResult_extern(_ jsObject: Int32, _ result: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_handleResult(_ jsObject: Int32, _ result: Int32) -> Void {
-    return _extern_handleResult_extern(jsObject, result)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_handleResult(_ jsObject: Int32, _ result: Int32) -> Void {
+    return bjs_MyViewControllerDelegate_handleResult_extern(jsObject, result)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_MyViewControllerDelegate_getResult")
-fileprivate func _extern_getResult_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_MyViewControllerDelegate_getResult_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_getResult_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_MyViewControllerDelegate_getResult_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_getResult(_ jsObject: Int32) -> Int32 {
-    return _extern_getResult_extern(jsObject)
+@inline(never) fileprivate func bjs_MyViewControllerDelegate_getResult(_ jsObject: Int32) -> Int32 {
+    return bjs_MyViewControllerDelegate_getResult_extern(jsObject)
 }
 
 #if arch(wasm32)
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.swift
index f02cd4019..bc63b1f65 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.swift
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.swift
@@ -257,14 +257,16 @@ public func _invoke_swift_closure_TestModule_10TestModuley_10RenderableP(_ boxPt
     #endif
 }
 
-struct AnyRenderable: Renderable, _BridgedSwiftProtocolWrapper {
-    let jsObject: JSObject
-
+extension Renderable where Self: _BridgedSwiftProtocolWrapper {
     func render() -> String {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_render(jsObjectValue)
+        let ret = bjs_Renderable_render(jsObjectValue)
         return String.bridgeJSLiftReturn(ret)
     }
+}
+
+struct AnyRenderable: Renderable, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyRenderable(jsObject: JSObject(id: UInt32(bitPattern: value)))
@@ -273,14 +275,14 @@ struct AnyRenderable: Renderable, _BridgedSwiftProtocolWrapper {
 
 #if arch(wasm32)
 @_extern(wasm, module: "TestModule", name: "bjs_Renderable_render")
-fileprivate func _extern_render_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_Renderable_render_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_render_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_Renderable_render_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_render(_ jsObject: Int32) -> Int32 {
-    return _extern_render_extern(jsObject)
+@inline(never) fileprivate func bjs_Renderable_render(_ jsObject: Int32) -> Int32 {
+    return bjs_Renderable_render_extern(jsObject)
 }
 
 @_expose(wasm, "bjs_processRenderable")
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.d.ts b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.d.ts
index 026713ce3..8ff2aad15 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.d.ts
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.d.ts
@@ -4,6 +4,17 @@
 // To update this file, just rebuild your project or run
 // `swift package bridge-js`.
 
+export interface GenericReadable {
+    read(): number;
+}
+
+export interface GenericWritable {
+    value: number;
+}
+
+export interface GenericNode extends GenericReadable, GenericWritable {
+}
+
 export const GenericColorValues: {
     readonly Red: 0;
     readonly Green: 1;
@@ -53,6 +64,9 @@ export interface GenericConsumer {
     accept<T>(value: T): void;
     identity<T>(value: T): T;
 }
+export interface ConstrainedConsumer {
+    accept<T extends GenericNode>(value: T): T;
+}
 export type Exports = {
     GenericColor: GenericColorObject
     GenericMode: GenericModeObject
@@ -70,6 +84,8 @@ export type Imports = {
     importGenericOptional<T>(value: T | null): T | null;
     importGenericDictionary<T>(values: Record<string, T>): Record<string, T>;
     importGenericAfterOptionalArray<T>(values: number[] | null, value: T): T;
+    constrainedRoundTrip<T extends GenericNode>(value: T): T;
+    constrainedComposition<T extends GenericWritable>(value: T): T;
     GenericPairFactory: {
         new<T, U>(tag: string, first: T, second: U): GenericPairFactory;
     }
@@ -77,6 +93,10 @@ export type Imports = {
         new<T>(value: T): GenericConsumer;
         box<T>(value: T): T;
     }
+    ConstrainedConsumer: {
+        new<T extends GenericNode>(value: T): ConstrainedConsumer;
+        identity<T extends GenericNode>(value: T): T;
+    }
 }
 export function createInstantiator(options: {
     imports: Imports;
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.js b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.js
index d8b1fdf15..529f1772e 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.js
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/GenericImports.js
@@ -428,6 +428,30 @@ export async function createInstantiator(options, swift) {
             return enumValue;
         },
     };
+    const __bjs_codec_M10TestModuleT15GenericReadable = {
+        lower: (v) => {
+            const objId = swift.memory.retain(v);
+            i32Stack.push(objId);
+        },
+        lift: () => {
+            const objId = i32Stack.pop();
+            const obj = swift.memory.getObject(objId);
+            swift.memory.release(objId);
+            return obj;
+        },
+    };
+    const __bjs_codec_M10TestModuleT11GenericNode = {
+        lower: (v) => {
+            const objId = swift.memory.retain(v);
+            i32Stack.push(objId);
+        },
+        lift: () => {
+            const objId = i32Stack.pop();
+            const obj = swift.memory.getObject(objId);
+            swift.memory.release(objId);
+            return obj;
+        },
+    };
 
     const __bjs_createStructHelpers_M10TestModuleT12GenericPoint = () => ({
         lower: (value) => {
@@ -586,6 +610,8 @@ export async function createInstantiator(options, swift) {
                     __bjs_codec_M10TestModuleT12GenericColor,
                     __bjs_stringCodec,
                     __bjs_codec_M10TestModuleT13GenericTagged,
+                    __bjs_codec_M10TestModuleT15GenericReadable,
+                    __bjs_codec_M10TestModuleT11GenericNode,
                 ];
                 const typeIds = new Int32Array(memory.buffer, base >>> 0, count >>> 0);
                 for (let i = 0; i < count; i++) {
@@ -783,6 +809,26 @@ export async function createInstantiator(options, swift) {
                     setException(error);
                 }
             }
+            TestModule["bjs_constrainedRoundTrip"] = function bjs_constrainedRoundTrip(tTypeId) {
+                try {
+                    const codecT = __bjs_codecForTypeId(tTypeId);
+                    const value = codecT.lift();
+                    let ret = imports.constrainedRoundTrip(value);
+                    codecT.lower(ret);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            TestModule["bjs_constrainedComposition"] = function bjs_constrainedComposition(tTypeId) {
+                try {
+                    const codecT = __bjs_codecForTypeId(tTypeId);
+                    const value = codecT.lift();
+                    let ret = imports.constrainedComposition(value);
+                    codecT.lower(ret);
+                } catch (error) {
+                    setException(error);
+                }
+            }
             TestModule["bjs_GenericPairFactory_init"] = function bjs_GenericPairFactory_init(tagBytes, tagCount, tTypeId, uTypeId) {
                 try {
                     const codecT = __bjs_codecForTypeId(tTypeId);
@@ -835,6 +881,61 @@ export async function createInstantiator(options, swift) {
                     setException(error);
                 }
             }
+            TestModule["bjs_ConstrainedConsumer_init"] = function bjs_ConstrainedConsumer_init(tTypeId) {
+                try {
+                    const codecT = __bjs_codecForTypeId(tTypeId);
+                    const value = codecT.lift();
+                    return swift.memory.retain(new imports.ConstrainedConsumer(value));
+                } catch (error) {
+                    setException(error);
+                    return 0
+                }
+            }
+            TestModule["bjs_ConstrainedConsumer_identity_static"] = function bjs_ConstrainedConsumer_identity_static(tTypeId) {
+                try {
+                    const codecT = __bjs_codecForTypeId(tTypeId);
+                    const value = codecT.lift();
+                    let ret = imports.ConstrainedConsumer.identity(value);
+                    codecT.lower(ret);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            TestModule["bjs_ConstrainedConsumer_accept"] = function bjs_ConstrainedConsumer_accept(self, tTypeId) {
+                try {
+                    const codecT = __bjs_codecForTypeId(tTypeId);
+                    const value = codecT.lift();
+                    let ret = swift.memory.getObject(self).accept(value);
+                    codecT.lower(ret);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            TestModule["bjs_GenericReadable_read"] = function bjs_GenericReadable_read(self) {
+                try {
+                    let ret = swift.memory.getObject(self).read();
+                    return ret;
+                } catch (error) {
+                    setException(error);
+                    return 0
+                }
+            }
+            TestModule["bjs_GenericWritable_value_get"] = function bjs_GenericWritable_value_get(self) {
+                try {
+                    let ret = swift.memory.getObject(self).value;
+                    return ret;
+                } catch (error) {
+                    setException(error);
+                    return 0
+                }
+            }
+            TestModule["bjs_GenericWritable_value_set"] = function bjs_GenericWritable_value_set(self, value) {
+                try {
+                    swift.memory.getObject(self).value = value;
+                } catch (error) {
+                    setException(error);
+                }
+            }
         },
         setInstance: (i) => {
             instance = i;
diff --git a/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Exporting-Swift/Exporting-Swift-Protocols.md b/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Exporting-Swift/Exporting-Swift-Protocols.md
index d62d71051..4c91ba749 100644
--- a/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Exporting-Swift/Exporting-Swift-Protocols.md
+++ b/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Exporting-Swift/Exporting-Swift-Protocols.md
@@ -15,6 +15,8 @@ When you mark a protocol with `@JS`, BridgeJS generates:
 
 Use `@JS("PublicName")` on a protocol to rename its TypeScript interface and generated type references. Swift still uses the original protocol name for conformances and signatures. JavaScript objects still satisfy the interface structurally; renaming does not create a protocol constructor or change how callbacks and protocol values cross the boundary. Unlike `@JS(as: Other.self)`, it does not change the representation, and combining the two options is not supported.
 
+An `@JS` protocol can refine other `@JS` protocols declared in the same module. Its generated TypeScript interface and Swift wrapper expose inherited methods and properties. Cross-module protocol refinement is not supported.
+
 ## Example: Counter Protocol
 
 Mark a Swift protocol with `@JS` to expose it:
@@ -220,8 +222,10 @@ struct AnyCounter: Counter, _BridgedSwiftProtocolWrapper {
 | Optional properties | ✅ |
 | Optional protocol methods | ❌ |
 | Associated types | ❌ |
-| Protocol inheritance | ❌ |
-| Protocol composition: `Protocol1 & Protocol2` | ❌ |
-| Generics | ❌ |
+| Same-module `@JS` protocol inheritance | ✅ |
+| Cross-module protocol inheritance | ❌ |
+| Existential protocol composition: `any Protocol1 & Protocol2` | ❌ |
+| Generic requirements | ❌ |
+| Protocol-valued properties, parameters, or results in requirements | ❌ |
 
-> Note: Protocol type support matches that of regular `@JS func` and `@JS class` exports. See <doc:Exporting-Swift-Function>, <doc:Exporting-Swift-Optional>, and <doc:Exporting-Swift-Enum> for more information.
+> Note: For supported requirement types, see <doc:Exporting-Swift-Function>, <doc:Exporting-Swift-Optional>, and <doc:Exporting-Swift-Enum>.
diff --git a/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Importing-JavaScript/Importing-JS-Function.md b/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Importing-JavaScript/Importing-JS-Function.md
index ebc9ac857..02f0a349d 100644
--- a/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Importing-JavaScript/Importing-JS-Function.md
+++ b/Sources/JavaScriptKit/Documentation.docc/Articles/BridgeJS/Importing-JavaScript/Importing-JS-Function.md
@@ -89,6 +89,17 @@ let user: User = try parse(jsonString)   // T inferred from the call site
 
 `T` can be any supported primitive, `String`, `JSValue`, or a `@JS` struct, `@JS` enum, or `final @JS class` (see <doc:Supported-Types>), used bare or wrapped as `[T]`, `T?`, or `[String: T]`. A function may declare multiple type parameters, and a return-only generic (`func make<T>() -> T`) works too. Generic initializers, methods, and static methods on `@JSClass` types are supported the same way. `async` generic functions and `where` clauses are not supported.
 
+Generic imports can also constrain `T` to `@JS` protocols, as in `T: BridgedSwiftGenericBridgeable & P & Q`. If `P` inherits `BridgedSwiftGenericBridgeable`, use `T: P`:
+
+```swift
+import JavaScriptKit
+
+@JS protocol Named: BridgedSwiftGenericBridgeable { var name: String { get } }
+@JSFunction func display<T: Named>(_ value: T) throws(JSException)
+```
+
+Constraints may use `@JS` protocols from dependency modules, including qualified names such as `T: BridgedSwiftGenericBridgeable & Models.Named`. Concrete conformers must expose the required members to JavaScript too, including marking methods with `@JS`. This does not enable existential compositions such as `any P & Q`; the generic-import limitations above still apply.
+
 ## Supported features
 
 | Feature | Status |
@@ -96,4 +107,5 @@ let user: User = try parse(jsonString)   // T inferred from the call site
 | Primitive parameter/result types (e.g. `Double`, `Bool`) | ✅ |
 | `String` parameter/result type | ✅ |
 | Generic parameter/result types (constrained to `BridgedSwiftGenericBridgeable`) | ✅ |
+| `@JS` protocol constraints on generic imports | ✅ |
 | Async function | ❌ |
diff --git a/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift b/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift
index 4496316e7..acb3e23f1 100644
--- a/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift
+++ b/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift
@@ -4247,9 +4247,7 @@ public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestsy_y
     #endif
 }
 
-struct AnyArrayElementProtocol: ArrayElementProtocol, _BridgedSwiftProtocolWrapper {
-    let jsObject: JSObject
-
+extension ArrayElementProtocol where Self: _BridgedSwiftProtocolWrapper {
     var value: Int {
         get {
             let jsObjectValue = jsObject.bridgeJSLowerParameter()
@@ -4262,6 +4260,10 @@ struct AnyArrayElementProtocol: ArrayElementProtocol, _BridgedSwiftProtocolWrapp
             bjs_ArrayElementProtocol_value_set(jsObjectValue, newValueValue)
         }
     }
+}
+
+struct AnyArrayElementProtocol: ArrayElementProtocol, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyArrayElementProtocol(jsObject: JSObject(id: UInt32(bitPattern: value)))
@@ -4292,18 +4294,16 @@ fileprivate func bjs_ArrayElementProtocol_value_set_extern(_ jsObject: Int32, _
     return bjs_ArrayElementProtocol_value_set_extern(jsObject, newValue)
 }
 
-struct AnyDataProcessor: DataProcessor, _BridgedSwiftProtocolWrapper {
-    let jsObject: JSObject
-
+extension DataProcessor where Self: _BridgedSwiftProtocolWrapper {
     func increment(by amount: Int) -> Void {
         let amountValue = amount.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_increment(jsObjectValue, amountValue)
+        bjs_DataProcessor_increment(jsObjectValue, amountValue)
     }
 
     func getValue() -> Int {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_getValue(jsObjectValue)
+        let ret = bjs_DataProcessor_getValue(jsObjectValue)
         return Int.bridgeJSLiftReturn(ret)
     }
 
@@ -4311,58 +4311,58 @@ struct AnyDataProcessor: DataProcessor, _BridgedSwiftProtocolWrapper {
         labelPrefix.bridgeJSWithLoweredParameter { (labelPrefixBytes, labelPrefixLength) in
             labelSuffix.bridgeJSWithLoweredParameter { (labelSuffixBytes, labelSuffixLength) in
                 let jsObjectValue = jsObject.bridgeJSLowerParameter()
-                _extern_setLabelElements(jsObjectValue, labelPrefixBytes, labelPrefixLength, labelSuffixBytes, labelSuffixLength)
+                bjs_DataProcessor_setLabelElements(jsObjectValue, labelPrefixBytes, labelPrefixLength, labelSuffixBytes, labelSuffixLength)
             }
         }
     }
 
     func getLabel() -> String {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_getLabel(jsObjectValue)
+        let ret = bjs_DataProcessor_getLabel(jsObjectValue)
         return String.bridgeJSLiftReturn(ret)
     }
 
     func isEven() -> Bool {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_isEven(jsObjectValue)
+        let ret = bjs_DataProcessor_isEven(jsObjectValue)
         return Bool.bridgeJSLiftReturn(ret)
     }
 
     func processGreeter(_ greeter: Greeter) -> String {
         let greeterPointer = greeter.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_processGreeter(jsObjectValue, greeterPointer)
+        let ret = bjs_DataProcessor_processGreeter(jsObjectValue, greeterPointer)
         return String.bridgeJSLiftReturn(ret)
     }
 
     func createGreeter() -> Greeter {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_createGreeter(jsObjectValue)
+        let ret = bjs_DataProcessor_createGreeter(jsObjectValue)
         return Greeter.bridgeJSLiftReturn(ret)
     }
 
     func processOptionalGreeter(_ greeter: Optional<Greeter>) -> String {
         let (greeterIsSome, greeterPointer) = greeter.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_processOptionalGreeter(jsObjectValue, greeterIsSome, greeterPointer)
+        let ret = bjs_DataProcessor_processOptionalGreeter(jsObjectValue, greeterIsSome, greeterPointer)
         return String.bridgeJSLiftReturn(ret)
     }
 
     func createOptionalGreeter() -> Optional<Greeter> {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_createOptionalGreeter(jsObjectValue)
+        let ret = bjs_DataProcessor_createOptionalGreeter(jsObjectValue)
         return Optional<Greeter>.bridgeJSLiftReturn(ret)
     }
 
     func handleAPIResult(_ result: Optional<APIResult>) -> Void {
         let (resultIsSome, resultCaseId) = result.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        _extern_handleAPIResult(jsObjectValue, resultIsSome, resultCaseId)
+        bjs_DataProcessor_handleAPIResult(jsObjectValue, resultIsSome, resultCaseId)
     }
 
     func getAPIResult() -> Optional<APIResult> {
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_getAPIResult(jsObjectValue)
+        let ret = bjs_DataProcessor_getAPIResult(jsObjectValue)
         return Optional<APIResult>.bridgeJSLiftReturn(ret)
     }
 
@@ -4492,6 +4492,10 @@ struct AnyDataProcessor: DataProcessor, _BridgedSwiftProtocolWrapper {
             bjs_DataProcessor_optionalHelper_set(jsObjectValue, newValueIsSome, newValuePointer)
         }
     }
+}
+
+struct AnyDataProcessor: DataProcessor, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyDataProcessor(jsObject: JSObject(id: UInt32(bitPattern: value)))
@@ -4500,134 +4504,134 @@ struct AnyDataProcessor: DataProcessor, _BridgedSwiftProtocolWrapper {
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_increment")
-fileprivate func _extern_increment_extern(_ jsObject: Int32, _ amount: Int32) -> Void
+fileprivate func bjs_DataProcessor_increment_extern(_ jsObject: Int32, _ amount: Int32) -> Void
 #else
-fileprivate func _extern_increment_extern(_ jsObject: Int32, _ amount: Int32) -> Void {
+fileprivate func bjs_DataProcessor_increment_extern(_ jsObject: Int32, _ amount: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_increment(_ jsObject: Int32, _ amount: Int32) -> Void {
-    return _extern_increment_extern(jsObject, amount)
+@inline(never) fileprivate func bjs_DataProcessor_increment(_ jsObject: Int32, _ amount: Int32) -> Void {
+    return bjs_DataProcessor_increment_extern(jsObject, amount)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_getValue")
-fileprivate func _extern_getValue_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_DataProcessor_getValue_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_getValue_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_DataProcessor_getValue_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_getValue(_ jsObject: Int32) -> Int32 {
-    return _extern_getValue_extern(jsObject)
+@inline(never) fileprivate func bjs_DataProcessor_getValue(_ jsObject: Int32) -> Int32 {
+    return bjs_DataProcessor_getValue_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_setLabelElements")
-fileprivate func _extern_setLabelElements_extern(_ jsObject: Int32, _ labelPrefixBytes: Int32, _ labelPrefixLength: Int32, _ labelSuffixBytes: Int32, _ labelSuffixLength: Int32) -> Void
+fileprivate func bjs_DataProcessor_setLabelElements_extern(_ jsObject: Int32, _ labelPrefixBytes: Int32, _ labelPrefixLength: Int32, _ labelSuffixBytes: Int32, _ labelSuffixLength: Int32) -> Void
 #else
-fileprivate func _extern_setLabelElements_extern(_ jsObject: Int32, _ labelPrefixBytes: Int32, _ labelPrefixLength: Int32, _ labelSuffixBytes: Int32, _ labelSuffixLength: Int32) -> Void {
+fileprivate func bjs_DataProcessor_setLabelElements_extern(_ jsObject: Int32, _ labelPrefixBytes: Int32, _ labelPrefixLength: Int32, _ labelSuffixBytes: Int32, _ labelSuffixLength: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_setLabelElements(_ jsObject: Int32, _ labelPrefixBytes: Int32, _ labelPrefixLength: Int32, _ labelSuffixBytes: Int32, _ labelSuffixLength: Int32) -> Void {
-    return _extern_setLabelElements_extern(jsObject, labelPrefixBytes, labelPrefixLength, labelSuffixBytes, labelSuffixLength)
+@inline(never) fileprivate func bjs_DataProcessor_setLabelElements(_ jsObject: Int32, _ labelPrefixBytes: Int32, _ labelPrefixLength: Int32, _ labelSuffixBytes: Int32, _ labelSuffixLength: Int32) -> Void {
+    return bjs_DataProcessor_setLabelElements_extern(jsObject, labelPrefixBytes, labelPrefixLength, labelSuffixBytes, labelSuffixLength)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_getLabel")
-fileprivate func _extern_getLabel_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_DataProcessor_getLabel_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_getLabel_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_DataProcessor_getLabel_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_getLabel(_ jsObject: Int32) -> Int32 {
-    return _extern_getLabel_extern(jsObject)
+@inline(never) fileprivate func bjs_DataProcessor_getLabel(_ jsObject: Int32) -> Int32 {
+    return bjs_DataProcessor_getLabel_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_isEven")
-fileprivate func _extern_isEven_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_DataProcessor_isEven_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_isEven_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_DataProcessor_isEven_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_isEven(_ jsObject: Int32) -> Int32 {
-    return _extern_isEven_extern(jsObject)
+@inline(never) fileprivate func bjs_DataProcessor_isEven(_ jsObject: Int32) -> Int32 {
+    return bjs_DataProcessor_isEven_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_processGreeter")
-fileprivate func _extern_processGreeter_extern(_ jsObject: Int32, _ greeter: UnsafeMutableRawPointer) -> Int32
+fileprivate func bjs_DataProcessor_processGreeter_extern(_ jsObject: Int32, _ greeter: UnsafeMutableRawPointer) -> Int32
 #else
-fileprivate func _extern_processGreeter_extern(_ jsObject: Int32, _ greeter: UnsafeMutableRawPointer) -> Int32 {
+fileprivate func bjs_DataProcessor_processGreeter_extern(_ jsObject: Int32, _ greeter: UnsafeMutableRawPointer) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_processGreeter(_ jsObject: Int32, _ greeter: UnsafeMutableRawPointer) -> Int32 {
-    return _extern_processGreeter_extern(jsObject, greeter)
+@inline(never) fileprivate func bjs_DataProcessor_processGreeter(_ jsObject: Int32, _ greeter: UnsafeMutableRawPointer) -> Int32 {
+    return bjs_DataProcessor_processGreeter_extern(jsObject, greeter)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_createGreeter")
-fileprivate func _extern_createGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
+fileprivate func bjs_DataProcessor_createGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
 #else
-fileprivate func _extern_createGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+fileprivate func bjs_DataProcessor_createGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_createGreeter(_ jsObject: Int32) -> UnsafeMutableRawPointer {
-    return _extern_createGreeter_extern(jsObject)
+@inline(never) fileprivate func bjs_DataProcessor_createGreeter(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+    return bjs_DataProcessor_createGreeter_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_processOptionalGreeter")
-fileprivate func _extern_processOptionalGreeter_extern(_ jsObject: Int32, _ greeterIsSome: Int32, _ greeterPointer: UnsafeMutableRawPointer) -> Int32
+fileprivate func bjs_DataProcessor_processOptionalGreeter_extern(_ jsObject: Int32, _ greeterIsSome: Int32, _ greeterPointer: UnsafeMutableRawPointer) -> Int32
 #else
-fileprivate func _extern_processOptionalGreeter_extern(_ jsObject: Int32, _ greeterIsSome: Int32, _ greeterPointer: UnsafeMutableRawPointer) -> Int32 {
+fileprivate func bjs_DataProcessor_processOptionalGreeter_extern(_ jsObject: Int32, _ greeterIsSome: Int32, _ greeterPointer: UnsafeMutableRawPointer) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_processOptionalGreeter(_ jsObject: Int32, _ greeterIsSome: Int32, _ greeterPointer: UnsafeMutableRawPointer) -> Int32 {
-    return _extern_processOptionalGreeter_extern(jsObject, greeterIsSome, greeterPointer)
+@inline(never) fileprivate func bjs_DataProcessor_processOptionalGreeter(_ jsObject: Int32, _ greeterIsSome: Int32, _ greeterPointer: UnsafeMutableRawPointer) -> Int32 {
+    return bjs_DataProcessor_processOptionalGreeter_extern(jsObject, greeterIsSome, greeterPointer)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_createOptionalGreeter")
-fileprivate func _extern_createOptionalGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
+fileprivate func bjs_DataProcessor_createOptionalGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer
 #else
-fileprivate func _extern_createOptionalGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+fileprivate func bjs_DataProcessor_createOptionalGreeter_extern(_ jsObject: Int32) -> UnsafeMutableRawPointer {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_createOptionalGreeter(_ jsObject: Int32) -> UnsafeMutableRawPointer {
-    return _extern_createOptionalGreeter_extern(jsObject)
+@inline(never) fileprivate func bjs_DataProcessor_createOptionalGreeter(_ jsObject: Int32) -> UnsafeMutableRawPointer {
+    return bjs_DataProcessor_createOptionalGreeter_extern(jsObject)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_handleAPIResult")
-fileprivate func _extern_handleAPIResult_extern(_ jsObject: Int32, _ resultIsSome: Int32, _ resultCaseId: Int32) -> Void
+fileprivate func bjs_DataProcessor_handleAPIResult_extern(_ jsObject: Int32, _ resultIsSome: Int32, _ resultCaseId: Int32) -> Void
 #else
-fileprivate func _extern_handleAPIResult_extern(_ jsObject: Int32, _ resultIsSome: Int32, _ resultCaseId: Int32) -> Void {
+fileprivate func bjs_DataProcessor_handleAPIResult_extern(_ jsObject: Int32, _ resultIsSome: Int32, _ resultCaseId: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_handleAPIResult(_ jsObject: Int32, _ resultIsSome: Int32, _ resultCaseId: Int32) -> Void {
-    return _extern_handleAPIResult_extern(jsObject, resultIsSome, resultCaseId)
+@inline(never) fileprivate func bjs_DataProcessor_handleAPIResult(_ jsObject: Int32, _ resultIsSome: Int32, _ resultCaseId: Int32) -> Void {
+    return bjs_DataProcessor_handleAPIResult_extern(jsObject, resultIsSome, resultCaseId)
 }
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_DataProcessor_getAPIResult")
-fileprivate func _extern_getAPIResult_extern(_ jsObject: Int32) -> Int32
+fileprivate func bjs_DataProcessor_getAPIResult_extern(_ jsObject: Int32) -> Int32
 #else
-fileprivate func _extern_getAPIResult_extern(_ jsObject: Int32) -> Int32 {
+fileprivate func bjs_DataProcessor_getAPIResult_extern(_ jsObject: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_getAPIResult(_ jsObject: Int32) -> Int32 {
-    return _extern_getAPIResult_extern(jsObject)
+@inline(never) fileprivate func bjs_DataProcessor_getAPIResult(_ jsObject: Int32) -> Int32 {
+    return bjs_DataProcessor_getAPIResult_extern(jsObject)
 }
 
 #if arch(wasm32)
@@ -4858,15 +4862,266 @@ fileprivate func bjs_DataProcessor_optionalHelper_set_extern(_ jsObject: Int32,
     return bjs_DataProcessor_optionalHelper_set_extern(jsObject, newValueIsSome, newValuePointer)
 }
 
-struct AnyJSNameTransformer: JSNameTransformer, _BridgedSwiftProtocolWrapper {
+extension GenericRTPosition where Self: _BridgedSwiftProtocolWrapper {
+    func sum() -> Int {
+        let jsObjectValue = jsObject.bridgeJSLowerParameter()
+        let ret = bjs_GenericRTPosition_sum(jsObjectValue)
+        return Int.bridgeJSLiftReturn(ret)
+    }
+
+    var x: Int {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_GenericRTPosition_x_get(jsObjectValue)
+            return Int.bridgeJSLiftReturn(ret)
+        }
+    }
+}
+
+struct AnyGenericRTPosition: GenericRTPosition, _BridgedSwiftProtocolWrapper {
     let jsObject: JSObject
 
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyGenericRTPosition(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_GenericRTPosition_sum")
+fileprivate func bjs_GenericRTPosition_sum_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_GenericRTPosition_sum_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_GenericRTPosition_sum(_ jsObject: Int32) -> Int32 {
+    return bjs_GenericRTPosition_sum_extern(jsObject)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_GenericRTPosition_x_get")
+fileprivate func bjs_GenericRTPosition_x_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_GenericRTPosition_x_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_GenericRTPosition_x_get(_ jsObject: Int32) -> Int32 {
+    return bjs_GenericRTPosition_x_get_extern(jsObject)
+}
+
+extension GenericRTNode where Self: _BridgedSwiftProtocolWrapper {
+    var y: Int {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_GenericRTNode_y_get(jsObjectValue)
+            return Int.bridgeJSLiftReturn(ret)
+        }
+    }
+}
+
+struct AnyGenericRTNode: GenericRTNode, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyGenericRTNode(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_GenericRTNode_y_get")
+fileprivate func bjs_GenericRTNode_y_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_GenericRTNode_y_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_GenericRTNode_y_get(_ jsObject: Int32) -> Int32 {
+    return bjs_GenericRTNode_y_get_extern(jsObject)
+}
+
+extension RefineIdentified where Self: _BridgedSwiftProtocolWrapper {
+    var id: String {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_RefineIdentified_id_get(jsObjectValue)
+            return String.bridgeJSLiftReturn(ret)
+        }
+    }
+
+    var score: Int {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_RefineIdentified_score_get(jsObjectValue)
+            return Int.bridgeJSLiftReturn(ret)
+        }
+        set {
+            let newValueValue = newValue.bridgeJSLowerParameter()
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            bjs_RefineIdentified_score_set(jsObjectValue, newValueValue)
+        }
+    }
+}
+
+struct AnyRefineIdentified: RefineIdentified, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyRefineIdentified(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineIdentified_id_get")
+fileprivate func bjs_RefineIdentified_id_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_RefineIdentified_id_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineIdentified_id_get(_ jsObject: Int32) -> Int32 {
+    return bjs_RefineIdentified_id_get_extern(jsObject)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineIdentified_score_get")
+fileprivate func bjs_RefineIdentified_score_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_RefineIdentified_score_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineIdentified_score_get(_ jsObject: Int32) -> Int32 {
+    return bjs_RefineIdentified_score_get_extern(jsObject)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineIdentified_score_set")
+fileprivate func bjs_RefineIdentified_score_set_extern(_ jsObject: Int32, _ newValue: Int32) -> Void
+#else
+fileprivate func bjs_RefineIdentified_score_set_extern(_ jsObject: Int32, _ newValue: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineIdentified_score_set(_ jsObject: Int32, _ newValue: Int32) -> Void {
+    return bjs_RefineIdentified_score_set_extern(jsObject, newValue)
+}
+
+extension RefineNamed where Self: _BridgedSwiftProtocolWrapper {
+    func label() -> String {
+        let jsObjectValue = jsObject.bridgeJSLowerParameter()
+        let ret = bjs_RefineNamed_label(jsObjectValue)
+        return String.bridgeJSLiftReturn(ret)
+    }
+
+    var name: String {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_RefineNamed_name_get(jsObjectValue)
+            return String.bridgeJSLiftReturn(ret)
+        }
+    }
+}
+
+struct AnyRefineNamed: RefineNamed, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyRefineNamed(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineNamed_label")
+fileprivate func bjs_RefineNamed_label_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_RefineNamed_label_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineNamed_label(_ jsObject: Int32) -> Int32 {
+    return bjs_RefineNamed_label_extern(jsObject)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineNamed_name_get")
+fileprivate func bjs_RefineNamed_name_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_RefineNamed_name_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineNamed_name_get(_ jsObject: Int32) -> Int32 {
+    return bjs_RefineNamed_name_get_extern(jsObject)
+}
+
+extension RefineEntity where Self: _BridgedSwiftProtocolWrapper {
+    func label() -> String {
+        let jsObjectValue = jsObject.bridgeJSLowerParameter()
+        let ret = bjs_RefineEntity_label(jsObjectValue)
+        return String.bridgeJSLiftReturn(ret)
+    }
+
+    var id: String {
+        get {
+            let jsObjectValue = jsObject.bridgeJSLowerParameter()
+            let ret = bjs_RefineEntity_id_get(jsObjectValue)
+            return String.bridgeJSLiftReturn(ret)
+        }
+    }
+}
+
+struct AnyRefineEntity: RefineEntity, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyRefineEntity(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineEntity_label")
+fileprivate func bjs_RefineEntity_label_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_RefineEntity_label_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineEntity_label(_ jsObject: Int32) -> Int32 {
+    return bjs_RefineEntity_label_extern(jsObject)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_RefineEntity_id_get")
+fileprivate func bjs_RefineEntity_id_get_extern(_ jsObject: Int32) -> Int32
+#else
+fileprivate func bjs_RefineEntity_id_get_extern(_ jsObject: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_RefineEntity_id_get(_ jsObject: Int32) -> Int32 {
+    return bjs_RefineEntity_id_get_extern(jsObject)
+}
+
+struct AnyRefineTagged: RefineTagged, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
+
+    static func bridgeJSLiftParameter(_ value: Int32) -> Self {
+        return AnyRefineTagged(jsObject: JSObject(id: UInt32(bitPattern: value)))
+    }
+}
+
+extension JSNameTransformer where Self: _BridgedSwiftProtocolWrapper {
     func apply(_ value: Int) -> Int {
         let valueValue = value.bridgeJSLowerParameter()
         let jsObjectValue = jsObject.bridgeJSLowerParameter()
-        let ret = _extern_apply(jsObjectValue, valueValue)
+        let ret = bjs_JSNameTransformer_apply(jsObjectValue, valueValue)
         return Int.bridgeJSLiftReturn(ret)
     }
+}
+
+struct AnyJSNameTransformer: JSNameTransformer, _BridgedSwiftProtocolWrapper {
+    let jsObject: JSObject
 
     static func bridgeJSLiftParameter(_ value: Int32) -> Self {
         return AnyJSNameTransformer(jsObject: JSObject(id: UInt32(bitPattern: value)))
@@ -4875,14 +5130,14 @@ struct AnyJSNameTransformer: JSNameTransformer, _BridgedSwiftProtocolWrapper {
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_JSNameTransformer_apply")
-fileprivate func _extern_apply_extern(_ jsObject: Int32, _ value: Int32) -> Int32
+fileprivate func bjs_JSNameTransformer_apply_extern(_ jsObject: Int32, _ value: Int32) -> Int32
 #else
-fileprivate func _extern_apply_extern(_ jsObject: Int32, _ value: Int32) -> Int32 {
+fileprivate func bjs_JSNameTransformer_apply_extern(_ jsObject: Int32, _ value: Int32) -> Int32 {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func _extern_apply(_ jsObject: Int32, _ value: Int32) -> Int32 {
-    return _extern_apply_extern(jsObject, value)
+@inline(never) fileprivate func bjs_JSNameTransformer_apply(_ jsObject: Int32, _ value: Int32) -> Int32 {
+    return bjs_JSNameTransformer_apply_extern(jsObject, value)
 }
 
 extension Severity: _BridgedSwiftCaseEnum {
@@ -7841,6 +8096,18 @@ fileprivate func _bjs_struct_lift_GenericRTPoint_extern() -> Int32 {
     return _bjs_struct_lift_GenericRTPoint_extern()
 }
 
+@_expose(wasm, "bjs_GenericRTPoint_sum")
+@_cdecl("bjs_GenericRTPoint_sum")
+public func _bjs_GenericRTPoint_sum() -> Int32 {
+    #if arch(wasm32)
+    let _self = GenericRTPoint.bridgeJSLiftParameter()
+    let ret = _self.sum()
+    return ret.bridgeJSLowerReturn()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
 extension GenericRTNamespace.Metadata: _BridgedSwiftStruct {
     @_spi(BridgeJS) @_transparent public static func bridgeJSStackPop() -> GenericRTNamespace.Metadata {
         let count = Int.bridgeJSStackPop()
@@ -11254,6 +11521,30 @@ public func _bjs_roundTripMessage(_ message: Int32) -> Void {
     #endif
 }
 
+@_expose(wasm, "bjs_describeRefinedEntity")
+@_cdecl("bjs_describeRefinedEntity")
+public func _bjs_describeRefinedEntity(_ entity: Int32) -> Void {
+    #if arch(wasm32)
+    let entity = AnyRefineEntity.bridgeJSLiftParameter(entity)
+    let ret = describeRefinedEntity(_: entity)
+    return ret.bridgeJSLowerReturn()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+@_expose(wasm, "bjs_describeTaggedEntity")
+@_cdecl("bjs_describeTaggedEntity")
+public func _bjs_describeTaggedEntity(_ entity: Int32) -> Void {
+    #if arch(wasm32)
+    let entity = AnyRefineTagged.bridgeJSLiftParameter(entity)
+    let ret = describeTaggedEntity(_: entity)
+    return ret.bridgeJSLowerReturn()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
 @_expose(wasm, "bjs_renamedEcho")
 @_cdecl("bjs_renamedEcho")
 public func _bjs_renamedEcho(_ valueBytes: Int32, _ valueLength: Int32) -> Void {
@@ -15910,6 +16201,14 @@ extension APIOptionalResult: BridgedSwiftGenericBridgeable {
     @_spi(BridgeJS) public static let bridgeJSTypeHandle = APIOptionalResult.bridgeJSMakeTypeHandle()
 }
 
+extension AnyGenericRTPosition: BridgedSwiftGenericBridgeable {
+    @_spi(BridgeJS) public static let bridgeJSTypeHandle = AnyGenericRTPosition.bridgeJSMakeTypeHandle()
+}
+
+extension AnyGenericRTNode: BridgedSwiftGenericBridgeable {
+    @_spi(BridgeJS) public static let bridgeJSTypeHandle = AnyGenericRTNode.bridgeJSMakeTypeHandle()
+}
+
 @JSFunction func Promise_reject(_ promise: JSObject, _ value: JSValue) throws(JSException)
 
 #if arch(wasm32)
@@ -19464,6 +19763,47 @@ func _$jsGenericThrowOrRoundTrip<T: BridgedSwiftGenericBridgeable>(_ shouldThrow
     return T.bridgeJSStackPop()
 }
 
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_jsGenericNodeRoundTrip")
+fileprivate func bjs_jsGenericNodeRoundTrip_extern(_ _generic0TypeId: Int32) -> Void
+#else
+fileprivate func bjs_jsGenericNodeRoundTrip_extern(_ _generic0TypeId: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_jsGenericNodeRoundTrip(_ _generic0TypeId: Int32) -> Void {
+    return bjs_jsGenericNodeRoundTrip_extern(_generic0TypeId)
+}
+
+func _$jsGenericNodeRoundTrip<T: BridgedSwiftGenericBridgeable & GenericRTNode>(_ value: T) throws(JSException) -> T {
+    value.bridgeJSStackPush()
+    bjs_jsGenericNodeRoundTrip(T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return T.bridgeJSStackPop()
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_jsGenericMakeNode")
+fileprivate func bjs_jsGenericMakeNode_extern(_ _generic0TypeId: Int32) -> Void
+#else
+fileprivate func bjs_jsGenericMakeNode_extern(_ _generic0TypeId: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_jsGenericMakeNode(_ _generic0TypeId: Int32) -> Void {
+    return bjs_jsGenericMakeNode_extern(_generic0TypeId)
+}
+
+func _$jsGenericMakeNode<T: BridgedSwiftGenericBridgeable & GenericRTPosition & GenericRTNode>() throws(JSException) -> T {
+    bjs_jsGenericMakeNode(T.bridgeJSTypeID)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return T.bridgeJSStackPop()
+}
+
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_ImportGenericConsumer_init")
 fileprivate func bjs_ImportGenericConsumer_init_extern() -> Int32
@@ -21026,6 +21366,8 @@ public func _bjs_BridgeJSRuntimeTests_register_type_handles() {
         GenericRTOutcome.bridgeJSTypeID,
         OptionalAllTypesResult.bridgeJSTypeID,
         APIOptionalResult.bridgeJSTypeID,
+        AnyGenericRTPosition.bridgeJSTypeID,
+        AnyGenericRTNode.bridgeJSTypeID,
     ]
     typeIds.withUnsafeBufferPointer { buffer in
         _bjs_BridgeJSRuntimeTests_register_type_handles_extern(buffer.baseAddress, Int32(buffer.count))
diff --git a/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json b/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json
index 0084d9f6a..4749c6eb3 100644
--- a/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json
+++ b/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json
@@ -17671,6 +17671,56 @@
           }
         }
       },
+      {
+        "abiName" : "bjs_describeRefinedEntity",
+        "effects" : {
+          "isAsync" : false,
+          "isStatic" : false,
+          "isThrows" : false
+        },
+        "name" : "describeRefinedEntity",
+        "parameters" : [
+          {
+            "label" : "_",
+            "name" : "entity",
+            "type" : {
+              "swiftProtocol" : {
+                "_0" : "RefineEntity"
+              }
+            }
+          }
+        ],
+        "returnType" : {
+          "string" : {
+
+          }
+        }
+      },
+      {
+        "abiName" : "bjs_describeTaggedEntity",
+        "effects" : {
+          "isAsync" : false,
+          "isStatic" : false,
+          "isThrows" : false
+        },
+        "name" : "describeTaggedEntity",
+        "parameters" : [
+          {
+            "label" : "_",
+            "name" : "entity",
+            "type" : {
+              "swiftProtocol" : {
+                "_0" : "RefineTagged"
+              }
+            }
+          }
+        ],
+        "returnType" : {
+          "string" : {
+
+          }
+        }
+      },
       {
         "abiName" : "bjs_renamedEcho",
         "effects" : {
@@ -18984,6 +19034,181 @@
           }
         ]
       },
+      {
+        "isGenericBridgeable" : true,
+        "methods" : [
+          {
+            "abiName" : "bjs_GenericRTPosition_sum",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : false
+            },
+            "name" : "sum",
+            "parameters" : [
+
+            ],
+            "returnType" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
+        ],
+        "name" : "GenericRTPosition",
+        "properties" : [
+          {
+            "isReadonly" : true,
+            "name" : "x",
+            "type" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
+        ]
+      },
+      {
+        "inheritedJSProtocols" : [
+          "GenericRTPosition"
+        ],
+        "isGenericBridgeable" : true,
+        "methods" : [
+
+        ],
+        "name" : "GenericRTNode",
+        "properties" : [
+          {
+            "isReadonly" : true,
+            "name" : "y",
+            "type" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
+        ]
+      },
+      {
+        "methods" : [
+
+        ],
+        "name" : "RefineIdentified",
+        "properties" : [
+          {
+            "isReadonly" : true,
+            "name" : "id",
+            "type" : {
+              "string" : {
+
+              }
+            }
+          },
+          {
+            "isReadonly" : false,
+            "name" : "score",
+            "type" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
+        ]
+      },
+      {
+        "methods" : [
+          {
+            "abiName" : "bjs_RefineNamed_label",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : false
+            },
+            "name" : "label",
+            "parameters" : [
+
+            ],
+            "returnType" : {
+              "string" : {
+
+              }
+            }
+          }
+        ],
+        "name" : "RefineNamed",
+        "properties" : [
+          {
+            "isReadonly" : true,
+            "name" : "name",
+            "type" : {
+              "string" : {
+
+              }
+            }
+          }
+        ]
+      },
+      {
+        "inheritedJSProtocols" : [
+          "RefineIdentified",
+          "RefineNamed"
+        ],
+        "methods" : [
+          {
+            "abiName" : "bjs_RefineEntity_label",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : false
+            },
+            "name" : "label",
+            "parameters" : [
+
+            ],
+            "returnType" : {
+              "string" : {
+
+              }
+            }
+          }
+        ],
+        "name" : "RefineEntity",
+        "properties" : [
+          {
+            "isReadonly" : true,
+            "name" : "id",
+            "type" : {
+              "string" : {
+
+              }
+            }
+          }
+        ]
+      },
+      {
+        "inheritedJSProtocols" : [
+          "RefineEntity"
+        ],
+        "methods" : [
+
+        ],
+        "name" : "RefineTagged",
+        "properties" : [
+
+        ]
+      },
       {
         "jsName" : "CounterTransform",
         "methods" : [
@@ -19377,7 +19602,26 @@
       },
       {
         "methods" : [
+          {
+            "abiName" : "bjs_GenericRTPoint_sum",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : false
+            },
+            "name" : "sum",
+            "parameters" : [
 
+            ],
+            "returnType" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          }
         ],
         "name" : "GenericRTPoint",
         "properties" : [
@@ -25257,7 +25501,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericRoundTrip",
             "parameters" : [
@@ -25284,7 +25530,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericRoundTripClass",
             "parameters" : [
@@ -25311,7 +25559,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericParsePoint",
             "parameters" : [
@@ -25338,7 +25588,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsImportPickFirst",
             "parameters" : [
@@ -25373,7 +25625,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsImportMakeInt",
             "parameters" : [
@@ -25393,8 +25647,12 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T",
-              "U"
+              {
+                "name" : "T"
+              },
+              {
+                "name" : "U"
+              }
             ],
             "name" : "jsImportCombineSecond",
             "parameters" : [
@@ -25429,7 +25687,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericArrayRoundTrip",
             "parameters" : [
@@ -25464,7 +25724,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericOptionalRoundTrip",
             "parameters" : [
@@ -25501,7 +25763,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericDictRoundTrip",
             "parameters" : [
@@ -25536,7 +25800,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericAfterOptionalArray",
             "parameters" : [
@@ -25583,7 +25849,9 @@
               "isThrows" : true
             },
             "genericParameters" : [
-              "T"
+              {
+                "name" : "T"
+              }
             ],
             "name" : "jsGenericThrowOrRoundTrip",
             "parameters" : [
@@ -25609,6 +25877,64 @@
                 "_0" : "T"
               }
             }
+          },
+          {
+            "accessLevel" : "internal",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "genericParameters" : [
+              {
+                "constraints" : [
+                  "GenericRTNode"
+                ],
+                "name" : "T"
+              }
+            ],
+            "name" : "jsGenericNodeRoundTrip",
+            "parameters" : [
+              {
+                "name" : "value",
+                "type" : {
+                  "generic" : {
+                    "_0" : "T"
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "generic" : {
+                "_0" : "T"
+              }
+            }
+          },
+          {
+            "accessLevel" : "internal",
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "genericParameters" : [
+              {
+                "constraints" : [
+                  "GenericRTPosition",
+                  "GenericRTNode"
+                ],
+                "name" : "T"
+              }
+            ],
+            "name" : "jsGenericMakeNode",
+            "parameters" : [
+
+            ],
+            "returnType" : {
+              "generic" : {
+                "_0" : "T"
+              }
+            }
           }
         ],
         "types" : [
@@ -25632,7 +25958,9 @@
                   "isThrows" : true
                 },
                 "genericParameters" : [
-                  "T"
+                  {
+                    "name" : "T"
+                  }
                 ],
                 "name" : "identity",
                 "parameters" : [
@@ -25665,7 +25993,9 @@
                   "isThrows" : true
                 },
                 "genericParameters" : [
-                  "T"
+                  {
+                    "name" : "T"
+                  }
                 ],
                 "name" : "box",
                 "parameters" : [
@@ -25691,7 +26021,9 @@
             "constructor" : {
               "accessLevel" : "internal",
               "genericParameters" : [
-                "T"
+                {
+                  "name" : "T"
+                }
               ],
               "parameters" : [
                 {
@@ -25716,7 +26048,9 @@
                   "isThrows" : true
                 },
                 "genericParameters" : [
-                  "T"
+                  {
+                    "name" : "T"
+                  }
                 ],
                 "name" : "unwrap",
                 "parameters" : [
diff --git a/Tests/BridgeJSRuntimeTests/ImportGenericAPIs.swift b/Tests/BridgeJSRuntimeTests/ImportGenericAPIs.swift
index bfd63839f..c5484edc6 100644
--- a/Tests/BridgeJSRuntimeTests/ImportGenericAPIs.swift
+++ b/Tests/BridgeJSRuntimeTests/ImportGenericAPIs.swift
@@ -79,7 +79,34 @@ import JavaScriptKit
     @JSFunction func unwrap<T: BridgedSwiftGenericBridgeable>() throws(JSException) -> T
 }
 
+@JS protocol GenericRTPosition: BridgedSwiftGenericBridgeable {
+    var x: Int { get }
+    func sum() -> Int
+}
+
+@JS protocol GenericRTNode: GenericRTPosition {
+    var y: Int { get }
+}
+
+extension GenericRTPoint: GenericRTNode {
+    @JS func sum() -> Int { x + y }
+}
+
+@JSFunction func jsGenericNodeRoundTrip<T: GenericRTNode>(_ value: T) throws(JSException) -> T
+@JSFunction func jsGenericMakeNode<T: BridgedSwiftGenericBridgeable & GenericRTPosition & GenericRTNode>()
+    throws(JSException) -> T
+
 @Suite struct ImportGenericAPITests {
+    @Test func constrainedProtocolRoundTrip() throws {
+        let point = try jsGenericNodeRoundTrip(GenericRTPoint(x: 1, y: 2))
+        #expect(point.sum() == 3)
+        let node: AnyGenericRTNode = try jsGenericMakeNode()
+        #expect(node.x == 3)
+        #expect(node.y == 4)
+        #expect(node.sum() == 7)
+        #expect(try jsGenericNodeRoundTrip(node).jsObject == node.jsObject)
+    }
+
     @Test func genericRoundTripScalars() throws {
         #expect(try jsGenericRoundTrip(42) == 42)
         #expect(try jsGenericRoundTrip(-7) == -7)
@@ -278,3 +305,30 @@ import JavaScriptKit
         #expect(color == .green)
     }
 }
+
+@JS protocol RefineIdentified {
+    var id: String { get }
+    var score: Int { get set }
+}
+
+@JS protocol RefineNamed {
+    var name: String { get }
+    func label() -> String
+}
+
+@JS protocol RefineEntity: RefineIdentified, RefineNamed {
+    var id: String { get }
+    func label() -> String
+}
+
+@JS func describeRefinedEntity(_ entity: RefineEntity) -> String {
+    var identified: any RefineIdentified = entity
+    identified.score = entity.score + 1
+    return "\(entity.id):\(entity.name):\(entity.label()):\(identified.score)"
+}
+
+@JS protocol RefineTagged: RefineEntity {}
+
+@JS func describeTaggedEntity(_ entity: RefineTagged) -> String {
+    "\(entity.id)/\(entity.name)/\(entity.score)"
+}
diff --git a/Tests/prelude.mjs b/Tests/prelude.mjs
index 977a1f386..5287df791 100644
--- a/Tests/prelude.mjs
+++ b/Tests/prelude.mjs
@@ -178,6 +178,11 @@ export async function setupOptions(options, context) {
                 jsGenericOptionalRoundTrip: (v) => v,
                 jsGenericDictRoundTrip: (v) => v,
                 jsGenericAfterOptionalArray: (a, b) => `${JSON.stringify(a)}|${JSON.stringify(b)}`,
+                jsGenericNodeRoundTrip: (value) => {
+                    if (value.sum() !== value.x + value.y) throw new Error("Invalid protocol method result");
+                    return value;
+                },
+                jsGenericMakeNode: () => ({ x: 3, y: 4, sum() { return this.x + this.y; } }),
                 ImportGenericConsumer: class {
                     identity(value) {
                         return value;
@@ -296,6 +301,10 @@ function BridgeJSRuntimeTests_runJsWorks(instance, exports) {
     const optDict = { hello: "world" };
     assert.deepEqual(exports.roundTripOptionalDictionaryExport(optDict), optDict);
     assert.equal(exports.roundTripOptionalDictionaryExport(null), null);
+    const entity = { id: "e1", name: "Main", score: 10, label() { return "L" + this.score; } };
+    assert.equal(exports.describeRefinedEntity(entity), "e1:Main:L11:11");
+    assert.equal(entity.score, 11);
+    assert.equal(exports.describeTaggedEntity(entity), "e1/Main/11");
     const arrayStruct = { ints: [1, 2, 3], optStrings: ["a", "b"] };
     const arrayStructRoundTrip = exports.roundTripArrayMembers(arrayStruct);
     assert.deepEqual(arrayStructRoundTrip.ints, [1, 2, 3]);