diff --git a/Sources/SwiftGtkGenCore/CodeGen.swift b/Sources/SwiftGtkGenCore/CodeGen.swift
index 9d7ef56..1835ec3 100644
--- a/Sources/SwiftGtkGenCore/CodeGen.swift
+++ b/Sources/SwiftGtkGenCore/CodeGen.swift
@@ -196,6 +196,115 @@ public struct CodeGenerator {
         return files
     }
 
+    /// Generates Swift source for all modules in a monorepo.
+    ///
+    /// Iterates over all packages in the analysis, producing per-type Swift
+    /// files for each module. Each file includes the appropriate `import`
+    /// statements for the module's direct dependencies.
+    ///
+    /// - Parameter analysis: The resolved multi-package analysis.
+    /// - Returns: Module name → (filename → source code) nested dictionary.
+    /// - Throws: `CodeGenError` if generation fails.
+    public func generateMonorepo(analysis: MultiPackageAnalysis) throws -> [String: [String: String]] {
+        var allOutputs: [String: [String: String]] = [:]
+
+        for (moduleName, repo) in analysis.repositories {
+            guard let cfg = analysis.packageConfigs[moduleName] else { continue }
+            guard let ns = repo.namespaces.first(where: { $0.name == moduleName })
+                    ?? repo.namespaces.first else { continue }
+
+            let directImports = analysis.directDependencies[moduleName] ?? []
+            let nsToModule = buildNamespaceToModuleMap(from: analysis)
+            _ = nsToModule
+
+            let rootModuleName = moduleName
+
+            let analyzer = Analyzer(config: cfg)
+            let singleAnalysis = analyzer.analyze(repository: repo)
+
+            let classNames = Set(ns.classes.map(\.name))
+            let shouldGenerateAll = singleAnalysis.generatedTypes.isEmpty
+
+            var sourceFiles: [String: String] = [:]
+
+            let header = fileHeader(moduleName: rootModuleName, directImports: directImports)
+
+            for cls in ns.classes {
+                let fullName = "\(ns.name).\(cls.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(cls.name).swift"] = header + "\n" + generateClass(cls, namespace: ns.name, analysis: singleAnalysis, classTypeNames: classNames)
+            }
+            for enm in ns.enumerations {
+                let fullName = "\(ns.name).\(enm.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(enm.name).swift"] = header + "\n" + generateEnum(enm)
+            }
+            for bf in ns.bitfields {
+                let fullName = "\(ns.name).\(bf.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(bf.name).swift"] = header + "\n" + generateBitfield(bf)
+            }
+            for iface in ns.interfaces {
+                let fullName = "\(ns.name).\(iface.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(iface.name).swift"] = header + "\n" + generateInterface(iface)
+            }
+            for cb in ns.callbacks {
+                let fullName = "\(ns.name).\(cb.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(cb.name).swift"] = header + "\n" + generateCallback(cb)
+            }
+            for fn in ns.functions {
+                let fullName = "\(ns.name).\(fn.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(Self.pascalCaseName(fn.name)).swift"] = header + "\n" + generateGlobalFunction(fn, namespace: ns.name, classTypeNames: classNames)
+            }
+            for rec in ns.records {
+                let fullName = "\(ns.name).\(rec.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(rec.name).swift"] = header + "\n" + generateRecord(rec, namespace: ns.name, analysis: singleAnalysis, classTypeNames: classNames)
+            }
+            for cst in ns.constants {
+                let fullName = "\(ns.name).\(cst.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(cst.name).swift"] = header + "\n" + generateConstant(cst)
+            }
+            for alias in ns.aliases {
+                let fullName = "\(ns.name).\(alias.name)"
+                if !shouldGenerateAll && !singleAnalysis.generatedTypes.contains(fullName) { continue }
+                sourceFiles["\(alias.name).swift"] = header + "\n" + generateAlias(alias)
+            }
+
+            allOutputs[rootModuleName] = sourceFiles
+        }
+
+        return allOutputs
+    }
+
+    /// Generates the standard file header for monorepo source files.
+    private func fileHeader(moduleName: String, directImports: Set<String>) -> String {
+        var imports = "import C\(moduleName)\nimport Foundation\n"
+        for imp in directImports.sorted() {
+            imports += "import \(imp)\n"
+        }
+        return """
+        // Generated by SwiftGtkGen. DO NOT EDIT.
+
+        \(imports)
+        """
+    }
+
+    /// Builds a mapping from GIR namespace name to Swift module name.
+    private func buildNamespaceToModuleMap(from analysis: MultiPackageAnalysis) -> [String: String] {
+        var map: [String: String] = [:]
+        for (moduleName, repo) in analysis.repositories {
+            for ns in repo.namespaces {
+                map[ns.name] = moduleName
+            }
+        }
+        return map
+    }
+
     // MARK: - Class Generation
 
     /// Generates a Swift class declaration from a GIR class definition.
@@ -954,6 +1063,32 @@ public struct CodeGenerator {
         }
     }
 
+    /// Converts a GIR type to a Swift type string, qualifying cross-namespace
+    /// type references with their Swift module name prefix.
+    ///
+    /// Cross-namespace references (`.typeRef(name, namespace: "Gdk")`) produce
+    /// `Gdk.Rectangle` when the current module is not `Gdk`. Same-namespace
+    /// references produce the bare `name`.
+    ///
+    /// - Parameters:
+    ///   - type: The GIR type to map.
+    ///   - currentModule: The Swift module name currently being generated.
+    ///   - nsToModule: Map from GIR namespace name to Swift module name.
+    /// - Returns: A qualified Swift type name.
+    static func qualifiedTypeToSwift(_ type: GIRType, currentModule: String, nsToModule: [String: String]) -> String {
+        switch type {
+        case .typeRef(let name, let namespace):
+            if let ns = namespace, let module = nsToModule[ns], module != currentModule {
+                return "\(module).\(name)"
+            }
+            return name
+        case .array(let inner): return "[\(qualifiedTypeToSwift(inner, currentModule: currentModule, nsToModule: nsToModule))]"
+        case .cArray(let inner): return "UnsafeBufferPointer<\(qualifiedTypeToSwift(inner, currentModule: currentModule, nsToModule: nsToModule))>"
+        case .optional(let inner): return "\(qualifiedTypeToSwift(inner, currentModule: currentModule, nsToModule: nsToModule))?"
+        default: return Self.typeToSwift(type)
+        }
+    }
+
     /// Converts a snake_case GIR name to a camelCase Swift property name.
     ///
     /// Splits on underscores and lowercases the first part while capitalizing