diff --git a/Lara-JS/.gitignore b/Lara-JS/.gitignore
index e258f446e..91765175e 100644
--- a/Lara-JS/.gitignore
+++ b/Lara-JS/.gitignore
@@ -1,7 +1,5 @@
 ##### User-added #####
 woven_code/
-/api/
-/code/
 package-lock.json
 docs/
 java-binaries
diff --git a/Lara-JS/src-api/Graal.d.ts b/Lara-JS/api/Graal.d.ts
similarity index 100%
rename from Lara-JS/src-api/Graal.d.ts
rename to Lara-JS/api/Graal.d.ts
diff --git a/Lara-JS/src-api/LaraJoinPoint.ts b/Lara-JS/api/LaraJoinPoint.ts
similarity index 94%
rename from Lara-JS/src-api/LaraJoinPoint.ts
rename to Lara-JS/api/LaraJoinPoint.ts
index 0de111894..e1d7efd31 100644
--- a/Lara-JS/src-api/LaraJoinPoint.ts
+++ b/Lara-JS/api/LaraJoinPoint.ts
@@ -1,10 +1,10 @@
 //////////////////////////////////////////////////////
-// This file is generated by build-LaraJoinPoint.js //
+// This file is generated by build-LaraJoinPoint.ts //
 //////////////////////////////////////////////////////
 
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
-import JavaTypes from "./lara/util/JavaTypes.js";
+import JavaTypes from "./lara/util/JavaTypes.ts";
 
 /**
  * Type for type equality assertion. If T is equal to U, return Y, otherwise return N.
@@ -125,11 +125,17 @@ export class LaraJoinPoint {
   toString(): string { return wrapJoinPoint(this._javaObject.toString()); }
 }
 
-export enum InsertPosition {
-  before = "before",
-  after = "after",
-  replace = "replace",
-}
+/**
+ * This is supposed to be an enum, but Node.js v25 does bot support TS' enums, only erasable-syntax.
+ * Revert to an enum when Node.js supports it, or when we move to a different engine that supports it.
+ * This and the "type" declaration below.
+ */
+export const InsertPosition = {
+  before: "before",
+  after: "after",
+  replace: "replace",
+} as const;
+export type InsertPosition = typeof InsertPosition[keyof typeof InsertPosition];
 
 /**
  * Converts Java join point objects to TypeScript objects.
diff --git a/Lara-JS/src-api/LegacyIntegrationTests - API.test.ts b/Lara-JS/api/LegacyIntegrationTests - API.test.ts
similarity index 98%
rename from Lara-JS/src-api/LegacyIntegrationTests - API.test.ts
rename to Lara-JS/api/LegacyIntegrationTests - API.test.ts
index 1f38171b7..d51fe65b9 100644
--- a/Lara-JS/src-api/LegacyIntegrationTests - API.test.ts	
+++ b/Lara-JS/api/LegacyIntegrationTests - API.test.ts	
@@ -1,4 +1,4 @@
-import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.js";
+import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.ts";
 import path from "path";
 
 /* eslint-disable jest/expect-expect */
diff --git a/Lara-JS/src-api/LegacyIntegrationTests - JsEngine.test.ts b/Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts
similarity index 92%
rename from Lara-JS/src-api/LegacyIntegrationTests - JsEngine.test.ts
rename to Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts
index ce1d16702..eb1c1c565 100644
--- a/Lara-JS/src-api/LegacyIntegrationTests - JsEngine.test.ts	
+++ b/Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts	
@@ -1,4 +1,4 @@
-import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.js";
+import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.ts";
 import path from "path";
 
 /* eslint-disable jest/expect-expect */
diff --git a/Lara-JS/src-api/LegacyIntegrationTests - Weaver.test.ts b/Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts
similarity index 88%
rename from Lara-JS/src-api/LegacyIntegrationTests - Weaver.test.ts
rename to Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts
index f5378c291..d6810eabf 100644
--- a/Lara-JS/src-api/LegacyIntegrationTests - Weaver.test.ts	
+++ b/Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts	
@@ -1,4 +1,4 @@
-import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.js";
+import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.ts";
 import path from "path";
 
 /* eslint-disable jest/expect-expect */
diff --git a/Lara-JS/src-api/core/output.ts b/Lara-JS/api/core/output.ts
similarity index 98%
rename from Lara-JS/src-api/core/output.ts
rename to Lara-JS/api/core/output.ts
index c908bcd1c..0d2e3261c 100644
--- a/Lara-JS/src-api/core/output.ts
+++ b/Lara-JS/api/core/output.ts
@@ -1,4 +1,4 @@
-import JavaTypes from "../lara/util/JavaTypes.js";
+import JavaTypes from "../lara/util/JavaTypes.ts";
 
 /**
  * Prints a message to the standard output.
diff --git a/Lara-JS/src-api/jest.config.js b/Lara-JS/api/jest.config.ts
similarity index 59%
rename from Lara-JS/src-api/jest.config.js
rename to Lara-JS/api/jest.config.ts
index a95951c23..11314baca 100644
--- a/Lara-JS/src-api/jest.config.js
+++ b/Lara-JS/api/jest.config.ts
@@ -1,32 +1,29 @@
+import { defineConfig } from "jest";
 import path from "path";
 import { fileURLToPath } from "url";
 
 export const weaverConfig = {
   weaverName: "DefaultWeaver",
   weaverPrettyName: "Default Weaver",
-  weaverFileName: "@specs-feup/lara/code/Weaver.js",
+  weaverFileName: "@specs-feup/lara/code/Weaver.ts",
   jarPath: path.join(
     path.dirname(path.dirname(path.dirname(fileURLToPath(import.meta.url)))),
-    "./DefaultWeaver/build/install/DefaultWeaver"
+    "./DefaultWeaver/build/install/DefaultWeaver",
   ),
   javaWeaverQualifiedName: "org.lara.interpreter.weaver.defaultweaver.DWWeaver",
 };
 
-
-const config = {
+export default defineConfig({
   preset: "ts-jest/presets/default-esm",
-  testEnvironment: "@specs-feup/lara/jest/jestEnvironment.js",
-  globalSetup: "@specs-feup/lara/jest/jestGlobalSetup.js",
-  globalTeardown: "@specs-feup/lara/jest/jestGlobalTeardown.js",
-  setupFiles: ["@specs-feup/lara/jest/setupFiles/sharedJavaModule.js"],
-  setupFilesAfterEnv: ["@specs-feup/lara/jest/setupFiles/importSideEffects.js"],
+  testEnvironment: "@specs-feup/lara/jest/jestEnvironment.ts",
+  globalSetup: "@specs-feup/lara/jest/jestGlobalSetup.ts",
+  globalTeardown: "@specs-feup/lara/jest/jestGlobalTeardown.ts",
+  setupFiles: ["@specs-feup/lara/jest/setupFiles/sharedJavaModule.ts"],
+  setupFilesAfterEnv: ["@specs-feup/lara/jest/setupFiles/importSideEffects.ts"],
   moduleNameMapper: {
-    "@specs-feup/lara/api/(.+).js": "@specs-feup/lara/src-api/$1",
     "(.+)\\.js": "$1",
   },
   testEnvironmentOptions: {
     weaverConfig,
   },
-};
-
-export default config;
+});
diff --git a/Lara-JS/src-api/lara/Check.ts b/Lara-JS/api/lara/Check.ts
similarity index 96%
rename from Lara-JS/src-api/lara/Check.ts
rename to Lara-JS/api/lara/Check.ts
index 188bee7af..dc75d4f64 100644
--- a/Lara-JS/src-api/lara/Check.ts
+++ b/Lara-JS/api/lara/Check.ts
@@ -1,6 +1,6 @@
-import { LaraJoinPoint } from "../LaraJoinPoint.js";
-import * as LaraCore from "./core/LaraCore.js";
-import JavaTypes from "./util/JavaTypes.js";
+import { LaraJoinPoint } from "../LaraJoinPoint.ts";
+import * as LaraCore from "./core/LaraCore.ts";
+import JavaTypes from "./util/JavaTypes.ts";
 
 /**
  * Utility methods to check preconditions.
diff --git a/Lara-JS/src-api/lara/Collections.ts b/Lara-JS/api/lara/Collections.ts
similarity index 96%
rename from Lara-JS/src-api/lara/Collections.ts
rename to Lara-JS/api/lara/Collections.ts
index 46e9b038d..bbc1bc137 100644
--- a/Lara-JS/src-api/lara/Collections.ts
+++ b/Lara-JS/api/lara/Collections.ts
@@ -1,5 +1,5 @@
-import JavaInterop from "./JavaInterop.js";
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
+import JavaInterop from "./JavaInterop.ts";
+import JavaTypes, { type JavaClasses } from "./util/JavaTypes.ts";
 
 /**
  *  Utility methods related to Collections.
diff --git a/Lara-JS/src-api/lara/Csv.ts b/Lara-JS/api/lara/Csv.ts
similarity index 97%
rename from Lara-JS/src-api/lara/Csv.ts
rename to Lara-JS/api/lara/Csv.ts
index 883e96016..20b3978f0 100644
--- a/Lara-JS/src-api/lara/Csv.ts
+++ b/Lara-JS/api/lara/Csv.ts
@@ -1,5 +1,5 @@
-import Io from "./Io.js";
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
+import Io from "./Io.ts";
+import JavaTypes, { type JavaClasses } from "./util/JavaTypes.ts";
 
 /**
  * Methods related with the CSV format.
diff --git a/Lara-JS/src-api/lara/Debug.ts b/Lara-JS/api/lara/Debug.ts
similarity index 100%
rename from Lara-JS/src-api/lara/Debug.ts
rename to Lara-JS/api/lara/Debug.ts
diff --git a/Lara-JS/src-api/lara/Io.test.ts b/Lara-JS/api/lara/Io.test.ts
similarity index 92%
rename from Lara-JS/src-api/lara/Io.test.ts
rename to Lara-JS/api/lara/Io.test.ts
index 6ff72b8ac..dcfd56631 100644
--- a/Lara-JS/src-api/lara/Io.test.ts
+++ b/Lara-JS/api/lara/Io.test.ts
@@ -1,5 +1,5 @@
-import Io from "./Io.js";
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
+import Io from "./Io.ts";
+import { type JavaClasses } from "./util/JavaTypes.ts";
 
 describe("Io", () => {
     
diff --git a/Lara-JS/src-api/lara/Io.ts b/Lara-JS/api/lara/Io.ts
similarity index 98%
rename from Lara-JS/src-api/lara/Io.ts
rename to Lara-JS/api/lara/Io.ts
index cc923f742..09ba4acf4 100644
--- a/Lara-JS/src-api/lara/Io.ts
+++ b/Lara-JS/api/lara/Io.ts
@@ -1,5 +1,5 @@
-import { JSONtoFile, fileToJSON } from "../core/output.js";
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
+import { JSONtoFile, fileToJSON } from "../core/output.ts";
+import JavaTypes, { type JavaClasses } from "./util/JavaTypes.ts";
 import fg from "fast-glob";
 import fs from "fs";
 
@@ -351,7 +351,7 @@ export default class Io {
   }
 
   /**
-   * @deprecated Use JSONtoFile from api/core/output.js instead
+   * @deprecated Use JSONtoFile from api/core/output.ts instead
    */
   static writeJson<T>(path: string, object: T) {
     JSONtoFile(path, object);
@@ -518,7 +518,7 @@ export default class Io {
    * If it is a string but does not end in json, assume it is a stringified object.
    * Otherwise, returns the object as it is.
    *
-   * @deprecated Use JSON.parse() instead or fileToJSON from api/core/output.js
+   * @deprecated Use JSON.parse() instead or fileToJSON from api/core/output.ts
    */
   static jsonObject<T>(value: T): T | string {
     if (typeof value === "string") {
diff --git a/Lara-JS/src-api/lara/JavaInterop.ts b/Lara-JS/api/lara/JavaInterop.ts
similarity index 94%
rename from Lara-JS/src-api/lara/JavaInterop.ts
rename to Lara-JS/api/lara/JavaInterop.ts
index 46ca579b4..72572ab82 100644
--- a/Lara-JS/src-api/lara/JavaInterop.ts
+++ b/Lara-JS/api/lara/JavaInterop.ts
@@ -1,4 +1,4 @@
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
+import JavaTypes, { type JavaClasses } from "./util/JavaTypes.ts";
 
 export default class JavaInterop {
   /**
diff --git a/Lara-JS/src-api/lara/Numbers.ts b/Lara-JS/api/lara/Numbers.ts
similarity index 100%
rename from Lara-JS/src-api/lara/Numbers.ts
rename to Lara-JS/api/lara/Numbers.ts
diff --git a/Lara-JS/src-api/lara/Platforms.ts b/Lara-JS/api/lara/Platforms.ts
similarity index 97%
rename from Lara-JS/src-api/lara/Platforms.ts
rename to Lara-JS/api/lara/Platforms.ts
index 5faa522eb..d3a73d198 100644
--- a/Lara-JS/src-api/lara/Platforms.ts
+++ b/Lara-JS/api/lara/Platforms.ts
@@ -1,4 +1,4 @@
-import JavaTypes from "./util/JavaTypes.js";
+import JavaTypes from "./util/JavaTypes.ts";
 
 /**
  * Information about the current platform (e.g., if it is Linux, Windows or Mac)
diff --git a/Lara-JS/src-api/lara/Strings.ts b/Lara-JS/api/lara/Strings.ts
similarity index 98%
rename from Lara-JS/src-api/lara/Strings.ts
rename to Lara-JS/api/lara/Strings.ts
index c024c980a..248b8a4a5 100644
--- a/Lara-JS/src-api/lara/Strings.ts
+++ b/Lara-JS/api/lara/Strings.ts
@@ -1,4 +1,4 @@
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
+import JavaTypes, { type JavaClasses } from "./util/JavaTypes.ts";
 
 /**
  *  Utility methods related to Strings.
diff --git a/Lara-JS/src-api/lara/System.ts b/Lara-JS/api/lara/System.ts
similarity index 96%
rename from Lara-JS/src-api/lara/System.ts
rename to Lara-JS/api/lara/System.ts
index b23a0ac08..0e24c375d 100644
--- a/Lara-JS/src-api/lara/System.ts
+++ b/Lara-JS/api/lara/System.ts
@@ -1,8 +1,8 @@
-import Io from "./Io.js";
-import Platforms from "./Platforms.js";
-import { info } from "./core/LaraCore.js";
-import JavaTypes, { JavaClasses } from "./util/JavaTypes.js";
-import TimeUnits, { TimerUnit } from "./util/TimeUnits.js";
+import Io from "./Io.ts";
+import Platforms from "./Platforms.ts";
+import { info } from "./core/LaraCore.ts";
+import JavaTypes, { type JavaClasses } from "./util/JavaTypes.ts";
+import TimeUnits, { TimerUnit } from "./util/TimeUnits.ts";
 
 export default class System {
   static getExecutableFile(
diff --git a/Lara-JS/src-api/lara/benchmark/BenchmarkCompilationEngine.ts b/Lara-JS/api/lara/benchmark/BenchmarkCompilationEngine.ts
similarity index 83%
rename from Lara-JS/src-api/lara/benchmark/BenchmarkCompilationEngine.ts
rename to Lara-JS/api/lara/benchmark/BenchmarkCompilationEngine.ts
index 0669a26f7..0913c1219 100644
--- a/Lara-JS/src-api/lara/benchmark/BenchmarkCompilationEngine.ts
+++ b/Lara-JS/api/lara/benchmark/BenchmarkCompilationEngine.ts
@@ -1,4 +1,4 @@
-import Tool from "../tool/Tool.js";
+import Tool from "../tool/Tool.ts";
 
 export default abstract class BenchmarkCompilationEngine extends Tool {
     constructor(name: string, disableWeaving: boolean = false) {
diff --git a/Lara-JS/src-api/lara/benchmark/BenchmarkInstance.ts b/Lara-JS/api/lara/benchmark/BenchmarkInstance.ts
similarity index 96%
rename from Lara-JS/src-api/lara/benchmark/BenchmarkInstance.ts
rename to Lara-JS/api/lara/benchmark/BenchmarkInstance.ts
index abebd221a..bdc9e6465 100644
--- a/Lara-JS/src-api/lara/benchmark/BenchmarkInstance.ts
+++ b/Lara-JS/api/lara/benchmark/BenchmarkInstance.ts
@@ -1,8 +1,8 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import Io from "../Io.js";
-import { JavaClasses } from "../util/JavaTypes.js";
-import ProcessExecutor from "../util/ProcessExecutor.js";
-import BenchmarkCompilationEngine from "./BenchmarkCompilationEngine.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import Io from "../Io.ts";
+import { type JavaClasses } from "../util/JavaTypes.ts";
+import ProcessExecutor from "../util/ProcessExecutor.ts";
+import BenchmarkCompilationEngine from "./BenchmarkCompilationEngine.ts";
 
 /**
  * Represents a set of BenchmarkInstances.
@@ -199,7 +199,6 @@ export default abstract class BenchmarkInstance {
     }
 
     this.currentExecutor.execute(
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-call
       this.currentExecutable.getAbsolutePath()
     );
   }
diff --git a/Lara-JS/src-api/lara/benchmark/BenchmarkSet.ts b/Lara-JS/api/lara/benchmark/BenchmarkSet.ts
similarity index 96%
rename from Lara-JS/src-api/lara/benchmark/BenchmarkSet.ts
rename to Lara-JS/api/lara/benchmark/BenchmarkSet.ts
index 38e16c3cc..6c796a1b5 100644
--- a/Lara-JS/src-api/lara/benchmark/BenchmarkSet.ts
+++ b/Lara-JS/api/lara/benchmark/BenchmarkSet.ts
@@ -1,5 +1,5 @@
-import ProcessExecutor from "../util/ProcessExecutor.js";
-import BenchmarkInstance from "./BenchmarkInstance.js";
+import ProcessExecutor from "../util/ProcessExecutor.ts";
+import BenchmarkInstance from "./BenchmarkInstance.ts";
 
 /**
  * Represents a set of BenchmarkInstances.
diff --git a/Lara-JS/src-api/lara/code/EnergyBase.ts b/Lara-JS/api/lara/code/EnergyBase.ts
similarity index 97%
rename from Lara-JS/src-api/lara/code/EnergyBase.ts
rename to Lara-JS/api/lara/code/EnergyBase.ts
index 7dd513517..76d14bbf6 100644
--- a/Lara-JS/src-api/lara/code/EnergyBase.ts
+++ b/Lara-JS/api/lara/code/EnergyBase.ts
@@ -1,4 +1,4 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
 
 /**
  * Class that measures the energy spent when executing a section of code.
diff --git a/Lara-JS/src-api/lara/code/LoggerBase.ts b/Lara-JS/api/lara/code/LoggerBase.ts
similarity index 99%
rename from Lara-JS/src-api/lara/code/LoggerBase.ts
rename to Lara-JS/api/lara/code/LoggerBase.ts
index faccc070c..13f8fc0d1 100644
--- a/Lara-JS/src-api/lara/code/LoggerBase.ts
+++ b/Lara-JS/api/lara/code/LoggerBase.ts
@@ -1,6 +1,6 @@
-import { InsertPosition, LaraJoinPoint } from "../../LaraJoinPoint.js";
-import JoinPoints from "../../weaver/JoinPoints.js";
-import { isJoinPoint } from "../core/LaraCore.js";
+import { InsertPosition, LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import JoinPoints from "../../weaver/JoinPoints.ts";
+import { isJoinPoint } from "../core/LaraCore.ts";
 
 type ElementType = { content: string | number; type: number };
 
diff --git a/Lara-JS/src-api/lara/code/TimerBase.ts b/Lara-JS/api/lara/code/TimerBase.ts
similarity index 95%
rename from Lara-JS/src-api/lara/code/TimerBase.ts
rename to Lara-JS/api/lara/code/TimerBase.ts
index 8f442cefe..1e85ba6f0 100644
--- a/Lara-JS/src-api/lara/code/TimerBase.ts
+++ b/Lara-JS/api/lara/code/TimerBase.ts
@@ -1,5 +1,5 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import TimeUnits, { TimerUnit } from "../util/TimeUnits.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import TimeUnits, { TimerUnit } from "../util/TimeUnits.ts";
 
 /**
  * Timer object, for timing sections of code.
diff --git a/Lara-JS/src-api/lara/core/LaraCore.ts b/Lara-JS/api/lara/core/LaraCore.ts
similarity index 98%
rename from Lara-JS/src-api/lara/core/LaraCore.ts
rename to Lara-JS/api/lara/core/LaraCore.ts
index 615eea62a..1a20d4c9d 100644
--- a/Lara-JS/src-api/lara/core/LaraCore.ts
+++ b/Lara-JS/api/lara/core/LaraCore.ts
@@ -1,6 +1,6 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import { object2string } from "../../core/output.js";
-import JavaTypes from "../util/JavaTypes.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import { object2string } from "../../core/output.ts";
+import JavaTypes from "../util/JavaTypes.ts";
 
 export let LARA_DEBUG = false;
 
diff --git a/Lara-JS/src-api/lara/dse/DseLoop.ts b/Lara-JS/api/lara/dse/DseLoop.ts
similarity index 66%
rename from Lara-JS/src-api/lara/dse/DseLoop.ts
rename to Lara-JS/api/lara/dse/DseLoop.ts
index 7302f12ce..4f67710f4 100644
--- a/Lara-JS/src-api/lara/dse/DseLoop.ts
+++ b/Lara-JS/api/lara/dse/DseLoop.ts
@@ -1,6 +1,6 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import Metric from "../metrics/Metric.js";
-import DseVariant from "./DseVariant.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import Metric from "../metrics/Metric.ts";
+import DseVariant from "./DseVariant.ts";
 
 /**
  * Performs Design-Space Exploration.
diff --git a/Lara-JS/src-api/lara/dse/DseValues.ts b/Lara-JS/api/lara/dse/DseValues.ts
similarity index 100%
rename from Lara-JS/src-api/lara/dse/DseValues.ts
rename to Lara-JS/api/lara/dse/DseValues.ts
diff --git a/Lara-JS/src-api/lara/dse/DseValuesList.ts b/Lara-JS/api/lara/dse/DseValuesList.ts
similarity index 92%
rename from Lara-JS/src-api/lara/dse/DseValuesList.ts
rename to Lara-JS/api/lara/dse/DseValuesList.ts
index 7d55cb9db..c1f6b8f15 100644
--- a/Lara-JS/src-api/lara/dse/DseValuesList.ts
+++ b/Lara-JS/api/lara/dse/DseValuesList.ts
@@ -1,5 +1,5 @@
-import { arrayFromArgs } from "../core/LaraCore.js";
-import DseValues from "./DseValues.js";
+import { arrayFromArgs } from "../core/LaraCore.ts";
+import DseValues from "./DseValues.ts";
 
 type T = any;
 
diff --git a/Lara-JS/src-api/lara/dse/DseValuesSet.ts b/Lara-JS/api/lara/dse/DseValuesSet.ts
similarity index 95%
rename from Lara-JS/src-api/lara/dse/DseValuesSet.ts
rename to Lara-JS/api/lara/dse/DseValuesSet.ts
index 2ed53cf08..0110aa409 100644
--- a/Lara-JS/src-api/lara/dse/DseValuesSet.ts
+++ b/Lara-JS/api/lara/dse/DseValuesSet.ts
@@ -1,5 +1,5 @@
-import { arrayFromArgs } from "../core/LaraCore.js";
-import DseValues from "./DseValues.js";
+import { arrayFromArgs } from "../core/LaraCore.ts";
+import DseValues from "./DseValues.ts";
 
 type T = any;
 
diff --git a/Lara-JS/src-api/lara/dse/DseVariant.ts b/Lara-JS/api/lara/dse/DseVariant.ts
similarity index 90%
rename from Lara-JS/src-api/lara/dse/DseVariant.ts
rename to Lara-JS/api/lara/dse/DseVariant.ts
index 3904106c7..54965aa81 100644
--- a/Lara-JS/src-api/lara/dse/DseVariant.ts
+++ b/Lara-JS/api/lara/dse/DseVariant.ts
@@ -1,4 +1,4 @@
-import DseValues from "./DseValues.js";
+import DseValues from "./DseValues.ts";
 
 /**
  * Represents a variant of the DSE.
diff --git a/Lara-JS/src-api/lara/dse/VariableVariant.ts b/Lara-JS/api/lara/dse/VariableVariant.ts
similarity index 86%
rename from Lara-JS/src-api/lara/dse/VariableVariant.ts
rename to Lara-JS/api/lara/dse/VariableVariant.ts
index a67d6b9ba..2ef317a14 100644
--- a/Lara-JS/src-api/lara/dse/VariableVariant.ts
+++ b/Lara-JS/api/lara/dse/VariableVariant.ts
@@ -1,7 +1,7 @@
-import { arrayFromArgs } from "../core/LaraCore.js";
-import DseValues from "./DseValues.js";
-import DseValuesList from "./DseValuesList.js";
-import DseVariant from "./DseVariant.js";
+import { arrayFromArgs } from "../core/LaraCore.ts";
+import DseValues from "./DseValues.ts";
+import DseValuesList from "./DseValuesList.ts";
+import DseVariant from "./DseVariant.ts";
 
 type T = any;
 
diff --git a/Lara-JS/src-api/lara/graphs/DotFormatter.ts b/Lara-JS/api/lara/graphs/DotFormatter.ts
similarity index 97%
rename from Lara-JS/src-api/lara/graphs/DotFormatter.ts
rename to Lara-JS/api/lara/graphs/DotFormatter.ts
index d9f322160..cbccf21f3 100644
--- a/Lara-JS/src-api/lara/graphs/DotFormatter.ts
+++ b/Lara-JS/api/lara/graphs/DotFormatter.ts
@@ -1,6 +1,6 @@
 import cytoscape from "cytoscape";
-import NodeData from "./NodeData.js";
-import EdgeData from "./EdgeData.js";
+import NodeData from "./NodeData.ts";
+import EdgeData from "./EdgeData.ts";
 
 export interface NodeAttribute {
   attr: string;
diff --git a/Lara-JS/src-api/lara/graphs/EdgeData.ts b/Lara-JS/api/lara/graphs/EdgeData.ts
similarity index 100%
rename from Lara-JS/src-api/lara/graphs/EdgeData.ts
rename to Lara-JS/api/lara/graphs/EdgeData.ts
diff --git a/Lara-JS/src-api/lara/graphs/Graph.ts b/Lara-JS/api/lara/graphs/Graph.ts
similarity index 82%
rename from Lara-JS/src-api/lara/graphs/Graph.ts
rename to Lara-JS/api/lara/graphs/Graph.ts
index f9d004190..fb86c48f7 100644
--- a/Lara-JS/src-api/lara/graphs/Graph.ts
+++ b/Lara-JS/api/lara/graphs/Graph.ts
@@ -1,6 +1,6 @@
 import cytoscape from "cytoscape";
-import DotFormatter from "./DotFormatter.js";
-import Graphs from "./Graphs.js";
+import DotFormatter from "./DotFormatter.ts";
+import Graphs from "./Graphs.ts";
 
 export default class Graph {
   /**
diff --git a/Lara-JS/src-api/lara/graphs/Graphs.ts b/Lara-JS/api/lara/graphs/Graphs.ts
similarity index 96%
rename from Lara-JS/src-api/lara/graphs/Graphs.ts
rename to Lara-JS/api/lara/graphs/Graphs.ts
index 96bddeb3c..bbd5bd0c0 100644
--- a/Lara-JS/src-api/lara/graphs/Graphs.ts
+++ b/Lara-JS/api/lara/graphs/Graphs.ts
@@ -1,6 +1,6 @@
-import DotFormatter from "./DotFormatter.js";
-import EdgeData from "./EdgeData.js";
-import NodeData from "./NodeData.js";
+import DotFormatter from "./DotFormatter.ts";
+import EdgeData from "./EdgeData.ts";
+import NodeData from "./NodeData.ts";
 
 import cytoscape from "cytoscape";
 
diff --git a/Lara-JS/src-api/lara/graphs/NodeData.ts b/Lara-JS/api/lara/graphs/NodeData.ts
similarity index 100%
rename from Lara-JS/src-api/lara/graphs/NodeData.ts
rename to Lara-JS/api/lara/graphs/NodeData.ts
diff --git a/Lara-JS/src-api/lara/iterators/LaraIterator.ts b/Lara-JS/api/lara/iterators/LaraIterator.ts
similarity index 100%
rename from Lara-JS/src-api/lara/iterators/LaraIterator.ts
rename to Lara-JS/api/lara/iterators/LaraIterator.ts
diff --git a/Lara-JS/src-api/lara/iterators/LineIterator.ts b/Lara-JS/api/lara/iterators/LineIterator.ts
similarity index 93%
rename from Lara-JS/src-api/lara/iterators/LineIterator.ts
rename to Lara-JS/api/lara/iterators/LineIterator.ts
index 5a66fbcf0..626c96def 100644
--- a/Lara-JS/src-api/lara/iterators/LineIterator.ts
+++ b/Lara-JS/api/lara/iterators/LineIterator.ts
@@ -1,5 +1,5 @@
-import JavaTypes, { JavaClasses } from "../util/JavaTypes.js";
-import LaraIterator from "./LaraIterator.js";
+import JavaTypes, { type JavaClasses } from "../util/JavaTypes.ts";
+import LaraIterator from "./LaraIterator.ts";
 
 /**
  * Iterates over a sequence of lines.
diff --git a/Lara-JS/src-api/lara/metrics/FileSizeMetric.ts b/Lara-JS/api/lara/metrics/FileSizeMetric.ts
similarity index 78%
rename from Lara-JS/src-api/lara/metrics/FileSizeMetric.ts
rename to Lara-JS/api/lara/metrics/FileSizeMetric.ts
index 2292707e4..2034dca6c 100644
--- a/Lara-JS/src-api/lara/metrics/FileSizeMetric.ts
+++ b/Lara-JS/api/lara/metrics/FileSizeMetric.ts
@@ -1,7 +1,7 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import ProcessExecutor from "../util/ProcessExecutor.js";
-import Metric from "./Metric.js";
-import MetricResult from "./MetricResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import ProcessExecutor from "../util/ProcessExecutor.ts";
+import Metric from "./Metric.ts";
+import MetricResult from "./MetricResult.ts";
 
 /**
  * Measures the size of the compiled executable.
diff --git a/Lara-JS/src-api/lara/metrics/Metric.ts b/Lara-JS/api/lara/metrics/Metric.ts
similarity index 86%
rename from Lara-JS/src-api/lara/metrics/Metric.ts
rename to Lara-JS/api/lara/metrics/Metric.ts
index e8da00be2..6cd347345 100644
--- a/Lara-JS/src-api/lara/metrics/Metric.ts
+++ b/Lara-JS/api/lara/metrics/Metric.ts
@@ -1,6 +1,6 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import ProcessExecutor from "../util/ProcessExecutor.js";
-import MetricResult from "./MetricResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import ProcessExecutor from "../util/ProcessExecutor.ts";
+import MetricResult from "./MetricResult.ts";
 
 /**
  * Reprents a metric we want to extract.
diff --git a/Lara-JS/src-api/lara/metrics/MetricResult.ts b/Lara-JS/api/lara/metrics/MetricResult.ts
similarity index 100%
rename from Lara-JS/src-api/lara/metrics/MetricResult.ts
rename to Lara-JS/api/lara/metrics/MetricResult.ts
diff --git a/Lara-JS/src-api/lara/mutation/IterativeMutation.ts b/Lara-JS/api/lara/mutation/IterativeMutation.ts
similarity index 80%
rename from Lara-JS/src-api/lara/mutation/IterativeMutation.ts
rename to Lara-JS/api/lara/mutation/IterativeMutation.ts
index d65938daa..9299a47da 100644
--- a/Lara-JS/src-api/lara/mutation/IterativeMutation.ts
+++ b/Lara-JS/api/lara/mutation/IterativeMutation.ts
@@ -1,6 +1,6 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import Mutation from "./Mutation.js";
-import MutationResult from "./MutationResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import Mutation from "./Mutation.ts";
+import MutationResult from "./MutationResult.ts";
 
 /**
  * Abstract mutation class that implements .getMutants(), but makes function Mutation.mutate($jp) abstract. Allows more efficient, generator-based Mutation implementations.
diff --git a/Lara-JS/src-api/lara/mutation/IterativeMutator.ts b/Lara-JS/api/lara/mutation/IterativeMutator.ts
similarity index 95%
rename from Lara-JS/src-api/lara/mutation/IterativeMutator.ts
rename to Lara-JS/api/lara/mutation/IterativeMutator.ts
index 43d667f39..695c782d9 100644
--- a/Lara-JS/src-api/lara/mutation/IterativeMutator.ts
+++ b/Lara-JS/api/lara/mutation/IterativeMutator.ts
@@ -1,8 +1,8 @@
-import { InsertPosition, LaraJoinPoint } from "../../LaraJoinPoint.js";
-import { arrayFromArgs } from "../core/LaraCore.js";
-import Mutation from "./Mutation.js";
-import MutationResult from "./MutationResult.js";
-import Mutator from "./Mutator.js";
+import { InsertPosition, LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import { arrayFromArgs } from "../core/LaraCore.ts";
+import Mutation from "./Mutation.ts";
+import MutationResult from "./MutationResult.ts";
+import Mutator from "./Mutator.ts";
 
 /**
  * Iterative mutator, allows to perform one mutation at a time, and restore the code before each mutation.
diff --git a/Lara-JS/src-api/lara/mutation/Mutation.ts b/Lara-JS/api/lara/mutation/Mutation.ts
similarity index 92%
rename from Lara-JS/src-api/lara/mutation/Mutation.ts
rename to Lara-JS/api/lara/mutation/Mutation.ts
index 9563a2ff4..ed1f18b12 100644
--- a/Lara-JS/src-api/lara/mutation/Mutation.ts
+++ b/Lara-JS/api/lara/mutation/Mutation.ts
@@ -1,5 +1,5 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import MutationResult from "./MutationResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import MutationResult from "./MutationResult.ts";
 
 /**
  * Base class that represents a code mutation.
diff --git a/Lara-JS/src-api/lara/mutation/MutationResult.ts b/Lara-JS/api/lara/mutation/MutationResult.ts
similarity index 86%
rename from Lara-JS/src-api/lara/mutation/MutationResult.ts
rename to Lara-JS/api/lara/mutation/MutationResult.ts
index e60e80d58..20dfde9f2 100644
--- a/Lara-JS/src-api/lara/mutation/MutationResult.ts
+++ b/Lara-JS/api/lara/mutation/MutationResult.ts
@@ -1,4 +1,4 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
 
 /**
  * Contains the results of a single mutation.
diff --git a/Lara-JS/src-api/lara/mutation/Mutator.ts b/Lara-JS/api/lara/mutation/Mutator.ts
similarity index 98%
rename from Lara-JS/src-api/lara/mutation/Mutator.ts
rename to Lara-JS/api/lara/mutation/Mutator.ts
index 2e490fd30..ff43f5257 100644
--- a/Lara-JS/src-api/lara/mutation/Mutator.ts
+++ b/Lara-JS/api/lara/mutation/Mutator.ts
@@ -1,4 +1,4 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
 
 /**
  * Base class that represents a code mutator.
diff --git a/Lara-JS/src-api/lara/pass/AdapterPass.ts b/Lara-JS/api/lara/pass/AdapterPass.ts
similarity index 89%
rename from Lara-JS/src-api/lara/pass/AdapterPass.ts
rename to Lara-JS/api/lara/pass/AdapterPass.ts
index 624f84171..789d610fc 100644
--- a/Lara-JS/src-api/lara/pass/AdapterPass.ts
+++ b/Lara-JS/api/lara/pass/AdapterPass.ts
@@ -1,8 +1,8 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import TraversalType from "../../weaver/TraversalType.js";
-import PassTransformationError from "./PassTransformationError.js";
-import SimplePass from "./SimplePass.js";
-import AggregatePassResult from "./results/AggregatePassResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import { TraversalType } from "../../weaver/TraversalType.ts";
+import PassTransformationError from "./PassTransformationError.ts";
+import SimplePass from "./SimplePass.ts";
+import AggregatePassResult from "./results/AggregatePassResult.ts";
 
 /**
  * Helper class to wrap existing code into a Lara transformation pass.
diff --git a/Lara-JS/src-api/lara/pass/Pass.ts b/Lara-JS/api/lara/pass/Pass.ts
similarity index 83%
rename from Lara-JS/src-api/lara/pass/Pass.ts
rename to Lara-JS/api/lara/pass/Pass.ts
index 25351947e..b23055060 100644
--- a/Lara-JS/src-api/lara/pass/Pass.ts
+++ b/Lara-JS/api/lara/pass/Pass.ts
@@ -1,7 +1,7 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import Query from "../../weaver/Query.js";
-import { debug } from "../core/LaraCore.js";
-import PassResult from "./results/PassResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import Query from "../../weaver/Query.ts";
+import { debug } from "../core/LaraCore.ts";
+import PassResult from "./results/PassResult.ts";
 
 /**
  * Represents a Lara transformation pass.
diff --git a/Lara-JS/src-api/lara/pass/PassTransformationError.ts b/Lara-JS/api/lara/pass/PassTransformationError.ts
similarity index 90%
rename from Lara-JS/src-api/lara/pass/PassTransformationError.ts
rename to Lara-JS/api/lara/pass/PassTransformationError.ts
index c7e93ed1d..8936ed564 100644
--- a/Lara-JS/src-api/lara/pass/PassTransformationError.ts
+++ b/Lara-JS/api/lara/pass/PassTransformationError.ts
@@ -1,5 +1,5 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import Pass from "./Pass.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import Pass from "./Pass.ts";
 
 export default class PassTransformationError extends Error {
   name = "PassTransformationError";
diff --git a/Lara-JS/src-api/lara/pass/SimplePass.ts b/Lara-JS/api/lara/pass/SimplePass.ts
similarity index 89%
rename from Lara-JS/src-api/lara/pass/SimplePass.ts
rename to Lara-JS/api/lara/pass/SimplePass.ts
index 30f264613..e6d6614e4 100644
--- a/Lara-JS/src-api/lara/pass/SimplePass.ts
+++ b/Lara-JS/api/lara/pass/SimplePass.ts
@@ -1,9 +1,9 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import TraversalType from "../../weaver/TraversalType.js";
-import Pass from "./Pass.js";
-import PassTransformationError from "./PassTransformationError.js";
-import AggregatePassResult from "./results/AggregatePassResult.js";
-import PassResult from "./results/PassResult.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import { TraversalType } from "../../weaver/TraversalType.ts";
+import Pass from "./Pass.ts";
+import PassTransformationError from "./PassTransformationError.ts";
+import AggregatePassResult from "./results/AggregatePassResult.ts";
+import PassResult from "./results/PassResult.ts";
 
 /**
  * Represents a Lara transformation pass.
diff --git a/Lara-JS/src-api/lara/pass/composition/PassApplyArg.ts b/Lara-JS/api/lara/pass/composition/PassApplyArg.ts
similarity index 100%
rename from Lara-JS/src-api/lara/pass/composition/PassApplyArg.ts
rename to Lara-JS/api/lara/pass/composition/PassApplyArg.ts
diff --git a/Lara-JS/src-api/lara/pass/composition/Passes.ts b/Lara-JS/api/lara/pass/composition/Passes.ts
similarity index 80%
rename from Lara-JS/src-api/lara/pass/composition/Passes.ts
rename to Lara-JS/api/lara/pass/composition/Passes.ts
index a626f5664..dde5dbaf9 100644
--- a/Lara-JS/src-api/lara/pass/composition/Passes.ts
+++ b/Lara-JS/api/lara/pass/composition/Passes.ts
@@ -1,7 +1,7 @@
-import { LaraJoinPoint } from "../../../LaraJoinPoint.js";
-import { arrayFromArgs } from "../../core/LaraCore.js";
-import Pass from "../Pass.js";
-import PassResult from "../results/PassResult.js";
+import { LaraJoinPoint } from "../../../LaraJoinPoint.ts";
+import { arrayFromArgs } from "../../core/LaraCore.ts";
+import Pass from "../Pass.ts";
+import PassResult from "../results/PassResult.ts";
 
 /**
  * @deprecated Use AdapterPass instead
diff --git a/Lara-JS/src-api/lara/pass/results/AggregatePassResult.ts b/Lara-JS/api/lara/pass/results/AggregatePassResult.ts
similarity index 94%
rename from Lara-JS/src-api/lara/pass/results/AggregatePassResult.ts
rename to Lara-JS/api/lara/pass/results/AggregatePassResult.ts
index 9508d784d..cc0e25b0c 100644
--- a/Lara-JS/src-api/lara/pass/results/AggregatePassResult.ts
+++ b/Lara-JS/api/lara/pass/results/AggregatePassResult.ts
@@ -1,7 +1,7 @@
-import { LaraJoinPoint } from "../../../LaraJoinPoint.js";
-import Pass from "../Pass.js";
-import PassTransformationError from "../PassTransformationError.js";
-import PassResult from "./PassResult.js";
+import { LaraJoinPoint } from "../../../LaraJoinPoint.ts";
+import Pass from "../Pass.ts";
+import PassTransformationError from "../PassTransformationError.ts";
+import PassResult from "./PassResult.ts";
 
 export default class AggregatePassResult extends PassResult {
   /**
diff --git a/Lara-JS/src-api/lara/pass/results/PassResult.ts b/Lara-JS/api/lara/pass/results/PassResult.ts
similarity index 96%
rename from Lara-JS/src-api/lara/pass/results/PassResult.ts
rename to Lara-JS/api/lara/pass/results/PassResult.ts
index c3bb77394..6e7fbeec6 100644
--- a/Lara-JS/src-api/lara/pass/results/PassResult.ts
+++ b/Lara-JS/api/lara/pass/results/PassResult.ts
@@ -1,5 +1,5 @@
-import { LaraJoinPoint } from "../../../LaraJoinPoint.js";
-import Pass from "../Pass.js";
+import { LaraJoinPoint } from "../../../LaraJoinPoint.ts";
+import Pass from "../Pass.ts";
 
 /**
  * The result of a Lara transformation pass
diff --git a/Lara-JS/src-api/lara/tool/Tool.ts b/Lara-JS/api/lara/tool/Tool.ts
similarity index 100%
rename from Lara-JS/src-api/lara/tool/Tool.ts
rename to Lara-JS/api/lara/tool/Tool.ts
diff --git a/Lara-JS/src-api/lara/tool/ToolUtils.ts b/Lara-JS/api/lara/tool/ToolUtils.ts
similarity index 79%
rename from Lara-JS/src-api/lara/tool/ToolUtils.ts
rename to Lara-JS/api/lara/tool/ToolUtils.ts
index f3296478a..d08a340f5 100644
--- a/Lara-JS/src-api/lara/tool/ToolUtils.ts
+++ b/Lara-JS/api/lara/tool/ToolUtils.ts
@@ -1,5 +1,5 @@
-import { JavaClasses } from "../util/JavaTypes.js";
-import Strings from "../Strings.js";
+import { type JavaClasses } from "../util/JavaTypes.ts";
+import Strings from "../Strings.ts";
 
 export default class ToolUtils {
   static parsePath(path: string | JavaClasses.File): string {
diff --git a/Lara-JS/src-api/lara/units/EnergyUnit.ts b/Lara-JS/api/lara/units/EnergyUnit.ts
similarity index 91%
rename from Lara-JS/src-api/lara/units/EnergyUnit.ts
rename to Lara-JS/api/lara/units/EnergyUnit.ts
index fad4ceee8..f41582c75 100644
--- a/Lara-JS/src-api/lara/units/EnergyUnit.ts
+++ b/Lara-JS/api/lara/units/EnergyUnit.ts
@@ -1,5 +1,5 @@
-import SiUnit from "./SiUnit.js";
-import SiModifier from "./SiModifier.js";
+import SiUnit from "./SiUnit.ts";
+import SiModifier from "./SiModifier.ts";
 
 /**
  * ! If you are ever in need of using this class, please PLEASE refactor it.
diff --git a/Lara-JS/src-api/lara/units/SiModifier.ts b/Lara-JS/api/lara/units/SiModifier.ts
similarity index 96%
rename from Lara-JS/src-api/lara/units/SiModifier.ts
rename to Lara-JS/api/lara/units/SiModifier.ts
index 5f9b88dda..a1946a052 100644
--- a/Lara-JS/src-api/lara/units/SiModifier.ts
+++ b/Lara-JS/api/lara/units/SiModifier.ts
@@ -1,4 +1,4 @@
-import UnitModifier from "./UnitModifier.js";
+import UnitModifier from "./UnitModifier.ts";
 
 /**
  * ! If you are ever in need of using this class, please PLEASE refactor it.
diff --git a/Lara-JS/src-api/lara/units/SiUnit.ts b/Lara-JS/api/lara/units/SiUnit.ts
similarity index 79%
rename from Lara-JS/src-api/lara/units/SiUnit.ts
rename to Lara-JS/api/lara/units/SiUnit.ts
index 4a8fd2e61..156d244ee 100644
--- a/Lara-JS/src-api/lara/units/SiUnit.ts
+++ b/Lara-JS/api/lara/units/SiUnit.ts
@@ -1,5 +1,5 @@
-import UnitWithModifier from "./UnitWithModifier.js";
-import SiModifier from "./SiModifier.js";
+import UnitWithModifier from "./UnitWithModifier.ts";
+import SiModifier from "./SiModifier.ts";
 
 /**
  * ! If you are ever in need of using this class, please PLEASE refactor it.
diff --git a/Lara-JS/src-api/lara/units/TimeModifier.ts b/Lara-JS/api/lara/units/TimeModifier.ts
similarity index 93%
rename from Lara-JS/src-api/lara/units/TimeModifier.ts
rename to Lara-JS/api/lara/units/TimeModifier.ts
index 2df86a7ac..b51f1ad26 100644
--- a/Lara-JS/src-api/lara/units/TimeModifier.ts
+++ b/Lara-JS/api/lara/units/TimeModifier.ts
@@ -1,4 +1,4 @@
-import SiModifier from "./SiModifier.js";
+import SiModifier from "./SiModifier.ts";
 
 /**
  * ! If you are ever in need of using this class, please PLEASE refactor it.
diff --git a/Lara-JS/src-api/lara/units/TimeUnit.ts b/Lara-JS/api/lara/units/TimeUnit.ts
similarity index 95%
rename from Lara-JS/src-api/lara/units/TimeUnit.ts
rename to Lara-JS/api/lara/units/TimeUnit.ts
index c44737efb..dd82ce50b 100644
--- a/Lara-JS/src-api/lara/units/TimeUnit.ts
+++ b/Lara-JS/api/lara/units/TimeUnit.ts
@@ -1,5 +1,5 @@
-import SiUnit from "./SiUnit.js";
-import TimeModifier from "./TimeModifier.js";
+import SiUnit from "./SiUnit.ts";
+import TimeModifier from "./TimeModifier.ts";
 
 /**
  * ! If you are ever in need of using this class, please PLEASE refactor it.
diff --git a/Lara-JS/src-api/lara/units/Unit.ts b/Lara-JS/api/lara/units/Unit.ts
similarity index 100%
rename from Lara-JS/src-api/lara/units/Unit.ts
rename to Lara-JS/api/lara/units/Unit.ts
diff --git a/Lara-JS/src-api/lara/units/UnitModifier.ts b/Lara-JS/api/lara/units/UnitModifier.ts
similarity index 100%
rename from Lara-JS/src-api/lara/units/UnitModifier.ts
rename to Lara-JS/api/lara/units/UnitModifier.ts
diff --git a/Lara-JS/src-api/lara/units/UnitWithModifier.ts b/Lara-JS/api/lara/units/UnitWithModifier.ts
similarity index 95%
rename from Lara-JS/src-api/lara/units/UnitWithModifier.ts
rename to Lara-JS/api/lara/units/UnitWithModifier.ts
index 01cc4e826..0b02a3857 100644
--- a/Lara-JS/src-api/lara/units/UnitWithModifier.ts
+++ b/Lara-JS/api/lara/units/UnitWithModifier.ts
@@ -1,5 +1,5 @@
-import Unit from "./Unit.js";
-import UnitModifier from "./UnitModifier.js";
+import Unit from "./Unit.ts";
+import UnitModifier from "./UnitModifier.ts";
 
 /**
  * ! If you are ever in need of using this class, please PLEASE refactor it.
diff --git a/Lara-JS/src-api/lara/util/AbstractClassError.ts b/Lara-JS/api/lara/util/AbstractClassError.ts
similarity index 100%
rename from Lara-JS/src-api/lara/util/AbstractClassError.ts
rename to Lara-JS/api/lara/util/AbstractClassError.ts
diff --git a/Lara-JS/src-api/lara/util/Accumulator.test.ts b/Lara-JS/api/lara/util/Accumulator.test.ts
similarity index 93%
rename from Lara-JS/src-api/lara/util/Accumulator.test.ts
rename to Lara-JS/api/lara/util/Accumulator.test.ts
index 9877cb1d9..62370d0e4 100644
--- a/Lara-JS/src-api/lara/util/Accumulator.test.ts
+++ b/Lara-JS/api/lara/util/Accumulator.test.ts
@@ -1,4 +1,4 @@
-import Accumulator from "./Accumulator.js";
+import Accumulator from "./Accumulator.ts";
 
 describe("Accumulator", () => {
   describe("add", () => {
@@ -16,7 +16,7 @@ describe("Accumulator", () => {
       const acc = new Accumulator;
       expect(acc.get("step1")).toBe(0);
     });
-    it("is 0 for step1 after adding an array with a step1 and a step2 and 1 for tuple step1,step2 ", () => {
+    it("is 0 for step1 after adding an array with a step1 and a step2 and 1 for tuple step1,step2", () => {
       const acc  = new Accumulator;
       acc.add("step1", "step2");
       expect(acc.get("step1")).toBe(0);
@@ -70,7 +70,6 @@ describe("Accumulator", () => {
       acc.add("step1","step2");
       acc.add("step1");
       acc.add(["step1","step2"]);
-      const res = [["step1"],["step1","step2"]];
       expect(acc.keys()[0]).toStrictEqual(["step1"]);
       expect(acc.keys()[1]).toStrictEqual(["step1", "step2"]);
     })
diff --git a/Lara-JS/src-api/lara/util/Accumulator.ts b/Lara-JS/api/lara/util/Accumulator.ts
similarity index 97%
rename from Lara-JS/src-api/lara/util/Accumulator.ts
rename to Lara-JS/api/lara/util/Accumulator.ts
index 669983f12..12a65a775 100644
--- a/Lara-JS/src-api/lara/util/Accumulator.ts
+++ b/Lara-JS/api/lara/util/Accumulator.ts
@@ -71,7 +71,7 @@ export default class Accumulator {
   }
 
   copy(...args: any) {
-    let copy: Accumulator = new Accumulator();
+    const copy: Accumulator = new Accumulator();
 
     for (const key of this.keys()) {
       const value: number = this.get(key);
@@ -125,7 +125,7 @@ export default class Accumulator {
       throw "Accumulator._parseArguments: Expected arguments to have length 1";
     }
 
-    let functionArguments = args[0];
+    const functionArguments = args[0];
 
     // If one argument and array, return it
     if (
diff --git a/Lara-JS/src-api/lara/util/Checkpoint.ts b/Lara-JS/api/lara/util/Checkpoint.ts
similarity index 94%
rename from Lara-JS/src-api/lara/util/Checkpoint.ts
rename to Lara-JS/api/lara/util/Checkpoint.ts
index f9cba7fae..ef5fedda2 100644
--- a/Lara-JS/src-api/lara/util/Checkpoint.ts
+++ b/Lara-JS/api/lara/util/Checkpoint.ts
@@ -1,6 +1,6 @@
-import Io from "../Io.js";
-import JavaTypes from "./JavaTypes.js";
-import TimeUnits, { TimerUnit } from "./TimeUnits.js";
+import Io from "../Io.ts";
+import JavaTypes from "./JavaTypes.ts";
+import TimeUnits, { TimerUnit } from "./TimeUnits.ts";
 
 /**
  * Allows checkpointing of generic objects.
diff --git a/Lara-JS/src-api/lara/util/Combinations.ts b/Lara-JS/api/lara/util/Combinations.ts
similarity index 94%
rename from Lara-JS/src-api/lara/util/Combinations.ts
rename to Lara-JS/api/lara/util/Combinations.ts
index 775bf009c..31422d33f 100644
--- a/Lara-JS/src-api/lara/util/Combinations.ts
+++ b/Lara-JS/api/lara/util/Combinations.ts
@@ -1,5 +1,5 @@
-import Numbers from "../Numbers.js";
-import SequentialCombinations from "./SequentialCombinations.js";
+import Numbers from "../Numbers.ts";
+import SequentialCombinations from "./SequentialCombinations.ts";
 
 /**
  * Generates sequential sequences of combinations, according to the given number of elements.
diff --git a/Lara-JS/src-api/lara/util/DataStore.ts b/Lara-JS/api/lara/util/DataStore.ts
similarity index 98%
rename from Lara-JS/src-api/lara/util/DataStore.ts
rename to Lara-JS/api/lara/util/DataStore.ts
index 0779dfad8..c59924741 100644
--- a/Lara-JS/src-api/lara/util/DataStore.ts
+++ b/Lara-JS/api/lara/util/DataStore.ts
@@ -1,6 +1,6 @@
-import Io from "../Io.js";
-import { info } from "../core/LaraCore.js";
-import JavaTypes, { JavaClasses } from "./JavaTypes.js";
+import Io from "../Io.ts";
+import { info } from "../core/LaraCore.ts";
+import JavaTypes, { type JavaClasses } from "./JavaTypes.ts";
 
 /**
  * Interface with Java class DataStore, used for storing arbitrary information.
diff --git a/Lara-JS/src-api/lara/util/IdGenerator.test.ts b/Lara-JS/api/lara/util/IdGenerator.test.ts
similarity index 95%
rename from Lara-JS/src-api/lara/util/IdGenerator.test.ts
rename to Lara-JS/api/lara/util/IdGenerator.test.ts
index 614ebbf7e..da7e0191f 100644
--- a/Lara-JS/src-api/lara/util/IdGenerator.test.ts
+++ b/Lara-JS/api/lara/util/IdGenerator.test.ts
@@ -1,4 +1,4 @@
-import IdGenerator, { IdGeneratorClass } from "./IdGenerator.js";
+import IdGenerator, { IdGeneratorClass } from "./IdGenerator.ts";
 
 describe("IdGenerator", () => {
   describe("IdGenerator", () => {
diff --git a/Lara-JS/src-api/lara/util/IdGenerator.ts b/Lara-JS/api/lara/util/IdGenerator.ts
similarity index 100%
rename from Lara-JS/src-api/lara/util/IdGenerator.ts
rename to Lara-JS/api/lara/util/IdGenerator.ts
diff --git a/Lara-JS/src-api/lara/util/JavaTypes.test.ts b/Lara-JS/api/lara/util/JavaTypes.test.ts
similarity index 95%
rename from Lara-JS/src-api/lara/util/JavaTypes.test.ts
rename to Lara-JS/api/lara/util/JavaTypes.test.ts
index a2ffb8e29..12423c914 100644
--- a/Lara-JS/src-api/lara/util/JavaTypes.test.ts
+++ b/Lara-JS/api/lara/util/JavaTypes.test.ts
@@ -1,4 +1,4 @@
-import JavaTypes from "./JavaTypes.js";
+import JavaTypes from "./JavaTypes.ts";
 
 describe("JavaTypes", () => {
   describe("getLaraI", () => {
diff --git a/Lara-JS/src-api/lara/util/JavaTypes.ts b/Lara-JS/api/lara/util/JavaTypes.ts
similarity index 97%
rename from Lara-JS/src-api/lara/util/JavaTypes.ts
rename to Lara-JS/api/lara/util/JavaTypes.ts
index c4623fd38..a02153b43 100644
--- a/Lara-JS/src-api/lara/util/JavaTypes.ts
+++ b/Lara-JS/api/lara/util/JavaTypes.ts
@@ -10,7 +10,7 @@ export namespace JavaClasses {
     [key: string]: any;
   }
 
-  /* eslint-disable @typescript-eslint/no-empty-interface, @typescript-eslint/no-empty-object-type */
+  /* eslint-disable @typescript-eslint/no-empty-object-type */
   export interface LaraI extends JavaClass {}
   export interface LaraApiTools extends JavaClass {}
   export interface LaraSystemTools extends JavaClass {
@@ -71,7 +71,7 @@ export namespace JavaClasses {
   }
   export interface ProgressCounter extends JavaClasses.JavaClass {}
   export interface LineStream extends JavaClasses.JavaClass {}
-  /* eslint-enable @typescript-eslint/no-empty-interface, @typescript-eslint/no-empty-object-type */
+  /* eslint-enable @typescript-eslint/no-empty-object-type */
 }
 
 export default class JavaTypes {
diff --git a/Lara-JS/src-api/lara/util/JpFilter.ts b/Lara-JS/api/lara/util/JpFilter.ts
similarity index 94%
rename from Lara-JS/src-api/lara/util/JpFilter.ts
rename to Lara-JS/api/lara/util/JpFilter.ts
index d14197d53..306ee0099 100644
--- a/Lara-JS/src-api/lara/util/JpFilter.ts
+++ b/Lara-JS/api/lara/util/JpFilter.ts
@@ -1,5 +1,5 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import { laraGetter } from "../core/LaraCore.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import { laraGetter } from "../core/LaraCore.ts";
 
 type JpFilterTypes =
   | RegExp
diff --git a/Lara-JS/src-api/lara/util/LineInserter.ts b/Lara-JS/api/lara/util/LineInserter.ts
similarity index 92%
rename from Lara-JS/src-api/lara/util/LineInserter.ts
rename to Lara-JS/api/lara/util/LineInserter.ts
index 81452ba2a..b0c91dc06 100644
--- a/Lara-JS/src-api/lara/util/LineInserter.ts
+++ b/Lara-JS/api/lara/util/LineInserter.ts
@@ -1,5 +1,5 @@
-import LineIterator from "../iterators/LineIterator.js";
-import { JavaClasses } from "./JavaTypes.js";
+import LineIterator from "../iterators/LineIterator.ts";
+import { type JavaClasses } from "./JavaTypes.ts";
 
 /**
  * Helps inserting lines.
diff --git a/Lara-JS/src-api/lara/util/LocalFolder.ts b/Lara-JS/api/lara/util/LocalFolder.ts
similarity index 93%
rename from Lara-JS/src-api/lara/util/LocalFolder.ts
rename to Lara-JS/api/lara/util/LocalFolder.ts
index 4646bcab2..96b241499 100644
--- a/Lara-JS/src-api/lara/util/LocalFolder.ts
+++ b/Lara-JS/api/lara/util/LocalFolder.ts
@@ -1,7 +1,7 @@
-import { fileToJSON } from "../../core/output.js";
-import Io from "../Io.js";
-import JavaTypes, { JavaClasses } from "./JavaTypes.js";
-import System from "../System.js";
+import { fileToJSON } from "../../core/output.ts";
+import Io from "../Io.ts";
+import JavaTypes, { type JavaClasses } from "./JavaTypes.ts";
+import System from "../System.ts";
 
 /**
  * Provides access to files in a specific folder.
diff --git a/Lara-JS/src-api/lara/util/PredefinedStrings.ts b/Lara-JS/api/lara/util/PredefinedStrings.ts
similarity index 96%
rename from Lara-JS/src-api/lara/util/PredefinedStrings.ts
rename to Lara-JS/api/lara/util/PredefinedStrings.ts
index fbbd76cf2..3c5211c1a 100644
--- a/Lara-JS/src-api/lara/util/PredefinedStrings.ts
+++ b/Lara-JS/api/lara/util/PredefinedStrings.ts
@@ -1,4 +1,4 @@
-import { arrayFromArgs } from "../core/LaraCore.js";
+import { arrayFromArgs } from "../core/LaraCore.ts";
 
 /**
  * Represents a set of predefined strings.
diff --git a/Lara-JS/src-api/lara/util/PrintOnce.test.ts b/Lara-JS/api/lara/util/PrintOnce.test.ts
similarity index 92%
rename from Lara-JS/src-api/lara/util/PrintOnce.test.ts
rename to Lara-JS/api/lara/util/PrintOnce.test.ts
index bb271d851..36b9a0f18 100644
--- a/Lara-JS/src-api/lara/util/PrintOnce.test.ts
+++ b/Lara-JS/api/lara/util/PrintOnce.test.ts
@@ -1,4 +1,4 @@
-import PrintOnce from "./PrintOnce.js"
+import PrintOnce from "./PrintOnce.ts"
 
 describe("PrintOnce", () => {
   describe("message", () => {
diff --git a/Lara-JS/src-api/lara/util/PrintOnce.ts b/Lara-JS/api/lara/util/PrintOnce.ts
similarity index 100%
rename from Lara-JS/src-api/lara/util/PrintOnce.ts
rename to Lara-JS/api/lara/util/PrintOnce.ts
diff --git a/Lara-JS/src-api/lara/util/ProcessExecutor.ts b/Lara-JS/api/lara/util/ProcessExecutor.ts
similarity index 96%
rename from Lara-JS/src-api/lara/util/ProcessExecutor.ts
rename to Lara-JS/api/lara/util/ProcessExecutor.ts
index 9a83f6770..70c1e7c4c 100644
--- a/Lara-JS/src-api/lara/util/ProcessExecutor.ts
+++ b/Lara-JS/api/lara/util/ProcessExecutor.ts
@@ -1,8 +1,8 @@
-import Io from "../Io.js";
-import JavaInterop from "../JavaInterop.js";
-import { arrayFromArgs, checkType } from "../core/LaraCore.js";
-import JavaTypes, { JavaClasses } from "./JavaTypes.js";
-import TimeUnits, { TimerUnit } from "./TimeUnits.js";
+import Io from "../Io.ts";
+import JavaInterop from "../JavaInterop.ts";
+import { arrayFromArgs, checkType } from "../core/LaraCore.ts";
+import JavaTypes, { type JavaClasses } from "./JavaTypes.ts";
+import TimeUnits, { TimerUnit } from "./TimeUnits.ts";
 
 /**
  * Launches processes.
diff --git a/Lara-JS/src-api/lara/util/Random.ts b/Lara-JS/api/lara/util/Random.ts
similarity index 93%
rename from Lara-JS/src-api/lara/util/Random.ts
rename to Lara-JS/api/lara/util/Random.ts
index e57a8bd75..019add1c6 100644
--- a/Lara-JS/src-api/lara/util/Random.ts
+++ b/Lara-JS/api/lara/util/Random.ts
@@ -1,4 +1,4 @@
-import JavaTypes from "./JavaTypes.js";
+import JavaTypes from "./JavaTypes.ts";
 
 /**
  * Can generate random numbers from a user-defined seed.
diff --git a/Lara-JS/src-api/lara/util/Replacer.ts b/Lara-JS/api/lara/util/Replacer.ts
similarity index 90%
rename from Lara-JS/src-api/lara/util/Replacer.ts
rename to Lara-JS/api/lara/util/Replacer.ts
index ed783ce6a..23d433ceb 100644
--- a/Lara-JS/src-api/lara/util/Replacer.ts
+++ b/Lara-JS/api/lara/util/Replacer.ts
@@ -1,5 +1,5 @@
-import Io from "../Io.js";
-import JavaTypes, { JavaClasses } from "./JavaTypes.js";
+import Io from "../Io.ts";
+import JavaTypes, { type JavaClasses } from "./JavaTypes.ts";
 
 /**
  * Replaces strings inside a larger string.
diff --git a/Lara-JS/src-api/lara/util/SequentialCombinations.ts b/Lara-JS/api/lara/util/SequentialCombinations.ts
similarity index 97%
rename from Lara-JS/src-api/lara/util/SequentialCombinations.ts
rename to Lara-JS/api/lara/util/SequentialCombinations.ts
index 2d334d717..072bddec0 100644
--- a/Lara-JS/src-api/lara/util/SequentialCombinations.ts
+++ b/Lara-JS/api/lara/util/SequentialCombinations.ts
@@ -1,4 +1,4 @@
-import Numbers from "../Numbers.js";
+import Numbers from "../Numbers.ts";
 
 /**
  * Generates sequential sequences of combinations, according to the given number of elements.
diff --git a/Lara-JS/src-api/lara/util/StringSet.ts b/Lara-JS/api/lara/util/StringSet.ts
similarity index 100%
rename from Lara-JS/src-api/lara/util/StringSet.ts
rename to Lara-JS/api/lara/util/StringSet.ts
diff --git a/Lara-JS/src-api/lara/util/TimeUnits.ts b/Lara-JS/api/lara/util/TimeUnits.ts
similarity index 81%
rename from Lara-JS/src-api/lara/util/TimeUnits.ts
rename to Lara-JS/api/lara/util/TimeUnits.ts
index 714d0e0b0..02cc48b2f 100644
--- a/Lara-JS/src-api/lara/util/TimeUnits.ts
+++ b/Lara-JS/api/lara/util/TimeUnits.ts
@@ -5,15 +5,21 @@ interface TimerUnitI {
   magnitudeFactorNanoseconds: number;
 }
 
-export enum TimerUnit {
-  NANOSECONDS = 1,
-  MICROSECONDS = 2,
-  MILLISECONDS = 3,
-  SECONDS = 4,
-  MINUTES = 5,
-  HOURS = 6,
-  DAYS = 7,
-}
+/**
+ * This is supposed to be an enum, but Node.js v25 does bot support TS' enums, only erasable-syntax.
+ * Revert to an enum when Node.js supports it, or when we move to a different engine that supports it.
+ * This and the "type" declaration below.
+ */
+export const TimerUnit = {
+  NANOSECONDS: 1,
+  MICROSECONDS: 2,
+  MILLISECONDS: 3,
+  SECONDS: 4,
+  MINUTES: 5,
+  HOURS: 6,
+  DAYS: 7,
+} as const;
+export type TimerUnit = typeof TimerUnit[keyof typeof TimerUnit];
 
 const timerUnitData: Record<TimerUnit, TimerUnitI> = {
   [TimerUnit.NANOSECONDS]: {
diff --git a/Lara-JS/src-api/lara/util/TupleId.ts b/Lara-JS/api/lara/util/TupleId.ts
similarity index 100%
rename from Lara-JS/src-api/lara/util/TupleId.ts
rename to Lara-JS/api/lara/util/TupleId.ts
diff --git a/Lara-JS/src-api/weaver/JoinPoints.ts b/Lara-JS/api/weaver/JoinPoints.ts
similarity index 96%
rename from Lara-JS/src-api/weaver/JoinPoints.ts
rename to Lara-JS/api/weaver/JoinPoints.ts
index 29ee5da65..c74e9c6f6 100644
--- a/Lara-JS/src-api/weaver/JoinPoints.ts
+++ b/Lara-JS/api/weaver/JoinPoints.ts
@@ -1,6 +1,6 @@
-import { LaraJoinPoint, wrapJoinPoint } from "../LaraJoinPoint.js";
-import Weaver from "./Weaver.js";
-import JpPredicate from "./predicate/JpPredicate.js";
+import { LaraJoinPoint, wrapJoinPoint } from "../LaraJoinPoint.ts";
+import Weaver from "./Weaver.ts";
+import JpPredicate from "./predicate/JpPredicate.ts";
 
 /**
  * Object which provides low-level join point-related methods.
@@ -180,7 +180,6 @@ export default class JoinPoints {
     for (let obj = $jp; obj !== null; obj = Object.getPrototypeOf(obj)) {
       const descriptor = Object.getOwnPropertyDescriptor(obj, property);
       if (descriptor !== undefined) {
-        let attributeValue: any = undefined;
         if (Object.getOwnPropertyDescriptor(descriptor, "get")) {
           return descriptor.get?.call?.($jp);
         } else if (Object.getOwnPropertyDescriptor(descriptor, "value")) {
diff --git a/Lara-JS/src-api/weaver/Query.ts b/Lara-JS/api/weaver/Query.ts
similarity index 98%
rename from Lara-JS/src-api/weaver/Query.ts
rename to Lara-JS/api/weaver/Query.ts
index fd5b6fb15..3705dc3c5 100644
--- a/Lara-JS/src-api/weaver/Query.ts
+++ b/Lara-JS/api/weaver/Query.ts
@@ -1,10 +1,10 @@
-import { LaraJoinPoint } from "../LaraJoinPoint.js";
-import JoinPoints from "./JoinPoints.js";
+import { LaraJoinPoint } from "../LaraJoinPoint.ts";
+import JoinPoints from "./JoinPoints.ts";
 import Selector, {
   type Filter_StringVariant,
   type Filter_WrapperVariant,
-} from "./Selector.js";
-import TraversalType from "./TraversalType.js";
+} from "./Selector.ts";
+import { TraversalType } from "./TraversalType.ts";
 
 /**
  * Class for selection of join points. Provides an API similar to the keyword 'select'.
diff --git a/Lara-JS/src-api/weaver/Script.ts b/Lara-JS/api/weaver/Script.ts
similarity index 96%
rename from Lara-JS/src-api/weaver/Script.ts
rename to Lara-JS/api/weaver/Script.ts
index ed942d506..018693a16 100644
--- a/Lara-JS/src-api/weaver/Script.ts
+++ b/Lara-JS/api/weaver/Script.ts
@@ -1,4 +1,4 @@
-import Weaver from "./Weaver.js";
+import Weaver from "./Weaver.ts";
 
 /**
  * Utility methods related to execution of scripts in a LARA environment.
diff --git a/Lara-JS/src-api/weaver/Selector.ts b/Lara-JS/api/weaver/Selector.ts
similarity index 96%
rename from Lara-JS/src-api/weaver/Selector.ts
rename to Lara-JS/api/weaver/Selector.ts
index 956807d35..a5e45e874 100644
--- a/Lara-JS/src-api/weaver/Selector.ts
+++ b/Lara-JS/api/weaver/Selector.ts
@@ -2,16 +2,16 @@ import {
   LaraJoinPoint,
   type NameFromWrapperClass,
   type DefaultAttribute,
-} from "../LaraJoinPoint.js";
-import { laraGetter } from "../lara/core/LaraCore.js";
-import Accumulator from "../lara/util/Accumulator.js";
-import { type JpFilterRules } from "../lara/util/JpFilter.js";
-import JoinPoints from "./JoinPoints.js";
-import TraversalType from "./TraversalType.js";
-import Weaver from "./Weaver.js";
-import JpPredicate from "./predicate/JpPredicate.js";
-import StringPredicate from "./predicate/StringPredicate.js";
-import TypePredicate from "./predicate/TypePredicate.js";
+} from "../LaraJoinPoint.ts";
+import { laraGetter } from "../lara/core/LaraCore.ts";
+import Accumulator from "../lara/util/Accumulator.ts";
+import { type JpFilterRules } from "../lara/util/JpFilter.ts";
+import JoinPoints from "./JoinPoints.ts";
+import { TraversalType } from "./TraversalType.ts";
+import Weaver from "./Weaver.ts";
+import JpPredicate from "./predicate/JpPredicate.ts";
+import StringPredicate from "./predicate/StringPredicate.ts";
+import TypePredicate from "./predicate/TypePredicate.ts";
 
 /**
  * @internal Lara Common Language dirty hack. IMPROPER USAGE WILL BREAK THE WHOLE WEAVER!
@@ -318,7 +318,6 @@ export default class Selector<
         break;
       default:
         throw new Error(
-          // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
           `Traversal type not implemented: ${traversal}`
         );
     }
diff --git a/Lara-JS/api/weaver/TraversalType.ts b/Lara-JS/api/weaver/TraversalType.ts
new file mode 100644
index 000000000..cc4fb7ca2
--- /dev/null
+++ b/Lara-JS/api/weaver/TraversalType.ts
@@ -0,0 +1,12 @@
+/**
+ * Enumeration of AST traversal types.
+ *
+ * This is supposed to be an enum, but Node.js v25 does bot support TS' enums, only erasable-syntax.
+ * Revert to an enum when Node.js supports it, or when we move to a different engine that supports it.
+ * This and the "type" declaration below.
+ */
+export const TraversalType = {
+  PREORDER: "preorder",
+  POSTORDER: "postorder",
+} as const;
+export type TraversalType = typeof TraversalType[keyof typeof TraversalType];
diff --git a/Lara-JS/src-api/weaver/Weaver.ts b/Lara-JS/api/weaver/Weaver.ts
similarity index 93%
rename from Lara-JS/src-api/weaver/Weaver.ts
rename to Lara-JS/api/weaver/Weaver.ts
index d64b6c131..b0bdd4366 100644
--- a/Lara-JS/src-api/weaver/Weaver.ts
+++ b/Lara-JS/api/weaver/Weaver.ts
@@ -1,12 +1,12 @@
 import {
   LaraJoinPoint,
   getJoinpointMappers,
-} from "../LaraJoinPoint.js";
-import Io from "../lara/Io.js";
-import JavaInterop from "../lara/JavaInterop.js";
-import DataStore from "../lara/util/DataStore.js";
-import JavaTypes, { JavaClasses } from "../lara/util/JavaTypes.js";
-import WeaverOptions from "./WeaverOptions.js";
+} from "../LaraJoinPoint.ts";
+import Io from "../lara/Io.ts";
+import JavaInterop from "../lara/JavaInterop.ts";
+import DataStore from "../lara/util/DataStore.ts";
+import JavaTypes, { type JavaClasses } from "../lara/util/JavaTypes.ts";
+import WeaverOptions from "./WeaverOptions.ts";
 
 /**
  * @internal Lara Common Language dirty hack. IMPROPER USAGE WILL BREAK THE WHOLE WEAVER!
@@ -207,7 +207,6 @@ export default class Weaver {
   }
 
   static get laraArgs(): any {
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
     const datastore = new DataStore(Weaver.getWeaverEngine().getData().get());
     let jsonString = datastore.get(
       JavaTypes.LaraiKeys.ASPECT_ARGS as string
diff --git a/Lara-JS/src-api/weaver/WeaverLauncherBase.ts b/Lara-JS/api/weaver/WeaverLauncherBase.ts
similarity index 94%
rename from Lara-JS/src-api/weaver/WeaverLauncherBase.ts
rename to Lara-JS/api/weaver/WeaverLauncherBase.ts
index 19e3c934e..066ddea1d 100644
--- a/Lara-JS/src-api/weaver/WeaverLauncherBase.ts
+++ b/Lara-JS/api/weaver/WeaverLauncherBase.ts
@@ -1,4 +1,4 @@
-import WeaverOptions from "./WeaverOptions.js";
+import WeaverOptions from "./WeaverOptions.ts";
 
 /**
  * Object for launching weaver instances.
diff --git a/Lara-JS/src-api/weaver/WeaverOptions.ts b/Lara-JS/api/weaver/WeaverOptions.ts
similarity index 85%
rename from Lara-JS/src-api/weaver/WeaverOptions.ts
rename to Lara-JS/api/weaver/WeaverOptions.ts
index 52ad88698..42963791c 100644
--- a/Lara-JS/src-api/weaver/WeaverOptions.ts
+++ b/Lara-JS/api/weaver/WeaverOptions.ts
@@ -1,5 +1,5 @@
-import Weaver from "./Weaver.js";
-import WeaverDataStore from "./util/WeaverDataStore.js";
+import Weaver from "./Weaver.ts";
+import WeaverDataStore from "./util/WeaverDataStore.ts";
 
 /**
  * Contains configuration-related methods of the weaver.
diff --git a/Lara-JS/api/weaver/predicate/JpPredicate.ts b/Lara-JS/api/weaver/predicate/JpPredicate.ts
new file mode 100644
index 000000000..a94218a6c
--- /dev/null
+++ b/Lara-JS/api/weaver/predicate/JpPredicate.ts
@@ -0,0 +1,21 @@
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+
+export default abstract class JpPredicate {
+  
+    /**
+     * @returns The name of the join point
+     */
+    abstract jpName() : string;
+
+    /**
+     * @returns True if the underlying type is THE class LaraJoinPoint
+     */
+    abstract isLaraJoinPoint() : boolean;
+
+    /**
+     * 
+     * @param jp - The join point we want to test
+     * @returns True if the join point is accepted by this predicate 
+     */
+    abstract isInstance<T extends LaraJoinPoint>(jp: T):boolean
+}
\ No newline at end of file
diff --git a/Lara-JS/src-api/weaver/predicate/StringPredicate.ts b/Lara-JS/api/weaver/predicate/StringPredicate.ts
similarity index 62%
rename from Lara-JS/src-api/weaver/predicate/StringPredicate.ts
rename to Lara-JS/api/weaver/predicate/StringPredicate.ts
index e3d98fb16..257d78e36 100644
--- a/Lara-JS/src-api/weaver/predicate/StringPredicate.ts
+++ b/Lara-JS/api/weaver/predicate/StringPredicate.ts
@@ -1,10 +1,13 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import JpPredicate from "./JpPredicate.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import JpPredicate from "./JpPredicate.ts";
 
 export default class StringPredicate extends JpPredicate {
 
-    constructor(private name: string) {
+    private name: string;
+
+    constructor(name: string) {
         super();
+        this.name = name;
     }
 
     jpName(): string {
diff --git a/Lara-JS/src-api/weaver/predicate/TypePredicate.ts b/Lara-JS/api/weaver/predicate/TypePredicate.ts
similarity index 66%
rename from Lara-JS/src-api/weaver/predicate/TypePredicate.ts
rename to Lara-JS/api/weaver/predicate/TypePredicate.ts
index 226ce0295..f6d69ffd5 100644
--- a/Lara-JS/src-api/weaver/predicate/TypePredicate.ts
+++ b/Lara-JS/api/weaver/predicate/TypePredicate.ts
@@ -1,11 +1,14 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-import JpPredicate from "./JpPredicate.js";
-import Weaver from "../Weaver.js";
+import { LaraJoinPoint } from "../../LaraJoinPoint.ts";
+import JpPredicate from "./JpPredicate.ts";
+import Weaver from "../Weaver.ts";
 
 export default class TypePredicate<T extends typeof LaraJoinPoint> extends JpPredicate {
 
-    constructor(private type: T) {
+    private type: T;
+
+    constructor(type: T) {
         super();
+        this.type = type;
     }
 
     jpName(): string {
diff --git a/Lara-JS/src-api/weaver/util/WeaverDataStore.ts b/Lara-JS/api/weaver/util/WeaverDataStore.ts
similarity index 90%
rename from Lara-JS/src-api/weaver/util/WeaverDataStore.ts
rename to Lara-JS/api/weaver/util/WeaverDataStore.ts
index 87b94d293..4319a981f 100644
--- a/Lara-JS/src-api/weaver/util/WeaverDataStore.ts
+++ b/Lara-JS/api/weaver/util/WeaverDataStore.ts
@@ -1,7 +1,6 @@
-import Io from "../../lara/Io.js";
-import DataStore from "../../lara/util/DataStore.js";
-import JavaTypes, { JavaClasses } from "../../lara/util/JavaTypes.js";
-import Weaver from "../Weaver.js";
+import Io from "../../lara/Io.ts";
+import DataStore from "../../lara/util/DataStore.ts";
+import JavaTypes, { type JavaClasses } from "../../lara/util/JavaTypes.ts";
 
 /**
  * DataStore used in LaraI weavers.
diff --git a/Lara-JS/src-code/ChildProcessHandling.test.ts b/Lara-JS/code/ChildProcessHandling.test.ts
similarity index 98%
rename from Lara-JS/src-code/ChildProcessHandling.test.ts
rename to Lara-JS/code/ChildProcessHandling.test.ts
index 1682c4da4..74af93916 100644
--- a/Lara-JS/src-code/ChildProcessHandling.test.ts
+++ b/Lara-JS/code/ChildProcessHandling.test.ts
@@ -3,7 +3,7 @@ import {
   addActiveChildProcess,
   handleExit,
   getActiveChildProcesses,
-} from "./ChildProcessHandling.js";
+} from "./ChildProcessHandling.ts";
 
 describe("ChildProcessHandling", () => {
   describe("addActiveChildProcess", () => {
diff --git a/Lara-JS/src-code/ChildProcessHandling.ts b/Lara-JS/code/ChildProcessHandling.ts
similarity index 100%
rename from Lara-JS/src-code/ChildProcessHandling.ts
rename to Lara-JS/code/ChildProcessHandling.ts
diff --git a/Lara-JS/src-code/FileExtensions.test.ts b/Lara-JS/code/FileExtensions.test.ts
similarity index 93%
rename from Lara-JS/src-code/FileExtensions.test.ts
rename to Lara-JS/code/FileExtensions.test.ts
index 29fe5f576..7b0785d09 100644
--- a/Lara-JS/src-code/FileExtensions.test.ts
+++ b/Lara-JS/code/FileExtensions.test.ts
@@ -1,5 +1,4 @@
-import { jest } from "@jest/globals";
-import { isValidFileExtension, FileExtensions } from "./FileExtensions.js";
+import { isValidFileExtension, FileExtensions } from "./FileExtensions.ts";
 
 describe("FileExtensions", () => {
   describe("isValidFileExtension", () => {
diff --git a/Lara-JS/code/FileExtensions.ts b/Lara-JS/code/FileExtensions.ts
new file mode 100644
index 000000000..4eacb7b6b
--- /dev/null
+++ b/Lara-JS/code/FileExtensions.ts
@@ -0,0 +1,21 @@
+/**
+ * This is supposed to be an enum, but Node.js v25 does bot support TS' enums, only erasable-syntax.
+ * Revert to an enum when Node.js supports it, or when we move to a different engine that supports it.
+ * This and the "type" declaration below.
+ */
+export const FileExtensions = {
+  JS: ".js",
+  MJS: ".mjs",
+  CJS: ".cjs",
+} as const;
+export type FileExtensions = typeof FileExtensions[keyof typeof FileExtensions];
+
+/**
+ * Checks if a file extension is valid.
+ *
+ * @param extension - The file extension to check.
+ * @returns `true` if the file extension is valid, `false` otherwise.
+ */
+export const isValidFileExtension = (extension: string): boolean => {
+  return Object.values(FileExtensions).includes(extension as FileExtensions);
+};
diff --git a/Lara-JS/src-code/JavaError.ts b/Lara-JS/code/JavaError.ts
similarity index 82%
rename from Lara-JS/src-code/JavaError.ts
rename to Lara-JS/code/JavaError.ts
index 698f93053..170f188a5 100644
--- a/Lara-JS/src-code/JavaError.ts
+++ b/Lara-JS/code/JavaError.ts
@@ -9,6 +9,5 @@ export default interface JavaError {
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export function isJavaError(obj: any): obj is JavaError {
-  // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
   return obj.cause != undefined;
 }
diff --git a/Lara-JS/src-code/Weaver.ts b/Lara-JS/code/Weaver.ts
similarity index 95%
rename from Lara-JS/src-code/Weaver.ts
rename to Lara-JS/code/Weaver.ts
index 32631982d..4cf0beed0 100644
--- a/Lara-JS/src-code/Weaver.ts
+++ b/Lara-JS/code/Weaver.ts
@@ -4,9 +4,9 @@ import EventEmitter from "events";
 import java from "java";
 import Debug from "debug";
 import { fileURLToPath, pathToFileURL } from "url";
-import { isJavaError } from "./JavaError.js";
-import { isValidFileExtension } from "./FileExtensions.js";
-import WeaverMessageFromLauncher from "./WeaverMessageFromLauncher.js";
+import { isJavaError } from "./JavaError.ts";
+import { isValidFileExtension } from "./FileExtensions.ts";
+import type WeaverMessageFromLauncher from "./WeaverMessageFromLauncher.ts";
 import assert from "assert";
 
 let directExecution = false;
@@ -159,7 +159,6 @@ export class Weaver {
   }
 
   static start() {
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
     Weaver.javaWeaver.run(Weaver.datastore);
   }
 
@@ -217,7 +216,6 @@ export class Weaver {
 
   static shutdown() {
     Weaver.debug("Exiting...");
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, @typescript-eslint/no-unsafe-call
     Weaver.javaWeaver.end();
   }
 }
diff --git a/Lara-JS/src-code/WeaverConfiguration.ts b/Lara-JS/code/WeaverConfiguration.ts
similarity index 94%
rename from Lara-JS/src-code/WeaverConfiguration.ts
rename to Lara-JS/code/WeaverConfiguration.ts
index 77fed7965..b8fa830d3 100644
--- a/Lara-JS/src-code/WeaverConfiguration.ts
+++ b/Lara-JS/code/WeaverConfiguration.ts
@@ -31,7 +31,7 @@ export default interface WeaverConfiguration {
    * This is useful for registering the joinpoint mappers for the weaver.
    * Files must be importable using the ES6 import syntax.
    *
-   * @example ["@specs-feup/clava/api/Joinpoints.js"]
+   * @example ["@specs-feup/clava/api/Joinpoints.ts"]
    */
   importForSideEffects?: string[];
 }
diff --git a/Lara-JS/src-code/WeaverLauncher.ts b/Lara-JS/code/WeaverLauncher.ts
similarity index 96%
rename from Lara-JS/src-code/WeaverLauncher.ts
rename to Lara-JS/code/WeaverLauncher.ts
index f98fcfbbb..312a97188 100644
--- a/Lara-JS/src-code/WeaverLauncher.ts
+++ b/Lara-JS/code/WeaverLauncher.ts
@@ -1,5 +1,5 @@
 import Debug from "debug";
-import yargs, { Arguments } from "yargs";
+import yargs, { type Arguments } from "yargs";
 import * as path from "path";
 import * as chokidar from "chokidar";
 import { hideBin } from "yargs/helpers";
@@ -10,11 +10,11 @@ import {
   addActiveChildProcess,
   getActiveChildProcesses,
   listenForTerminationSignals,
-} from "./ChildProcessHandling.js";
-import WeaverConfiguration from "./WeaverConfiguration.js";
-import WeaverMessageFromLauncher from "./WeaverMessageFromLauncher.js";
+} from "./ChildProcessHandling.ts";
+import type WeaverConfiguration from "./WeaverConfiguration.ts";
+import type WeaverMessageFromLauncher from "./WeaverMessageFromLauncher.ts";
 
-import { Weaver } from "./Weaver.js";
+import { Weaver } from "./Weaver.ts";
 
 listenForTerminationSignals();
 
@@ -146,7 +146,7 @@ export default class WeaverLauncher {
 
     const weaverScript = this.config.weaverFileName
       ? fileURLToPath(import.meta.resolve(this.config.weaverFileName))
-      : path.join(dirname(fileURLToPath(import.meta.url)), "Weaver.js");
+      : path.join(dirname(fileURLToPath(import.meta.url)), "Weaver.ts");
 
     this.debug("Launcher weaver using the script '" + weaverScript + "'");
 
diff --git a/Lara-JS/src-code/WeaverMessageFromLauncher.ts b/Lara-JS/code/WeaverMessageFromLauncher.ts
similarity index 50%
rename from Lara-JS/src-code/WeaverMessageFromLauncher.ts
rename to Lara-JS/code/WeaverMessageFromLauncher.ts
index 17b6747cb..1e4f4c6ef 100644
--- a/Lara-JS/src-code/WeaverMessageFromLauncher.ts
+++ b/Lara-JS/code/WeaverMessageFromLauncher.ts
@@ -1,5 +1,5 @@
-import { Arguments } from "yargs";
-import WeaverConfiguration from "./WeaverConfiguration.js";
+import { type Arguments } from "yargs";
+import type WeaverConfiguration from "./WeaverConfiguration.ts";
 
 export default interface WeaverMessageFromLauncher {
   config: WeaverConfiguration;
diff --git a/Lara-JS/src-code/jest.config.js b/Lara-JS/code/jest.config.ts
similarity index 62%
rename from Lara-JS/src-code/jest.config.js
rename to Lara-JS/code/jest.config.ts
index f8502043b..76873b4a2 100644
--- a/Lara-JS/src-code/jest.config.js
+++ b/Lara-JS/code/jest.config.ts
@@ -1,9 +1,9 @@
-const config = {
+import { defineConfig } from "jest";
+
+export default defineConfig({
   preset: "ts-jest/presets/default-esm",
   testEnvironment: "node",
   moduleNameMapper: {
     "(.+)\\.js": "$1",
   },
-};
-
-export default config;
+});
diff --git a/Lara-JS/eslint.config.js b/Lara-JS/eslint.config.ts
similarity index 81%
rename from Lara-JS/eslint.config.js
rename to Lara-JS/eslint.config.ts
index 2273574c5..7df9bdcf0 100644
--- a/Lara-JS/eslint.config.js
+++ b/Lara-JS/eslint.config.ts
@@ -1,21 +1,19 @@
-import { fileURLToPath } from "url";
-import { dirname } from "path";
-import typescriptEslint from "typescript-eslint";
-import tsdoc from "eslint-plugin-tsdoc";
-import jest from "eslint-plugin-jest";
 import js from "@eslint/js";
 import eslintConfigPrettier from "eslint-config-prettier";
+import jest from "eslint-plugin-jest";
+import tsdoc from "eslint-plugin-tsdoc";
+import { defineConfig } from "eslint/config";
+import { dirname } from "path";
+import typescriptEslint from "typescript-eslint";
+import { fileURLToPath } from "url";
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
 
-export default [
+export default defineConfig([
   js.configs.recommended,
   eslintConfigPrettier,
   ...typescriptEslint.configs.recommended,
-  {
-    ignores: ["**/*.d.ts", "**/*.config.js"],
-  },
   {
     plugins: {
       "@typescript-eslint": typescriptEslint.plugin,
@@ -28,7 +26,7 @@ export default [
       sourceType: "script",
 
       parserOptions: {
-        project: ["./*/tsconfig.json", "./tsconfig.*.json"],
+        project: ["./tsconfig.json", "./tsconfig.*.json"],
         tsconfigRootDir: __dirname,
       },
     },
@@ -37,10 +35,6 @@ export default [
       "tsdoc/syntax": "warn",
     },
   },
-  {
-    ...typescriptEslint.configs.disableTypeChecked,
-    files: ["scripts/**/*.js"],
-  },
   {
     ...jest.configs["flat/recommended"],
     files: ["**/*.spec.ts", "**/*.test.ts"],
@@ -55,4 +49,4 @@ export default [
       },
     },
   },
-];
+]);
diff --git a/Lara-JS/jest.config.js b/Lara-JS/jest.config.ts
similarity index 77%
rename from Lara-JS/jest.config.js
rename to Lara-JS/jest.config.ts
index 416cabfaf..3036d5e59 100644
--- a/Lara-JS/jest.config.js
+++ b/Lara-JS/jest.config.ts
@@ -1,4 +1,6 @@
-const config = {
+import { defineConfig } from "jest";
+
+export default defineConfig({
   preset: "ts-jest/presets/default-esm",
   testEnvironment: "node",
   moduleNameMapper: {
@@ -12,7 +14,5 @@ const config = {
   coverageReporters: ["text", "lcov"],
   collectCoverageFrom: ["**/*[^.d].(t|j)s"],
   coverageProvider: "v8",
-  projects: ["src-api", "src-code"],
-};
-
-export default config;
+  projects: ["api", "code"],
+});
diff --git a/Lara-JS/jest/WeaverLegacyTester.ts b/Lara-JS/jest/WeaverLegacyTester.ts
index c3892daf8..c428a1468 100644
--- a/Lara-JS/jest/WeaverLegacyTester.ts
+++ b/Lara-JS/jest/WeaverLegacyTester.ts
@@ -1,11 +1,11 @@
+import { jest } from "@jest/globals";
 import JavaTypes, {
-  JavaClasses,
-} from "@specs-feup/lara/api/lara/util/JavaTypes.js";
-import Weaver from "@specs-feup/lara/api/weaver/Weaver.js";
+  type JavaClasses,
+} from "@specs-feup/lara/api/lara/util/JavaTypes.ts";
+import Weaver from "@specs-feup/lara/api/weaver/Weaver.ts";
 import fs from "fs";
-import util from "util";
-import { jest } from "@jest/globals";
 import path from "path";
+import util from "util";
 
 afterAll(() => {
   const javaWeaver = Weaver.getWeaverEngine();
diff --git a/Lara-JS/jest/jestEnvironment.js b/Lara-JS/jest/jestEnvironment.ts
similarity index 51%
rename from Lara-JS/jest/jestEnvironment.js
rename to Lara-JS/jest/jestEnvironment.ts
index 0c6aeed44..a9cde408a 100644
--- a/Lara-JS/jest/jestEnvironment.js
+++ b/Lara-JS/jest/jestEnvironment.ts
@@ -1,14 +1,20 @@
-import { TestEnvironment } from "jest-environment-node";
+import type {
+  EnvironmentContext,
+  JestEnvironmentConfig,
+} from "@jest/environment";
+import type WeaverConfiguration from "@specs-feup/lara/code/WeaverConfiguration.ts";
 import java from "java";
+import { TestEnvironment } from "jest-environment-node";
 
 export default class LaraWeaverEnvironment extends TestEnvironment {
-  constructor(config, context) {
+  private weaverConfig: WeaverConfiguration;
+
+  constructor(config: JestEnvironmentConfig, context: EnvironmentContext) {
     super(config, context);
-    this.weaverConfig = config?.projectConfig?.testEnvironmentOptions?.weaverConfig;
+    this.weaverConfig = config.projectConfig.testEnvironmentOptions
+      .weaverConfig as WeaverConfiguration;
   }
 
-  weaverConfig;
-
   async setup() {
     await super.setup();
     this.global.__SHARED_MODULE__ = java;
@@ -19,8 +25,4 @@ export default class LaraWeaverEnvironment extends TestEnvironment {
   async teardown() {
     await super.teardown();
   }
-
-  runScript(script) {
-    return super.runScript(script);
-  }
 }
diff --git a/Lara-JS/jest/jestGlobalSetup.js b/Lara-JS/jest/jestGlobalSetup.js
deleted file mode 100644
index 864e7e8bb..000000000
--- a/Lara-JS/jest/jestGlobalSetup.js
+++ /dev/null
@@ -1,26 +0,0 @@
-import { Weaver } from "@specs-feup/lara/code/Weaver.js";
-
-async function oneTimeSetup(globalConfig, projectConfig) {
-  const weaverMessageFromLauncher = {
-    args: {
-      _: [],
-      $0: "",
-    },
-    config: projectConfig.testEnvironmentOptions.weaverConfig,
-  };
-
-  await Weaver.setupWeaver(
-    weaverMessageFromLauncher.args,
-    weaverMessageFromLauncher.config
-  );
-}
-
-let setupDone = false;
-
-export default async function (globalConfig, projectConfig) {
-  if (!setupDone) {
-    await oneTimeSetup(globalConfig, projectConfig);
-    setupDone = true;
-  }
-  Weaver.start();
-}
diff --git a/Lara-JS/jest/jestGlobalSetup.ts b/Lara-JS/jest/jestGlobalSetup.ts
new file mode 100644
index 000000000..d4ae593f3
--- /dev/null
+++ b/Lara-JS/jest/jestGlobalSetup.ts
@@ -0,0 +1,36 @@
+import type { Config } from "@jest/types";
+import { Weaver } from "@specs-feup/lara/code/Weaver.ts";
+import type WeaverMessageFromLauncher from "@specs-feup/lara/code/WeaverMessageFromLauncher.ts";
+import type WeaverConfiguration from "../code/WeaverConfiguration.ts";
+
+async function oneTimeSetup(
+  globalConfig: Config.GlobalConfig,
+  projectConfig: Config.ProjectConfig,
+) {
+  const weaverMessageFromLauncher: WeaverMessageFromLauncher = {
+    args: {
+      _: [],
+      $0: "",
+    },
+    config: projectConfig.testEnvironmentOptions
+      .weaverConfig as WeaverConfiguration,
+  };
+
+  await Weaver.setupWeaver(
+    weaverMessageFromLauncher.args,
+    weaverMessageFromLauncher.config,
+  );
+}
+
+let setupDone = false;
+
+export default async function (
+  globalConfig: Config.GlobalConfig,
+  projectConfig: Config.ProjectConfig,
+) {
+  if (!setupDone) {
+    await oneTimeSetup(globalConfig, projectConfig);
+    setupDone = true;
+  }
+  Weaver.start();
+}
diff --git a/Lara-JS/jest/jestGlobalTeardown.js b/Lara-JS/jest/jestGlobalTeardown.js
deleted file mode 100644
index bf203e9af..000000000
--- a/Lara-JS/jest/jestGlobalTeardown.js
+++ /dev/null
@@ -1,5 +0,0 @@
-import { Weaver } from "@specs-feup/lara/code/Weaver.js";
-
-export default function () {
-  Weaver.shutdown();
-}
diff --git a/Lara-JS/jest/jestGlobalTeardown.ts b/Lara-JS/jest/jestGlobalTeardown.ts
new file mode 100644
index 000000000..3891ecf22
--- /dev/null
+++ b/Lara-JS/jest/jestGlobalTeardown.ts
@@ -0,0 +1,5 @@
+import { Weaver } from "@specs-feup/lara/code/Weaver.ts";
+
+export default function () {
+  Weaver.shutdown();
+}
diff --git a/Lara-JS/jest/jestHelpers.ts b/Lara-JS/jest/jestHelpers.ts
index 4424663b9..503af5e0e 100644
--- a/Lara-JS/jest/jestHelpers.ts
+++ b/Lara-JS/jest/jestHelpers.ts
@@ -1,5 +1,5 @@
-import Weaver from "@specs-feup/lara/api/weaver/Weaver.js";
-import JavaTypes from "@specs-feup/lara/api/lara/util/JavaTypes.js";
+import JavaTypes from "@specs-feup/lara/api/lara/util/JavaTypes.ts";
+import Weaver from "@specs-feup/lara/api/weaver/Weaver.ts";
 
 /**
  * Registers the source code that will be used by the weaver for the purpose of this test suite.
diff --git a/Lara-JS/jest/setupFiles/importSideEffects.js b/Lara-JS/jest/setupFiles/importSideEffects.ts
similarity index 82%
rename from Lara-JS/jest/setupFiles/importSideEffects.js
rename to Lara-JS/jest/setupFiles/importSideEffects.ts
index 51295b256..87874f1ec 100644
--- a/Lara-JS/jest/setupFiles/importSideEffects.js
+++ b/Lara-JS/jest/setupFiles/importSideEffects.ts
@@ -1,10 +1,12 @@
-/* global globalThis */
-
 // Take a look at https://github.com/specs-feup/lara-framework/issues/93 for context.
 
 // This file is executed after the test environment is set up, so we can access
 // global variables set in the test environment.
 
+declare global {
+  var __LARA_IMPORT_FOR_SIDE_EFFECTS__: string[] | undefined;
+}
+
 const importForSideEffects = globalThis.__LARA_IMPORT_FOR_SIDE_EFFECTS__ ?? [];
 
 for (const specifier of importForSideEffects) {
diff --git a/Lara-JS/jest/setupFiles/sharedJavaModule.js b/Lara-JS/jest/setupFiles/sharedJavaModule.ts
similarity index 57%
rename from Lara-JS/jest/setupFiles/sharedJavaModule.js
rename to Lara-JS/jest/setupFiles/sharedJavaModule.ts
index 6e4c93a7e..2c0e6f0f7 100644
--- a/Lara-JS/jest/setupFiles/sharedJavaModule.js
+++ b/Lara-JS/jest/setupFiles/sharedJavaModule.ts
@@ -1,5 +1,7 @@
-/* global global */
-
 import { jest } from "@jest/globals";
 
+declare global {
+  var __SHARED_MODULE__: typeof import("java");
+}
+
 jest.mock("java", () => global.__SHARED_MODULE__);
diff --git a/Lara-JS/jest/tsconfig.json b/Lara-JS/jest/tsconfig.json
deleted file mode 100644
index 06dbc4d49..000000000
--- a/Lara-JS/jest/tsconfig.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "extends": "../tsconfig.json",
-  "compilerOptions": {
-    "noEmit": true,
-  },
-}
\ No newline at end of file
diff --git a/Lara-JS/package.json b/Lara-JS/package.json
index 6251d5b7f..29c947848 100644
--- a/Lara-JS/package.json
+++ b/Lara-JS/package.json
@@ -4,39 +4,55 @@
   "description": "A js port of the popular framework for building source-to-source compilers",
   "type": "module",
   "bin": {
-    "lara-build-interfaces": "scripts/build-interfaces.js"
+    "lara-build-interfaces": "./scripts/build-interfaces.ts"
+  },
+  "exports": {
+    "./api/*.test.ts": null,
+    "./api/*.config.ts": null,
+    "./api/*.js": "./api/*.ts",
+    "./api/*": "./api/*.ts",
+    "./api/*.ts": "./api/*.ts",
+    "./code/*.test.ts": null,
+    "./code/*.config.ts": null,
+    "./code/*.js": "./code/*.ts",
+    "./code/*": "./code/*.ts",
+    "./code/*.ts": "./code/*.ts",
+    "./jest/*.test.ts": null,
+    "./jest/*.config.ts": null,
+    "./jest/*.js": "./jest/*.ts",
+    "./jest/*": "./jest/*.ts",
+    "./jest/*.ts": "./jest/*.ts",
+    "./eslint.config.ts": "./eslint.config.ts",
+    "./jest.config.ts": "./jest.config.ts",
+    "./LaraJoinPointSpecification.json": "./LaraJoinPointSpecification.json",
+    "./typedoc.base.json": "./typedoc.base.json"
   },
   "files": [
     "api",
     "code",
     "jest",
     "scripts",
-    "src-api",
-    "src-code",
     ".gitignore",
-    "eslint.config.js",
-    "jest.config.js",
+    "eslint.config.ts",
+    "jest.config.ts",
     "LaraJoinPointSpecification.json",
     "LICENSE",
     "package.json",
     "README.md",
-    "tsconfig.jest.json",
     "tsconfig.json",
     "typedoc.base.json",
-    "typedoc.json"
+    "typedoc.config.js"
   ],
   "scripts": {
-    "build": "npx tsc -b src-api src-code",
-    "build:api": "npx tsc -b src-api",
-    "build:code": "npx tsc -b src-code",
+    "build": "tsc",
     "build:watch": "npm run build -- --watch",
-    "lint": "eslint .",
+    "lint": "eslint --flag unstable_native_nodejs_ts_config .",
     "test": "cross-env NODE_OPTIONS=\"$NODE_OPTIONS --experimental-vm-modules\" jest --detectOpenHandles --forceExit",
-    "test:api": "npm run test -- src-api",
-    "test:code": "npm run test -- src-code",
+    "test:api": "npm run test -- api",
+    "test:code": "npm run test -- code",
     "test:cov": "npm run test -- --coverage",
     "test:watch": "npm run test -- --watch",
-    "build-interfaces": "node scripts/build-LaraJoinPoint --input LaraJoinPointSpecification.json --output src-api/LaraJoinPoint.ts"
+    "build-interfaces": "node scripts/build-LaraJoinPoint.ts --input LaraJoinPointSpecification.json --output api/LaraJoinPoint.ts"
   },
   "repository": {
     "type": "git",
@@ -57,7 +73,7 @@
   },
   "homepage": "https://github.com/specs-feup/lara-framework#readme",
   "engines": {
-    "node": ">=18.18"
+    "node": ">=24.0.0"
   },
   "dependencies": {
     "chokidar": "^5.0.0",
@@ -72,7 +88,7 @@
     "@jest/globals": "^30.2.0",
     "@types/debug": "^4.1.12",
     "@types/jest": "^30.0.0",
-    "@types/node": "^20.14.10",
+    "@types/node": "^25.0.0",
     "@types/yargs": "^17.0.35",
     "cross-env": "^10.1.0",
     "eslint": "^9.39.2",
@@ -82,7 +98,7 @@
     "jest": "^30.2.0",
     "node-notifier": "^10.0.1",
     "ts-jest": "^29.4.6",
-    "typescript": "^5.9.3",
+    "typescript": "^6.0.3",
     "typescript-eslint": "^8.52.0"
   }
 }
diff --git a/Lara-JS/scripts/build-LaraJoinPoint.js b/Lara-JS/scripts/build-LaraJoinPoint.ts
similarity index 91%
rename from Lara-JS/scripts/build-LaraJoinPoint.js
rename to Lara-JS/scripts/build-LaraJoinPoint.ts
index 55b7b13ca..4610deb20 100644
--- a/Lara-JS/scripts/build-LaraJoinPoint.js
+++ b/Lara-JS/scripts/build-LaraJoinPoint.ts
@@ -3,12 +3,12 @@
 import fs from "fs";
 import yargs from "yargs";
 import { hideBin } from "yargs/helpers";
-import { convertSpecification } from "./convert-joinpoint-specification.js";
+import { convertSpecification, type ConvertedJoinpoint, type JSON_LanguageSpecification } from "./convert-joinpoint-specification.ts";
 
-import { generateJoinpoints, generateEnums } from "./generate-ts-joinpoints.js";
+import { generateJoinpoints, generateEnums } from "./generate-ts-joinpoints.ts";
 
-function buildLaraJoinPoint(inputFileName, outputFileName) {
-  console.log("Hello from build-LaraJoinPoint.js");
+function buildLaraJoinPoint(inputFileName: string, outputFileName: string) {
+  console.log("Hello from build-LaraJoinPoint.ts");
   console.log("inputFile:", inputFileName);
   console.log("outputFile:", outputFileName);
 
@@ -22,12 +22,12 @@ function buildLaraJoinPoint(inputFileName, outputFileName) {
   fs.writeSync(
     outputFile,
     `//////////////////////////////////////////////////////
-// This file is generated by build-LaraJoinPoint.js //
+// This file is generated by build-LaraJoinPoint.ts //
 //////////////////////////////////////////////////////
 
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
-import JavaTypes from "./lara/util/JavaTypes.js";
+import JavaTypes from "./lara/util/JavaTypes.ts";
 
 /**
  * Type for type equality assertion. If T is equal to U, return Y, otherwise return N.
@@ -77,7 +77,7 @@ export type NameFromWrapperClass<T extends typeof LaraJoinPoint> = NameFromWrapp
   fs.closeSync(outputFile);
 }
 
-function promoteToStringFromAttributeToAction(specification) {
+function promoteToStringFromAttributeToAction(specification: JSON_LanguageSpecification) {
   specification.children?.forEach((child) => {
     if (child.type === "joinpoint") {
       child.children?.forEach((member) => {
@@ -93,7 +93,7 @@ function promoteToStringFromAttributeToAction(specification) {
   });
 }
 
-function generateJoinpointWrapper(joinpoints, outputFile) {
+function generateJoinpointWrapper(joinpoints: ConvertedJoinpoint[], outputFile: number) {
   fs.writeSync(
     outputFile,
     `/**
@@ -280,15 +280,17 @@ const args = yargs(hideBin(process.argv))
     alias: "input",
     describe: "Path to JSON config file",
     type: "string",
+    demandOption: true,
   })
   .option("o", {
     alias: "output",
     describe: "Path to the output file",
     type: "string",
+    demandOption: true,
   })
   .help()
   .showHelpOnFail(true)
   .strict()
-  .parse();
+  .parseSync();
 
-buildLaraJoinPoint(args.input, args.output);
+buildLaraJoinPoint(args.i, args.o);
diff --git a/Lara-JS/scripts/build-interfaces.js b/Lara-JS/scripts/build-interfaces.ts
similarity index 80%
rename from Lara-JS/scripts/build-interfaces.js
rename to Lara-JS/scripts/build-interfaces.ts
index 8ec978ff6..71faf4b18 100755
--- a/Lara-JS/scripts/build-interfaces.js
+++ b/Lara-JS/scripts/build-interfaces.ts
@@ -3,16 +3,16 @@
 import fs from "fs";
 import yargs from "yargs";
 import { hideBin } from "yargs/helpers";
-import { convertSpecification } from "./convert-joinpoint-specification.js";
+import { convertSpecification, type ConvertedEnum, type ConvertedJoinpoint } from "./convert-joinpoint-specification.ts";
 
-import { generateJoinpoints, generateEnums } from "./generate-ts-joinpoints.js";
+import { generateJoinpoints, generateEnums } from "./generate-ts-joinpoints.ts";
 
 async function buildInterfaces(
-  inputFileName,
-  laraJoinPointSpecificationImportPath,
-  outputFileName
+  inputFileName: string,
+  laraJoinPointSpecificationImportPath: string,
+  outputFileName: string
 ) {
-  console.log("Hello from build-interfaces.js");
+  console.log("Hello from build-interfaces.ts");
   console.log("inputFile:", inputFileName);
   console.log(
     "LaraJoinPointSpecificationFile: ",
@@ -45,7 +45,7 @@ async function buildInterfaces(
   fs.writeSync(
     outputFile,
     `///////////////////////////////////////////////////
-// This file is generated by build-interfaces.js //
+// This file is generated by build-interfaces.ts //
 ///////////////////////////////////////////////////
 
 import {
@@ -54,7 +54,7 @@ import {
   wrapJoinPoint,
   unwrapJoinPoint,
 ${importedEnums.map((name) => `  ${name},`).join("\n")}
-} from "@specs-feup/lara/api/LaraJoinPoint.js";\n\n`
+} from "@specs-feup/lara/api/LaraJoinPoint.ts";\n\n`
   );
 
   generateDefaultAttributeMappers(specification.joinpoints, outputFile);
@@ -74,7 +74,7 @@ ${importedEnums.map((name) => `  ${name},`).join("\n")}
   fs.closeSync(outputFile);
 }
 
-function generateJoinpointMappers(joinpoints, enums, outputFile) {
+function generateJoinpointMappers(joinpoints: ConvertedJoinpoint[], enums: ConvertedEnum[], outputFile: number) {
   fs.writeSync(outputFile, `const JoinpointMapper = {\n`);
   for (const jp of joinpoints) {
     fs.writeSync(outputFile, `  ${jp.originalName}: ${jp.name},\n`);
@@ -91,7 +91,7 @@ if (!registered) {
   );
 }
 
-function generateDefaultAttributeMappers(joinpoints, outputFile) {
+function generateDefaultAttributeMappers(joinpoints: ConvertedJoinpoint[], outputFile: number) {
   fs.writeSync(outputFile, `type PrivateMapper = {\n`);
   for (const jp of joinpoints) {
     fs.writeSync(outputFile, `  "${jp.name}": typeof ${jp.name},\n`);
@@ -113,20 +113,23 @@ const args = yargs(hideBin(process.argv))
     alias: "input",
     describe: "Path to JSON config file",
     type: "string",
+    demandOption: true,
   })
   .option("l", {
     alias: "lara",
     describe: "Path to JSON config file that describes LaraJoinPoint",
     type: "string",
+    demandOption: true,
   })
   .option("o", {
     alias: "output",
     describe: "Path to the output file",
     type: "string",
+    demandOption: true,
   })
   .help()
   .showHelpOnFail(true)
   .strict()
-  .parse();
+  .parseSync();
 
-await buildInterfaces(args.input, args.lara, args.output);
+await buildInterfaces(args.i, args.l, args.o);
diff --git a/Lara-JS/scripts/convert-joinpoint-specification.js b/Lara-JS/scripts/convert-joinpoint-specification.ts
similarity index 67%
rename from Lara-JS/scripts/convert-joinpoint-specification.js
rename to Lara-JS/scripts/convert-joinpoint-specification.ts
index 47a9e469e..2195a25ac 100644
--- a/Lara-JS/scripts/convert-joinpoint-specification.js
+++ b/Lara-JS/scripts/convert-joinpoint-specification.ts
@@ -1,11 +1,88 @@
 #!/usr/bin/env node
 
-export function convertSpecification(input, baseJoinPointSpec = undefined) {
-  let typeNameSet = new Set();
-  let joinpointNameSet = new Set();
-  let unorderedJoinpoints = [];
-  let enumNameSet = new Set();
-  let unorderedEnums = [];
+export type JSON_LanguageSpecification = {
+  root: string;
+  rootAlias: string;
+  importEnums?: string[];
+  children: (JSON_JoinpointSpecification | JSON_EnumSpecification)[];
+};
+
+type JSON_JoinpointSpecification = {
+  type: "joinpoint";
+  name: string;
+  extends: string;
+  defaultAttr?: string;
+  tooltip?: string;
+  children?: JSON_JoinpointMemberSpecification[];
+};
+
+type JSON_JoinpointMemberSpecification = {
+  type: "attribute" | "action";
+  tooltip?: string;
+  children: JSON_ParameterSpecification[];
+};
+
+type JSON_ParameterSpecification = {
+  name: string;
+  type: string;
+  defaultValue: string;
+}
+
+type JSON_EnumSpecification = {
+  type: "enum";
+  name: string;
+  extends?: string;
+  children: { value: string }[];
+};
+
+export type ConvertedSpecification = {
+  joinpoints: ConvertedJoinpoint[];
+  enums: ConvertedEnum[];
+  importEnums: string[];
+};
+
+export type ConvertedJoinpoint = {
+  name: string;
+  originalName: string;
+  tooltip?: string;
+  extends?: string;
+  attributes: ConvertedAttribute[];
+  actions: ConvertedAction[];
+  defaultAttribute?: string;
+};
+
+export type ConvertedAttribute = {
+  name: string;
+  type: string;
+  tooltip?: string;
+};
+
+export type ConvertedAction = {
+  name: string;
+  tooltip?: string;
+  returnType: string;
+  parameters: ConvertedParameter[];
+  overloads: ConvertedAction[];
+};
+
+export type ConvertedParameter = {
+  name: string;
+  type: string;
+  default: string;
+};
+
+export type ConvertedEnum = {
+  name: string;
+  extends?: string;
+  entries: string[];
+};
+
+export function convertSpecification(input: JSON_LanguageSpecification, baseJoinPointSpec?: ConvertedSpecification | undefined): ConvertedSpecification {
+  const typeNameSet = new Set<string>();
+  const joinpointNameSet = new Set<string>();
+  const unorderedJoinpoints: JSON_JoinpointSpecification[] = [];
+  const enumNameSet = new Set<string>();
+  const unorderedEnums: JSON_EnumSpecification[] = [];
 
   input.children.forEach((child) => {
     typeNameSet.add(child.type);
@@ -19,10 +96,10 @@ export function convertSpecification(input, baseJoinPointSpec = undefined) {
     }
   });
 
-  let joinpoints = orderJoinpoints(unorderedJoinpoints);
-  let enums = orderJoinpoints(unorderedEnums);
+  const joinpoints = orderJoinpoints(unorderedJoinpoints);
+  const enums = orderJoinpoints(unorderedEnums);
 
-  let output = {
+  const output: ConvertedSpecification = {
     joinpoints: convertJoinpoints(joinpoints, joinpointNameSet, enumNameSet),
     enums: convertEnums(enums),
     importEnums: Array.isArray(input.importEnums) ? [...input.importEnums] : [],
@@ -37,10 +114,10 @@ export function convertSpecification(input, baseJoinPointSpec = undefined) {
   return output;
 }
 
-function orderJoinpoints(unorderedJoinpoints) {
-  let orderedNameSet = new Set();
-  let blockedJpSet = new Set();
-  let joinpoints = [];
+function orderJoinpoints<T extends JSON_JoinpointSpecification | JSON_EnumSpecification>(unorderedJoinpoints: T[]): T[] {
+  const orderedNameSet = new Set<string>();
+  const blockedJpSet = new Set<T>();
+  const joinpoints: T[] = [];
 
   unorderedJoinpoints.forEach((jp) => {
     if (jp.extends) {
@@ -57,7 +134,7 @@ function orderJoinpoints(unorderedJoinpoints) {
   });
   while (blockedJpSet.size > 0) {
     blockedJpSet.forEach((jp) => {
-      if (orderedNameSet.has(jp.extends)) {
+      if (jp.extends && orderedNameSet.has(jp.extends)) {
         joinpoints.push(jp);
         orderedNameSet.add(jp.name);
         blockedJpSet.delete(jp);
@@ -68,15 +145,8 @@ function orderJoinpoints(unorderedJoinpoints) {
   return joinpoints;
 }
 
-/**
- *
- * @param {*} joinpoints
- * @param {Set<string>} joinpointNameSet
- * @param {Set<string>} enumNameSet
- * @returns {ReturnType<convertJoinpoint>[]}
- */
-function convertJoinpoints(joinpoints, joinpointNameSet, enumNameSet) {
-  let convertedJoinpoints = [];
+function convertJoinpoints(joinpoints: JSON_JoinpointSpecification[], joinpointNameSet: Set<string>, enumNameSet: Set<string>) {
+  const convertedJoinpoints: ConvertedJoinpoint[] = [];
 
   joinpoints.forEach((jp) => {
     convertedJoinpoints.push(
@@ -87,17 +157,10 @@ function convertJoinpoints(joinpoints, joinpointNameSet, enumNameSet) {
   return convertedJoinpoints;
 }
 
-/**
- *
- * @param {*} jp
- * @param {Set<string>} joinpointNameSet
- * @param {Set<string>} enumNameSet
- * @returns { { name: string, originalName: string, tooltip: string, extends: string | undefined, attributes: ReturnType<convertJoinpointAttribute>[], actions: { name: string, tooltip: string, returnType: string, parameters: ReturnType<convertJoinpointActionParameter>[], overloads: never[] }[] }, defaultAttribute: string | undefined }
- */
-function convertJoinpoint(jp, joinpointNameSet, enumNameSet) {
-  let attributes = [];
-  let actions = [];
-  const actionNameSet = new Set();
+function convertJoinpoint(jp: JSON_JoinpointSpecification, joinpointNameSet: Set<string>, enumNameSet: Set<string>): ConvertedJoinpoint {
+  const attributes: ConvertedAttribute[] = [];
+  const actions: ConvertedAction[] = [];
+  const actionNameSet = new Set<string>();
 
   jp.children?.forEach((child) => {
     switch (child.type) {
@@ -125,11 +188,8 @@ function convertJoinpoint(jp, joinpointNameSet, enumNameSet) {
           actionNameSet
         );
         break;
-      case "select":
-        // Do nothing
-        break;
       default:
-        console.log("Unknown child type:", child.type);
+        console.log("Unknown child type:", (child as { type: string }).type);
     }
   });
 
@@ -150,35 +210,23 @@ function convertJoinpoint(jp, joinpointNameSet, enumNameSet) {
   };
 }
 
-/**
- *
- * @param {string} notice
- * @returns {string}
- */
-function convertDeprecationNotice(notice) {
+function convertDeprecationNotice(notice: string | undefined): string | undefined {
   if (notice?.includes("DEPRECATED")) {
     notice = notice.replace("[DEPRECATED:", "@deprecated");
     notice = notice.replace("DEPRECATED:", "@deprecated");
 
-    let splitTooltip = notice.split("]");
+    const splitTooltip = notice.split("]");
 
     notice = splitTooltip.slice(1).join("]") + "\n\n" + splitTooltip[0];
   }
   return capitalizeFirstLetter(notice)?.trim();
 }
 
-/**
- *
- * @param {*} attributeObject
- * @param {Set<string>} joinpointNameSet
- * @param {Set<string>} enumNameSet
- * @returns { { name: string, type: string, default: string } }
- */
 function convertJoinpointAttribute(
-  attributeObject,
-  joinpointNameSet,
-  enumNameSet
-) {
+  attributeObject: JSON_JoinpointMemberSpecification,
+  joinpointNameSet: Set<string>,
+  enumNameSet: Set<string>
+): ConvertedAttribute {
   const attribute = attributeObject.children[0];
 
   return {
@@ -188,18 +236,11 @@ function convertJoinpointAttribute(
   };
 }
 
-/**
- *
- * @param {*} parameterObject
- * @param {Set<string>} joinpointNameSet
- * @param {Set<string>} enumNameSet
- * @returns { { name: string, type: string, default: string } }
- */
 function convertJoinpointActionParameter(
-  parameterObject,
-  joinpointNameSet,
-  enumNameSet
-) {
+  parameterObject: JSON_ParameterSpecification,
+  joinpointNameSet: Set<string>,
+  enumNameSet: Set<string>
+): ConvertedParameter {
   const type = interpretType(
     parameterObject.type,
     joinpointNameSet,
@@ -214,7 +255,7 @@ function convertJoinpointActionParameter(
       parameterName = "elseStatement";
   }
 
-  let defaultValue = parameterObject.defaultValue;
+  let defaultValue: string | undefined = parameterObject.defaultValue;
   if (defaultValue === "") {
     defaultValue = undefined;
   }
@@ -226,24 +267,14 @@ function convertJoinpointActionParameter(
   };
 }
 
-/**
- *
- * @param {Object} actionObject
- * @param {Set<string>} joinpointNameSet
- * @param {Set<string>} enumNameSet
- * @param {Object[]} actions
- * @param {Set<string>} actionNameSet
- * @param {string} [overrideName=null]
- * @returns
- */
 function convertJoinpointAction(
-  actionObject,
-  joinpointNameSet,
-  enumNameSet,
-  actions,
-  actionNameSet,
-  overrideName = null
-) {
+  actionObject: JSON_JoinpointMemberSpecification,
+  joinpointNameSet: Set<string>,
+  enumNameSet: Set<string>,
+  actions: ConvertedAction[],
+  actionNameSet: Set<string>,
+  overrideName: string | null = null
+): void {
   const action = actionObject.children[0];
   const actionName = overrideName ?? action.name;
 
@@ -327,27 +358,11 @@ function convertJoinpointAction(
   actions.push(convertedAction);
 }
 
-/**
- *
- * @param {Object[]} enums
- * @returns {(ReturnType<convertEnum>)[]}
- */
-function convertEnums(enums) {
-  let convertedEnums = [];
-
-  enums.forEach((enumObj) => {
-    convertedEnums.push(convertEnum(enumObj));
-  });
-
-  return convertedEnums;
+function convertEnums(enums: JSON_EnumSpecification[]) {
+  return enums.map((enumObj) => convertEnum(enumObj));
 }
 
-/**
- *
- * @param {Object} e
- * @returns { {name: string, extends: string, entries: string[]} }
- */
-function convertEnum(e) {
+function convertEnum(e: JSON_EnumSpecification): ConvertedEnum {
   return {
     name: e.name,
     extends: e.extends,
@@ -359,11 +374,11 @@ function convertEnum(e) {
 
 /**
  * Splits `text` on `separator` occurrences that are not nested inside <> or [].
- * @param {string} text
- * @param {string} separator
- * @returns {string[]}
+ * @param text
+ * @param separator
+ * @returns
  */
-function splitTopLevel(text, separator) {
+function splitTopLevel(text: string, separator: string): string[] {
   const parts = [];
   let depth = 0;
   let current = "";
@@ -384,24 +399,15 @@ function splitTopLevel(text, separator) {
   return parts;
 }
 
-/**
- *
- * @param {string} string
- * @returns {string}
- */
-export function capitalizeFirstLetter(string) {
+export function capitalizeFirstLetter(string: string): string;
+export function capitalizeFirstLetter(string: undefined): undefined;
+export function capitalizeFirstLetter(string: string | undefined): string | undefined;
+export function capitalizeFirstLetter(string: string | undefined): string | undefined {
   if (!string) return string;
   return string.charAt(0).toUpperCase() + string.slice(1);
 }
 
-/**
- *
- * @param {string} typeString
- * @param {Set<string>} joinpointNameSet
- * @param {Set<string>} enumNameSet
- * @returns {string}
- */
-function interpretType(typeString, joinpointNameSet, enumNameSet) {
+function interpretType(typeString: string, joinpointNameSet: Set<string>, enumNameSet: Set<string>): string {
   if (typeString === "?") {
     return "any";
   }
@@ -454,7 +460,6 @@ function interpretType(typeString, joinpointNameSet, enumNameSet) {
     case "Double":
     case "double":
       return "number";
-      break;
     case "map<?, ?>":
     case "Map<?, ?>":
     case "map":
@@ -462,11 +467,10 @@ function interpretType(typeString, joinpointNameSet, enumNameSet) {
       return "Record<string, any>";
     default:
       return typeString.toLowerCase();
-      break;
   }
 }
 
-function deduplicateJoinpoints(joinpoints, baseJoinPointSpec = undefined) {
+function deduplicateJoinpoints(joinpoints: ConvertedJoinpoint[], baseJoinPointSpec?: ConvertedSpecification | undefined) {
   for (const joinpoint of joinpoints) {
     // Find the parent joinpoint
     let parentJoinpoint = joinpoints.find(
@@ -479,7 +483,7 @@ function deduplicateJoinpoints(joinpoints, baseJoinPointSpec = undefined) {
     }
 
     while (parentJoinpoint) {
-      for (const attributeIndex in joinpoint.attributes) {
+      for (let attributeIndex = 0; attributeIndex < joinpoint.attributes.length; attributeIndex++) {
         for (const parentAttribute of parentJoinpoint.attributes) {
           if (
             JSON.stringify(joinpoint.attributes[attributeIndex]) ===
@@ -490,7 +494,7 @@ function deduplicateJoinpoints(joinpoints, baseJoinPointSpec = undefined) {
         }
       }
 
-      for (const actionIndex in joinpoint.actions) {
+      for (let actionIndex = 0; actionIndex < joinpoint.actions.length; actionIndex++) {
         for (const parentAction of parentJoinpoint.actions) {
           if (
             JSON.stringify(joinpoint.actions[actionIndex]) ===
@@ -502,7 +506,7 @@ function deduplicateJoinpoints(joinpoints, baseJoinPointSpec = undefined) {
       }
 
       parentJoinpoint = joinpoints.find(
-        (jp) => jp.name === parentJoinpoint.extends
+        (jp) => jp.name === parentJoinpoint!.extends
       );
     }
   }
diff --git a/Lara-JS/scripts/copy-folder.js b/Lara-JS/scripts/copy-folder.ts
similarity index 78%
rename from Lara-JS/scripts/copy-folder.js
rename to Lara-JS/scripts/copy-folder.ts
index 24457f12c..085ead745 100644
--- a/Lara-JS/scripts/copy-folder.js
+++ b/Lara-JS/scripts/copy-folder.ts
@@ -2,9 +2,9 @@
 
 import fs from "fs";
 import path from "path";
+import { fileURLToPath } from "url";
 import yargs from "yargs";
 import { hideBin } from "yargs/helpers";
-import { fileURLToPath } from "url";
 
 if (fileURLToPath(import.meta.url) === process.argv[1]) {
   // This script is being executed directly
@@ -14,11 +14,13 @@ if (fileURLToPath(import.meta.url) === process.argv[1]) {
       alias: "inputFolder",
       describe: "Path to the source folder",
       type: "string",
+      demandOption: true,
     })
     .option("o", {
       alias: "outputFolder",
       describe: "Path to the destination folder",
       type: "string",
+      demandOption: true,
     })
     .option("e", {
       alias: "extension",
@@ -33,32 +35,21 @@ if (fileURLToPath(import.meta.url) === process.argv[1]) {
     .help()
     .showHelpOnFail(true)
     .strict()
-    .parse();
+    .parseSync();
 
-  copyFolder(
-    args.inputFolder,
-    args.outputFolder,
-    args.extension,
-    args.newExtension
-  );
+  copyFolder(args.i, args.o, args.e, args.newExtension);
 }
 
 /**
  * Copied files will have .mjs extension.
- *
- * @param {string} sourceDir
- * @param {string} destinationDir
- * @param {RegExp} extension
- * @param {RegExp} targetExtension
- * @returns
  */
 export default function copyFolder(
-  sourceDir,
-  destinationDir,
-  extension,
-  targetExtension = extension
+  sourceDir: string,
+  destinationDir: string,
+  extension?: string,
+  targetExtension = extension,
 ) {
-  const copiedFiles = [];
+  const copiedFiles: string[] = [];
 
   const files = fs.readdirSync(sourceDir);
   fs.mkdirSync(destinationDir, { recursive: true });
@@ -77,13 +68,15 @@ export default function copyFolder(
         sourcePath,
         newDestinationDir,
         extension,
-        targetExtension
+        targetExtension,
       );
 
       copiedFiles.push(...subDirectoryCopiedFiles);
     } else if (extension === undefined || file.endsWith(extension)) {
-      const targetFileName = extension === undefined ? file :
-        file.substring(0, file.length - extension.length) + targetExtension;
+      const targetFileName =
+        extension === undefined
+          ? file
+          : file.substring(0, file.length - extension.length) + targetExtension;
 
       const destinationPath = path.join(destinationDir, targetFileName);
 
diff --git a/Lara-JS/scripts/generate-ts-joinpoints.js b/Lara-JS/scripts/generate-ts-joinpoints.ts
similarity index 77%
rename from Lara-JS/scripts/generate-ts-joinpoints.js
rename to Lara-JS/scripts/generate-ts-joinpoints.ts
index 32358807d..9d6dbe111 100644
--- a/Lara-JS/scripts/generate-ts-joinpoints.js
+++ b/Lara-JS/scripts/generate-ts-joinpoints.ts
@@ -1,13 +1,13 @@
 import fs from "fs";
-import { capitalizeFirstLetter } from "./convert-joinpoint-specification.js";
+import { capitalizeFirstLetter, type ConvertedAction, type ConvertedAttribute, type ConvertedEnum, type ConvertedJoinpoint } from "./convert-joinpoint-specification.ts";
 
-export function generateJoinpoints(joinpoints, outputFile) {
+export function generateJoinpoints(joinpoints: ConvertedJoinpoint[], outputFile: number) {
   for (const jp of joinpoints) {
     generateJoinpoint(jp, outputFile, joinpoints);
   }
 }
 
-function generateJoinpoint(jp, outputFile, joinpoints) {
+function generateJoinpoint(jp: ConvertedJoinpoint, outputFile: number, joinpoints: ConvertedJoinpoint[]) {
   fs.writeSync(
     outputFile,
     `${generateDocumentation(jp.tooltip)}export class ${jp.name}${
@@ -66,14 +66,14 @@ function generateJoinpoint(jp, outputFile, joinpoints) {
   fs.writeSync(outputFile, `}\n\n`);
 }
 
-function generateDocumentation(tooltip) {
+function generateDocumentation(tooltip: string | undefined): string {
   if (!tooltip) {
     return "";
   }
   return `  /**\n   * ${tooltip.split("\n").join("\n   * ")}\n   */\n`;
 }
 
-function escapeJavaReservedKeywords(name) {
+function escapeJavaReservedKeywords(name: string): string {
   const reservedKeywords = new Set([
     "abstract", "assert", "boolean", "break", "byte", "case", "catch", "char",
     "class", "const", "continue", "default", "do", "double", "else", "enum",
@@ -91,7 +91,7 @@ function escapeJavaReservedKeywords(name) {
   return name;
 }
 
-function generateJoinpointAttribute(attribute, outputFile, joinpointActions) {
+function generateJoinpointAttribute(attribute: ConvertedAttribute, outputFile: number, joinpointActions: ConvertedAction[]) {
   if (attribute.name === "data") {
     fs.writeSync(
       outputFile,
@@ -120,7 +120,7 @@ function generateJoinpointAttribute(attribute, outputFile, joinpointActions) {
     setterActions = setterActions[0].overloads.filter((overload) => {
       const requiredParameters = overload.parameters.reduce(
         (acc, parameter) => {
-          if (parameter.defaultValue === undefined) {
+          if (parameter.default === undefined) {
             return acc + 1;
           }
           return acc;
@@ -137,7 +137,7 @@ function generateJoinpointAttribute(attribute, outputFile, joinpointActions) {
   }
 
   const setterParameterType = setterActions
-    .reduce((type, action) => {
+    .reduce((type: string[], action) => {
       if (action.parameters.length) {
         type.push(action.parameters[0].type);
       }
@@ -155,7 +155,7 @@ function generateJoinpointAttribute(attribute, outputFile, joinpointActions) {
   );
 }
 
-function generateJoinpointActionParameters(action) {
+function generateJoinpointActionParameters(action: ConvertedAction): string {
   return action.parameters
     .map((parameter) => {
       let paramStr = parameter.name;
@@ -173,7 +173,7 @@ function generateJoinpointActionParameters(action) {
     .join(", ");
 }
 
-function generateJoinpointAction(action, outputFile, joinpoints) {
+function generateJoinpointAction(action: ConvertedAction, outputFile: number, joinpoints: ConvertedJoinpoint[]) {
   const parameters = generateJoinpointActionParameters(action);
 
   const callParameters = action.parameters
@@ -193,16 +193,25 @@ function generateJoinpointAction(action, outputFile, joinpoints) {
   );
 }
 
-export function generateEnums(enums, outputFile) {
+export function generateEnums(enums: ConvertedEnum[], outputFile: number) {
   for (const e of enums) {
     generateEnum(e, outputFile);
   }
 }
 
-function generateEnum(e, outputFile) {
-  fs.writeSync(outputFile, `export enum ${e.name} {\n`);
+function generateEnum(e: ConvertedEnum, outputFile: number) {
+  fs.writeSync(outputFile, `/**
+ * This is supposed to be an enum, but Node.js v25 does bot support TS' enums, only erasable-syntax.
+ * Revert to an enum when Node.js supports it, or when we move to a different engine that supports it.
+ * This and the "type" declaration below.
+ */\n`);
+  fs.writeSync(outputFile, `export const ${e.name} = {\n`);
   e.entries.forEach((entry) => {
-    fs.writeSync(outputFile, `  ${entry} = "${entry.toLowerCase()}",\n`);
+    fs.writeSync(outputFile, `  ${entry}: "${entry.toLowerCase()}",\n`);
   });
-  fs.writeSync(outputFile, `}\n\n`);
+  fs.writeSync(outputFile, `} as const;\n`);
+  fs.writeSync(
+    outputFile,
+    `export type ${e.name} = typeof ${e.name}[keyof typeof ${e.name}];\n\n`
+  );
 }
diff --git a/Lara-JS/src-api/lara/graphs/GraphEdge.ts b/Lara-JS/src-api/lara/graphs/GraphEdge.ts
deleted file mode 100644
index 5b932b483..000000000
--- a/Lara-JS/src-api/lara/graphs/GraphEdge.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import EdgeData from "./EdgeData.js";
-
-/**
- * Base class for graph edges.
- *
- * @deprecated use lara.graphs.EdgeData instead
- */
-type GraphEdge = EdgeData;
-export default GraphEdge;
diff --git a/Lara-JS/src-api/lara/graphs/GraphNode.ts b/Lara-JS/src-api/lara/graphs/GraphNode.ts
deleted file mode 100644
index 786ca20c3..000000000
--- a/Lara-JS/src-api/lara/graphs/GraphNode.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import NodeData from "./NodeData.js";
-
-/**
- * Base class for graph nodes.
- *
- * @deprecated use lara.graphs.NodeData instead
- */
-type GraphNode = NodeData;
-export default GraphNode;
diff --git a/Lara-JS/src-api/tsconfig.json b/Lara-JS/src-api/tsconfig.json
deleted file mode 100644
index b03a6a89e..000000000
--- a/Lara-JS/src-api/tsconfig.json
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-  "extends": "../tsconfig.json",
-  "compilerOptions": {
-    "outDir": "../api"
-  },
-  "exclude": ["node_modules", "**/*.spec.ts", "**/*.test.ts"],
-  "references": [{ "path": "../src-code" }]
-}
diff --git a/Lara-JS/src-api/weaver/TraversalType.ts b/Lara-JS/src-api/weaver/TraversalType.ts
deleted file mode 100644
index 41614aa16..000000000
--- a/Lara-JS/src-api/weaver/TraversalType.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * Enumeration of AST traversal types.
- */
-enum TraversalType {
-  PREORDER = "preorder",
-  POSTORDER = "postorder",
-}
-
-export default TraversalType;
diff --git a/Lara-JS/src-api/weaver/predicate/JpPredicate.ts b/Lara-JS/src-api/weaver/predicate/JpPredicate.ts
deleted file mode 100644
index c30f6e3d5..000000000
--- a/Lara-JS/src-api/weaver/predicate/JpPredicate.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import { LaraJoinPoint } from "../../LaraJoinPoint.js";
-
-export default abstract class JpPredicate {
-  
-    /**
-     * @returns the name of the join point
-     */
-    abstract jpName() : string;
-
-    /**
-     * @returns true if the underlying type is THE class LaraJoinPoint
-     */
-    abstract isLaraJoinPoint() : boolean;
-
-    /**
-     * 
-     * @param jp the join point we want to test
-     * @returns true if the join point is accepted by this predicate 
-     */
-    abstract isInstance<T extends LaraJoinPoint>(jp: T):boolean
-}
\ No newline at end of file
diff --git a/Lara-JS/src-code/FileExtensions.ts b/Lara-JS/src-code/FileExtensions.ts
deleted file mode 100644
index a1e392832..000000000
--- a/Lara-JS/src-code/FileExtensions.ts
+++ /dev/null
@@ -1,15 +0,0 @@
-export enum FileExtensions {
-  JS = ".js",
-  MJS = ".mjs",
-  CJS = ".cjs",
-}
-
-/**
- * Checks if a file extension is valid.
- *
- * @param extension - The file extension to check.
- * @returns `true` if the file extension is valid, `false` otherwise.
- */
-export const isValidFileExtension = (extension: string): boolean => {
-  return Object.values(FileExtensions).includes(extension as FileExtensions);
-};
diff --git a/Lara-JS/src-code/tsconfig.json b/Lara-JS/src-code/tsconfig.json
deleted file mode 100644
index 8061f3caf..000000000
--- a/Lara-JS/src-code/tsconfig.json
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-  "extends": "../tsconfig.json",
-  "compilerOptions": {
-    "outDir": "../code",
-    "composite": true
-  },
-  "exclude": ["node_modules", "**/*.spec.ts", "**/*.test.ts"]
-}
diff --git a/Lara-JS/tsconfig.jest.json b/Lara-JS/tsconfig.jest.json
deleted file mode 100644
index dd7eedda3..000000000
--- a/Lara-JS/tsconfig.jest.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-  "extends": "./tsconfig.json",
-  "include": ["**/*.spec.ts", "**/*.test.ts"],
-  "exclude": ["node_modules"]
-}
diff --git a/Lara-JS/tsconfig.json b/Lara-JS/tsconfig.json
index f67bd95ee..45c211456 100644
--- a/Lara-JS/tsconfig.json
+++ b/Lara-JS/tsconfig.json
@@ -1,18 +1,14 @@
 {
   "compilerOptions": {
-    "target": "ES2022",
+    "noEmit": true,
     "module": "NodeNext",
     "declaration": true,
-    "outDir": "./dist",
     "strict": true,
-    //"allowJs": true,
-    //"checkJs": true,
-    "moduleResolution": "NodeNext",
     "isolatedModules": true,
-    "sourceMap": true,
-    "declarationMap": true,
     "allowSyntheticDefaultImports": true,
-    //"esModuleInterop": true
-    "types": ["node", "jest"]
+    "types": ["node", "jest"],
+    "rewriteRelativeImportExtensions": true,
+    "erasableSyntaxOnly": true,
+    "verbatimModuleSyntax": true
   }
 }
diff --git a/Lara-JS/typedoc.config.js b/Lara-JS/typedoc.config.js
new file mode 100644
index 000000000..fd50edfe6
--- /dev/null
+++ b/Lara-JS/typedoc.config.js
@@ -0,0 +1,9 @@
+import { fileURLToPath } from "url";
+
+export default {
+  extends: [
+    fileURLToPath(import.meta.resolve("@specs-feup/lara/typedoc.base.json")),
+  ],
+  entryPoints: ["api/"],
+  tsconfig: "tsconfig.json",
+}
diff --git a/Lara-JS/typedoc.json b/Lara-JS/typedoc.json
deleted file mode 100644
index d9a0c80a8..000000000
--- a/Lara-JS/typedoc.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-  "extends": ["./typedoc.base.json"],
-  "entryPoints": ["src-api/"],
-  "tsconfig": "src-api/tsconfig.json",
-}