diff --git a/src/index.js b/src/index.js
new file mode 100644
index 0000000..4b90b3c
--- /dev/null
+++ b/src/index.js
@@ -0,0 +1,34 @@
+import { HiLexer } from './lexer.js';
+import { parser } from './parser.js';
+import { astBuilder } from './ast-builder.js';
+import { generate } from './generator.js';
+
+/**
+ * Transpiles a string of Hi source code into JavaScript.
+ * @param {string} sourceCode The Hi source code.
+ * @returns {string} The equivalent JavaScript code.
+ */
+export function hi2js(sourceCode) {
+    if (!sourceCode.trim()) {
+        return "";
+    }
+    // 1. Lexing
+    const lexResult = HiLexer.tokenize(sourceCode);
+    if (lexResult.errors.length > 0) {
+        throw new Error(`Lexing error: ${lexResult.errors[0].message}`);
+    }
+
+    // 2. Parsing
+    parser.input = lexResult.tokens;
+    const cst = parser.program();
+    if (parser.errors.length > 0) {
+        const err = parser.errors[0];
+        throw new Error(`Parsing error: ${err.message}`);
+    }
+
+    // 3. Building AST from CST
+    const ast = astBuilder.visit(cst);
+
+    // 4. Generating JavaScript from AST
+    return generate(ast);
+}