diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9bd9343..3777a11 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,27 +1,13 @@
 name: CI
 on:
   push:
-    paths:
-      - ".github/workflows/ci.yml"
-      - ".github/workflows/release.yml"
-      - "hatch_build.py"
-      - "package.json"
-      - "pyproject.toml"
-      - "rollup.config.js"
-      - "run.ts"
-      - "src/**"
-      - "yt_dlp_ejs/**"
+    paths-ignore:
+      - 'README.md'
+      - 'LICENSE'
   pull_request:
-    paths:
-      - ".github/workflows/ci.yml"
-      - ".github/workflows/release.yml"
-      - "hatch_build.py"
-      - "package.json"
-      - "pyproject.toml"
-      - "rollup.config.js"
-      - "run.ts"
-      - "src/**"
-      - "yt_dlp_ejs/**"
+    paths-ignore:
+      - 'README.md'
+      - 'LICENSE'
 
 permissions:
   contents: read
@@ -31,6 +17,56 @@ concurrency:
   cancel-in-progress: ${{ github.event_name == 'pull_request' }}
 
 jobs:
+  ruff-format:
+    name: Ruff format check
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v5
+    - uses: astral-sh/ruff-action@v3
+      with:
+        args: "check --output-format github"
+
+  ruff-lint:
+    name: Ruff linting check
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v5
+    - uses: astral-sh/ruff-action@v3
+      with:
+        args: "format --check --diff"
+
+  prettier:
+    name: Prettier check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - name: Install Deno v2.x (latest)
+        uses: denoland/setup-deno@v2
+        with:
+          deno-version: v2.x
+      - name: Install Deno requirements
+        run: |
+          deno install
+      - name: Run Prettier check
+        run: |
+          deno task fmt:check
+
+  eslint:
+    name: ESLint check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - name: Install Deno v2.x (latest)
+        uses: denoland/setup-deno@v2
+        with:
+          deno-version: v2.x
+      - name: Install Deno requirements
+        run: |
+          deno install
+      - name: Run ESLint check
+        run: |
+          deno task lint
+
   python_tests:
     name: Python tests
     runs-on: ubuntu-latest
@@ -304,7 +340,17 @@ jobs:
           node --test
 
   all_passed:
-    needs: [deno_build, deno_tests, bun_build, bun_tests, node_build, node_tests]
+    needs:
+      - ruff-format
+      - ruff-lint
+      - prettier
+      - eslint
+      - deno_build
+      - deno_tests
+      - bun_build
+      - bun_tests
+      - node_build
+      - node_tests
     runs-on: ubuntu-latest
     steps:
       - name: All checks passed
diff --git a/eslint.config.js b/eslint.config.js
new file mode 100644
index 0000000..2dc3b7e
--- /dev/null
+++ b/eslint.config.js
@@ -0,0 +1,14 @@
+import js from "@eslint/js";
+import globals from "globals";
+import tseslint from "typescript-eslint";
+import { defineConfig } from "eslint/config";
+
+export default defineConfig([
+  {
+    files: ["**/*.{js,mjs,cjs,ts,mts,cts}"],
+    plugins: { js },
+    extends: ["js/recommended"],
+    languageOptions: { globals: globals.node },
+  },
+  tseslint.configs.recommended,
+]);
diff --git a/hatch_build.py b/hatch_build.py
index 65a5285..09a40f3 100644
--- a/hatch_build.py
+++ b/hatch_build.py
@@ -28,12 +28,15 @@ class CustomBuildHook(BuildHookInterface):
         else:
             raise RuntimeError(
                 "One of 'deno', 'bun', or 'npm' could not be found. "
-                "Please install one of them to proceed with the build.")
+                "Please install one of them to proceed with the build."
+            )
 
-        build_data["force_include"].update({
-            "dist/yt.solver.core.min.js": "yt_dlp_ejs/yt/solver/core.min.js",
-            "dist/yt.solver.lib.min.js": "yt_dlp_ejs/yt/solver/lib.min.js",
-        })
+        build_data["force_include"].update(
+            {
+                "dist/yt.solver.core.min.js": "yt_dlp_ejs/yt/solver/core.min.js",
+                "dist/yt.solver.lib.min.js": "yt_dlp_ejs/yt/solver/lib.min.js",
+            }
+        )
 
     def clean(self, versions):
         shutil.rmtree("node_modules", ignore_errors=True)
diff --git a/package.json b/package.json
index 1ebb0c0..89fe89d 100644
--- a/package.json
+++ b/package.json
@@ -3,21 +3,27 @@
   "type": "module",
   "scripts": {
     "bundle": "rollup -c",
-    "fmt": "prettier --write \"src/**.ts\" \"package.json\" \"rollup.config.js\" \"run.ts\""
+    "fmt": "prettier --write \"src/**.ts\" \"package.json\" \"rollup.config.js\" \"run.ts\" \"eslint.config.js\"",
+    "fmt:check": "prettier --check \"src/**.ts\" \"package.json\" \"rollup.config.js\" \"run.ts\" \"eslint.config.js\"",
+    "lint": "eslint src"
   },
   "dependencies": {
     "astring": "1.9.0",
     "meriyah": "6.1.4"
   },
   "devDependencies": {
+    "@eslint/js": "9.38.0",
     "@rollup/plugin-node-resolve": "16.0.3",
     "@rollup/plugin-sucrase": "5.0.2",
     "@rollup/plugin-terser": "0.4.4",
-    "rollup-plugin-license": "3.6.0",
     "@types/bun": "1.3.0",
     "@types/deno": "2.5.0",
     "@types/node": "24.8.1",
+    "eslint": "9.38.0",
+    "globals": "16.4.0",
+    "prettier": "3.6.2",
     "rollup": "4.52.5",
-    "prettier": "3.6.2"
+    "rollup-plugin-license": "3.6.0",
+    "typescript-eslint": "8.46.2"
   }
 }
diff --git a/pyproject.toml b/pyproject.toml
index 3e8e720..f3b4786 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,6 +30,11 @@ classifiers = [
 ]
 dependencies = []
 
+[dependency-groups]
+dev = [
+    "ruff>=0.14.1",
+]
+
 [project.urls]
 Documentation = "https://github.com/yt-dlp/ejs#readme"
 Issues = "https://github.com/yt-dlp/ejs/issues"
@@ -51,3 +56,33 @@ packages = ["yt_dlp_ejs"]
 version-file = "yt_dlp_ejs/_version.py"
 
 [tool.hatch.build.targets.wheel.hooks.custom]
+
+[tool.ruff.lint]
+select = [
+  "C4",
+  "E",
+  "F",
+  "I",
+  "PLC",
+  "PLE",
+  "PLW",
+  "PYI",
+  "RET",
+  "RUF",
+  "SIM",
+  "TD",
+  "TID",
+  "W",
+]
+ignore = [
+  "TD003",
+  "E402",
+  "E501",
+  "PLR09",
+]
+
+[tool.ruff.lint.isort]
+force-single-line = true
+
+[tool.ruff.lint.flake8-tidy-imports]
+ban-relative-imports = "all"
diff --git a/rollup.config.js b/rollup.config.js
index d5c9d31..ea6cffc 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -31,7 +31,9 @@ function printHash() {
       for (const [fileName, assetInfo] of Object.entries(bundle)) {
         if (assetInfo.code) {
           try {
-            const digest = createHash("sha3-512").update(assetInfo.code).digest("hex");
+            const digest = createHash("sha3-512")
+              .update(assetInfo.code)
+              .digest("hex");
             console.log(`SHA3-512 for ${assetInfo.fileName}: ${digest}`);
           } catch (err) {
             console.error(`Error hashing ${fileName}:`, err.message);
diff --git a/src/utils.ts b/src/utils.ts
index a3553a0..9580668 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -25,7 +25,9 @@ export function matchesStructure<T extends ESTree.Node>(
     if ("anykey" in structure && Array.isArray(structure.anykey)) {
       // Handle `{ anykey: [a, b] }`
       const haystack = Array.isArray(obj) ? obj : Object.values(obj);
-      return structure.anykey.every(value => haystack.some((el) => matchesStructure(el, value)));
+      return structure.anykey.every((value) =>
+        haystack.some((el) => matchesStructure(el, value)),
+      );
     }
     for (const [key, value] of Object.entries(structure)) {
       if (!matchesStructure(obj[key as keyof typeof obj], value)) {
diff --git a/src/yt/solver/test/io.ts b/src/yt/solver/test/io.ts
index a7ae0aa..bbfd929 100644
--- a/src/yt/solver/test/io.ts
+++ b/src/yt/solver/test/io.ts
@@ -24,6 +24,7 @@ export async function getIO(): Promise<IO> {
 
 async function _getIO(): Promise<IO> {
   // Old Deno requires casting to any as globalThis lacks an index signature
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   if ((globalThis as any).process?.release?.name === "node") {
     // Assume node compatibility
     const { access, readFile } = await import("node:fs/promises");
diff --git a/test/test_modules.py b/test/test_modules.py
index 7549237..e98e65f 100644
--- a/test/test_modules.py
+++ b/test/test_modules.py
@@ -4,15 +4,21 @@ from pathlib import Path
 import yt_dlp_ejs.yt.solver
 
 BASE_PATH = Path(__file__).parent.parent
-CORE_PATH = BASE_PATH / 'yt_dlp_ejs/yt/solver/core.min.js'
-LIB_PATH = BASE_PATH / 'yt_dlp_ejs/yt/solver/lib.min.js'
+CORE_PATH = BASE_PATH / "yt_dlp_ejs/yt/solver/core.min.js"
+LIB_PATH = BASE_PATH / "yt_dlp_ejs/yt/solver/lib.min.js"
 
 
 class TestModules(unittest.TestCase):
     def test_yt_solver(self):
-        self.assertEqual(yt_dlp_ejs.yt.solver.core(), CORE_PATH.read_text(encoding='utf-8'))
-        self.assertEqual(yt_dlp_ejs.yt.solver.lib(), LIB_PATH.read_text(encoding='utf-8'))
+        self.assertEqual(
+            yt_dlp_ejs.yt.solver.core(),
+            CORE_PATH.read_text(encoding="utf-8"),
+        )
+        self.assertEqual(
+            yt_dlp_ejs.yt.solver.lib(),
+            LIB_PATH.read_text(encoding="utf-8"),
+        )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     unittest.main()
diff --git a/yt_dlp_ejs/__init__.py b/yt_dlp_ejs/__init__.py
index ceb8d4d..9d7217e 100644
--- a/yt_dlp_ejs/__init__.py
+++ b/yt_dlp_ejs/__init__.py
@@ -1,7 +1,3 @@
 from yt_dlp_ejs._version import version
-from yt_dlp_ejs import yt
 
-__all__ = [
-    "version",
-    "yt"
-]
+__all__ = ["version"]
diff --git a/yt_dlp_ejs/yt/__init__.py b/yt_dlp_ejs/yt/__init__.py
index 2e3887a..e69de29 100644
--- a/yt_dlp_ejs/yt/__init__.py
+++ b/yt_dlp_ejs/yt/__init__.py
@@ -1,3 +0,0 @@
-from . import solver
-
-__all__ = ["solver"]
\ No newline at end of file
diff --git a/yt_dlp_ejs/yt/solver/__init__.py b/yt_dlp_ejs/yt/solver/__init__.py
index 7e53f27..1bd323e 100644
--- a/yt_dlp_ejs/yt/solver/__init__.py
+++ b/yt_dlp_ejs/yt/solver/__init__.py
@@ -2,6 +2,7 @@ import importlib.resources
 
 import yt_dlp_ejs.yt.solver
 
+
 def core() -> str:
     """
     Read the contents of the JavaScript core solver bundle as string.