diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..f6df1cf
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,33 @@
+name: ci
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - run: corepack enable
+      - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+        with:
+          node-version: lts/*
+          cache: pnpm
+
+      - name: 📦 Install dependencies
+        run: pnpm install
+
+      - name: 💪 Test types
+        run: pnpm test:types
+
+      # - name: 🧪 Test project
+      #   run: pnpm test:unit -- --coverage
+
+      # - name: 🟩 Coverage
+      #   uses: codecov/codecov-action@v5
diff --git a/package.json b/package.json
index 87493c3..65f0d86 100644
--- a/package.json
+++ b/package.json
@@ -6,11 +6,11 @@
   "author": "Daniel Roe <daniel@roe.dev>",
   "license": "MIT",
   "scripts": {
-    "typecheck": "tsc --noEmit"
+    "test:types": "tsgo --noEmit"
   },
   "devDependencies": {
     "@types/node": "^24.0.0",
-    "typescript": "^5.9.2"
+    "@typescript/native-preview": "7.0.0-dev.20260421.2"
   },
   "packageManager": "pnpm@10.15.0"
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 4578ee4..f8061dc 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -11,18 +11,52 @@ importers:
       '@types/node':
         specifier: ^24.0.0
         version: 24.12.4
-      typescript:
-        specifier: ^5.9.2
-        version: 5.9.3
+      '@typescript/native-preview':
+        specifier: 7.0.0-dev.20260421.2
+        version: 7.0.0-dev.20260421.2
 
 packages:
 
   '@types/node@24.12.4':
     resolution: {integrity: sha512-GUUEShf+PBCGW2KaXwcIt3Yk+e3pkKwWKb9GSyM9WQVE+ep2jzmHdGsHzu4wgcZy5fN9FBdVzjpBQsYlpfpgLA==}
 
-  typescript@5.9.3:
-    resolution: {integrity: sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==}
-    engines: {node: '>=14.17'}
+  '@typescript/native-preview-darwin-arm64@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-fHv1r3ZmVo6zxuAIFmuX3w9QxbcauoG0SsWhmDwm6VmRubLlOJIcmTtlmV3JAb9oOnq8LuzZljzT7Q39fSMQDw==}
+    cpu: [arm64]
+    os: [darwin]
+
+  '@typescript/native-preview-darwin-x64@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-KWTR6xbW9t+JS7D5DQIzo75pqVXVWUxF9PMv/+S6xsnOjCVd6g0ixHcFpFMJMKSUQpGPr8Z5f7b8ks6LHW01jg==}
+    cpu: [x64]
+    os: [darwin]
+
+  '@typescript/native-preview-linux-arm64@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-VLMEuml3BhUb+jaL0TXQ4xvVODxJF+RhkI+tBWvlynsJI4khTXEiwWh+wPOJrsfBRYFRMXEu28Odl/HXkYze8w==}
+    cpu: [arm64]
+    os: [linux]
+
+  '@typescript/native-preview-linux-arm@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-BWLQO3nemLDSV5PoE5GPHe1dU9Dth77Kv8/cle9Ujcp4LhPo0KincdPqFH/qKeU/xvW25mgFueflZ1nc4rKuww==}
+    cpu: [arm]
+    os: [linux]
+
+  '@typescript/native-preview-linux-x64@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-qUrJWTB5/wv4wnRG0TRXElAxc2kykNiRNyEIEqBbLmzDlrcvAW7RRy8MXoY1ZyTiKGMu14itZ3x9oW6+blFpRw==}
+    cpu: [x64]
+    os: [linux]
+
+  '@typescript/native-preview-win32-arm64@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-Rc6NsWlZmCs5YUKVzKgwoBOoRUGsPzct4BDMRX0csD1devLBBc4AbUXWKsJRbpwIAnqMO1ld4sNHEb+wXgfNHQ==}
+    cpu: [arm64]
+    os: [win32]
+
+  '@typescript/native-preview-win32-x64@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-GQv1+dya1t6EqF2Cpsb+xoozovdX10JUSf6Kl/8xNkTapzmlHd+uMr+8ku3jIASTxoRGn0Mklgjj3MDKrOTuLg==}
+    cpu: [x64]
+    os: [win32]
+
+  '@typescript/native-preview@7.0.0-dev.20260421.2':
+    resolution: {integrity: sha512-CmajHI25HpVWE9R1XFoxr+cphJPxoYD3eFioQtAvXYkMFKnLdICMS9pXre9Pybizb75ejRxjKD5/CVG055rEIg==}
     hasBin: true
 
   undici-types@7.16.0:
@@ -34,6 +68,35 @@ snapshots:
     dependencies:
       undici-types: 7.16.0
 
-  typescript@5.9.3: {}
+  '@typescript/native-preview-darwin-arm64@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview-darwin-x64@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview-linux-arm64@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview-linux-arm@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview-linux-x64@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview-win32-arm64@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview-win32-x64@7.0.0-dev.20260421.2':
+    optional: true
+
+  '@typescript/native-preview@7.0.0-dev.20260421.2':
+    optionalDependencies:
+      '@typescript/native-preview-darwin-arm64': 7.0.0-dev.20260421.2
+      '@typescript/native-preview-darwin-x64': 7.0.0-dev.20260421.2
+      '@typescript/native-preview-linux-arm': 7.0.0-dev.20260421.2
+      '@typescript/native-preview-linux-arm64': 7.0.0-dev.20260421.2
+      '@typescript/native-preview-linux-x64': 7.0.0-dev.20260421.2
+      '@typescript/native-preview-win32-arm64': 7.0.0-dev.20260421.2
+      '@typescript/native-preview-win32-x64': 7.0.0-dev.20260421.2
 
   undici-types@7.16.0: {}