diff --git a/.prettierignore b/.prettierignore
new file mode 100644
index 0000000..d43bd34
--- /dev/null
+++ b/.prettierignore
@@ -0,0 +1,7 @@
+.devenv/
+.direnv/
+node_modules/
+result/
+package-lock.json
+docs/
+devenv.yaml
diff --git a/.prettierrc.json b/.prettierrc.json
new file mode 100644
index 0000000..47174e4
--- /dev/null
+++ b/.prettierrc.json
@@ -0,0 +1,6 @@
+{
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "all",
+  "printWidth": 100
+}
diff --git a/devenv.nix b/devenv.nix
index a855c8e..6b80616 100644
--- a/devenv.nix
+++ b/devenv.nix
@@ -6,9 +6,15 @@
 }: {
   # https://devenv.sh/packages/
   packages = with pkgs; [
+    guile
     just
     # Nix code formatter
     alejandra
+    # TypeScript tooling
+    nodePackages.typescript
+    nodePackages.typescript-language-server
+    # JavaScript/TypeScript formatter
+    nodePackages.prettier
   ];
 
   # https://devenv.sh/languages/
@@ -25,6 +31,7 @@
   # https://devenv.sh/pre-commit-hooks/
   git-hooks.hooks = {
     alejandra.enable = true;
+    prettier.enable = true;
     check-added-large-files = {
       enable = true;
       args = ["--maxkb=16384"];
diff --git a/package.json b/package.json
index d15cd71..a125c05 100644
--- a/package.json
+++ b/package.json
@@ -1,5 +1,10 @@
 {
   "devDependencies": {
     "@mariozechner/pi-coding-agent": "^0.65.0"
+  },
+  "scripts": {
+    "typecheck": "tsc --noEmit",
+    "format": "prettier . --write",
+    "format:check": "prettier . --check"
   }
 }
diff --git a/src/index.ts b/src/index.ts
new file mode 100644
index 0000000..6412b58
--- /dev/null
+++ b/src/index.ts
@@ -0,0 +1 @@
+export const hello = (name: string): string => `Hello, ${name}!`;
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..41d855c
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "skipLibCheck": true,
+    "noEmit": true
+  },
+  "include": ["src/**/*.ts", "scripts/**/*.ts", "*.ts"]
+}