diff --git a/scripts/build-ts.sh b/scripts/build-ts.sh
deleted file mode 100755
index 27a7410..0000000
--- a/scripts/build-ts.sh
+++ /dev/null
@@ -1,26 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-started_at=$(date +%s%N)
-
-steps=(
-    "player:bun build ./static/player/main.ts --outdir ./dist/static/player --target browser --splitting"
-    "app:bun build ./static/app.ts --outdir ./dist/static --target browser --root ./static --entry-naming [name].js"
-)
-
-for step in "${steps[@]}"; do
-    name="${step%%:*}"
-    cmd="${step#*:}"
-    echo "building $name..."
-    if ! eval "$cmd"; then
-        echo "ts build failed at $name" >&2
-        exit 1
-    fi
-done
-
-mkdir -p ./dist/static
-cp ./node_modules/htmx.org/dist/htmx.min.js ./dist/static/htmx-lib.js
-
-total_entries=2
-elapsed_ms=$((($(date +%s%N) - started_at) / 1000000))
-echo "ts build ok ($total_entries entries, ${elapsed_ms}ms)"
\ No newline at end of file
diff --git a/scripts/build-ts.ts b/scripts/build-ts.ts
new file mode 100644
index 0000000..4712e9f
--- /dev/null
+++ b/scripts/build-ts.ts
@@ -0,0 +1,70 @@
+import { spawnSync } from "node:child_process";
+import { cp, mkdir } from "node:fs/promises";
+import { performance } from "node:perf_hooks";
+
+type BuildStep = {
+  name: string;
+  args: string[];
+};
+
+const buildSteps: BuildStep[] = [
+  {
+    name: "player",
+    args: [
+      "build",
+      "./static/player/main.ts",
+      "--outdir",
+      "./dist/static/player",
+      "--target",
+      "browser",
+      "--splitting",
+    ],
+  },
+  {
+    name: "app",
+    args: [
+      "build",
+      "./static/app.ts",
+      "--outdir",
+      "./dist/static",
+      "--target",
+      "browser",
+      "--root",
+      "./static",
+      "--entry-naming",
+      "[name].js",
+    ],
+  },
+];
+
+const runBuildStep = (step: BuildStep): void => {
+  console.log(`building ${step.name}...`);
+
+  const result = spawnSync("bun", step.args, { stdio: "inherit" });
+  if (result.error) {
+    throw new Error(`failed to start ${step.name} build: ${result.error.message}`);
+  }
+  if (result.signal) {
+    throw new Error(`ts build interrupted at ${step.name} (${result.signal})`);
+  }
+  if (result.status !== 0) {
+    throw new Error(`ts build failed at ${step.name}`);
+  }
+};
+
+const main = async (): Promise<void> => {
+  const startedAt = performance.now();
+
+  buildSteps.forEach(runBuildStep);
+
+  await mkdir("./dist/static", { recursive: true });
+  await cp("./node_modules/htmx.org/dist/htmx.min.js", "./dist/static/htmx-lib.js");
+
+  const elapsedMs = Math.round(performance.now() - startedAt);
+  console.log(`ts build ok (${buildSteps.length} entries, ${elapsedMs}ms)`);
+};
+
+main().catch((error: unknown) => {
+  console.error(error instanceof Error ? error.message : String(error));
+  process.exitCode = 1;
+});