diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 00000000..e58bbc2c
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,60 @@
+name: CI
+
+on:
+  pull_request:
+    paths-ignore:
+      - '**/*.md'
+      - 'docs/**'
+  push:
+    branches: [main]
+    paths-ignore:
+      - '**/*.md'
+      - 'docs/**'
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  quality:
+    name: Typecheck
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: .nvmrc
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Typecheck
+        run: pnpm typecheck
+
+  unit:
+    name: Unit tests
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: .nvmrc
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Web tests
+        run: pnpm test:web
+
+      - name: CLI tests
+        run: pnpm test:cli
diff --git a/src/app/api/macro/flat/data/route.ts b/src/app/api/macro/flat/data/route.ts
index e3a0da0e..ab69f781 100644
--- a/src/app/api/macro/flat/data/route.ts
+++ b/src/app/api/macro/flat/data/route.ts
@@ -5,7 +5,8 @@ export async function GET() {
   const buf = await getMacroFlatData();
   if (!buf) return new NextResponse('Not found', { status: 404 });
   // Cache binary strongly; it only changes when prep runs
-  return new NextResponse(buf, { status: 200, headers: { 'Content-Type': 'application/octet-stream', 'Cache-Control': 'public, max-age=86400, immutable' } });
+  return new NextResponse(
+    new Blob([Uint8Array.from(buf)]),
+    { status: 200, headers: { 'Content-Type': 'application/octet-stream', 'Cache-Control': 'public, max-age=86400, immutable' } },
+  );
 }
-
-
diff --git a/src/app/api/macro/flat/models/[modelId]/data/route.ts b/src/app/api/macro/flat/models/[modelId]/data/route.ts
index 8538a6b8..fc50dc56 100644
--- a/src/app/api/macro/flat/models/[modelId]/data/route.ts
+++ b/src/app/api/macro/flat/models/[modelId]/data/route.ts
@@ -5,7 +5,8 @@ export async function GET(_: Request, ctx: { params: Promise<{ modelId: string }
   const params = await ctx.params;
   const buf = await getMacroPerModelData(params.modelId);
   if (!buf) return new NextResponse('Not found', { status: 404 });
-  return new NextResponse(buf, { status: 200, headers: { 'Content-Type': 'application/octet-stream', 'Cache-Control': 'public, max-age=86400, immutable' } });
+  return new NextResponse(
+    new Blob([Uint8Array.from(buf)]),
+    { status: 200, headers: { 'Content-Type': 'application/octet-stream', 'Cache-Control': 'public, max-age=86400, immutable' } },
+  );
 }
-
-
diff --git a/src/app/api/macro/tiles/[z]/[x]/[y]/route.ts b/src/app/api/macro/tiles/[z]/[x]/[y]/route.ts
index 8dc885e0..0b5ba89f 100644
--- a/src/app/api/macro/tiles/[z]/[x]/[y]/route.ts
+++ b/src/app/api/macro/tiles/[z]/[x]/[y]/route.ts
@@ -8,7 +8,8 @@ export async function GET(_: Request, ctx: { params: Promise<{ z: string; x: str
   const y = parseInt(params.y, 10);
   const buf = await getMacroTile(z, x, y);
   if (!buf) return new NextResponse('Not found', { status: 404 });
-  return new NextResponse(buf, { status: 200, headers: { 'Content-Type': 'application/octet-stream', 'Cache-Control': 'public, max-age=31536000, immutable' } });
+  return new NextResponse(
+    new Blob([Uint8Array.from(buf)]),
+    { status: 200, headers: { 'Content-Type': 'application/octet-stream', 'Cache-Control': 'public, max-age=31536000, immutable' } },
+  );
 }
-
-
diff --git a/src/app/api/sandbox/auto-wiki/route.ts b/src/app/api/sandbox/auto-wiki/route.ts
index 5dd80aad..7404a39c 100644
--- a/src/app/api/sandbox/auto-wiki/route.ts
+++ b/src/app/api/sandbox/auto-wiki/route.ts
@@ -150,13 +150,14 @@ export async function POST(req: NextRequest) {
     }
     
     // wtf.fetch can return an array if it follows redirects, take the last one.
-    if (Array.isArray(doc)) {
-      doc = doc[doc.length - 1];
+    const article = Array.isArray(doc) ? doc[doc.length - 1] : doc;
+    if (!article) {
+      return NextResponse.json({ error: 'Could not resolve the Wikipedia article.' }, { status: 404 });
     }
 
-    const articleText = doc.text();
-    const articleSummary = (doc as any).summary() || 'No summary available.';
-    const title = doc.title() || articleTitle;
+    const articleText = article.text();
+    const articleSummary = (article as any).summary() || 'No summary available.';
+    const title = article.title() || articleTitle;
 
     if (!articleText || articleText.length < 100) {
         return NextResponse.json({ error: 'The article content is too short to generate a meaningful blueprint.' }, { status: 400 });
@@ -200,4 +201,4 @@ export async function POST(req: NextRequest) {
     console.error('[Auto-Wiki Error]', error);
     return NextResponse.json({ error: 'An unexpected error occurred.', details: error.message }, { status: 500 });
   }
-}
\ No newline at end of file
+}