diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..56e817d
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,17 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/setup-uv@v5
+        with:
+          enable-cache: true
+      - run: uv sync --frozen
+      - run: uv run pytest
diff --git a/app.py b/app.py
index 318c9db..99723a3 100644
--- a/app.py
+++ b/app.py
@@ -9,6 +9,7 @@ Run it:  uv run uvicorn app:app --reload
 
 import re
 from collections import defaultdict
+from contextlib import asynccontextmanager
 from functools import lru_cache
 from pathlib import Path
 
@@ -18,7 +19,19 @@ from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
 from wordfreq import zipf_frequency
 
-app = FastAPI(title="RhymePad")
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    # warm the slow lazy bits at boot, not on the first keystroke
+    try:
+        g2p_phones("warmup")
+    except Exception:
+        pass  # model unavailable; spelling fallbacks still work
+    get_slant_index()
+    yield
+
+
+app = FastAPI(title="RhymePad", lifespan=lifespan)
 
 _g2p = None