diff --git a/pyproject.toml b/pyproject.toml
index 3dbcfab..96700c4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,6 +33,9 @@ dependencies = [
 
 [dependency-groups]
 dev = [
+    # `httpx` is a dependency of FastAPI's `TestClient` class.
+    # Docs: https://fastapi.tiangolo.com/tutorial/testing/#using-testclient
+    "httpx>=0.28.1",
     "pre-commit>=4.1.0",
     "pyright>=1.1.386",
     "pytest>=8.3.5",
diff --git a/src/README.md b/src/README.md
index a3be001..7ae4822 100644
--- a/src/README.md
+++ b/src/README.md
@@ -9,3 +9,4 @@
 - `lib/`: Library of helper functions, constants, etc.
 - `README.md`: This document
 - `server.py`: The BERtron API
+- `tests/`: Tests targeting things implemented in this directory
diff --git a/src/models.py b/src/models.py
index 0ea55df..4770658 100644
--- a/src/models.py
+++ b/src/models.py
@@ -1,10 +1,15 @@
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 from typing import Optional
 
 
 class HealthResponse(BaseModel):
     r"""A response containing system health information."""
 
+    # Raise a `ValidationError` if extra parameters are passed in when instantiating this class.
+    # Note: This facilitates having our tests confirm API responses don't include extra fields.
+    # Docs: https://docs.pydantic.dev/latest/api/config/#pydantic.config.ConfigDict.extra
+    model_config = ConfigDict(extra="forbid")
+
     web_server: bool = Field(
         ...,
         title="Web server health",
@@ -20,6 +25,8 @@ class HealthResponse(BaseModel):
 class VersionResponse(BaseModel):
     r"""A response containing system version information."""
 
+    model_config = ConfigDict(extra="forbid")
+
     api: Optional[str] = Field(
         ...,
         title="API version",
diff --git a/src/server.py b/src/server.py
index a46054e..201d5e6 100644
--- a/src/server.py
+++ b/src/server.py
@@ -24,7 +24,7 @@
         "[View source](https://github.com/ber-data/bertron/blob/main/src/server.py)\n\n"
         f"[BERtron schema](https://ber-data.github.io/bertron-schema/) version: `{get_package_version('bertron-schema')}`"
     ),
-    version=get_package_version("bertron"),
+    version=f"{get_package_version('bertron')}",
 )
 
 
diff --git a/src/tests/test_server.py b/src/tests/test_server.py
new file mode 100644
index 0000000..1181047
--- /dev/null
+++ b/src/tests/test_server.py
@@ -0,0 +1,34 @@
+r"""
+This file contains tests targeting `src/server.py`.
+
+You can learn about testing FastAPI apps here:
+https://fastapi.tiangolo.com/tutorial/testing/
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from starlette import status
+
+from models import VersionResponse
+from server import app
+
+
+@pytest.fixture
+def test_client():
+    test_client = TestClient(app)
+    yield test_client
+
+
+def test_root_endpoint_redirects_to_api_docs(test_client: TestClient):
+    response = test_client.get("/", follow_redirects=False)
+    assert response.status_code == status.HTTP_307_TEMPORARY_REDIRECT
+    assert response.headers["location"] == "/docs"
+
+
+def test_version_endpoint_returns_version_response(test_client: TestClient):
+    response = test_client.get("/version")
+    assert response.status_code == status.HTTP_200_OK
+    # Note: This will raise a `ValidationError` if the response is not
+    #       a valid `VersionResponse` (e.g. if it has extra fields or
+    #       its fields' values are of an incompatible data type).
+    _ = VersionResponse(**response.json())
diff --git a/uv.lock b/uv.lock
index b96765d..4a408ea 100644
--- a/uv.lock
+++ b/uv.lock
@@ -119,6 +119,7 @@ dependencies = [
 
 [package.dev-dependencies]
 dev = [
+    { name = "httpx" },
     { name = "pre-commit" },
     { name = "pyright" },
     { name = "pytest" },
@@ -138,6 +139,7 @@ requires-dist = [
 
 [package.metadata.requires-dev]
 dev = [
+    { name = "httpx", specifier = ">=0.28.1" },
     { name = "pre-commit", specifier = ">=4.1.0" },
     { name = "pyright", specifier = ">=1.1.386" },
     { name = "pytest", specifier = ">=8.3.5" },
@@ -439,7 +441,7 @@ name = "exceptiongroup"
 version = "1.3.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
-    { name = "typing-extensions", marker = "python_full_version < '3.13'" },
+    { name = "typing-extensions", marker = "python_full_version < '3.11'" },
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/0b/9f/a65090624ecf468cdca03533906e7c69ed7588582240cfe7cc9e770b50eb/exceptiongroup-1.3.0.tar.gz", hash = "sha256:b241f5885f560bc56a59ee63ca4c6a8bfa46ae4ad651af316d4e81817bb9fd88", size = 29749, upload-time = "2025-05-10T17:42:51.123Z" }
 wheels = [