diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..aa377d8
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+docs/*.md linguist-generated
diff --git a/docs/rules.md b/docs/rules.md
index 4531a1a..da6ace2 100644
--- a/docs/rules.md
+++ b/docs/rules.md
@@ -1,38 +1,54 @@
 <!-- Generated with Stardoc: http://skydoc.bazel.build -->
 
-Public API
+Use pytest to run tests, using a wrapper script to interface with Bazel.
 
-<a id="py_pytest_test"></a>
+Example:
 
-## py_pytest_test
+```starlark
+load("@caseyduquettesc_rules_python_pytest//python_pytest:defs.bzl", "py_pytest_test")
 
-<pre>
-py_pytest_test(<a href="#py_pytest_test-name">name</a>, <a href="#py_pytest_test-srcs">srcs</a>, <a href="#py_pytest_test-deps">deps</a>, <a href="#py_pytest_test-args">args</a>, <a href="#py_pytest_test-kwargs">kwargs</a>)
-</pre>
+py_pytest_test(
+    name = "test_w_pytest",
+    size = "small",
+    srcs = ["test.py"],
+)
+```
 
-Use pytest to run tests, using a wrapper script to interface with Bazel.
+By default, `@pip//pytest` is added to `deps`.
+If sharding is used (when `shard_count &gt; 1`) then `@pip//pytest_shard` is also added.
+To instead provide explicit deps for the pytest library, set `pytest_deps`:
 
-```py
+```starlark
 py_pytest_test(
-  name = "test_w_pytest",
-  size = "small",
-  srcs = ["test.py"],
-  deps = [
-    # TODO Add this for the user
-    requirement("pytest"),
-  ],
+    name = "test_w_my_pytest",
+    shard_count = 2,
+    srcs = ["test.py"],
+    pytest_deps = [requirement("pytest"), requirement("pytest-shard"), ...],
 )
 ```
 
+
+<a id="py_pytest_test"></a>
+
+## py_pytest_test
+
+<pre>
+py_pytest_test(<a href="#py_pytest_test-name">name</a>, <a href="#py_pytest_test-srcs">srcs</a>, <a href="#py_pytest_test-deps">deps</a>, <a href="#py_pytest_test-args">args</a>, <a href="#py_pytest_test-pytest_deps">pytest_deps</a>, <a href="#py_pytest_test-pip_repo">pip_repo</a>, <a href="#py_pytest_test-kwargs">kwargs</a>)
+</pre>
+
+    Wrapper macro for `py_test` which supports pytest.
+
 **PARAMETERS**
 
 
 | Name  | Description | Default Value |
 | :------------- | :------------- | :------------- |
-| <a id="py_pytest_test-name"></a>name |  <p align="center"> - </p>   |  none |
-| <a id="py_pytest_test-srcs"></a>srcs |  <p align="center"> - </p>   |  none |
-| <a id="py_pytest_test-deps"></a>deps |  <p align="center"> - </p>   |  <code>[]</code> |
-| <a id="py_pytest_test-args"></a>args |  <p align="center"> - </p>   |  <code>[]</code> |
-| <a id="py_pytest_test-kwargs"></a>kwargs |  <p align="center"> - </p>   |  none |
+| <a id="py_pytest_test-name"></a>name |  A unique name for this target.   |  none |
+| <a id="py_pytest_test-srcs"></a>srcs |  Python source files.   |  none |
+| <a id="py_pytest_test-deps"></a>deps |  Dependencies, typically <code>py_library</code>.   |  <code>[]</code> |
+| <a id="py_pytest_test-args"></a>args |  Additional command-line arguments to pytest. See https://docs.pytest.org/en/latest/how-to/usage.html   |  <code>[]</code> |
+| <a id="py_pytest_test-pytest_deps"></a>pytest_deps |  Labels of the pytest tool and other packages it may import.   |  <code>None</code> |
+| <a id="py_pytest_test-pip_repo"></a>pip_repo |  Name of the external repository where Python packages are installed. It's typically created by <code>pip.parse</code>. This attribute is used only when <code>pytest_deps</code> is unset.   |  <code>"pip"</code> |
+| <a id="py_pytest_test-kwargs"></a>kwargs |  Additional named parameters to py_test.   |  none |
 
 
diff --git a/e2e/smoke/BUILD.bazel b/e2e/smoke/BUILD.bazel
index 693ef3b..f609a3e 100644
--- a/e2e/smoke/BUILD.bazel
+++ b/e2e/smoke/BUILD.bazel
@@ -19,11 +19,11 @@ py_pytest_test(
     name = "test_sharded",
     size = "small",
     srcs = ["test_sharded.py"],
-    shard_count = 2,
-    deps = [
+    pytest_deps = [
         requirement("pytest"),
         requirement("pytest-shard"),
     ],
+    shard_count = 2,
 )
 
 build_test(
diff --git a/python_pytest/defs.bzl b/python_pytest/defs.bzl
index cc6cd5a..971d272 100644
--- a/python_pytest/defs.bzl
+++ b/python_pytest/defs.bzl
@@ -1,25 +1,56 @@
-"""Public API"""
+"""Use pytest to run tests, using a wrapper script to interface with Bazel.
+
+Example:
+
+```starlark
+load("@caseyduquettesc_rules_python_pytest//python_pytest:defs.bzl", "py_pytest_test")
+
+py_pytest_test(
+    name = "test_w_pytest",
+    size = "small",
+    srcs = ["test.py"],
+)
+```
+
+By default, `@pip//pytest` is added to `deps`.
+If sharding is used (when `shard_count > 1`) then `@pip//pytest_shard` is also added.
+To instead provide explicit deps for the pytest library, set `pytest_deps`:
+
+```starlark
+py_pytest_test(
+    name = "test_w_my_pytest",
+    shard_count = 2,
+    srcs = ["test.py"],
+    pytest_deps = [requirement("pytest"), requirement("pytest-shard"), ...],
+)
+```
+"""
 
 load("@rules_python//python:defs.bzl", "py_test")
-# load("@py_deps//:requirements.bzl", "requirement")
-
-def py_pytest_test(name, srcs, deps = [], args = [], **kwargs):
-    """Use pytest to run tests, using a wrapper script to interface with Bazel.
-
-    ```py
-    py_pytest_test(
-      name = "test_w_pytest",
-      size = "small",
-      srcs = ["test.py"],
-      deps = [
-        # TODO Add this for the user
-        requirement("pytest"),
-      ],
-    )
-    ```
+
+def py_pytest_test(name, srcs, deps = [], args = [], pytest_deps = None, pip_repo = "pip", **kwargs):
+    """
+    Wrapper macro for `py_test` which supports pytest.
+
+    Args:
+      name: A unique name for this target.
+      srcs: Python source files.
+      deps: Dependencies, typically `py_library`.
+      args: Additional command-line arguments to pytest.
+        See https://docs.pytest.org/en/latest/how-to/usage.html
+      pytest_deps: Labels of the pytest tool and other packages it may import.
+      pip_repo: Name of the external repository where Python packages are installed.
+        It's typically created by `pip.parse`.
+        This attribute is used only when `pytest_deps` is unset.
+      **kwargs: Additional named parameters to py_test.
     """
     shim_label = Label("//python_pytest:pytest_shim.py")
 
+    if pytest_deps == None:
+        pytest_deps = ["@{}//pytest".format(pip_repo)]
+        if kwargs.get("shard_count", 1) > 1:
+            pytest_deps.append("@{}//pytest_shard".format(pip_repo))
+
     py_test(
         name = name,
         srcs = [
@@ -31,10 +62,6 @@ def py_pytest_test(name, srcs, deps = [], args = [], **kwargs):
         ] + args + ["$(location :%s)" % x for x in srcs],
         # python_version = "PY3",
         # srcs_version = "PY3",
-        # TODO It'd be nice to implicitly include pytest, but I don't know how to know the requirements repo nme
-        # deps = deps + [
-        #     requirement("pytest"),
-        # ],
-        deps = deps,
+        deps = deps + pytest_deps,
         **kwargs
     )