diff --git a/.github/workflows/pypi.yml b/.github/workflows/pypi.yml
index f00be31..55d41e7 100644
--- a/.github/workflows/pypi.yml
+++ b/.github/workflows/pypi.yml
@@ -10,10 +10,9 @@
       runs-on: ubuntu-latest
       steps:
         - uses: actions/checkout@v4
-        - name: Extract branch name
+        - name: Extract version from tag
           shell: bash
-          run: |
-            echo "##[set-output name=ver;]$(echo ${GITHUB_REF#refs/*/})"
+          run: echo "ver=${GITHUB_REF#refs/*/}" >> "$GITHUB_OUTPUT"
           id: extract_name_and_version
         - run: sed -i 's/0.0.0/'"${{ steps.extract_name_and_version.outputs.ver }}"'/' pyproject.toml
         - run: head -n 10 pyproject.toml
diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..5e5b8ab
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,35 @@
+# AGENTS.md
+
+## Project overview
+
+`winregistry` is a single-file Python library (`winregistry.py`) that wraps the Windows `winreg` module with a Pythonic API. It also provides Robot Framework keywords via the `robot` class. The package is Windows-only.
+
+## Tech stack
+
+- Python 3.8+
+- Linter/formatter: ruff
+- Tests: Robot Framework (`winregistry_tests.robot`)
+- Task runner: just (Justfile)
+- Package manager: uv
+
+## After every code change
+
+Run the following commands and fix any issues before committing:
+
+```sh
+just fmt lint tests
+```
+
+- `just fmt` — format code with ruff
+- `just lint` — lint with ruff (strict rule set, see `pyproject.toml`)
+- `just tests` — run Robot Framework tests (requires Windows)
+
+If tests cannot run (e.g. on macOS/Linux), at minimum run `just fmt lint`.
+
+## Code style
+
+- Single source file: all library code lives in `winregistry.py`
+- Line length limit: 120 characters
+- Use type annotations everywhere
+- Follow existing patterns — do not introduce new abstractions without need
+- Commit messages: conventional commits (`fix:`, `feat:`, `chore:`, etc.)
diff --git a/winregistry.py b/winregistry.py
index 3bb0143..a0a25b2 100644
--- a/winregistry.py
+++ b/winregistry.py
@@ -131,7 +131,7 @@ class RegistryValueData(TypedDict):
 }
 
 KeyInfo = namedtuple("KeyInfo", ["child_keys_count", "values_count", "modified_at"])
-ValueInfo = namedtuple("RawValueInfo", ["data", "type"])
+ValueInfo = namedtuple("ValueInfo", ["data", "type"])
 
 
 class RegEntity(
@@ -815,8 +815,6 @@ def open_value(
 
 
 class robot:  # noqa: N801
-    ROBOT_LIBRARY_DOC_FORMAT = "ROBOT"
-
     """Robot Framework library for Windows Registry operations.
 
     = Usage =
@@ -841,6 +839,8 @@ class robot:  # noqa: N801
 
     """
 
+    ROBOT_LIBRARY_DOC_FORMAT = "ROBOT"
+
     @staticmethod
     def registry_key_should_exist(
         key_name: str,
@@ -975,19 +975,16 @@ def create_registry_key(
         |     ${items}=    Get Registry Key Sub Keys    HKEY_LOCAL_MACHINE\\SOFTWARE
         |     List Should Contain Value    ${items}    _ROBOT_TESTS_
         """
-        sub_key_name = None
-        if "\\" in key_name:
-            key_name, sub_key_name = key_name.split("\\", maxsplit=1)
-        if sub_key_name and "\\" in sub_key_name:
-            sub_key_name, new_key_name = sub_key_name.rsplit("\\", maxsplit=1)
+        if "\\" not in key_name:
+            raise ValueError(f"Cannot create a root key: {key_name}")
+        key_name, sub_key_name = key_name.rsplit("\\", maxsplit=1)
         with open_key(
             key_name,
-            sub_key=sub_key_name,
             sub_key_ensure=True,
             sub_key_access=winreg.KEY_ALL_ACCESS,
             auto_refresh=False,
         ) as client:
-            client.create_key(new_key_name)
+            client.create_key(sub_key_name)
 
     @staticmethod
     def delete_registry_key(
@@ -1012,6 +1009,8 @@ def delete_registry_key(
         |     Delete Registry Key    HKEY_LOCAL_MACHINE\\SOFTWARE\\_ROBOT_TESTS_\\FOO\\BAR\\BAZ    recursive=True
         |     Registry Key Should Not Exist    HKEY_LOCAL_MACHINE\\SOFTWARE\\_ROBOT_TESTS_\\FOO\\BAR\\BAZ
         """
+        if "\\" not in key_name:
+            raise ValueError(f"Cannot delete a root key: {key_name}")
         key_name, sub_key_name = key_name.rsplit("\\", maxsplit=1)
         with open_key(
             key_name,