diff --git a/README.md b/README.md
index 18ff3c5..efd2dc4 100644
--- a/README.md
+++ b/README.md
@@ -21,4 +21,4 @@ set_global_runner(GraphRunner(get_global_runner()))  # Use GraphRunner middlewar
 
 print(get_global_runner().mermaid())  # Print mermaid diagram
 
-```
\ No newline at end of file
+```
diff --git a/poetry.lock b/poetry.lock
index fc67000..25d5d4b 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.8.3 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.8.2 and should not be changed by hand.
 
 [[package]]
 name = "cfgv"
@@ -528,6 +528,17 @@ files = [
 docs = ["furo", "jaraco.packaging (>=9.3)", "jaraco.tidelift (>=1.4)", "pygments-github-lexers (==0.0.5)", "pyproject-hooks (!=1.1)", "rst.linker (>=1.9)", "sphinx (>=3.5)", "sphinx-favicon", "sphinx-inline-tabs", "sphinx-lint", "sphinx-notfound-page (>=1,<2)", "sphinx-reredirects", "sphinxcontrib-towncrier"]
 testing = ["build[virtualenv] (>=1.0.3)", "filelock (>=3.4.0)", "importlib-metadata", "ini2toml[lite] (>=0.14)", "jaraco.develop (>=7.21)", "jaraco.envs (>=2.2)", "jaraco.path (>=3.2.0)", "mypy (==1.9)", "packaging (>=23.2)", "pip (>=19.1)", "pyproject-hooks (!=1.1)", "pytest (>=6,!=8.1.1)", "pytest-checkdocs (>=2.4)", "pytest-cov", "pytest-enabler (>=2.2)", "pytest-home (>=0.5)", "pytest-mypy", "pytest-perf", "pytest-ruff (>=0.2.1)", "pytest-subprocess", "pytest-timeout", "pytest-xdist (>=3)", "tomli", "tomli-w (>=1.0.0)", "virtualenv (>=13.0.0)", "wheel"]
 
+[[package]]
+name = "styxdefs"
+version = "0.1.5"
+description = "Styx definitions and minimal runtime"
+optional = false
+python-versions = ">=3.10"
+files = [
+    {file = "styxdefs-0.1.5-py3-none-any.whl", hash = "sha256:41b93e16a22d9edbf422a6c8e51cd2204a972ec92280382ef97df28bb6beb543"},
+    {file = "styxdefs-0.1.5.tar.gz", hash = "sha256:33c2e57aeae3826f93314d3aef7ea8f7220efb61291ba1bbb2e7025344907944"},
+]
+
 [[package]]
 name = "typing-extensions"
 version = "4.9.0"
@@ -562,4 +573,4 @@ test = ["covdefaults (>=2.3)", "coverage (>=7.2.7)", "coverage-enable-subprocess
 [metadata]
 lock-version = "2.0"
 python-versions = "~3.11"
-content-hash = "3144076938a7ab8b4f584898351705cb6d0a7402154150afed6f8d33a5332f21"
+content-hash = "9aae9d66dabc6552c058b2c2fdd90645d79e401890a3283a56828eacab0a28c1"
diff --git a/pyproject.toml b/pyproject.toml
index 5c928ca..82afdb6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,6 +9,7 @@ packages = [{include = "styxgraph", from = "src"}]
 
 [tool.poetry.dependencies]
 python = "~3.11"
+styxdefs = "^0.1.5"
 
 [tool.poetry.group.dev.dependencies]
 pytest = "^8.2.2"
diff --git a/src/styxgraph/__init__.py b/src/styxgraph/__init__.py
index 8ea7b85..7a58ee5 100644
--- a/src/styxgraph/__init__.py
+++ b/src/styxgraph/__init__.py
@@ -1,26 +1,43 @@
 """.. include:: ../../README.md"""  # noqa: D415
 
 import pathlib
-from styxdefs import set_global_runner, get_global_runner, Runner, Execution, Metadata, InputPathType, OutputPathType
+
+from styxdefs import (
+    Execution,
+    InputPathType,
+    Metadata,
+    OutputPathType,
+    Runner,
+)
 
 
 class _GraphExecution(Execution):
-    def __init__(self, base: Execution, graph_runner: 'GraphRunner', metadata: Metadata) -> None:
+    """Graph execution."""
+
+    def __init__(
+        self, base: Execution, graph_runner: "GraphRunner", metadata: Metadata
+    ) -> None:
+        """Create a new GraphExecution."""
         self.base = base
         self.graph_runner = graph_runner
         self.metadata = metadata
-        self.input_files = []
-        self.output_files = []
+        self.input_files: list[InputPathType] = []
+        self.output_files: list[OutputPathType] = []
 
     def input_file(self, host_file: InputPathType) -> str:
+        """Resolve input file."""
         self.input_files.append(host_file)
         return self.base.input_file(host_file)
 
     def run(self, cargs: list[str]) -> None:
-        self.graph_runner.graph_append(self.metadata, self.input_files, self.output_files)
+        """Run the command."""
+        self.graph_runner.graph_append(
+            self.metadata, self.input_files, self.output_files
+        )
         return self.base.run(cargs)
 
     def output_file(self, local_file: str, optional: bool = False) -> OutputPathType:
+        """Resolve output file."""
         output_file = self.base.output_file(local_file, optional)
         self.output_files.append(output_file)
         return output_file
@@ -28,21 +45,32 @@ def output_file(self, local_file: str, optional: bool = False) -> OutputPathType
 
 # Define a new runner
 class GraphRunner(Runner):
-    def __init__(self, base: Runner):
+    """Graph runner."""
+
+    def __init__(self, base: Runner) -> None:
+        """Create a new GraphRunner."""
         self.base = base
         self.graph: list[tuple[str, list[InputPathType], list[OutputPathType]]] = []
 
     def start_execution(self, metadata: Metadata) -> Execution:
+        """Start a new execution."""
         return _GraphExecution(self.base.start_execution(metadata), self, metadata)
-    
-    def graph_append(self, metadata: Metadata, input_file: list[InputPathType], output_file: list[OutputPathType]) -> None:
-        print(f'Appending {metadata.name} with {input_file} and {output_file}')
+
+    def graph_append(
+        self,
+        metadata: Metadata,
+        input_file: list[InputPathType],
+        output_file: list[OutputPathType],
+    ) -> None:
+        """Append a node to the graph."""
+        print(f"Appending {metadata.name} with {input_file} and {output_file}")
         self.graph.append((metadata.name, input_file, output_file))
 
     def mermaid(self) -> str:
-        connections = []
-        inputs_lookup = {}
-        outputs_lookup = {}
+        """Generate a mermaid graph of the graph."""
+        connections: list[str] = []
+        inputs_lookup: dict[str, list[str]] = {}
+        outputs_lookup: dict[str, str] = {}
         for id, inputs, outputs in self.graph:
             for input in inputs:
                 if input not in inputs_lookup:
@@ -54,13 +82,15 @@ def mermaid(self) -> str:
         for id, inputs, _ in self.graph:
             for input in inputs:
                 for output, output_id in outputs_lookup.items():
-                    if pathlib.Path(input).is_relative_to(output):  # is subfolder/file in output root
-                        connections.append(f'{output_id} --> {id}')
-        
+                    if pathlib.Path(input).is_relative_to(
+                        output
+                    ):  # is subfolder/file in output root
+                        connections.append(f"{output_id} --> {id}")
+
         # Generate mermaid
-        mermaid = 'graph TD\n'
+        mermaid = "graph TD\n"
         for id, _, _ in self.graph:
-            mermaid += f'  {id}\n'
+            mermaid += f"  {id}\n"
         for connection in connections:
-            mermaid += f'  {connection}\n'
+            mermaid += f"  {connection}\n"
         return mermaid