diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index ae27921..6b289a5 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -9,12 +9,12 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
-        with: {python-version: '3.12'}
+        with: {python-version: '3.11'}
       - name: Install dependencies
-        run: pip install "mkdocs-material>=9,<10" pdoc
-      - name: Install package in development mode
-        run: pip install -e .
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install '.[dev]'
       - name: Generate auto-generated API documentation
-        run: python scripts/generate_api_docs.py
+        run: python dev/generate_api_docs.py
       - name: Deploy documentation
         run: mkdocs gh-deploy --force --clean
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
new file mode 100644
index 0000000..cb97eb4
--- /dev/null
+++ b/.github/workflows/publish.yml
@@ -0,0 +1,51 @@
+name: Publish to PyPI
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+    inputs:
+      test_pypi:
+        description: 'Publish to Test PyPI instead of PyPI'
+        required: false
+        default: false
+        type: boolean
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write  # Required for trusted publishing
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install build dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install build twine
+
+      - name: Build package
+        run: python -m build
+
+      - name: Check package
+        run: python -m twine check dist/*
+
+      - name: Publish to Test PyPI
+        if: ${{ github.event.inputs.test_pypi == 'true' }}
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          repository-url: https://test.pypi.org/legacy/
+          print-hash: true
+
+      - name: Publish to PyPI
+        if: ${{ github.event_name == 'release' && github.event.action == 'published' }}
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          print-hash: true
diff --git a/.github/workflows/python-test.yml b/.github/workflows/python-test.yml
index 9757886..d69ddf1 100644
--- a/.github/workflows/python-test.yml
+++ b/.github/workflows/python-test.yml
@@ -1,25 +1,32 @@
-# Run unit tests and check test coverage
-name: Python-test
+# Run tests, linting, and type checking
+name: CI
 
 on: [push, pull_request]
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.13"]
+        python-version: ["3.11", "3.12", "3.13"]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           python -m pip install '.[dev]'
-      - name: Test with pytest and check test coverage
+      - name: Lint with Ruff
         run: |
-          pytest
\ No newline at end of file
+          ruff check .
+          ruff format --check .
+      - name: Type check with Pyright
+        run: |
+          pyright
+      - name: Test with pytest and check coverage
+        run: |
+          pytest
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..c662ccc
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,24 @@
+repos:
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.11.13
+    hooks:
+      - id: ruff
+        args: [--fix]
+      - id: ruff-format
+
+  - repo: https://github.com/RobertCraigie/pyright-python
+    rev: v1.1.401
+    hooks:
+      - id: pyright
+        args: [--project, pyproject.toml]
+        additional_dependencies: ['geopy', 'networkx', 'pyyaml', 'numpy', 'pandas', 'matplotlib', 'seaborn']
+
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-toml
+      - id: check-merge-conflict
+      - id: check-added-large-files
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..dd6a397
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,177 @@
+# NetGraph Development Makefile
+# This Makefile provides convenient shortcuts for common development tasks
+
+.PHONY: help setup install dev-install check test clean docs build check-dist publish-test publish docker-build docker-run
+
+# Default target - show help
+.DEFAULT_GOAL := help
+
+help:
+	@echo "🔧 NetGraph Development Commands"
+	@echo ""
+	@echo "Setup & Installation:"
+	@echo "  make setup         - Full development environment setup (install + hooks)"
+	@echo "  make install       - Install package in development mode (no dev deps)"
+	@echo "  make dev-install   - Install package with all dev dependencies"
+	@echo ""
+	@echo "Code Quality & Testing:"
+	@echo "  make check         - Run all pre-commit checks and tests"
+	@echo "  make lint          - Run only linting (ruff + pyright)"
+	@echo "  make format        - Auto-format code with ruff"
+	@echo "  make test          - Run tests with coverage"
+	@echo "  make test-quick    - Run tests without coverage"
+	@echo ""
+	@echo "Documentation:"
+	@echo "  make docs          - Generate API documentation"
+	@echo "  make docs-test     - Test API documentation generation"
+	@echo "  make docs-serve    - Serve documentation locally"
+	@echo ""
+	@echo "Build & Package:"
+	@echo "  make build         - Build distribution packages"
+	@echo "  make clean         - Clean build artifacts and cache files"
+	@echo ""
+	@echo "Publishing:"
+	@echo "  make check-dist    - Check distribution packages with twine"
+	@echo "  make publish-test  - Publish to Test PyPI"
+	@echo "  make publish       - Publish to PyPI"
+	@echo ""
+	@echo "Docker (if available):"
+	@echo "  make docker-build  - Build Docker image"
+	@echo "  make docker-run    - Run Docker container with Jupyter"
+	@echo ""
+	@echo "Utilities:"
+	@echo "  make info          - Show project information"
+
+# Setup and Installation
+setup:
+	@echo "🚀 Setting up development environment..."
+	@bash dev/setup-dev.sh
+
+install:
+	@echo "📦 Installing package in development mode (no dev dependencies)..."
+	pip install -e .
+
+dev-install:
+	@echo "📦 Installing package with dev dependencies..."
+	pip install -e '.[dev]'
+
+# Code Quality and Testing
+check:
+	@echo "🔍 Running complete code quality checks and tests..."
+	@bash dev/run-checks.sh
+
+lint:
+	@echo "🧹 Running linting checks..."
+	@pre-commit run ruff --all-files
+	@pre-commit run pyright --all-files
+
+format:
+	@echo "✨ Auto-formatting code..."
+	@pre-commit run ruff-format --all-files
+
+test:
+	@echo "🧪 Running tests with coverage..."
+	@pytest
+
+test-quick:
+	@echo "⚡ Running tests without coverage..."
+	@pytest --no-cov
+
+# Documentation
+docs:
+	@echo "📚 Generating API documentation..."
+	@echo "ℹ️  This regenerates docs/reference/api-full.md from source code"
+	@python dev/generate_api_docs.py --write-file
+
+docs-test:
+	@echo "🧪 Testing API documentation generation..."
+	@python dev/test_doc_generation.py
+
+docs-serve:
+	@echo "🌐 Serving documentation locally..."
+	@if command -v mkdocs >/dev/null 2>&1; then \
+		mkdocs serve; \
+	else \
+		echo "❌ mkdocs not installed. Install dev dependencies with: make dev-install"; \
+		exit 1; \
+	fi
+
+# Build and Package
+build:
+	@echo "🏗️  Building distribution packages..."
+	@if python -c "import build" >/dev/null 2>&1; then \
+		python -m build; \
+	else \
+		echo "❌ build module not installed. Install dev dependencies with: make dev-install"; \
+		exit 1; \
+	fi
+
+clean:
+	@echo "🧹 Cleaning build artifacts and cache files..."
+	@rm -rf build/
+	@rm -rf dist/
+	@rm -rf *.egg-info/
+	@find . -type f -name "*.pyc" -delete
+	@find . -type d -name "__pycache__" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type f -name "*.pyo" -delete
+	@find . -type f -name "*~" -delete
+	@find . -type f -name "*.orig" -delete
+	@echo "✅ Cleanup complete!"
+
+# Docker commands (optional)
+docker-build:
+	@echo "🐳 Building Docker image..."
+	@if [ -f "Dockerfile" ]; then \
+		bash run.sh build; \
+	else \
+		echo "❌ Dockerfile not found"; \
+		exit 1; \
+	fi
+
+docker-run:
+	@echo "🐳 Running Docker container with Jupyter..."
+	@if [ -f "run.sh" ]; then \
+		bash run.sh run; \
+	else \
+		echo "❌ run.sh not found"; \
+		exit 1; \
+	fi
+
+# Publishing
+check-dist:
+	@echo "🔍 Checking distribution packages..."
+	@if python -c "import twine" >/dev/null 2>&1; then \
+		python -m twine check dist/*; \
+	else \
+		echo "❌ twine not installed. Install dev dependencies with: make dev-install"; \
+		exit 1; \
+	fi
+
+publish-test:
+	@echo "📦 Publishing to Test PyPI..."
+	@if python -c "import twine" >/dev/null 2>&1; then \
+		python -m twine upload --repository testpypi dist/*; \
+	else \
+		echo "❌ twine not installed. Install dev dependencies with: make dev-install"; \
+		exit 1; \
+	fi
+
+publish:
+	@echo "🚀 Publishing to PyPI..."
+	@if python -c "import twine" >/dev/null 2>&1; then \
+		python -m twine upload dist/*; \
+	else \
+		echo "❌ twine not installed. Install dev dependencies with: make dev-install"; \
+		exit 1; \
+	fi
+
+# Project Information
+info:
+	@echo "📋 NetGraph Project Information"
+	@echo "================================"
+	@echo "Python version: $$(python --version)"
+	@echo "Package version: $$(python -c 'import ngraph; print(ngraph.__version__)' 2>/dev/null || echo 'Not installed')"
+	@echo "Virtual environment: $$(echo $$VIRTUAL_ENV | sed 's|.*/||' || echo 'None active')"
+	@echo "Pre-commit installed: $$(pre-commit --version 2>/dev/null || echo 'Not installed')"
+	@echo "Git status:"
+	@git status --porcelain | head -5 || echo "Not a git repository"
diff --git a/README.md b/README.md
index 9687ff5..ee74497 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ NetGraph is a scenario-based network modeling and analysis framework written in
 - **Scenario-Based Modeling** [DONE]: Define complete network scenarios in YAML with topology, failures, traffic, and workflow
 - **Hierarchical Blueprints** [DONE]: Reusable network templates with nested structures and parameterization
 - **Demand Placement** [DONE]: Place traffic demands on the network with various flow placement strategies (e.g., shortest path only, ECMP/UCMP, etc.)
-- **Capacity Calculation** [DONE]: Calculate capacity with different flow placement strategies 
+- **Capacity Calculation** [DONE]: Calculate capacity with different flow placement strategies
 - **Failure Simulation** [DONE]: Model component and risk groups failures for availability analysis
 - **Network Analysis** [IN PROGRESS]: Analyze capacity, failure tolerance, and efficiency
 
diff --git a/dev/dev.md b/dev/dev.md
new file mode 100644
index 0000000..99dece7
--- /dev/null
+++ b/dev/dev.md
@@ -0,0 +1,66 @@
+# NetGraph Development Guide
+
+## Essential Commands
+
+```bash
+make setup         # Complete dev environment setup
+make check         # Run all quality checks + tests
+make test          # Run tests with coverage
+make docs          # Generate API documentation
+make docs-serve    # Serve docs locally
+```
+
+**For all available commands**: `make help`
+
+## Documentation
+
+### Generating API Documentation
+
+The API documentation is auto-generated from source code docstrings:
+
+```bash
+# Generate API documentation
+make docs
+# or
+python dev/generate_api_docs.py
+```
+
+**Important**: API documentation is **not** regenerated during pytest runs to avoid constant file changes. The doc generation test is skipped by default. To test doc generation:
+
+```bash
+GENERATE_DOCS=true pytest tests/test_api_docs.py::test_api_doc_generation_output
+```
+
+### Documentation Types
+
+- `docs/reference/api.md` - Curated, example-driven API guide (manually maintained)
+- `docs/reference/api-full.md` - Complete auto-generated reference (regenerated via `make docs`)
+- `docs/reference/cli.md` - Command-line interface documentation
+- `docs/reference/dsl.md` - YAML DSL syntax reference
+
+## Publishing
+
+**Manual**: `make clean && make build && make publish-test && make publish`
+
+**Automated**: Create GitHub release → auto-publishes to PyPI
+
+**Version**: Update `version = "x.y.z"` in `pyproject.toml` before publishing
+
+## Key Development Files
+
+```
+pyproject.toml              # Package config, dependencies, tool settings
+Makefile                    # Development commands
+.pre-commit-config.yaml     # Code quality hooks
+dev/setup-dev.sh           # Development environment setup script
+dev/run-checks.sh           # Manual code quality checks
+```
+
+## Git Workflows
+
+```
+.github/workflows/
+├── python-test.yml         # CI: tests, linting, type checking
+├── docs.yml                # Auto-deploy documentation
+└── publish.yml             # Auto-publish to PyPI on releases
+```
diff --git a/scripts/generate_api_docs.py b/dev/generate_api_docs.py
similarity index 79%
rename from scripts/generate_api_docs.py
rename to dev/generate_api_docs.py
index 1954f27..8a4ab37 100755
--- a/scripts/generate_api_docs.py
+++ b/dev/generate_api_docs.py
@@ -2,15 +2,19 @@
 """
 Generate API documentation for NetGraph
 This script should be run from the project root directory.
+
+By default, outputs documentation to stdout.
+Use --write-file to write to docs/reference/api-full.md instead.
 """
 
-import inspect
+import argparse
+import dataclasses
 import importlib
-import sys
+import inspect
 import os
-import dataclasses
-from pathlib import Path
+import sys
 from datetime import datetime
+from pathlib import Path
 
 # Add the current directory to Python path for development installs
 if os.path.exists("ngraph"):
@@ -61,7 +65,7 @@ def get_class_info(cls):
                 try:
                     # Try to call the factory to get a representative value
                     default_val = field.default_factory()
-                except:
+                except Exception:
                     default_val = f"{field.default_factory.__name__}()"
             else:
                 default_val = None
@@ -145,8 +149,16 @@ def document_module(module_name):
     return doc
 
 
-def generate_api_documentation():
-    """Generate the complete API documentation."""
+def generate_api_documentation(output_to_file=False):
+    """Generate the complete API documentation.
+
+    Args:
+        output_to_file (bool): If True, write to docs/reference/api-full.md.
+                               If False, return the documentation string.
+
+    Returns:
+        str: The generated documentation (when output_to_file=False)
+    """
 
     # Modules to document (in order)
     modules = [
@@ -177,7 +189,7 @@ def generate_api_documentation():
     timestamp = datetime.now().strftime("%B %d, %Y at %H:%M UTC")
     header = f"""# NetGraph API Reference (Auto-Generated)
 
-This is the complete auto-generated API documentation for NetGraph. 
+This is the complete auto-generated API documentation for NetGraph.
 For a curated, example-driven API guide, see **[api.md](api.md)**.
 
 > **📋 Documentation Types:**
@@ -230,19 +242,45 @@ def generate_api_documentation():
 
     doc += footer
 
-    # Ensure output directory exists
-    output_path = Path("docs/reference/api-full.md")
-    output_path.parent.mkdir(parents=True, exist_ok=True)
+    if output_to_file:
+        # Ensure output directory exists
+        output_path = Path("docs/reference/api-full.md")
+        output_path.parent.mkdir(parents=True, exist_ok=True)
 
-    # Write to file
-    with open(output_path, "w", encoding="utf-8") as f:
-        f.write(doc)
+        # Write to file
+        with open(output_path, "w", encoding="utf-8") as f:
+            f.write(doc)
 
-    print(f"✅ API documentation generated successfully!")
-    print(f"📄 Written to: {output_path}")
-    print(f"📊 Size: {len(doc):,} characters")
-    print(f"📚 Modules documented: {len(modules)}")
+        print("✅ API documentation generated successfully!")
+        print(f"📄 Written to: {output_path}")
+        print(f"📊 Size: {len(doc):,} characters")
+        print(f"📚 Modules documented: {len(modules)}")
+    else:
+        # Return the documentation string
+        return doc
 
 
 if __name__ == "__main__":
-    generate_api_documentation()
+    parser = argparse.ArgumentParser(
+        description="Generate API documentation for NetGraph",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+  python generate_api_docs.py                # Output to stdout
+  python generate_api_docs.py --write-file   # Write to docs/reference/api-full.md
+        """,
+    )
+    parser.add_argument(
+        "--write-file",
+        action="store_true",
+        help="Write documentation to docs/reference/api-full.md instead of stdout",
+    )
+
+    args = parser.parse_args()
+
+    if args.write_file:
+        generate_api_documentation(output_to_file=True)
+    else:
+        # Output to stdout
+        doc = generate_api_documentation(output_to_file=False)
+        print(doc)
diff --git a/dev/run-checks.sh b/dev/run-checks.sh
new file mode 100755
index 0000000..9ad285b
--- /dev/null
+++ b/dev/run-checks.sh
@@ -0,0 +1,55 @@
+#!/bin/bash
+# Run all code quality checks and tests
+# This script runs the complete validation suite: pre-commit hooks + tests
+
+set -e  # Exit on any error
+
+echo "🔍 Running complete code quality checks and tests..."
+echo ""
+
+# Check if pre-commit is installed
+if ! command -v pre-commit &> /dev/null; then
+    echo "❌ pre-commit is not installed. Please run 'pip install pre-commit' first."
+    exit 1
+fi
+
+# Check if pytest is installed
+if ! command -v pytest &> /dev/null; then
+    echo "❌ pytest is not installed. Please run 'pip install -e .[dev]' first."
+    exit 1
+fi
+
+# Check if pre-commit hooks are installed
+if [ ! -f .git/hooks/pre-commit ]; then
+    echo "⚠️  Pre-commit hooks not installed. Installing now..."
+    pre-commit install
+    echo ""
+fi
+
+# Run pre-commit checks
+echo "🏃 Running pre-commit on all files..."
+pre-commit run --all-files
+
+if [ $? -ne 0 ]; then
+    echo ""
+    echo "❌ Pre-commit checks failed. Please fix the issues above before running tests."
+    echo "💡 Tip: Most formatting issues can be auto-fixed by running the checks again."
+    exit 1
+fi
+
+echo ""
+echo "✅ Pre-commit checks passed!"
+echo ""
+
+# Run tests with coverage
+echo "🧪 Running tests with coverage..."
+pytest
+
+if [ $? -eq 0 ]; then
+    echo ""
+    echo "🎉 All checks and tests passed! Your code is ready for commit."
+else
+    echo ""
+    echo "❌ Some tests failed. Please fix the issues above and try again."
+    exit 1
+fi
diff --git a/dev/setup-dev.sh b/dev/setup-dev.sh
new file mode 100755
index 0000000..6d90e49
--- /dev/null
+++ b/dev/setup-dev.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+# Setup script for developers
+
+echo "🔧 Setting up development environment..."
+
+# Install the package with dev dependencies
+echo "📦 Installing package with dev dependencies..."
+pip install -e '.[dev]'
+
+# Install pre-commit hooks
+echo "🪝 Installing pre-commit hooks..."
+pre-commit install
+
+# Run pre-commit on all files to ensure everything is set up correctly
+echo "✅ Running pre-commit checks..."
+pre-commit run --all-files
+
+echo "🎉 Development environment setup complete!"
+echo ""
+echo "🚀 You're ready to contribute! Pre-commit hooks will now run automatically on each commit."
+echo "💡 To manually run all checks: pre-commit run --all-files"
diff --git a/docs/examples/basic.md b/docs/examples/basic.md
index 61e62ff..7a5ea61 100644
--- a/docs/examples/basic.md
+++ b/docs/examples/basic.md
@@ -1,6 +1,6 @@
 # Basic Example
 
-In this toy example, we'll create a simple graph with parallel edges and alternative paths, then run max flow analysis with different flow placement policies. 
+In this toy example, we'll create a simple graph with parallel edges and alternative paths, then run max flow analysis with different flow placement policies.
 
 ### Creating a Simple Network
 
@@ -27,7 +27,7 @@ from ngraph.lib.algorithms.base import FlowPlacement
 scenario_yaml = """
 network:
   name: "fundamentals_example"
-  
+
   # Create individual nodes
   nodes:
     A: {}
@@ -48,8 +48,8 @@ network:
       link_params:
         capacity: 2
         cost: 1
-    
-    # Parallel edges between B→C  
+
+    # Parallel edges between B→C
     - source: B
       target: C
       link_params:
@@ -60,7 +60,7 @@ network:
       link_params:
         capacity: 2
         cost: 1
-    
+
     # Alternative path A→D→C
     - source: A
       target: D
@@ -102,9 +102,9 @@ print(f"Flow on shortest paths: {max_flow_shortest}")
 
 # 3. Equal-balanced flow placement on shortest paths
 max_flow_shortest_balanced = network.max_flow(
-    source_path="A", 
-    sink_path="C", 
-    shortest_path=True, 
+    source_path="A",
+    sink_path="C",
+    shortest_path=True,
     flow_placement=FlowPlacement.EQUAL_BALANCED
 )
 print(f"Equal-balanced flow: {max_flow_shortest_balanced}")
diff --git a/docs/examples/clos-fabric.md b/docs/examples/clos-fabric.md
index 5e4330d..cdd0964 100644
--- a/docs/examples/clos-fabric.md
+++ b/docs/examples/clos-fabric.md
@@ -7,7 +7,7 @@ This example demonstrates how to model and analyze a 3-tier Clos network fabric
 We'll create two separate 3-tier Clos networks and analyze the maximum flow capacity between them. This scenario showcases:
 
 - Hierarchical blueprint composition
-- Complex adjacency patterns  
+- Complex adjacency patterns
 - Flow analysis with different placement policies
 - ECMP vs UCMP traffic distribution
 
@@ -102,7 +102,7 @@ print(f"Maximum flow with ECMP: {max_flow_ecmp}")
 
 The result `{('b1|b2', 'b1|b2'): 256.0}` means:
 - **Source**: All t1 nodes in both b1 and b2 segments of my_clos1
-- **Sink**: All t1 nodes in both b1 and b2 segments of my_clos2  
+- **Sink**: All t1 nodes in both b1 and b2 segments of my_clos2
 - **Capacity**: Maximum flow of 256.0 units
 
 ## Traffic Engineering Comparison
@@ -115,7 +115,7 @@ The result `{('b1|b2', 'b1|b2'): 256.0}` means:
 # ECMP: Equal distribution across all paths
 max_flow_ecmp = network.max_flow(
     source_path=r"my_clos1.*(b[0-9]*)/t1",
-    sink_path=r"my_clos2.*(b[0-9]*)/t1", 
+    sink_path=r"my_clos2.*(b[0-9]*)/t1",
     mode="combine",
     flow_placement=FlowPlacement.EQUAL_BALANCED
 )
@@ -124,7 +124,7 @@ max_flow_ecmp = network.max_flow(
 max_flow_ucmp = network.max_flow(
     source_path=r"my_clos1.*(b[0-9]*)/t1",
     sink_path=r"my_clos2.*(b[0-9]*)/t1",
-    mode="combine", 
+    mode="combine",
     flow_placement=FlowPlacement.PROPORTIONAL
 )
 
diff --git a/docs/getting-started/installation.md b/docs/getting-started/installation.md
index 96cc8f7..46b3216 100644
--- a/docs/getting-started/installation.md
+++ b/docs/getting-started/installation.md
@@ -78,7 +78,7 @@ To exit the JupyterLab server, press `Ctrl+C` in the terminal where the server i
             node_count: 4
             name_template: "leaf-{node_num}"
         spine:
-            node_count: 2  
+            node_count: 2
             name_template: "spine-{node_num}"
     adjacency:
         - source: /leaf
diff --git a/docs/getting-started/tutorial.md b/docs/getting-started/tutorial.md
index 052fe65..c66c424 100644
--- a/docs/getting-started/tutorial.md
+++ b/docs/getting-started/tutorial.md
@@ -17,7 +17,7 @@ network:
       node_count: 4
       name_template: "leaf-{node_num}"
     spine:
-      node_count: 2  
+      node_count: 2
       name_template: "spine-{node_num}"
   adjacency:
     - source: /leaf
@@ -149,21 +149,21 @@ from ngraph.lib.flow_policy import FlowPlacement
 # Calculate MaxFlow from pod1 servers to pod2 servers
 max_flow = network.max_flow(
     source_path="pod1/servers",
-    sink_path="pod2/servers", 
+    sink_path="pod2/servers",
 )
 print(f"Maximum flow pod1→pod2: {max_flow}")
 
 # Calculate MaxFlow from pod1 leaf to pod2 leaf
 max_flow_leaf = network.max_flow(
     source_path="pod1/leaf",
-    sink_path="pod2/leaf", 
+    sink_path="pod2/leaf",
 )
 print(f"Maximum flow pod1→pod2 leaf: {max_flow_leaf}")
 
 # Calculate MaxFlow from pod1 spine to pod2 spine
 max_flow_spine = network.max_flow(
     source_path="pod1/spine",
-    sink_path="pod2/spine", 
+    sink_path="pod2/spine",
 )
 print(f"Maximum flow pod1→pod2 spine: {max_flow_spine}")
 ```
diff --git a/docs/reference/api-full.md b/docs/reference/api-full.md
index 3db1345..0bf2baf 100644
--- a/docs/reference/api-full.md
+++ b/docs/reference/api-full.md
@@ -1,6 +1,6 @@
 # NetGraph API Reference (Auto-Generated)
 
-This is the complete auto-generated API documentation for NetGraph. 
+This is the complete auto-generated API documentation for NetGraph.
 For a curated, example-driven API guide, see **[api.md](api.md)**.
 
 > **📋 Documentation Types:**
@@ -10,7 +10,7 @@ For a curated, example-driven API guide, see **[api.md](api.md)**.
 > - **[CLI Reference](cli.md)** - Command-line interface
 > - **[DSL Reference](dsl.md)** - YAML syntax guide
 
-**Generated from source code on:** June 05, 2025 at 03:11 UTC
+**Generated from source code on:** June 08, 2025 at 01:15 UTC
 
 ---
 
@@ -439,7 +439,7 @@ Attributes:
     priority (int): A priority class for this demand (default=0).
     demand (float): The total demand volume (default=0.0).
     demand_placed (float): The portion of this demand that has been placed so far.
-    flow_policy_config ((Optional[FlowPolicyConfig]): The routing/placement policy config.
+    flow_policy_config (Optional[FlowPolicyConfig]): The routing/placement policy config.
     flow_policy (Optional[FlowPolicy]): A fully constructed FlowPolicy instance.
         If provided, it overrides flow_policy_config.
     mode (str): Expansion mode for generating sub-demands.
@@ -532,7 +532,7 @@ Attributes:
 
 **Methods:**
 
-- `apply_failures(self, network_nodes: 'Dict[str, Any]', network_links: 'Dict[str, Any]', network_risk_groups: 'Dict[str, Any]' = None) -> 'List[str]'`
+- `apply_failures(self, network_nodes: 'Dict[str, Any]', network_links: 'Dict[str, Any]', network_risk_groups: 'Dict[str, Any] | None' = None) -> 'List[str]'`
   - Identify which entities fail given the defined rules, then optionally
 
 ### FailureRule
@@ -729,7 +729,7 @@ Inherits from:
   - Add a directed edge from u_for_edge to v_for_edge.
 - `add_edges_from(self, ebunch_to_add, **attr)`
   - Add all the edges in ebunch_to_add.
-- `add_node(self, n: 'NodeID', **attr: 'Any') -> 'None'`
+- `add_node(self, node_for_adding: 'NodeID', **attr: 'Any') -> 'None'`
   - Add a single node, disallowing duplicates.
 - `add_nodes_from(self, nodes_for_adding, **attr)`
   - Add multiple nodes.
@@ -773,8 +773,8 @@ Inherits from:
   - Returns an iterator over nodes contained in nbunch that are
 - `neighbors(self, n)`
   - Returns an iterator over successor nodes of n.
-- `new_edge_key(src_node: 'NodeID', dst_node: 'NodeID') -> 'EdgeID'`
-  - Generate a unique edge key.
+- `new_edge_key(self, u, v)`
+  - Returns an unused key for edges between nodes `u` and `v`.
 - `number_of_edges(self, u=None, v=None)`
   - Returns the number of edges between two nodes.
 - `number_of_nodes(self)`
@@ -889,7 +889,7 @@ Returns:
 
 ## ngraph.lib.algorithms.spf
 
-### ksp(graph: ngraph.lib.graph.StrictMultiDiGraph, src_node: Hashable, dst_node: Hashable, edge_select: ngraph.lib.algorithms.base.EdgeSelect = <EdgeSelect.ALL_MIN_COST: 1>, edge_select_func: Optional[Callable[[ngraph.lib.graph.StrictMultiDiGraph, Hashable, Hashable, Dict[Hashable, Dict[str, Any]], Set[Hashable], Set[Hashable]], Tuple[Union[int, float], List[Hashable]]]] = None, max_k: Optional[int] = None, max_path_cost: Union[int, float, NoneType] = inf, max_path_cost_factor: Optional[float] = None, multipath: bool = True, excluded_edges: Optional[Set[Hashable]] = None, excluded_nodes: Optional[Set[Hashable]] = None) -> Iterator[Tuple[Dict[Hashable, Union[int, float]], Dict[Hashable, Dict[Hashable, List[Hashable]]]]]
+### ksp(graph: ngraph.lib.graph.StrictMultiDiGraph, src_node: Hashable, dst_node: Hashable, edge_select: ngraph.lib.algorithms.base.EdgeSelect = <EdgeSelect.ALL_MIN_COST: 1>, edge_select_func: Optional[Callable[[ngraph.lib.graph.StrictMultiDiGraph, Hashable, Hashable, Dict[Hashable, Dict[str, Any]], Set[Hashable], Set[Hashable]], Tuple[Union[int, float], List[Hashable]]]] = None, max_k: Optional[int] = None, max_path_cost: Union[int, float] = inf, max_path_cost_factor: Optional[float] = None, multipath: bool = True, excluded_edges: Optional[Set[Hashable]] = None, excluded_nodes: Optional[Set[Hashable]] = None) -> Iterator[Tuple[Dict[Hashable, Union[int, float]], Dict[Hashable, Dict[Hashable, List[Hashable]]]]]
 
 Generator of up to k shortest paths from src_node to dst_node using a Yen-like algorithm.
 
@@ -1087,8 +1087,8 @@ Attributes:
 **Attributes:**
 
 - `name` (str)
-- `source_path` (Pattern[str])
-- `sink_path` (Pattern[str])
+- `source_path` (str)
+- `sink_path` (str)
 - `mode` (str) = combine
 - `probe_reverse` (bool) = False
 - `shortest_path` (bool) = False
diff --git a/docs/reference/api.md b/docs/reference/api.md
index 385937a..2bb6f9e 100644
--- a/docs/reference/api.md
+++ b/docs/reference/api.md
@@ -19,7 +19,7 @@ from ngraph.scenario import Scenario
 # Create from YAML
 scenario = Scenario.from_yaml(yaml_content)
 
-# Create programmatically  
+# Create programmatically
 scenario = Scenario()
 scenario.network = Network()
 scenario.run()
@@ -118,7 +118,7 @@ from ngraph.traffic_demand import TrafficDemand
 demand = TrafficDemand(
     name="web_traffic",
     source_path="web_servers",
-    sink_path="databases", 
+    sink_path="databases",
     volume=1000,
     mode="full_mesh"
 )
@@ -207,7 +207,7 @@ restored_graph = from_digraph(nx_digraph)
 restored_graph = from_graph(nx_graph)
 ```
 
-### Graph Algorithms  
+### Graph Algorithms
 Low-level graph analysis functions.
 
 ```python
diff --git a/docs/reference/dsl.md b/docs/reference/dsl.md
index 30553db..2c43c21 100644
--- a/docs/reference/dsl.md
+++ b/docs/reference/dsl.md
@@ -118,7 +118,7 @@ network:
 The bracket expansion syntax supports:
 
 - **Numeric ranges**: `[1-4]` expands to `1`, `2`, `3`, `4`
-- **Character ranges**: `[a-c]` expands to `a`, `b`, `c`  
+- **Character ranges**: `[a-c]` expands to `a`, `b`, `c`
 - **Explicit lists**: `[red,blue,green]` expands to `red`, `blue`, `green`
 - **Multiple expansions**: `dc[1-2]/rack[a-b]` creates `dc1/racka`, `dc1/rackb`, `dc2/racka`, `dc2/rackb`
 
@@ -133,11 +133,11 @@ adjacency:
     target: "spine{s}"
     expand_vars:
       p: [1, 2]
-      r: ["a", "b"] 
+      r: ["a", "b"]
       s: [1, 2, 3]
     expansion_mode: "cartesian"  # Creates all combinations
     pattern: "mesh"
-    
+
   # Zip expansion (pairs elements by index)
   - source: "server{idx}"
     target: "switch{idx}"
@@ -164,7 +164,7 @@ You can override specific attributes of nodes and links after they are created b
 ```yaml
 network:
   # ... groups and adjacency definitions ...
-  
+
   node_overrides:
     - path: "^my_clos1/spine/switch-(1|3|5)$"  # Specific spine switches
       disabled: true
@@ -266,7 +266,7 @@ blueprints:
           idx: [1, 2, 3, 4, 5, 6, 7, 8]
         expansion_mode: "zip"  # Pairs source[i] with target[i]
         pattern: "mesh"
-        link_params: 
+        link_params:
           capacity: 3200
 ```
 
@@ -320,7 +320,7 @@ components:
         capacity: 12800.0  # 32x400G ports
         ports: 32
         count: 4
-        
+
   Optic400GLR4:
     component_type: "optic"
     description: "400G LR4 pluggable optic"
@@ -585,7 +585,7 @@ workflow:
   - step_type: EnableNodes
     path: "^my_clos2/leaf/switch-\\d+$"  # All leaf switches
     count: 4
-    
+
   - step_type: CapacityProbe
     source_path: "^(dc\\d+)/client"  # Capturing group creates per-DC groups
     sink_path: "^(dc\\d+)/server"
@@ -595,7 +595,7 @@ workflow:
 ### Best Practices
 
 1. **Use anchors for precision**: Always use `$` at the end if you want exact matches
-2. **Escape special characters in YAML**: 
+2. **Escape special characters in YAML**:
    - For digit patterns: Use `\\d+` instead of `\d+` in quoted YAML strings
    - For simple wildcards: `.*/spine/.*` works directly in YAML
    - In Python code: Use raw strings `r"pattern"` or double escaping `"\\d+"`
@@ -607,15 +607,15 @@ workflow:
 
 1. **Missing end anchors**: `switch-1` matches `switch-10`, `switch-11`, etc.
    - Fix: Use `switch-1$` for exact match
-   
-2. **YAML escaping inconsistencies**: 
+
+2. **YAML escaping inconsistencies**:
    - Simple patterns like `.*` work directly: `path: .*/spine/.*`
    - Complex patterns need escaping: `path: "spine-\\d+$"`
    - Python code always needs proper escaping: `"(SEA/leaf\\d)"`
-   
+
 3. **Greedy matching**: `.*` can match more than intended
    - Fix: Use specific patterns like `[^/]+` to match within path segments
-   
+
 4. **Empty groups**: Patterns that don't match any nodes create empty results
    - Fix: Test patterns against your actual node names
 
@@ -630,7 +630,7 @@ adjacency:
   - source: .*/spine/.*    # Matches any spine nodes
     target: .*/spine/.*
 
-# Complex patterns - use quotes and double backslashes  
+# Complex patterns - use quotes and double backslashes
 node_overrides:
   - path: "spine-\\d+$"    # Matches spine-1, spine-2, etc.
     attrs:
diff --git a/ngraph/__init__.py b/ngraph/__init__.py
index 6cf9a8a..427d228 100644
--- a/ngraph/__init__.py
+++ b/ngraph/__init__.py
@@ -1,5 +1,5 @@
 from __future__ import annotations
-from . import cli, transform
 
+from . import cli, transform
 
 __all__ = ["cli", "transform"]
diff --git a/ngraph/blueprints.py b/ngraph/blueprints.py
index 7f6e828..c9d7774 100644
--- a/ngraph/blueprints.py
+++ b/ngraph/blueprints.py
@@ -9,7 +9,7 @@
 from ngraph.network import Link, Network, Node
 
 
-@dataclass(slots=True)
+@dataclass
 class Blueprint:
     """
     Represents a reusable blueprint for hierarchical sub-topologies.
@@ -33,7 +33,7 @@ class Blueprint:
     adjacency: List[Dict[str, Any]]
 
 
-@dataclass(slots=True)
+@dataclass
 class DSLExpansionContext:
     """
     Carries the blueprint definitions and the final Network instance
@@ -162,7 +162,7 @@ def _expand_group(
     parent_path: str,
     group_name: str,
     group_def: Dict[str, Any],
-    inherited_risk_groups: Set[str] = frozenset(),
+    inherited_risk_groups: Set[str] | None = None,
 ) -> None:
     """
     Expands a single group definition into either:
@@ -191,6 +191,8 @@ def _expand_group(
         group_def (Dict[str, Any]): The group definition (node_count, name_template, etc.).
         inherited_risk_groups (Set[str]): Risk groups inherited from a higher-level group.
     """
+    if inherited_risk_groups is None:
+        inherited_risk_groups = set()
     expanded_names = _expand_name_patterns(group_name)
     # If bracket expansions exist, replicate for each expansion
     if len(expanded_names) > 1 or expanded_names[0] != group_name:
@@ -416,7 +418,7 @@ def _expand_adjacency_with_variables(
             )
 
         for combo_tuple in zip_longest(*lists_of_values, fillvalue=None):
-            combo_dict = dict(zip(var_names, combo_tuple))
+            combo_dict = dict(zip(var_names, combo_tuple, strict=False))
             expanded_src = _join_paths(
                 parent_path, source_template.format(**combo_dict)
             )
@@ -429,7 +431,7 @@ def _expand_adjacency_with_variables(
     else:
         # "cartesian" default
         for combo_tuple in product(*lists_of_values):
-            combo_dict = dict(zip(var_names, combo_tuple))
+            combo_dict = dict(zip(var_names, combo_tuple, strict=False))
             expanded_src = _join_paths(
                 parent_path, source_template.format(**combo_dict)
             )
diff --git a/ngraph/components.py b/ngraph/components.py
index b1bac5d..df2d07b 100644
--- a/ngraph/components.py
+++ b/ngraph/components.py
@@ -1,12 +1,13 @@
 from __future__ import annotations
 
-import yaml
 from copy import deepcopy
 from dataclasses import dataclass, field
-from typing import Dict, Any, Optional
+from typing import Any, Dict, Optional
+
+import yaml
 
 
-@dataclass(slots=True)
+@dataclass
 class Component:
     """
     A generic component that can represent chassis, line cards, optics, etc.
@@ -124,7 +125,7 @@ def as_dict(self, include_children: bool = True) -> Dict[str, Any]:
         return data
 
 
-@dataclass(slots=True)
+@dataclass
 class ComponentsLibrary:
     """
     Holds a collection of named Components. Each entry is a top-level "template"
@@ -207,7 +208,7 @@ def from_dict(cls, data: Dict[str, Any]) -> ComponentsLibrary:
         components_map: Dict[str, Component] = {}
         for comp_name, comp_def in data.items():
             components_map[comp_name] = cls._build_component(comp_name, comp_def)
-        return cls(components=components_map)
+        return ComponentsLibrary(components=components_map)
 
     @classmethod
     def _build_component(cls, name: str, definition_data: Dict[str, Any]) -> Component:
diff --git a/ngraph/explorer.py b/ngraph/explorer.py
index 38140f6..554714f 100644
--- a/ngraph/explorer.py
+++ b/ngraph/explorer.py
@@ -2,10 +2,10 @@
 
 import logging
 from dataclasses import dataclass, field
-from typing import Dict, List, Set, Optional
+from typing import Dict, List, Optional, Set
 
-from ngraph.network import Network, Node, Link
 from ngraph.components import ComponentsLibrary
+from ngraph.network import Network, Node
 
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.DEBUG)
diff --git a/ngraph/failure_manager.py b/ngraph/failure_manager.py
index 860e560..be6810f 100644
--- a/ngraph/failure_manager.py
+++ b/ngraph/failure_manager.py
@@ -4,12 +4,13 @@
 import statistics
 from collections import defaultdict
 from concurrent.futures import ThreadPoolExecutor, as_completed
-from typing import List, Dict, Optional, Tuple, Any
+from typing import Any, Dict, List, Optional, Tuple
 
+from ngraph.failure_policy import FailurePolicy
+from ngraph.lib.flow_policy import FlowPolicyConfig
 from ngraph.network import Network
 from ngraph.traffic_demand import TrafficDemand
 from ngraph.traffic_manager import TrafficManager, TrafficResult
-from ngraph.failure_policy import FailurePolicy
 
 
 class FailureManager:
@@ -29,7 +30,7 @@ def __init__(
         network: Network,
         traffic_demands: List[TrafficDemand],
         failure_policy: Optional[FailurePolicy] = None,
-        default_flow_policy_config=None,
+        default_flow_policy_config: Optional[FlowPolicyConfig] = None,
     ) -> None:
         """
         Initialize a FailureManager.
@@ -56,7 +57,7 @@ def apply_failures(self) -> None:
 
         # Collect node/links as dicts {id: attrs}, matching FailurePolicy expectations
         node_map = {n_name: n.attrs for n_name, n in self.network.nodes.items()}
-        link_map = {l_id: l.attrs for l_id, l in self.network.links.items()}
+        link_map = {link_id: link.attrs for link_id, link in self.network.links.items()}
 
         failed_ids = self.failure_policy.apply_failures(node_map, link_map)
 
@@ -84,7 +85,8 @@ def run_single_failure_scenario(self) -> List[TrafficResult]:
         tmgr = TrafficManager(
             network=self.network,
             traffic_demands=copy.deepcopy(self.traffic_demands),
-            default_flow_policy_config=self.default_flow_policy_config,
+            default_flow_policy_config=self.default_flow_policy_config
+            or FlowPolicyConfig.SHORTEST_PATHS_ECMP,
         )
         tmgr.build_graph()
         tmgr.expand_demands()
diff --git a/ngraph/failure_policy.py b/ngraph/failure_policy.py
index 013f917..edcb800 100644
--- a/ngraph/failure_policy.py
+++ b/ngraph/failure_policy.py
@@ -1,9 +1,9 @@
 from __future__ import annotations
 
+from collections import defaultdict, deque
 from dataclasses import dataclass, field
-from typing import Any, Dict, List, Literal, Optional, Set
 from random import random, sample
-from collections import defaultdict, deque
+from typing import Any, Dict, List, Literal, Set
 
 
 @dataclass
@@ -126,7 +126,7 @@ def apply_failures(
         self,
         network_nodes: Dict[str, Any],
         network_links: Dict[str, Any],
-        network_risk_groups: Dict[str, Any] = None,
+        network_risk_groups: Dict[str, Any] | None = None,
     ) -> List[str]:
         """
         Identify which entities fail given the defined rules, then optionally
diff --git a/ngraph/lib/algorithms/base.py b/ngraph/lib/algorithms/base.py
index 0b309c3..893dc88 100644
--- a/ngraph/lib/algorithms/base.py
+++ b/ngraph/lib/algorithms/base.py
@@ -1,8 +1,9 @@
 from __future__ import annotations
 
 from enum import IntEnum
-from typing import Union, Tuple
-from ngraph.lib.graph import NodeID, EdgeID
+from typing import Tuple, Union
+
+from ngraph.lib.graph import EdgeID, NodeID
 
 #: Represents numeric cost in the network (e.g. distance, latency, etc.).
 Cost = Union[int, float]
diff --git a/ngraph/lib/algorithms/calc_capacity.py b/ngraph/lib/algorithms/calc_capacity.py
index e8889c6..34b2fee 100644
--- a/ngraph/lib/algorithms/calc_capacity.py
+++ b/ngraph/lib/algorithms/calc_capacity.py
@@ -3,8 +3,8 @@
 from collections import defaultdict, deque
 from typing import Deque, Dict, List, Set, Tuple
 
-from ngraph.lib.graph import EdgeID, StrictMultiDiGraph, NodeID
 from ngraph.lib.algorithms.base import MIN_CAP, MIN_FLOW, FlowPlacement
+from ngraph.lib.graph import EdgeID, NodeID, StrictMultiDiGraph
 
 
 def _init_graph_data(
diff --git a/ngraph/lib/algorithms/edge_select.py b/ngraph/lib/algorithms/edge_select.py
index 842f9c3..ed48e13 100644
--- a/ngraph/lib/algorithms/edge_select.py
+++ b/ngraph/lib/algorithms/edge_select.py
@@ -1,8 +1,8 @@
 from math import isclose
 from typing import Any, Callable, Dict, List, Optional, Set, Tuple
 
-from ngraph.lib.graph import StrictMultiDiGraph, NodeID, EdgeID, AttrDict
-from ngraph.lib.algorithms.base import Cost, MIN_CAP, EdgeSelect
+from ngraph.lib.algorithms.base import MIN_CAP, Cost, EdgeSelect
+from ngraph.lib.graph import AttrDict, EdgeID, NodeID, StrictMultiDiGraph
 
 
 def edge_select_fabric(
diff --git a/ngraph/lib/algorithms/max_flow.py b/ngraph/lib/algorithms/max_flow.py
index cec39a3..0662a60 100644
--- a/ngraph/lib/algorithms/max_flow.py
+++ b/ngraph/lib/algorithms/max_flow.py
@@ -1,8 +1,8 @@
-from ngraph.lib.algorithms.spf import spf
-from ngraph.lib.algorithms.place_flow import place_flow_on_graph
 from ngraph.lib.algorithms.base import EdgeSelect, FlowPlacement
-from ngraph.lib.graph import NodeID, StrictMultiDiGraph
 from ngraph.lib.algorithms.flow_init import init_flow_graph
+from ngraph.lib.algorithms.place_flow import place_flow_on_graph
+from ngraph.lib.algorithms.spf import spf
+from ngraph.lib.graph import NodeID, StrictMultiDiGraph
 
 
 def calc_max_flow(
diff --git a/ngraph/lib/algorithms/path_utils.py b/ngraph/lib/algorithms/path_utils.py
index 798edfc..8a9c325 100644
--- a/ngraph/lib/algorithms/path_utils.py
+++ b/ngraph/lib/algorithms/path_utils.py
@@ -1,10 +1,10 @@
 from __future__ import annotations
 
 from itertools import product
-from typing import Dict, Iterator, List
+from typing import Any, Dict, Iterator, List
 
-from ngraph.lib.graph import NodeID, EdgeID
 from ngraph.lib.algorithms.base import PathTuple
+from ngraph.lib.graph import EdgeID, NodeID
 
 
 def resolve_to_paths(
@@ -31,7 +31,7 @@ def resolve_to_paths(
 
     seen = {dst_node}
     # Each stack entry: [(current_node, tuple_of_edgeIDs), predecessor_index]
-    stack: List[List[object]] = [[(dst_node, ()), 0]]
+    stack: List[List[Any]] = [[(dst_node, ()), 0]]
     top = 0
 
     while top >= 0:
diff --git a/ngraph/lib/algorithms/place_flow.py b/ngraph/lib/algorithms/place_flow.py
index b1e3d75..a985d0b 100644
--- a/ngraph/lib/algorithms/place_flow.py
+++ b/ngraph/lib/algorithms/place_flow.py
@@ -3,8 +3,8 @@
 from dataclasses import dataclass, field
 from typing import Dict, Hashable, List, Optional, Set
 
-from ngraph.lib.algorithms.calc_capacity import calc_graph_capacity
 from ngraph.lib.algorithms.base import FlowPlacement
+from ngraph.lib.algorithms.calc_capacity import calc_graph_capacity
 from ngraph.lib.graph import EdgeID, NodeID, StrictMultiDiGraph
 
 
@@ -120,9 +120,9 @@ def place_flow_on_graph(
                                     edges[eid][3][flows_attr].setdefault(
                                         flow_index, 0.0
                                     )
-                                    edges[eid][3][flows_attr][
-                                        flow_index
-                                    ] += edge_subflow
+                                    edges[eid][3][flows_attr][flow_index] += (
+                                        edge_subflow
+                                    )
 
                 elif flow_placement == FlowPlacement.EQUAL_BALANCED:
                     # Split equally across all parallel edges in edge_list.
@@ -153,7 +153,7 @@ def remove_flow_from_graph(
         flows_attr: The per-flow attribute name on edges.
     """
     edges = flow_graph.get_edges()
-    for edge_id, (_, _, _, edge_attr) in edges.items():
+    for _edge_id, (_, _, _, edge_attr) in edges.items():
         if flow_index is not None and flow_index in edge_attr[flows_attr]:
             # Subtract only the specified flow
             removed = edge_attr[flows_attr][flow_index]
diff --git a/ngraph/lib/algorithms/spf.py b/ngraph/lib/algorithms/spf.py
index 5bd988d..aa7500f 100644
--- a/ngraph/lib/algorithms/spf.py
+++ b/ngraph/lib/algorithms/spf.py
@@ -9,19 +9,19 @@
     Tuple,
 )
 
-from ngraph.lib.graph import (
-    AttrDict,
-    NodeID,
-    EdgeID,
-    StrictMultiDiGraph,
-)
 from ngraph.lib.algorithms.base import (
+    MIN_CAP,
     Cost,
     EdgeSelect,
-    MIN_CAP,
 )
 from ngraph.lib.algorithms.edge_select import edge_select_fabric
 from ngraph.lib.algorithms.path_utils import resolve_to_paths
+from ngraph.lib.graph import (
+    AttrDict,
+    EdgeID,
+    NodeID,
+    StrictMultiDiGraph,
+)
 
 
 def _spf_fast_all_min_cost_dijkstra(
@@ -50,7 +50,7 @@ def _spf_fast_all_min_cost_dijkstra(
             from the predecessor to that node. If multipath=True, there may be
             multiple predecessors for the same node.
     """
-    outgoing_adjacencies = graph._adj
+    outgoing_adjacencies = graph._adj  # type: ignore[attr-defined]
     if src_node not in outgoing_adjacencies:
         raise KeyError(f"Source node '{src_node}' is not in the graph.")
 
@@ -115,7 +115,7 @@ def _spf_fast_all_min_cost_with_cap_remaining_dijkstra(
           - pred: For each reachable node, a dict of predecessor -> list of edges
             from the predecessor to that node.
     """
-    outgoing_adjacencies = graph._adj
+    outgoing_adjacencies = graph._adj  # type: ignore[attr-defined]
     if src_node not in outgoing_adjacencies:
         raise KeyError(f"Source node '{src_node}' is not in the graph.")
 
@@ -223,7 +223,11 @@ def spf(
         else:
             edge_select_func = edge_select_fabric(edge_select)
 
-    outgoing_adjacencies = graph._adj
+    # Ensure edge_select_func is set at this point
+    if edge_select_func is None:
+        edge_select_func = edge_select_fabric(edge_select)
+
+    outgoing_adjacencies = graph._adj  # type: ignore[attr-defined]
     if src_node not in outgoing_adjacencies:
         raise KeyError(f"Source node '{src_node}' is not in the graph.")
 
@@ -284,7 +288,7 @@ def ksp(
         ]
     ] = None,
     max_k: Optional[int] = None,
-    max_path_cost: Optional[Cost] = float("inf"),
+    max_path_cost: Cost = float("inf"),
     max_path_cost_factor: Optional[float] = None,
     multipath: bool = True,
     excluded_edges: Optional[Set[EdgeID]] = None,
@@ -370,7 +374,7 @@ def ksp(
         # For each realized path from src->dst in the last SPF
         for path in resolve_to_paths(src_node, dst_node, root_pred):
             # Spur node iteration
-            for idx, (spur_node, edges_list) in enumerate(path[:-1]):
+            for idx, (spur_node, _edges_list) in enumerate(path[:-1]):
                 # The path up to but not including spur_node
                 root_path = path[:idx]
 
@@ -380,7 +384,7 @@ def ksp(
 
                 # Remove edges (and possibly nodes) used in previous shortest paths that
                 # share the same root_path
-                for sp_costs, sp_pred, sp_ex_e, sp_ex_n in shortest_paths:
+                for _sp_costs, sp_pred, sp_ex_e, sp_ex_n in shortest_paths:
                     for p in resolve_to_paths(src_node, dst_node, sp_pred):
                         if p[:idx] == root_path:
                             excl_e.update(sp_ex_e)
diff --git a/ngraph/lib/flow.py b/ngraph/lib/flow.py
index 0543ed1..0279e1e 100644
--- a/ngraph/lib/flow.py
+++ b/ngraph/lib/flow.py
@@ -19,14 +19,15 @@ class FlowIndex(NamedTuple):
     Attributes:
         src_node (NodeID): The source node of the flow.
         dst_node (NodeID): The destination node of the flow.
-        flow_class (int): Integer representing the 'class' of this flow (e.g., traffic class).
-        flow_id (str): A unique ID for this flow.
+        flow_class (Hashable): Identifier representing the 'class' of this flow (e.g., traffic class).
+                               Can be int, str, or any hashable type for flexibility.
+        flow_id (int): A unique ID for this flow.
     """
 
     src_node: NodeID
     dst_node: NodeID
-    flow_class: int
-    flow_id: str
+    flow_class: Hashable
+    flow_id: int
 
 
 class Flow:
@@ -42,7 +43,7 @@ class Flow:
     def __init__(
         self,
         path_bundle: PathBundle,
-        flow_index: Hashable,
+        flow_index: FlowIndex,
         excluded_edges: Optional[Set[EdgeID]] = None,
         excluded_nodes: Optional[Set[NodeID]] = None,
     ) -> None:
@@ -51,12 +52,12 @@ def __init__(
 
         Args:
             path_bundle (PathBundle): The set of paths this flow uses.
-            flow_index (Hashable): A unique identifier for this flow (e.g., MPLS label, tuple, etc.).
+            flow_index (FlowIndex): A unique identifier for this flow.
             excluded_edges (Optional[Set[EdgeID]]): Edges to exclude from usage.
             excluded_nodes (Optional[Set[NodeID]]): Nodes to exclude from usage.
         """
         self.path_bundle: PathBundle = path_bundle
-        self.flow_index: Hashable = flow_index
+        self.flow_index: FlowIndex = flow_index
         self.excluded_edges: Set[EdgeID] = excluded_edges or set()
         self.excluded_nodes: Set[NodeID] = excluded_nodes or set()
 
diff --git a/ngraph/lib/flow_policy.py b/ngraph/lib/flow_policy.py
index d4dd341..b2a6dcd 100644
--- a/ngraph/lib/flow_policy.py
+++ b/ngraph/lib/flow_policy.py
@@ -3,12 +3,12 @@
 import copy
 from collections import deque
 from enum import IntEnum
-from typing import Any, Callable, Dict, List, Optional, Set, Tuple
+from typing import Any, Callable, Dict, Hashable, List, Optional, Set, Tuple
 
-from ngraph.lib.flow import Flow, FlowIndex
-from ngraph.lib.algorithms import spf, base, edge_select
+from ngraph.lib.algorithms import base, edge_select, spf
 from ngraph.lib.algorithms.place_flow import FlowPlacement
-from ngraph.lib.graph import AttrDict, NodeID, EdgeID, StrictMultiDiGraph
+from ngraph.lib.flow import Flow, FlowIndex
+from ngraph.lib.graph import AttrDict, EdgeID, NodeID, StrictMultiDiGraph
 from ngraph.lib.path_bundle import PathBundle
 
 
@@ -46,7 +46,14 @@ def __init__(
         static_paths: Optional[List[PathBundle]] = None,
         edge_select_func: Optional[
             Callable[
-                [StrictMultiDiGraph, NodeID, NodeID, Dict[EdgeID, AttrDict]],
+                [
+                    StrictMultiDiGraph,
+                    NodeID,
+                    NodeID,
+                    Dict[EdgeID, AttrDict],
+                    Optional[Set[EdgeID]],
+                    Optional[Set[NodeID]],
+                ],
                 Tuple[base.Cost, List[EdgeID]],
             ]
         ] = None,
@@ -150,7 +157,7 @@ def _build_flow_index(
         self,
         src_node: NodeID,
         dst_node: NodeID,
-        flow_class: int,
+        flow_class: Hashable,
         flow_id: int,
     ) -> FlowIndex:
         """
@@ -241,7 +248,7 @@ def _create_flow(
         flow_graph: StrictMultiDiGraph,
         src_node: NodeID,
         dst_node: NodeID,
-        flow_class: int,
+        flow_class: Hashable,
         min_flow: Optional[float] = None,
         path_bundle: Optional[PathBundle] = None,
         excluded_edges: Optional[Set[EdgeID]] = None,
@@ -281,7 +288,7 @@ def _create_flows(
         flow_graph: StrictMultiDiGraph,
         src_node: NodeID,
         dst_node: NodeID,
-        flow_class: int,
+        flow_class: Hashable,
         min_flow: Optional[float] = None,
     ) -> None:
         """
@@ -387,7 +394,7 @@ def place_demand(
         flow_graph: StrictMultiDiGraph,
         src_node: NodeID,
         dst_node: NodeID,
-        flow_class: int,
+        flow_class: Hashable,
         volume: float,
         target_flow_volume: Optional[float] = None,
         min_flow: Optional[float] = None,
@@ -474,7 +481,7 @@ def rebalance_demand(
         flow_graph: StrictMultiDiGraph,
         src_node: NodeID,
         dst_node: NodeID,
-        flow_class: int,
+        flow_class: Hashable,
         target_flow_volume: float,
     ) -> Tuple[float, float]:
         """
diff --git a/ngraph/lib/graph.py b/ngraph/lib/graph.py
index 8857c3f..68fcb94 100644
--- a/ngraph/lib/graph.py
+++ b/ngraph/lib/graph.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
-import uuid
 import base64
+import uuid
 from pickle import dumps, loads
 from typing import Any, Dict, Hashable, List, Optional, Tuple
 
@@ -61,23 +61,6 @@ def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)
         self._edges: Dict[EdgeID, EdgeTuple] = {}
 
-    @staticmethod
-    def new_edge_key(src_node: NodeID, dst_node: NodeID) -> EdgeID:
-        """
-        Generate a unique edge key.
-
-        By default, creates a Base64-encoded UUID. Subclasses may override this
-        to provide an alternative scheme, such as a numeric counter.
-
-        Args:
-            src_node (NodeID): The source node of the new edge.
-            dst_node (NodeID): The target node of the new edge.
-
-        Returns:
-            EdgeID: The newly generated edge key.
-        """
-        return new_base64_uuid()
-
     def copy(self, as_view: bool = False, pickle: bool = True) -> StrictMultiDiGraph:
         """
         Create a copy of this graph.
@@ -95,26 +78,26 @@ def copy(self, as_view: bool = False, pickle: bool = True) -> StrictMultiDiGraph
             StrictMultiDiGraph: A new instance (or view) of the graph.
         """
         if not pickle:
-            return super().copy(as_view=as_view)
+            return super().copy(as_view=as_view)  # type: ignore[return-value]
         return loads(dumps(self))
 
     #
     # Node management
     #
-    def add_node(self, n: NodeID, **attr: Any) -> None:
+    def add_node(self, node_for_adding: NodeID, **attr: Any) -> None:
         """
         Add a single node, disallowing duplicates.
 
         Args:
-            n (NodeID): The node to add.
+            node_for_adding (NodeID): The node to add.
             **attr: Arbitrary attributes for this node.
 
         Raises:
             ValueError: If the node already exists in the graph.
         """
-        if n in self:
-            raise ValueError(f"Node '{n}' already exists in this graph.")
-        super().add_node(n, **attr)
+        if node_for_adding in self:
+            raise ValueError(f"Node '{node_for_adding}' already exists in this graph.")
+        super().add_node(node_for_adding, **attr)
 
     def remove_node(self, n: NodeID) -> None:
         """
@@ -173,17 +156,19 @@ def add_edge(
             raise ValueError(f"Target node '{v_for_edge}' does not exist.")
 
         if key is None:
-            key = self.new_edge_key(u_for_edge, v_for_edge)
+            key = new_base64_uuid()
         else:
             if key in self._edges:
                 raise ValueError(f"Edge with id '{key}' already exists.")
 
         super().add_edge(u_for_edge, v_for_edge, key=key, **attr)
+        # At this point, key is guaranteed to be non-None (either provided or generated)
+        assert key is not None
         self._edges[key] = (
             u_for_edge,
             v_for_edge,
             key,
-            self[u_for_edge][v_for_edge][key],
+            self[u_for_edge][v_for_edge][key],  # pyright: ignore[reportArgumentType]
         )
         return key
 
diff --git a/ngraph/lib/io.py b/ngraph/lib/io.py
index 1f05532..382d543 100644
--- a/ngraph/lib/io.py
+++ b/ngraph/lib/io.py
@@ -1,8 +1,8 @@
 from __future__ import annotations
 
-from typing import Dict, Iterable, List, Optional, Any
+from typing import Any, Dict, Iterable, List, Optional
 
-from ngraph.lib.graph import StrictMultiDiGraph, NodeID
+from ngraph.lib.graph import NodeID, StrictMultiDiGraph
 
 
 def graph_to_node_link(graph: StrictMultiDiGraph) -> Dict[str, Any]:
@@ -148,7 +148,7 @@ def edgelist_to_graph(
                 f"Line '{line}' does not match expected columns {columns} (token count mismatch)."
             )
 
-        line_dict = dict(zip(columns, tokens))
+        line_dict = dict(zip(columns, tokens, strict=False))
         src_id = line_dict[source]
         dst_id = line_dict[target]
         edge_key = line_dict.get(key, None)
diff --git a/ngraph/lib/path.py b/ngraph/lib/path.py
index 826a5c2..bb5bcb5 100644
--- a/ngraph/lib/path.py
+++ b/ngraph/lib/path.py
@@ -2,10 +2,10 @@
 
 from dataclasses import dataclass, field
 from functools import cached_property
-from typing import Iterator, Set, Tuple, Any
+from typing import Any, Iterator, Set, Tuple
 
 from ngraph.lib.algorithms.base import Cost, PathTuple
-from ngraph.lib.graph import EdgeID, StrictMultiDiGraph, NodeID
+from ngraph.lib.graph import EdgeID, NodeID, StrictMultiDiGraph
 
 
 @dataclass
diff --git a/ngraph/lib/path_bundle.py b/ngraph/lib/path_bundle.py
index 283e123..3032ef8 100644
--- a/ngraph/lib/path_bundle.py
+++ b/ngraph/lib/path_bundle.py
@@ -6,7 +6,7 @@
 from ngraph.lib.algorithms.base import Cost, EdgeSelect
 from ngraph.lib.algorithms.edge_select import edge_select_fabric
 from ngraph.lib.algorithms.path_utils import resolve_to_paths
-from ngraph.lib.graph import EdgeID, StrictMultiDiGraph, NodeID
+from ngraph.lib.graph import AttrDict, EdgeID, NodeID, StrictMultiDiGraph
 from ngraph.lib.path import Path
 
 
@@ -86,8 +86,10 @@ def __lt__(self, other: PathBundle) -> bool:
         """Compare two PathBundles by cost (for sorting)."""
         return self.cost < other.cost
 
-    def __eq__(self, other: PathBundle) -> bool:
+    def __eq__(self, other: object) -> bool:
         """Check equality of two PathBundles by (src, dst, cost, edges)."""
+        if not isinstance(other, PathBundle):
+            return False
         return (
             self.src_node == other.src_node
             and self.dst_node == other.dst_node
@@ -96,17 +98,12 @@ def __eq__(self, other: PathBundle) -> bool:
         )
 
     def __hash__(self) -> int:
-        """Create a unique hash based on (src, dst, cost, sorted edges)."""
-        return hash(
-            (self.src_node, self.dst_node, self.cost, tuple(sorted(self.edges)))
-        )
+        """Create a unique hash based on (src, dst, cost, frozenset of edges)."""
+        return hash((self.src_node, self.dst_node, self.cost, frozenset(self.edges)))
 
     def __repr__(self) -> str:
         """String representation of this PathBundle."""
-        return (
-            f"PathBundle("
-            f"{self.src_node}, {self.dst_node}, {self.pred}, {self.cost})"
-        )
+        return f"PathBundle({self.src_node}, {self.dst_node}, {self.pred}, {self.cost})"
 
     def add(self, other: PathBundle) -> PathBundle:
         """
@@ -177,6 +174,10 @@ def from_path(
                 raise ValueError(
                     "A StrictMultiDiGraph `graph` is required when resolve_edges=True."
                 )
+            if edge_select is None:
+                raise ValueError(
+                    "edge_select must be provided when resolve_edges=True."
+                )
             edge_selector = edge_select_fabric(
                 edge_select,
                 cost_attr=cost_attr,
@@ -185,24 +186,32 @@ def from_path(
         else:
             edge_selector = None
 
-        src_node = path[0][0]
-        dst_node = path[-1][0]
+        src_node = path.path_tuple[0][0]
+        dst_node = path.path_tuple[-1][0]
         pred_map: Dict[NodeID, Dict[NodeID, List[EdgeID]]] = {src_node: {}}
         total_cost: Cost = 0
 
         # Build the predecessor map from each hop
-        for (a_node, a_edges), (z_node, _) in zip(path[:-1], path[1:]):
+        for (a_node, a_edges), (z_node, _) in zip(
+            path.path_tuple[:-1], path.path_tuple[1:], strict=True
+        ):
             pred_map.setdefault(z_node, {})
             # If we're not resolving edges, just copy whatever the path has
             if not resolve_edges:
                 pred_map[z_node][a_node] = list(a_edges)
             else:
                 # Re-select edges from a_node to z_node
-                min_cost, edge_list = edge_selector(
-                    graph, a_node, z_node, graph[a_node][z_node]
-                )
-                pred_map[z_node][a_node] = edge_list
-                total_cost += min_cost
+                if edge_selector is not None and graph is not None:
+                    # Convert edges_dict to the expected Dict[EdgeID, AttrDict] format
+                    # Since EdgeID is just Hashable, we can cast the keys directly
+                    typed_edges_dict: Dict[EdgeID, AttrDict] = {
+                        k: v for k, v in graph[a_node][z_node].items()
+                    }
+                    min_cost, edge_list = edge_selector(
+                        graph, a_node, z_node, typed_edges_dict, None, None
+                    )
+                    pred_map[z_node][a_node] = edge_list
+                    total_cost += min_cost
 
         if resolve_edges:
             return cls(src_node, dst_node, pred_map, total_cost)
diff --git a/ngraph/lib/util.py b/ngraph/lib/util.py
index 150122e..a6ed848 100644
--- a/ngraph/lib/util.py
+++ b/ngraph/lib/util.py
@@ -1,7 +1,8 @@
-from typing import Optional, Callable, Any
+from typing import Callable, Optional
+
 import networkx as nx
 
-from ngraph.lib.graph import StrictMultiDiGraph, NodeID
+from ngraph.lib.graph import NodeID, StrictMultiDiGraph
 
 
 def to_digraph(
@@ -31,11 +32,13 @@ def to_digraph(
     nx_graph = nx.DiGraph()
     nx_graph.add_nodes_from(graph.get_nodes())
 
-    # Iterate over nodes and their neighbors using the internal _adj attribute.
-    for u, neighbors in graph._adj.items():
+    # Iterate over nodes and their neighbors using the adjacency method.
+    for u, neighbors in graph.adjacency():
         for v, edges in neighbors.items():
+            # Convert edges to the expected dict format
+            typed_edges: dict = dict(edges)
             if edge_func:
-                edge_data = edge_func(graph, u, v, edges)
+                edge_data = edge_func(graph, u, v, typed_edges)
                 nx_graph.add_edge(u, v, **edge_data)
             else:
                 nx_graph.add_edge(u, v)
@@ -44,7 +47,7 @@ def to_digraph(
                 # Store the original multi-edge data in the '_uv_edges' attribute.
                 edge_attr = nx_graph.edges[u, v]
                 edge_attr.setdefault("_uv_edges", [])
-                edge_attr["_uv_edges"].append((u, v, edges))
+                edge_attr["_uv_edges"].append((u, v, typed_edges))
     return nx_graph
 
 
@@ -65,7 +68,7 @@ def from_digraph(nx_graph: nx.DiGraph) -> StrictMultiDiGraph:
     graph.add_nodes_from(nx_graph.nodes)
 
     # Restore original multi-edges from the consolidated edge attribute.
-    for u, v, data in nx_graph.edges(data=True):
+    for _u, _v, data in nx_graph.edges(data=True):
         uv_edges = data.get("_uv_edges", [])
         for orig_u, orig_v, edges in uv_edges:
             for edge_id, edge_data in edges.items():
@@ -96,11 +99,13 @@ def to_graph(
     nx_graph = nx.Graph()
     nx_graph.add_nodes_from(graph.get_nodes())
 
-    # Iterate over the internal _adj attribute to consolidate edges.
-    for u, neighbors in graph._adj.items():
+    # Iterate over the adjacency to consolidate edges.
+    for u, neighbors in graph.adjacency():
         for v, edges in neighbors.items():
+            # Convert edges to the expected dict format
+            typed_edges: dict = dict(edges)
             if edge_func:
-                edge_data = edge_func(graph, u, v, edges)
+                edge_data = edge_func(graph, u, v, typed_edges)
                 nx_graph.add_edge(u, v, **edge_data)
             else:
                 nx_graph.add_edge(u, v)
@@ -108,7 +113,7 @@ def to_graph(
             if revertible:
                 edge_attr = nx_graph.edges[u, v]
                 edge_attr.setdefault("_uv_edges", [])
-                edge_attr["_uv_edges"].append((u, v, edges))
+                edge_attr["_uv_edges"].append((u, v, typed_edges))
     return nx_graph
 
 
@@ -129,7 +134,7 @@ def from_graph(nx_graph: nx.Graph) -> StrictMultiDiGraph:
     graph.add_nodes_from(nx_graph.nodes)
 
     # Restore multi-edge data from each edge's '_uv_edges' attribute.
-    for u, v, data in nx_graph.edges(data=True):
+    for _u, _v, data in nx_graph.edges(data=True):
         uv_edges = data.get("_uv_edges", [])
         for orig_u, orig_v, edges in uv_edges:
             for edge_id, edge_data in edges.items():
diff --git a/ngraph/network.py b/ngraph/network.py
index 1459ea7..93b7ff3 100644
--- a/ngraph/network.py
+++ b/ngraph/network.py
@@ -4,7 +4,7 @@
 import re
 import uuid
 from dataclasses import dataclass, field
-from typing import Any, Dict, List, Optional, Tuple, Set
+from typing import Any, Dict, List, Optional, Set, Tuple
 
 from ngraph.lib.algorithms.base import FlowPlacement
 from ngraph.lib.algorithms.max_flow import calc_max_flow
@@ -21,7 +21,7 @@ def new_base64_uuid() -> str:
     return base64.urlsafe_b64encode(uuid.uuid4().bytes).decode("ascii").rstrip("=")
 
 
-@dataclass(slots=True)
+@dataclass
 class Node:
     """
     Represents a node in the network.
@@ -42,7 +42,7 @@ class Node:
     attrs: Dict[str, Any] = field(default_factory=dict)
 
 
-@dataclass(slots=True)
+@dataclass
 class Link:
     """
     Represents a directed link between two nodes in the network.
@@ -74,7 +74,7 @@ def __post_init__(self) -> None:
         self.id = f"{self.source}|{self.target}|{new_base64_uuid()}"
 
 
-@dataclass(slots=True)
+@dataclass
 class RiskGroup:
     """
     Represents a shared-risk or failure domain, which may have nested children.
@@ -92,7 +92,7 @@ class RiskGroup:
     attrs: Dict[str, Any] = field(default_factory=dict)
 
 
-@dataclass(slots=True)
+@dataclass
 class Network:
     """
     A container for network nodes and links.
@@ -312,7 +312,7 @@ def _compute_flow_single_group(
             sources (List[Node]): List of source nodes.
             sinks (List[Node]): List of sink nodes.
             shortest_path (bool): If True, restrict flows to shortest paths only.
-            flow_placement (FlowPlacement or None): Strategy for placing flow among
+            flow_placement (Optional[FlowPlacement]): Strategy for placing flow among
                 parallel equal-cost paths. If None, defaults to FlowPlacement.PROPORTIONAL.
 
         Returns:
@@ -450,8 +450,8 @@ def find_links(
         Search for links using optional regex patterns for source or target node names.
 
         Args:
-            source_regex (str or None): Regex to match link.source. If None, matches all sources.
-            target_regex (str or None): Regex to match link.target. If None, matches all targets.
+            source_regex (Optional[str]): Regex to match link.source. If None, matches all sources.
+            target_regex (Optional[str]): Regex to match link.target. If None, matches all targets.
             any_direction (bool): If True, also match reversed source/target.
 
         Returns:
diff --git a/ngraph/results.py b/ngraph/results.py
index 5422045..b2a737d 100644
--- a/ngraph/results.py
+++ b/ngraph/results.py
@@ -2,7 +2,7 @@
 from typing import Any, Dict
 
 
-@dataclass(slots=True)
+@dataclass
 class Results:
     """
     A container for storing arbitrary key-value data that arises during workflow steps.
@@ -23,9 +23,10 @@ def put(self, step_name: str, key: str, value: Any) -> None:
         Store a value under (step_name, key).
         If the step_name sub-dict does not exist, it is created.
 
-        :param step_name: The workflow step that produced the result.
-        :param key: A short label describing the data (e.g. "total_capacity").
-        :param value: The actual data to store (can be any Python object).
+        Args:
+            step_name (str): The workflow step that produced the result.
+            key (str): A short label describing the data (e.g. "total_capacity").
+            value (Any): The actual data to store (can be any Python object).
         """
         if step_name not in self._store:
             self._store[step_name] = {}
@@ -35,10 +36,13 @@ def get(self, step_name: str, key: str, default: Any = None) -> Any:
         """
         Retrieve the value from (step_name, key). If the key is missing, return `default`.
 
-        :param step_name: The workflow step name.
-        :param key: The key under which the data was stored.
-        :param default: Value to return if the (step_name, key) is not present.
-        :return: The data, or `default` if not found.
+        Args:
+            step_name (str): The workflow step name.
+            key (str): The key under which the data was stored.
+            default (Any): Value to return if the (step_name, key) is not present.
+
+        Returns:
+            Any: The data, or `default` if not found.
         """
         return self._store.get(step_name, {}).get(key, default)
 
@@ -46,8 +50,11 @@ def get_all(self, key: str) -> Dict[str, Any]:
         """
         Retrieve a dictionary of {step_name: value} for all step_names that contain the specified key.
 
-        :param key: The key to look up in each step.
-        :return: A dict mapping step_name -> value for all steps that have stored something under 'key'.
+        Args:
+            key (str): The key to look up in each step.
+
+        Returns:
+            Dict[str, Any]: A dict mapping step_name -> value for all steps that have stored something under 'key'.
         """
         result = {}
         for step_name, data in self._store.items():
@@ -56,5 +63,10 @@ def get_all(self, key: str) -> Dict[str, Any]:
         return result
 
     def to_dict(self) -> Dict[str, Dict[str, Any]]:
-        """Return a dictionary representation of all stored results."""
+        """
+        Return a dictionary representation of all stored results.
+
+        Returns:
+            Dict[str, Dict[str, Any]]: Dictionary representation of all stored results.
+        """
         return {step: data.copy() for step, data in self._store.items()}
diff --git a/ngraph/scenario.py b/ngraph/scenario.py
index c43ff53..62dd230 100644
--- a/ngraph/scenario.py
+++ b/ngraph/scenario.py
@@ -1,23 +1,24 @@
 from __future__ import annotations
 
-import yaml
 from dataclasses import dataclass, field
 from typing import Any, Dict, List, Optional
 
-from ngraph.network import Network, RiskGroup
+import yaml
+
+from ngraph.blueprints import expand_network_dsl
+from ngraph.components import ComponentsLibrary
 from ngraph.failure_policy import (
+    FailureCondition,
     FailurePolicy,
     FailureRule,
-    FailureCondition,
 )
-from ngraph.traffic_demand import TrafficDemand
+from ngraph.network import Network, RiskGroup
 from ngraph.results import Results
-from ngraph.workflow.base import WorkflowStep, WORKFLOW_STEP_REGISTRY
-from ngraph.blueprints import expand_network_dsl
-from ngraph.components import ComponentsLibrary
+from ngraph.traffic_demand import TrafficDemand
+from ngraph.workflow.base import WORKFLOW_STEP_REGISTRY, WorkflowStep
 
 
-@dataclass(slots=True)
+@dataclass
 class Scenario:
     """
     Represents a complete scenario for building and executing network workflows.
@@ -153,7 +154,7 @@ def from_yaml(
                 if rg.disabled:
                     network_obj.disable_risk_group(rg.name, recursive=True)
 
-        return cls(
+        return Scenario(
             network=network_obj,
             failure_policy=failure_policy,
             traffic_demands=traffic_demands,
diff --git a/ngraph/traffic_demand.py b/ngraph/traffic_demand.py
index 03c9476..75238ae 100644
--- a/ngraph/traffic_demand.py
+++ b/ngraph/traffic_demand.py
@@ -1,11 +1,11 @@
 from dataclasses import dataclass, field
 from typing import Any, Dict, Optional
 
-from ngraph.lib.flow_policy import FlowPolicyConfig, FlowPolicy
+from ngraph.lib.flow_policy import FlowPolicy, FlowPolicyConfig
 from ngraph.network import new_base64_uuid
 
 
-@dataclass(slots=True)
+@dataclass
 class TrafficDemand:
     """
     Represents a single traffic demand in a network.
@@ -16,7 +16,7 @@ class TrafficDemand:
         priority (int): A priority class for this demand (default=0).
         demand (float): The total demand volume (default=0.0).
         demand_placed (float): The portion of this demand that has been placed so far.
-        flow_policy_config ((Optional[FlowPolicyConfig]): The routing/placement policy config.
+        flow_policy_config (Optional[FlowPolicyConfig]): The routing/placement policy config.
         flow_policy (Optional[FlowPolicy]): A fully constructed FlowPolicy instance.
             If provided, it overrides flow_policy_config.
         mode (str): Expansion mode for generating sub-demands.
diff --git a/ngraph/traffic_manager.py b/ngraph/traffic_manager.py
index 7420b23..4ca89c6 100644
--- a/ngraph/traffic_manager.py
+++ b/ngraph/traffic_manager.py
@@ -1,12 +1,12 @@
+import statistics
 from collections import defaultdict
 from dataclasses import dataclass, field
-import statistics
-from typing import Dict, List, Optional, Tuple, Union, NamedTuple
+from typing import Dict, List, NamedTuple, Optional, Tuple, Union
 
 from ngraph.lib.algorithms import base
 from ngraph.lib.algorithms.flow_init import init_flow_graph
 from ngraph.lib.demand import Demand
-from ngraph.lib.flow_policy import FlowPolicyConfig, FlowPolicy, get_flow_policy
+from ngraph.lib.flow_policy import FlowPolicyConfig, get_flow_policy
 from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.network import Network, Node
 from ngraph.traffic_demand import TrafficDemand
@@ -177,6 +177,13 @@ def place_all_demands(
         if isinstance(placement_rounds, str) and placement_rounds.lower() == "auto":
             placement_rounds = self._estimate_rounds()
 
+        # Ensure placement_rounds is an int for range() and arithmetic operations
+        placement_rounds_int = (
+            int(placement_rounds)
+            if isinstance(placement_rounds, str)
+            else placement_rounds
+        )
+
         # Group demands by priority class
         prio_map: Dict[int, List[Demand]] = defaultdict(list)
         for dmd in self.demands:
@@ -188,9 +195,9 @@ def place_all_demands(
         for priority_class in sorted_priorities:
             demands_in_class = prio_map[priority_class]
 
-            for round_idx in range(placement_rounds):
+            for round_idx in range(placement_rounds_int):
                 placed_in_this_round = 0.0
-                rounds_left = placement_rounds - round_idx
+                rounds_left = placement_rounds_int - round_idx
 
                 for demand in demands_in_class:
                     leftover = demand.volume - demand.placed_demand
@@ -257,8 +264,8 @@ def get_flow_details(self) -> Dict[Tuple[int, int], Dict[str, object]]:
         for i, dmd in enumerate(self.demands):
             if not dmd.flow_policy:
                 continue
-            for f_idx, flow_obj in dmd.flow_policy.flows.items():
-                details[(i, f_idx)] = {
+            for j, (_f_idx, flow_obj) in enumerate(dmd.flow_policy.flows.items()):
+                details[(i, j)] = {
                     "placed_flow": flow_obj.placed_flow,
                     "src_node": flow_obj.src_node,
                     "dst_node": flow_obj.dst_node,
@@ -279,7 +286,7 @@ def summarize_link_usage(self) -> Dict[str, float]:
 
         for edge_key, edge_tuple in self.graph.get_edges().items():
             attr_dict = edge_tuple[3]
-            usage[edge_key] = attr_dict.get("flow", 0.0)
+            usage[str(edge_key)] = attr_dict.get("flow", 0.0)
 
         return usage
 
@@ -331,8 +338,8 @@ def get_traffic_results(self, detailed: bool = False) -> List[TrafficResult]:
                         total_volume=total_volume,
                         placed_volume=placed_volume,
                         unplaced_volume=unplaced_volume,
-                        src=dmd.src_node,
-                        dst=dmd.dst_node,
+                        src=str(dmd.src_node),
+                        dst=str(dmd.dst_node),
                     )
                 )
 
diff --git a/ngraph/transform/__init__.py b/ngraph/transform/__init__.py
index 0251f26..8f20805 100644
--- a/ngraph/transform/__init__.py
+++ b/ngraph/transform/__init__.py
@@ -1,15 +1,14 @@
 from __future__ import annotations
 
 from ngraph.transform.base import (
-    NetworkTransform,
     TRANSFORM_REGISTRY,
+    NetworkTransform,
     register_transform,
 )
-
-from ngraph.transform.enable_nodes import EnableNodesTransform
 from ngraph.transform.distribute_external import (
     DistributeExternalConnectivity,
 )
+from ngraph.transform.enable_nodes import EnableNodesTransform
 
 __all__ = [
     "NetworkTransform",
diff --git a/ngraph/transform/base.py b/ngraph/transform/base.py
index dc2ff7b..f07a459 100644
--- a/ngraph/transform/base.py
+++ b/ngraph/transform/base.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import abc
-from typing import Any, Dict, Type, Self
+from typing import Any, Dict, Self, Type
 
 from ngraph.scenario import Scenario
 from ngraph.workflow.base import WorkflowStep, register_workflow_step
diff --git a/ngraph/transform/distribute_external.py b/ngraph/transform/distribute_external.py
index c434d03..1b18d6c 100644
--- a/ngraph/transform/distribute_external.py
+++ b/ngraph/transform/distribute_external.py
@@ -23,7 +23,7 @@
 from ngraph.transform.base import NetworkTransform, register_transform
 
 
-@dataclass(slots=True)
+@dataclass
 class _StripeChooser:
     """Round-robin stripe selection."""
 
diff --git a/ngraph/transform/enable_nodes.py b/ngraph/transform/enable_nodes.py
index b0b45b6..7f91ccd 100644
--- a/ngraph/transform/enable_nodes.py
+++ b/ngraph/transform/enable_nodes.py
@@ -3,8 +3,8 @@
 import itertools
 from typing import List
 
-from ngraph.transform.base import NetworkTransform, register_transform, Scenario
 from ngraph.network import Network, Node
+from ngraph.transform.base import NetworkTransform, Scenario, register_transform
 
 
 @register_transform("EnableNodes")
diff --git a/ngraph/workflow/__init__.py b/ngraph/workflow/__init__.py
index 11b24d1..316c567 100644
--- a/ngraph/workflow/__init__.py
+++ b/ngraph/workflow/__init__.py
@@ -1,3 +1,5 @@
 from .base import WorkflowStep, register_workflow_step
 from .build_graph import BuildGraph
 from .capacity_probe import CapacityProbe
+
+__all__ = ["WorkflowStep", "register_workflow_step", "BuildGraph", "CapacityProbe"]
diff --git a/ngraph/workflow/base.py b/ngraph/workflow/base.py
index 0cc5a3f..8239e7a 100644
--- a/ngraph/workflow/base.py
+++ b/ngraph/workflow/base.py
@@ -1,7 +1,8 @@
 from __future__ import annotations
-from dataclasses import dataclass, field
+
 from abc import ABC, abstractmethod
-from typing import Dict, Type, TYPE_CHECKING
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Dict, Type
 
 if TYPE_CHECKING:
     # Only imported for type-checking; not at runtime, so no circular import occurs.
diff --git a/ngraph/workflow/build_graph.py b/ngraph/workflow/build_graph.py
index ea14cac..38123fb 100644
--- a/ngraph/workflow/build_graph.py
+++ b/ngraph/workflow/build_graph.py
@@ -1,4 +1,5 @@
 from __future__ import annotations
+
 from dataclasses import dataclass
 from typing import TYPE_CHECKING
 
diff --git a/ngraph/workflow/capacity_probe.py b/ngraph/workflow/capacity_probe.py
index b83fa6d..0cdd617 100644
--- a/ngraph/workflow/capacity_probe.py
+++ b/ngraph/workflow/capacity_probe.py
@@ -1,9 +1,10 @@
 from __future__ import annotations
 
-from dataclasses import dataclass, field
-from typing import TYPE_CHECKING, Dict, Tuple, Pattern
-from ngraph.workflow.base import WorkflowStep, register_workflow_step
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Dict, Tuple
+
 from ngraph.lib.algorithms.base import FlowPlacement
+from ngraph.workflow.base import WorkflowStep, register_workflow_step
 
 if TYPE_CHECKING:
     from ngraph.scenario import Scenario
@@ -26,8 +27,8 @@ class CapacityProbe(WorkflowStep):
         flow_placement (FlowPlacement): Handling strategy for parallel equal cost paths (default PROPORTIONAL).
     """
 
-    source_path: Pattern[str] = ""
-    sink_path: Pattern[str] = ""
+    source_path: str = ""
+    sink_path: str = ""
     mode: str = "combine"
     probe_reverse: bool = False
     shortest_path: bool = False
@@ -42,7 +43,7 @@ def __post_init__(self):
                 raise ValueError(
                     f"Invalid flow_placement '{self.flow_placement}'. "
                     f"Valid values are: {valid_values}"
-                )
+                ) from None
 
     def run(self, scenario: Scenario) -> None:
         """
diff --git a/notebooks/bb_fabric.ipynb b/notebooks/bb_fabric.ipynb
index feb61fd..57ce7a6 100644
--- a/notebooks/bb_fabric.ipynb
+++ b/notebooks/bb_fabric.ipynb
@@ -7,14 +7,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from ngraph.scenario import Scenario\n",
-    "from ngraph.traffic_demand import TrafficDemand\n",
-    "from ngraph.traffic_manager import TrafficManager\n",
-    "from ngraph.lib.flow_policy import FlowPolicyConfig, FlowPolicy, FlowPlacement\n",
-    "from ngraph.lib.algorithms.base import PathAlg, EdgeSelect\n",
-    "from ngraph.failure_manager import FailureManager\n",
-    "from ngraph.failure_policy import FailurePolicy, FailureRule, FailureCondition\n",
-    "from ngraph.explorer import NetworkExplorer"
+    "from ngraph.explorer import NetworkExplorer\n",
+    "from ngraph.scenario import Scenario"
    ]
   },
   {
diff --git a/notebooks/lib_examples.ipynb b/notebooks/lib_examples.ipynb
index 0388885..808e2dc 100644
--- a/notebooks/lib_examples.ipynb
+++ b/notebooks/lib_examples.ipynb
@@ -23,8 +23,8 @@
     }
    ],
    "source": [
-    "from ngraph.lib.graph import StrictMultiDiGraph\n",
     "from ngraph.lib.algorithms.max_flow import calc_max_flow\n",
+    "from ngraph.lib.graph import StrictMultiDiGraph\n",
     "\n",
     "# Create a graph\n",
     "g = StrictMultiDiGraph()\n",
@@ -47,10 +47,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
+    "from ngraph.lib.algorithms.base import FlowPlacement\n",
+    "from ngraph.lib.algorithms.max_flow import calc_max_flow\n",
+    "from ngraph.lib.graph import StrictMultiDiGraph\n",
+    "\n",
     "\"\"\"\n",
     "Tests max flow calculations on a graph with parallel edges.\n",
     "\n",
@@ -74,10 +78,6 @@
     "- Flow placement using an equal-balanced strategy on the shortest paths (expected flow: 2.0)\n",
     "\"\"\"\n",
     "\n",
-    "from ngraph.lib.graph import StrictMultiDiGraph\n",
-    "from ngraph.lib.algorithms.max_flow import calc_max_flow\n",
-    "from ngraph.lib.algorithms.base import FlowPlacement\n",
-    "\n",
     "g = StrictMultiDiGraph()\n",
     "for node in (\"A\", \"B\", \"C\", \"D\"):\n",
     "    g.add_node(node)\n",
@@ -108,10 +108,15 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
+    "from ngraph.lib.algorithms.flow_init import init_flow_graph\n",
+    "from ngraph.lib.demand import Demand\n",
+    "from ngraph.lib.flow_policy import FlowPolicyConfig, get_flow_policy\n",
+    "from ngraph.lib.graph import StrictMultiDiGraph\n",
+    "\n",
     "\"\"\"\n",
     "Demonstrates traffic engineering by placing two demands on a network.\n",
     "\n",
@@ -131,11 +136,6 @@
     "- The test verifies that each demand is fully placed at 20 units.\n",
     "\"\"\"\n",
     "\n",
-    "from ngraph.lib.graph import StrictMultiDiGraph\n",
-    "from ngraph.lib.algorithms.flow_init import init_flow_graph\n",
-    "from ngraph.lib.flow_policy import FlowPolicyConfig, get_flow_policy\n",
-    "from ngraph.lib.demand import Demand\n",
-    "\n",
     "# Build the graph.\n",
     "g = StrictMultiDiGraph()\n",
     "for node in (\"A\", \"B\", \"C\"):\n",
@@ -188,7 +188,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.13.1"
+   "version": "3.13.3"
   }
  },
  "nbformat": 4,
diff --git a/notebooks/scenario_dc.ipynb b/notebooks/scenario_dc.ipynb
index 5aa45fd..8747ad4 100644
--- a/notebooks/scenario_dc.ipynb
+++ b/notebooks/scenario_dc.ipynb
@@ -6,14 +6,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from ngraph.scenario import Scenario\n",
-    "from ngraph.traffic_demand import TrafficDemand\n",
-    "from ngraph.traffic_manager import TrafficManager\n",
-    "from ngraph.lib.flow_policy import FlowPolicyConfig, FlowPolicy, FlowPlacement\n",
-    "from ngraph.lib.algorithms.base import PathAlg, EdgeSelect\n",
-    "from ngraph.failure_manager import FailureManager\n",
-    "from ngraph.failure_policy import FailurePolicy, FailureRule, FailureCondition\n",
-    "from ngraph.explorer import NetworkExplorer"
+    "from ngraph.explorer import NetworkExplorer\n",
+    "from ngraph.scenario import Scenario"
    ]
   },
   {
diff --git a/notebooks/simple.ipynb b/notebooks/simple.ipynb
index 11ecf47..1c42e37 100644
--- a/notebooks/simple.ipynb
+++ b/notebooks/simple.ipynb
@@ -7,14 +7,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from ngraph.scenario import Scenario\n",
-    "from ngraph.traffic_demand import TrafficDemand\n",
-    "from ngraph.traffic_manager import TrafficManager\n",
-    "from ngraph.lib.flow_policy import FlowPolicyConfig, FlowPolicy, FlowPlacement\n",
-    "from ngraph.lib.algorithms.base import PathAlg, EdgeSelect\n",
-    "from ngraph.failure_manager import FailureManager\n",
-    "from ngraph.failure_policy import FailurePolicy, FailureRule, FailureCondition\n",
-    "from ngraph.explorer import NetworkExplorer"
+    "from ngraph.lib.flow_policy import FlowPlacement\n",
+    "from ngraph.scenario import Scenario"
    ]
   },
   {
diff --git a/notebooks/small_demo.ipynb b/notebooks/small_demo.ipynb
index ce1f9a1..15289bb 100644
--- a/notebooks/small_demo.ipynb
+++ b/notebooks/small_demo.ipynb
@@ -6,13 +6,12 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "from ngraph.failure_manager import FailureManager\n",
+    "from ngraph.failure_policy import FailurePolicy, FailureRule\n",
+    "from ngraph.lib.flow_policy import FlowPlacement, FlowPolicyConfig\n",
     "from ngraph.scenario import Scenario\n",
     "from ngraph.traffic_demand import TrafficDemand\n",
-    "from ngraph.traffic_manager import TrafficManager\n",
-    "from ngraph.lib.flow_policy import FlowPolicyConfig, FlowPolicy, FlowPlacement\n",
-    "from ngraph.lib.algorithms.base import PathAlg, EdgeSelect\n",
-    "from ngraph.failure_manager import FailureManager\n",
-    "from ngraph.failure_policy import FailurePolicy, FailureRule, FailureCondition"
+    "from ngraph.traffic_manager import TrafficManager"
    ]
   },
   {
@@ -187,7 +186,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": null,
    "metadata": {},
    "outputs": [
     {
@@ -210,10 +209,11 @@
     }
    ],
    "source": [
+    "from collections import defaultdict\n",
+    "\n",
+    "import matplotlib.pyplot as plt\n",
     "import pandas as pd\n",
     "import seaborn as sns\n",
-    "import matplotlib.pyplot as plt\n",
-    "from collections import defaultdict\n",
     "\n",
     "\n",
     "def plot_priority_cdf(results, complementary: bool = True):\n",
@@ -240,7 +240,7 @@
     "    # 1) Aggregate total placed volume for each iteration & priority\n",
     "    #    (similar logic as before, but we'll directly store iteration-level sums).\n",
     "    volume_per_iter_priority = defaultdict(float)\n",
-    "    for (src, dst, priority), data_list in by_src_dst.items():\n",
+    "    for (_src, _dst, priority), data_list in by_src_dst.items():\n",
     "        for entry in data_list:\n",
     "            it = entry[\"iteration\"]\n",
     "            volume_per_iter_priority[(it, priority)] += entry[\"placed_volume\"]\n",
diff --git a/pyproject.toml b/pyproject.toml
index 74e880b..55c7094 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,10 +11,13 @@ readme = "README.md"
 authors = [{ name = "Andrey Golovanov" }]
 license = "MIT"
 license-files = ["LICENSE"]
-requires-python = ">=3.9"
+requires-python = ">=3.11"
 
 classifiers = [
     "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
     "Operating System :: OS Independent",
 ]
 
@@ -29,30 +32,75 @@ dependencies = [
     "seaborn",
 ]
 
-# Dev/CI extras
+# Dev / CI extras
 [project.optional-dependencies]
 dev = [
+    # testing
     "pytest>=8",
     "pytest-cov",
     "pytest-benchmark",
     "pytest-mock",
-    "black",
-    "isort",
-    "pylint",
+    # docs
     "mkdocs-material",
     "pdoc",
+    # style + type checking
+    "ruff==0.11.13",
+    "pyright",
+    # pre-commit hooks
+    "pre-commit",
+    # build
+    "build",
+    # publishing
+    "twine",
 ]
+
 [project.scripts]
 ngraph = "ngraph.cli:main"
 
-
 # ---------------------------------------------------------------------
 # Pytest flags
 [tool.pytest.ini_options]
 addopts = "--cov=ngraph --cov-fail-under=85 --cov-report term-missing"
 
 # ---------------------------------------------------------------------
-# Tell setuptools to package ONLY the 'ngraph' package tree
+# Package discovery
 [tool.setuptools.packages.find]
-include = ["ngraph*"]          # anything under ngraph/
+include = ["ngraph*"]
 exclude = ["tests*", "notebooks*", "examples*", "dev*"]
+
+# ---------------------------------------------------------------------
+# Ruff
+[tool.ruff]
+line-length = 88
+indent-width = 4
+
+[tool.ruff.lint]
+select = ["E4", "E7", "E9", "F", "B", "I"]   # core + Bugbear + isort
+ignore = ["E501"]                             # long lines handled by formatter
+fixable = ["ALL"]
+
+[tool.ruff.lint.isort]
+known-first-party = ["ngraph"]
+
+[tool.ruff.format]
+quote-style = "double"
+skip-magic-trailing-comma = false
+
+# ---------------------------------------------------------------------
+# Pyright / Pylance
+[tool.pyright]
+typeCheckingMode = "standard"     # balanced level
+pythonVersion = "3.11"
+exclude = [
+    "tests/**",                   # tests often use dynamic patterns
+    "**/venv/**",                # virtual environments (generic)
+    "**/*venv/**",               # virtual environments (various naming)
+    "build/**",                  # build artifacts
+    "dist/**",                   # distribution files
+    "**/__pycache__/**",         # Python cache files
+    "**/*.egg-info/**"           # egg info directories
+]
+reportMissingTypeStubs = "warning"
+reportUnknownMemberType = "none"
+reportUnknownVariableType = "none"
+reportUnknownArgumentType = "none"
diff --git a/run.sh b/run.sh
index fde2539..596d7c0 100755
--- a/run.sh
+++ b/run.sh
@@ -206,4 +206,4 @@ case "$COMMAND" in
         printf "%b" "$USAGE" >&2
         exit 2
         ;;
-esac
\ No newline at end of file
+esac
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..1035f11
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,2 @@
+# Import all fixtures from sample_graphs to make them available to all test files
+pytest_plugins = ["tests.lib.algorithms.sample_graphs"]
diff --git a/tests/lib/algorithms/test_calc_capacity.py b/tests/lib/algorithms/test_calc_capacity.py
index 513c6d0..1eca6a0 100644
--- a/tests/lib/algorithms/test_calc_capacity.py
+++ b/tests/lib/algorithms/test_calc_capacity.py
@@ -1,10 +1,15 @@
 # pylint: disable=protected-access,invalid-name
+from typing import Dict, List
+
 import pytest
 
+from ngraph.lib.algorithms.calc_capacity import FlowPlacement, calc_graph_capacity
 from ngraph.lib.algorithms.flow_init import init_flow_graph
 from ngraph.lib.algorithms.spf import spf
-from ngraph.lib.algorithms.calc_capacity import calc_graph_capacity, FlowPlacement
-from tests.lib.algorithms.sample_graphs import *
+from ngraph.lib.graph import EdgeID, NodeID, StrictMultiDiGraph
+
+# Type alias to ensure consistency with library expectations
+PredDict = Dict[NodeID, Dict[NodeID, List[EdgeID]]]
 
 
 class TestGraphCapacity:
@@ -40,7 +45,7 @@ def test_calc_graph_capacity_no_cap(self):
         g.add_edge("A", "B", key=0, capacity=0)
         g.add_edge("B", "C", key=1, capacity=1)
         r = init_flow_graph(g)
-        pred = {"A": {}, "B": {"A": [0]}, "C": {"B": [1]}}
+        pred: PredDict = {"A": {}, "B": {"A": [0]}, "C": {"B": [1]}}
 
         # Expected max_flow = 0 because there is no capacity along the path
         max_flow, flow_dict = calc_graph_capacity(
@@ -50,6 +55,7 @@ def test_calc_graph_capacity_no_cap(self):
 
     def test_calc_graph_capacity_line1(self, line1):
         _, pred = spf(line1, "A")
+        pred: PredDict = pred  # Type annotation for clarity
         r = init_flow_graph(line1)
 
         max_flow, flow_dict = calc_graph_capacity(
diff --git a/tests/lib/algorithms/test_edge_select.py b/tests/lib/algorithms/test_edge_select.py
index 363aa78..1724af6 100644
--- a/tests/lib/algorithms/test_edge_select.py
+++ b/tests/lib/algorithms/test_edge_select.py
@@ -1,11 +1,12 @@
 from math import isclose
-import pytest
-from unittest.mock import MagicMock
 from typing import Dict, Set, Tuple
+from unittest.mock import MagicMock
+
+import pytest
 
-from ngraph.lib.graph import StrictMultiDiGraph, NodeID, EdgeID, AttrDict
+from ngraph.lib.algorithms.base import Cost
 from ngraph.lib.algorithms.edge_select import EdgeSelect, edge_select_fabric
-from ngraph.lib.algorithms.base import Cost, MIN_CAP
+from ngraph.lib.graph import AttrDict, EdgeID, NodeID, StrictMultiDiGraph
 
 
 @pytest.fixture
diff --git a/tests/lib/algorithms/test_max_flow.py b/tests/lib/algorithms/test_max_flow.py
index e32e745..d831a48 100644
--- a/tests/lib/algorithms/test_max_flow.py
+++ b/tests/lib/algorithms/test_max_flow.py
@@ -1,14 +1,9 @@
 import pytest
 from pytest import approx
 
-from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.lib.algorithms.base import FlowPlacement
 from ngraph.lib.algorithms.max_flow import calc_max_flow
-from tests.lib.algorithms.sample_graphs import (
-    line1,
-    square4,
-    graph5,
-)
+from ngraph.lib.graph import StrictMultiDiGraph
 
 
 class TestMaxFlowBasic:
diff --git a/tests/lib/algorithms/test_path_utils.py b/tests/lib/algorithms/test_path_utils.py
index 9f15ae8..8a33012 100644
--- a/tests/lib/algorithms/test_path_utils.py
+++ b/tests/lib/algorithms/test_path_utils.py
@@ -1,4 +1,3 @@
-import pytest
 from ngraph.lib.algorithms.path_utils import resolve_to_paths
 
 
diff --git a/tests/lib/algorithms/test_place_flow.py b/tests/lib/algorithms/test_place_flow.py
index 5156985..27570fd 100644
--- a/tests/lib/algorithms/test_place_flow.py
+++ b/tests/lib/algorithms/test_place_flow.py
@@ -1,13 +1,10 @@
-import pytest
+from ngraph.lib.algorithms.calc_capacity import FlowPlacement
 from ngraph.lib.algorithms.flow_init import init_flow_graph
 from ngraph.lib.algorithms.place_flow import (
     place_flow_on_graph,
     remove_flow_from_graph,
 )
-from ngraph.lib.algorithms.calc_capacity import FlowPlacement
-
 from ngraph.lib.algorithms.spf import spf
-from tests.lib.algorithms.sample_graphs import *
 
 
 class TestPlaceFlowOnGraph:
@@ -144,7 +141,7 @@ def test_place_flow_on_graph_line1_equal(self, line1):
         assert flow_placement_meta.nodes == {"A", "C", "B"}
         assert flow_placement_meta.edges == {0, 2, 4}
 
-    def test_place_flow_on_graph_line1_proportional(self, line1):
+    def test_place_flow_on_graph_line1_proportional_partial(self, line1):
         """
         In two steps, place 3 units of flow, then attempt another 3.
         Check partial flow placement when capacity is partially exhausted.
diff --git a/tests/lib/algorithms/test_spf.py b/tests/lib/algorithms/test_spf.py
index c967dd4..a990247 100644
--- a/tests/lib/algorithms/test_spf.py
+++ b/tests/lib/algorithms/test_spf.py
@@ -1,7 +1,5 @@
-import pytest
-from ngraph.lib.algorithms.spf import spf, ksp
 from ngraph.lib.algorithms.edge_select import EdgeSelect, edge_select_fabric
-from tests.lib.algorithms.sample_graphs import *
+from ngraph.lib.algorithms.spf import ksp, spf
 
 
 class TestSPF:
@@ -137,15 +135,14 @@ def test_ksp_5(self, graph5):
         """
         paths = list(ksp(graph5, "A", "B", multipath=True))
         visited = set()
-        for costs, pred in paths:
+        for _costs, pred in paths:
             edge_ids = tuple(
-                sorted(
-                    edge_id
-                    for nbrs in pred.values()
-                    for edge_list in nbrs.values()
-                    for edge_id in edge_list
-                )
+                str(edge_id)
+                for nbrs in pred.values()
+                for edge_list in nbrs.values()
+                for edge_id in edge_list
             )
+            edge_ids = tuple(sorted(edge_ids))
             if edge_ids in visited:
                 raise Exception(f"Duplicate path found: {edge_ids}")
             visited.add(edge_ids)
diff --git a/tests/lib/algorithms/test_spf_bench.py b/tests/lib/algorithms/test_spf_bench.py
index 5b12c6c..69d5624 100644
--- a/tests/lib/algorithms/test_spf_bench.py
+++ b/tests/lib/algorithms/test_spf_bench.py
@@ -1,9 +1,10 @@
 import random
-import pytest
+
 import networkx as nx
+import pytest
 
-from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.lib.algorithms.spf import spf
+from ngraph.lib.graph import StrictMultiDiGraph
 
 random.seed(0)
 
diff --git a/tests/lib/test_demand.py b/tests/lib/test_demand.py
index c286f21..010f8c1 100644
--- a/tests/lib/test_demand.py
+++ b/tests/lib/test_demand.py
@@ -1,10 +1,10 @@
 import pytest
-from ngraph.lib.algorithms.base import EdgeSelect, PathAlg, FlowPlacement
+
+from ngraph.lib.algorithms.base import EdgeSelect, FlowPlacement, PathAlg
 from ngraph.lib.algorithms.flow_init import init_flow_graph
 from ngraph.lib.demand import Demand
-from ngraph.lib.flow_policy import FlowPolicy, FlowPolicyConfig, get_flow_policy
 from ngraph.lib.flow import FlowIndex
-from .algorithms.sample_graphs import line1, square1, square2, triangle1, graph3
+from ngraph.lib.flow_policy import FlowPolicy, FlowPolicyConfig, get_flow_policy
 
 
 def create_flow_policy(
@@ -14,7 +14,7 @@ def create_flow_policy(
     edge_select: EdgeSelect,
     multipath: bool,
     max_flow_count: int = None,
-    max_path_cost_factor: float = None
+    max_path_cost_factor: float = None,
 ) -> FlowPolicy:
     """Helper to create a FlowPolicy for testing."""
     return FlowPolicy(
diff --git a/tests/lib/test_flow.py b/tests/lib/test_flow.py
index 2b85631..63f1ebe 100644
--- a/tests/lib/test_flow.py
+++ b/tests/lib/test_flow.py
@@ -1,15 +1,8 @@
-from ngraph.lib.algorithms.base import (
-    EdgeSelect,
-    PathAlg,
-    FlowPlacement,
-    MIN_FLOW,
-)
+from ngraph.lib.algorithms.base import FlowPlacement
 from ngraph.lib.algorithms.flow_init import init_flow_graph
 from ngraph.lib.flow import Flow, FlowIndex
 from ngraph.lib.path_bundle import PathBundle
 
-from .algorithms.sample_graphs import *
-
 
 class TestFlow:
     def test_flow_1(self, square1):
@@ -17,7 +10,7 @@ def test_flow_1(self, square1):
         path_bundle = PathBundle(
             "A", "C", {"A": {}, "C": {"B": [1]}, "B": {"A": [0]}}, 2
         )
-        flow = Flow(path_bundle, ("A", "C", "test_flow"))
+        flow = Flow(path_bundle, FlowIndex("A", "C", "test_flow", 0))
         placed_flow, remaining_flow = flow.place_flow(
             flow_graph, 0, flow_placement=FlowPlacement.EQUAL_BALANCED
         )
@@ -29,7 +22,7 @@ def test_flow_2(self, square1):
         path_bundle = PathBundle(
             "A", "C", {"A": {}, "C": {"B": [1]}, "B": {"A": [0]}}, 2
         )
-        flow = Flow(path_bundle, ("A", "C", "test_flow"))
+        flow = Flow(path_bundle, FlowIndex("A", "C", "test_flow", 0))
         placed_flow, remaining_flow = flow.place_flow(
             flow_graph, 1, flow_placement=FlowPlacement.EQUAL_BALANCED
         )
@@ -41,7 +34,7 @@ def test_flow_3(self, square1):
         path_bundle = PathBundle(
             "A", "C", {"A": {}, "C": {"B": [1]}, "B": {"A": [0]}}, 2
         )
-        flow = Flow(path_bundle, ("A", "C", "test_flow"))
+        flow = Flow(path_bundle, FlowIndex("A", "C", "test_flow", 0))
         placed_flow, remaining_flow = flow.place_flow(
             flow_graph, 1, flow_placement=FlowPlacement.EQUAL_BALANCED
         )
diff --git a/tests/lib/test_flow_policy.py b/tests/lib/test_flow_policy.py
index 09a5340..934ec25 100644
--- a/tests/lib/test_flow_policy.py
+++ b/tests/lib/test_flow_policy.py
@@ -1,16 +1,16 @@
+import pytest
+
 from ngraph.lib.algorithms.base import (
+    MIN_FLOW,
     EdgeSelect,
-    PathAlg,
     FlowPlacement,
-    MIN_FLOW,
+    PathAlg,
 )
 from ngraph.lib.algorithms.flow_init import init_flow_graph
-from ngraph.lib.flow import Flow, FlowIndex
+from ngraph.lib.flow import FlowIndex
 from ngraph.lib.flow_policy import FlowPolicy
 from ngraph.lib.path_bundle import PathBundle
 
-from .algorithms.sample_graphs import *
-
 
 class TestFlowPolicy:
     def test_flow_policy_1(self):
@@ -30,7 +30,8 @@ def test_flow_policy_get_path_bundle_1(self, square1):
             multipath=True,
         )
         r = init_flow_graph(square1)
-        path_bundle: PathBundle = flow_policy._get_path_bundle(r, "A", "C")
+        path_bundle = flow_policy._get_path_bundle(r, "A", "C")
+        assert path_bundle is not None
         assert path_bundle.pred == {"A": {}, "C": {"B": [1]}, "B": {"A": [0]}}
         assert path_bundle.edges == {0, 1}
         assert path_bundle.nodes == {"A", "B", "C"}
@@ -43,7 +44,8 @@ def test_flow_policy_get_path_bundle_2(self, square1):
             multipath=True,
         )
         r = init_flow_graph(square1)
-        path_bundle: PathBundle = flow_policy._get_path_bundle(r, "A", "C", 2)
+        path_bundle = flow_policy._get_path_bundle(r, "A", "C", 2)
+        assert path_bundle is not None
         assert path_bundle.pred == {"A": {}, "C": {"D": [3]}, "D": {"A": [2]}}
         assert path_bundle.edges == {2, 3}
         assert path_bundle.nodes == {"D", "C", "A"}
@@ -57,6 +59,7 @@ def test_flow_policy_create_flow_1(self, square1):
         )
         r = init_flow_graph(square1)
         flow = flow_policy._create_flow(r, "A", "C", "test_flow")
+        assert flow is not None
         assert flow.path_bundle.pred == {"A": {}, "C": {"B": [1]}, "B": {"A": [0]}}
 
     def test_flow_policy_create_flow_2(self, square1):
@@ -68,6 +71,7 @@ def test_flow_policy_create_flow_2(self, square1):
         )
         r = init_flow_graph(square1)
         flow = flow_policy._create_flow(r, "A", "C", "test_flow", 2)
+        assert flow is not None
         assert flow.path_bundle.pred == {"A": {}, "C": {"D": [3]}, "D": {"A": [2]}}
 
     def test_flow_policy_create_flow_3(self, square1):
@@ -754,7 +758,8 @@ def test_flow_policy_delete_flow(self, square1):
         flow_policy.place_demand(r, "A", "C", "test_flow", 2)
         initial_count = len(flow_policy.flows)
         # Pick any flow_index that was created
-        flow_index_to_delete = next(iter(flow_policy.flows.keys()))
+        flow_index_tuple = next(iter(flow_policy.flows.keys()))
+        flow_index_to_delete = FlowIndex(*flow_index_tuple)
         flow_policy._delete_flow(r, flow_index_to_delete)
         assert len(flow_policy.flows) == initial_count - 1
 
@@ -779,21 +784,23 @@ def test_flow_policy_reoptimize_flow(self, square1):
         placed_flow, remaining = flow_policy.place_demand(r, "A", "C", "test_flow", 1)
         assert placed_flow == 1
         # We'll pick the first flow index
-        flow_index_to_reopt = next(iter(flow_policy.flows.keys()))
+        flow_index_tuple = next(iter(flow_policy.flows.keys()))
+        flow_index_to_reopt = FlowIndex(*flow_index_tuple)
         # Reoptimize with additional "headroom" that might force a different path
         new_flow = flow_policy._reoptimize_flow(r, flow_index_to_reopt, headroom=1)
         # Because the alternative path has capacity=2, we expect re-optimization to succeed
         assert new_flow is not None
         # The old flow index still references the new flow
-        assert flow_policy.flows[flow_index_to_reopt] == new_flow
+        assert flow_policy.flows[flow_index_tuple] == new_flow
 
         # Now try re-optimizing with very large headroom; no path should be found, so revert
-        flow_index_to_reopt2 = next(iter(flow_policy.flows.keys()))
-        flow_before_reopt = flow_policy.flows[flow_index_to_reopt2]
+        flow_index_tuple2 = next(iter(flow_policy.flows.keys()))
+        flow_index_to_reopt2 = FlowIndex(*flow_index_tuple2)
+        flow_before_reopt = flow_policy.flows[flow_index_tuple2]
         reverted_flow = flow_policy._reoptimize_flow(
             r, flow_index_to_reopt2, headroom=10
         )
         # We expect a revert -> None returned
         assert reverted_flow is None
         # The flow in the dictionary should still be the same old flow
-        assert flow_policy.flows[flow_index_to_reopt2] == flow_before_reopt
+        assert flow_policy.flows[flow_index_tuple2] == flow_before_reopt
diff --git a/tests/lib/test_graph.py b/tests/lib/test_graph.py
index 736f321..0a1a20f 100644
--- a/tests/lib/test_graph.py
+++ b/tests/lib/test_graph.py
@@ -1,5 +1,5 @@
-import pytest
 import networkx as nx
+import pytest
 
 from ngraph.lib.graph import StrictMultiDiGraph
 
diff --git a/tests/lib/test_io.py b/tests/lib/test_io.py
index 7a212ed..8e48bc3 100644
--- a/tests/lib/test_io.py
+++ b/tests/lib/test_io.py
@@ -1,10 +1,11 @@
 import pytest
+
 from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.lib.io import (
-    graph_to_node_link,
-    node_link_to_graph,
     edgelist_to_graph,
     graph_to_edgelist,
+    graph_to_node_link,
+    node_link_to_graph,
 )
 
 
@@ -41,7 +42,7 @@ def test_graph_to_node_link_basic():
 
     # Check one link's structure
     # For example, find the link with key=e1
-    link_e1 = next(l for l in links if l["key"] == e1)
+    link_e1 = next(link for link in links if link["key"] == e1)
     assert link_e1["source"] == 0  # "A" => index 0
     assert link_e1["target"] == 1  # "B" => index 1
     assert link_e1["attr"] == {"weight": "10"} or {"weight": 10}
@@ -139,7 +140,7 @@ def test_edgelist_to_graph_basic():
     # Check each edge's attribute
     e_map = g.get_edges()
     # We can't assume numeric IDs, just find them by iteration
-    for eid, (src, dst, _, attrs) in e_map.items():
+    for _eid, (src, dst, _, attrs) in e_map.items():
         w = attrs["weight"]
         if src == "A" and dst == "B":
             assert w == "10"
@@ -192,10 +193,10 @@ def test_graph_to_edgelist_basic():
     g.add_node("B")
     g.add_node("C")
 
-    e1 = g.add_edge("A", "B", cost=10)
-    e2 = g.add_edge("B", "C", cost=20)
+    g.add_edge("A", "B", cost=10)
+    g.add_edge("B", "C", cost=20)
     # No custom keys for the rest -> random base64 IDs
-    e3 = g.add_edge("C", "A", label="X")
+    g.add_edge("C", "A", label="X")
 
     lines = graph_to_edgelist(g)
     # By default: [src, dst, key] + sorted(attributes)
@@ -214,7 +215,7 @@ def test_graph_to_edgelist_basic():
     # but for e1, e2 we have "cost" attribute, for e3 we have "label"
     # Check adjacency
     edges_seen = set()
-    for eid, (s, d, _, attrs) in e2_map.items():
+    for _eid, (s, d, _, _attrs) in e2_map.items():
         edges_seen.add((s, d))
         # if there's a "cost" in attrs, it might be "10" or "20"
         # if there's a "label" in attrs, it's "X"
@@ -229,7 +230,7 @@ def test_graph_to_edgelist_columns():
     g = StrictMultiDiGraph()
     g.add_node("A")
     g.add_node("B")
-    eAB = g.add_edge("A", "B", cost=10, color="red")
+    g.add_edge("A", "B", cost=10, color="red")
 
     lines = graph_to_edgelist(g, columns=["src", "dst", "cost", "color"], separator=",")
     # We expect one line: "A,B,10,red"
diff --git a/tests/lib/test_path.py b/tests/lib/test_path.py
index a6f6347..43a2a8d 100644
--- a/tests/lib/test_path.py
+++ b/tests/lib/test_path.py
@@ -1,6 +1,7 @@
 import pytest
-from ngraph.lib.graph import StrictMultiDiGraph, EdgeID
+
 from ngraph.lib.algorithms.base import PathTuple
+from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.lib.path import Path
 
 
diff --git a/tests/lib/test_path_bundle.py b/tests/lib/test_path_bundle.py
index 09000f0..7c09d66 100644
--- a/tests/lib/test_path_bundle.py
+++ b/tests/lib/test_path_bundle.py
@@ -1,9 +1,10 @@
-import pytest
 from typing import List, Set
-from ngraph.lib.graph import StrictMultiDiGraph
 
+import pytest
+
+from ngraph.lib.algorithms.base import EdgeSelect
+from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.lib.path_bundle import Path, PathBundle
-from ngraph.lib.algorithms.base import EdgeSelect, Cost
 
 
 @pytest.fixture
diff --git a/tests/lib/test_util.py b/tests/lib/test_util.py
index 7ed6fb4..149d6bb 100644
--- a/tests/lib/test_util.py
+++ b/tests/lib/test_util.py
@@ -1,8 +1,7 @@
-import pytest
 import networkx as nx
 
 from ngraph.lib.graph import StrictMultiDiGraph
-from ngraph.lib.util import to_digraph, from_digraph, to_graph, from_graph
+from ngraph.lib.util import from_digraph, from_graph, to_digraph, to_graph
 
 
 def create_sample_graph(with_attrs: bool = False) -> StrictMultiDiGraph:
diff --git a/tests/scenarios/scenario_3.yaml b/tests/scenarios/scenario_3.yaml
index 2eeaeb8..298c381 100644
--- a/tests/scenarios/scenario_3.yaml
+++ b/tests/scenarios/scenario_3.yaml
@@ -75,7 +75,7 @@ network:
         attrs:
           shared_risk_groups: ["SpineSRG"]
           hw_component: "400G-LR4"
-  
+
   # Example node overrides that assign SRGs and hardware types
   node_overrides:
     - path: my_clos1/b1/t1
@@ -88,7 +88,7 @@ network:
         shared_risk_groups: ["clos2-b2t1-SRG"]
         hw_component: "LeafHW-B"
 
-    - path: my_clos1/spine/t3.* 
+    - path: my_clos1/spine/t3.*
       attrs:
         shared_risk_groups: ["clos1-spine-SRG"]
         hw_component: "SpineHW"
diff --git a/tests/scenarios/test_scenario_1.py b/tests/scenarios/test_scenario_1.py
index 39d1a1a..a3958db 100644
--- a/tests/scenarios/test_scenario_1.py
+++ b/tests/scenarios/test_scenario_1.py
@@ -1,9 +1,8 @@
-import pytest
 from pathlib import Path
 
+from ngraph.failure_policy import FailurePolicy
 from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.scenario import Scenario
-from ngraph.failure_policy import FailurePolicy
 
 
 def test_scenario_1_build_graph() -> None:
@@ -28,32 +27,32 @@ def test_scenario_1_build_graph() -> None:
 
     # 4) Retrieve the graph built by BuildGraph
     graph = scenario.results.get("build_graph", "graph")
-    assert isinstance(
-        graph, StrictMultiDiGraph
-    ), "Expected a StrictMultiDiGraph in scenario.results under key ('build_graph', 'graph')."
+    assert isinstance(graph, StrictMultiDiGraph), (
+        "Expected a StrictMultiDiGraph in scenario.results under key ('build_graph', 'graph')."
+    )
 
     # 5) Check the total number of nodes matches what's listed in scenario_1.yaml
     #    For a 6-node scenario, we expect 6 nodes in the final Nx graph.
     expected_nodes = 6
     actual_nodes = len(graph.nodes)
-    assert (
-        actual_nodes == expected_nodes
-    ), f"Expected {expected_nodes} nodes, found {actual_nodes}"
+    assert actual_nodes == expected_nodes, (
+        f"Expected {expected_nodes} nodes, found {actual_nodes}"
+    )
 
     # 6) Each physical link from the YAML becomes 2 directed edges in MultiDiGraph.
     #    If the YAML has 10 link definitions, we expect 2 * 10 = 20 directed edges.
     expected_links = 10
     expected_nx_edges = expected_links * 2
     actual_edges = len(graph.edges)
-    assert (
-        actual_edges == expected_nx_edges
-    ), f"Expected {expected_nx_edges} directed edges, found {actual_edges}"
+    assert actual_edges == expected_nx_edges, (
+        f"Expected {expected_nx_edges} directed edges, found {actual_edges}"
+    )
 
     # 7) Verify the traffic demands.
     expected_demands = 4
-    assert (
-        len(scenario.traffic_demands) == expected_demands
-    ), f"Expected {expected_demands} traffic demands."
+    assert len(scenario.traffic_demands) == expected_demands, (
+        f"Expected {expected_demands} traffic demands."
+    )
 
     # 8) Check the multi-rule failure policy for "any single link".
     #    This should have exactly 1 rule that picks exactly 1 link from all links.
diff --git a/tests/scenarios/test_scenario_2.py b/tests/scenarios/test_scenario_2.py
index 60e6bec..956d9c0 100644
--- a/tests/scenarios/test_scenario_2.py
+++ b/tests/scenarios/test_scenario_2.py
@@ -1,9 +1,8 @@
-import pytest
 from pathlib import Path
 
+from ngraph.failure_policy import FailurePolicy
 from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.scenario import Scenario
-from ngraph.failure_policy import FailurePolicy
 
 
 def test_scenario_2_build_graph() -> None:
@@ -29,9 +28,9 @@ def test_scenario_2_build_graph() -> None:
 
     # 4) Retrieve the graph built by BuildGraph
     graph = scenario.results.get("build_graph", "graph")
-    assert isinstance(
-        graph, StrictMultiDiGraph
-    ), "Expected a StrictMultiDiGraph in scenario.results under key ('build_graph', 'graph')."
+    assert isinstance(graph, StrictMultiDiGraph), (
+        "Expected a StrictMultiDiGraph in scenario.results under key ('build_graph', 'graph')."
+    )
 
     # 5) Verify total node count after blueprint expansion
     #    city_cloud blueprint: (4 leaves + 6 spines + 4 edge_nodes) = 14
@@ -40,9 +39,9 @@ def test_scenario_2_build_graph() -> None:
     #    => 14 + 1 + 4 = 19 total
     expected_nodes = 19
     actual_nodes = len(graph.nodes)
-    assert (
-        actual_nodes == expected_nodes
-    ), f"Expected {expected_nodes} nodes, found {actual_nodes}"
+    assert actual_nodes == expected_nodes, (
+        f"Expected {expected_nodes} nodes, found {actual_nodes}"
+    )
 
     # 6) Verify total physical links before direction is applied to Nx
     #    - clos_2tier adjacency: 4 leaf * 6 spine = 24
@@ -60,15 +59,15 @@ def test_scenario_2_build_graph() -> None:
     expected_links = 56
     expected_nx_edges = expected_links * 2
     actual_edges = len(graph.edges)
-    assert (
-        actual_edges == expected_nx_edges
-    ), f"Expected {expected_nx_edges} directed edges, found {actual_edges}"
+    assert actual_edges == expected_nx_edges, (
+        f"Expected {expected_nx_edges} directed edges, found {actual_edges}"
+    )
 
     # 7) Verify the traffic demands (should have 4)
     expected_demands = 4
-    assert (
-        len(scenario.traffic_demands) == expected_demands
-    ), f"Expected {expected_demands} traffic demands."
+    assert len(scenario.traffic_demands) == expected_demands, (
+        f"Expected {expected_demands} traffic demands."
+    )
 
     # 8) Check the single-rule failure policy "anySingleLink"
     policy: FailurePolicy = scenario.failure_policy
@@ -88,9 +87,9 @@ def test_scenario_2_build_graph() -> None:
     # 9) Check presence of key expanded nodes
     #    For example: the overridden spine node "myspine-6" under "SEA/clos_instance/spine"
     #    and the single node blueprint "SFO/single/single-1".
-    assert (
-        "SEA/clos_instance/spine/myspine-6" in scenario.network.nodes
-    ), "Missing expected overridden spine node (myspine-6) in expanded blueprint."
-    assert (
-        "SFO/single/single-1" in scenario.network.nodes
-    ), "Missing expected single-node blueprint expansion under SFO."
+    assert "SEA/clos_instance/spine/myspine-6" in scenario.network.nodes, (
+        "Missing expected overridden spine node (myspine-6) in expanded blueprint."
+    )
+    assert "SFO/single/single-1" in scenario.network.nodes, (
+        "Missing expected single-node blueprint expansion under SFO."
+    )
diff --git a/tests/scenarios/test_scenario_3.py b/tests/scenarios/test_scenario_3.py
index bd73856..08cfeb0 100644
--- a/tests/scenarios/test_scenario_3.py
+++ b/tests/scenarios/test_scenario_3.py
@@ -1,9 +1,8 @@
-import pytest
 from pathlib import Path
 
+from ngraph.failure_policy import FailurePolicy
 from ngraph.lib.graph import StrictMultiDiGraph
 from ngraph.scenario import Scenario
-from ngraph.failure_policy import FailurePolicy
 
 
 def test_scenario_3_build_graph_and_capacity_probe() -> None:
@@ -32,17 +31,17 @@ def test_scenario_3_build_graph_and_capacity_probe() -> None:
 
     # 4) Retrieve the graph from the BuildGraph step
     graph = scenario.results.get("build_graph", "graph")
-    assert isinstance(
-        graph, StrictMultiDiGraph
-    ), "Expected a StrictMultiDiGraph in scenario.results under key ('build_graph', 'graph')."
+    assert isinstance(graph, StrictMultiDiGraph), (
+        "Expected a StrictMultiDiGraph in scenario.results under key ('build_graph', 'graph')."
+    )
 
     # 5) Verify total node count:
     #    Each 3-tier CLOS instance has 32 nodes -> 2 instances => 64 total.
     expected_nodes = 64
     actual_nodes = len(graph.nodes)
-    assert (
-        actual_nodes == expected_nodes
-    ), f"Expected {expected_nodes} nodes, found {actual_nodes}"
+    assert actual_nodes == expected_nodes, (
+        f"Expected {expected_nodes} nodes, found {actual_nodes}"
+    )
 
     # 6) Verify total physical links (before direction):
     #    Each 3-tier CLOS has 64 links internally => 2 instances => 128
@@ -51,9 +50,9 @@ def test_scenario_3_build_graph_and_capacity_probe() -> None:
     expected_links = 144
     expected_directed_edges = expected_links * 2
     actual_edges = len(graph.edges)
-    assert (
-        actual_edges == expected_directed_edges
-    ), f"Expected {expected_directed_edges} edges, found {actual_edges}"
+    assert actual_edges == expected_directed_edges, (
+        f"Expected {expected_directed_edges} edges, found {actual_edges}"
+    )
 
     # 7) Verify no traffic demands in this scenario
     assert len(scenario.traffic_demands) == 0, "Expected zero traffic demands."
@@ -63,24 +62,24 @@ def test_scenario_3_build_graph_and_capacity_probe() -> None:
     assert policy is None, "Expected no failure policy in this scenario."
 
     # 9) Check presence of some expanded nodes
-    assert (
-        "my_clos1/b1/t1/t1-1" in scenario.network.nodes
-    ), "Missing expected node 'my_clos1/b1/t1/t1-1' in expanded blueprint."
-    assert (
-        "my_clos2/spine/t3-16" in scenario.network.nodes
-    ), "Missing expected node 'my_clos2/spine/t3-16' in expanded blueprint."
+    assert "my_clos1/b1/t1/t1-1" in scenario.network.nodes, (
+        "Missing expected node 'my_clos1/b1/t1/t1-1' in expanded blueprint."
+    )
+    assert "my_clos2/spine/t3-16" in scenario.network.nodes, (
+        "Missing expected node 'my_clos2/spine/t3-16' in expanded blueprint."
+    )
 
     net = scenario.network
 
     # (A) Node attribute checks from node_overrides:
     # For "my_clos1/b1/t1/t1-1", we expect hw_component="LeafHW-A" and SRG="clos1-b1t1-SRG"
     node_a1 = net.nodes["my_clos1/b1/t1/t1-1"]
-    assert (
-        node_a1.attrs.get("hw_component") == "LeafHW-A"
-    ), "Expected hw_component=LeafHW-A for 'my_clos1/b1/t1/t1-1', but not found."
-    assert node_a1.attrs.get("shared_risk_groups") == [
-        "clos1-b1t1-SRG"
-    ], "Expected shared_risk_group=clos1-b1t1-SRG for 'my_clos1/b1/t1/t1-1'."
+    assert node_a1.attrs.get("hw_component") == "LeafHW-A", (
+        "Expected hw_component=LeafHW-A for 'my_clos1/b1/t1/t1-1', but not found."
+    )
+    assert node_a1.attrs.get("shared_risk_groups") == ["clos1-b1t1-SRG"], (
+        "Expected shared_risk_group=clos1-b1t1-SRG for 'my_clos1/b1/t1/t1-1'."
+    )
 
     # For "my_clos2/b2/t1/t1-1", check hw_component="LeafHW-B" and SRG="clos2-b2t1-SRG"
     node_b2 = net.nodes["my_clos2/b2/t1/t1-1"]
@@ -115,12 +114,12 @@ def test_scenario_3_build_graph_and_capacity_probe() -> None:
     )
     assert link_id_2, "Spine link (t3-2) not found for override check."
     for link_obj in link_id_2:
-        assert link_obj.attrs.get("shared_risk_groups") == [
-            "SpineSRG"
-        ], "Expected SRG=SpineSRG on spine<->spine link."
-        assert (
-            link_obj.attrs.get("hw_component") == "400G-LR4"
-        ), "Expected hw_component=400G-LR4 on spine<->spine link."
+        assert link_obj.attrs.get("shared_risk_groups") == ["SpineSRG"], (
+            "Expected SRG=SpineSRG on spine<->spine link."
+        )
+        assert link_obj.attrs.get("hw_component") == "400G-LR4", (
+            "Expected hw_component=400G-LR4 on spine<->spine link."
+        )
 
     # 10) The capacity probe step computed forward and reverse flows in 'combine' mode
     # with PROPORTIONAL flow placement.
diff --git a/tests/test_api_docs.py b/tests/test_api_docs.py
index 2b2dc46..b8ab95f 100644
--- a/tests/test_api_docs.py
+++ b/tests/test_api_docs.py
@@ -5,80 +5,80 @@
 """
 
 import os
-import sys
 import subprocess
+import sys
 from pathlib import Path
+
 import pytest
 
 
 def test_api_doc_generation_imports():
-    """Test that the API documentation generator script exists and is executable."""
-    scripts_dir = Path(__file__).parent.parent / "scripts"
+    """Test that the API documentation generator script can run and generate docs."""
+    project_root = Path(__file__).parent.parent
+    scripts_dir = project_root / "dev"
     generator_script = scripts_dir / "generate_api_docs.py"
 
     # Verify script exists
-    assert (
-        generator_script.exists()
-    ), f"Generator script not found at {generator_script}"
+    assert generator_script.exists(), (
+        f"Generator script not found at {generator_script}"
+    )
 
     # Verify script is executable
     stat_info = generator_script.stat()
     assert stat_info.st_mode & 0o111, "Generator script is not executable"
 
-    # Test that script can be run with --help or similar (quick syntax check)
+    # Test that script can generate documentation to stdout (no file writes)
     try:
         result = subprocess.run(
-            [sys.executable, str(generator_script), "--help"],
+            [sys.executable, str(generator_script)],
             capture_output=True,
-            timeout=10,
-            cwd=scripts_dir.parent,  # Run from project root
+            text=True,
+            timeout=60,
+            cwd=project_root,
         )
-        # Script might not support --help, but it should at least not crash with syntax errors
-        # Exit code 0 (success) or 2 (argument error) are both acceptable
-        assert result.returncode in [
-            0,
-            2,
-        ], f"Script syntax check failed with code {result.returncode}"
-    except subprocess.TimeoutExpired:
-        pytest.fail("Generator script timed out - possible infinite loop")
 
+        assert result.returncode == 0, (
+            f"Generator script failed with code {result.returncode}:\n"
+            f"STDOUT: {result.stdout[:1000]}...\n"
+            f"STDERR: {result.stderr}"
+        )
 
-def test_api_doc_generation_output():
-    """Test that API documentation generation produces valid output."""
-    scripts_dir = Path(__file__).parent.parent / "scripts"
-    generator_script = scripts_dir / "generate_api_docs.py"
-    project_root = Path(__file__).parent.parent
+        # Verify the output contains expected documentation
+        output = result.stdout
+        assert len(output) > 10000, (
+            f"Generated docs seem too short: {len(output)} characters"
+        )
+        assert "NetGraph API Reference (Auto-Generated)" in output, (
+            "Missing expected header"
+        )
+        assert "ngraph.scenario" in output, "Module ngraph.scenario not found in output"
+        assert "ngraph.network" in output, "Module ngraph.network not found in output"
 
-    # Run the generator script
-    result = subprocess.run(
-        [sys.executable, str(generator_script)],
-        capture_output=True,
-        text=True,
-        timeout=60,
-        cwd=project_root,  # Run from project root (required by generator)
-    )
+    except subprocess.TimeoutExpired:
+        pytest.fail("Generator script timed out - possible infinite loop")
 
-    # Check that script ran successfully
-    assert (
-        result.returncode == 0
-    ), f"Generator script failed:\nSTDOUT: {result.stdout}\nSTDERR: {result.stderr}"
 
-    # Verify the file was created and has content
+def test_api_documentation_exists_and_valid():
+    """Test that the existing API documentation file has valid content."""
+    project_root = Path(__file__).parent.parent
     api_doc_path = project_root / "docs" / "reference" / "api-full.md"
 
-    assert api_doc_path.exists(), f"API documentation not generated at {api_doc_path}"
+    # The file should exist (generated separately via make docs)
+    assert api_doc_path.exists(), (
+        f"API documentation missing at {api_doc_path}. Run 'make docs' to generate it."
+    )
 
     content = api_doc_path.read_text()
 
     # Verify substantial content
-    assert (
-        len(content) > 10000
-    ), f"API documentation seems too short: {len(content)} characters"
+    assert len(content) > 10000, (
+        f"API documentation seems too short: {len(content)} characters"
+    )
 
     # Verify expected header
-    assert (
-        "NetGraph API Reference (Auto-Generated)" in content
-    ), "Missing expected header"
+    assert "NetGraph API Reference (Auto-Generated)" in content, (
+        "Missing expected header"
+    )
 
     # Verify key modules are documented
     expected_modules = [
@@ -96,6 +96,40 @@ def test_api_doc_generation_output():
     assert "**Attributes:**" in content, "No attribute documentation found"
 
 
+def test_api_doc_generator_can_run():
+    """Test that the API documentation generator script can be executed without errors."""
+    project_root = Path(__file__).parent.parent
+
+    # Test dry-run: just check that the script can import its modules without crashing
+    # We'll use Python's -c flag to test imports without actually generating docs
+    test_code = """
+import sys
+sys.path.insert(0, ".")
+try:
+    import ngraph.scenario
+    import ngraph.network
+    import ngraph.components
+    print("SUCCESS: All modules can be imported")
+except Exception as e:
+    print(f"ERROR: {e}")
+    sys.exit(1)
+"""
+
+    result = subprocess.run(
+        [sys.executable, "-c", test_code],
+        capture_output=True,
+        text=True,
+        timeout=30,
+        cwd=project_root,
+    )
+
+    assert result.returncode == 0, (
+        f"API doc generator dependencies failed to import:\n"
+        f"STDOUT: {result.stdout}\nSTDERR: {result.stderr}"
+    )
+    assert "SUCCESS" in result.stdout, "Expected success message not found"
+
+
 def test_documentation_cross_references():
     """Test that documentation files properly cross-reference each other."""
     docs_dir = Path(__file__).parent.parent / "docs" / "reference"
@@ -105,18 +139,18 @@ def test_documentation_cross_references():
     assert api_md.exists(), "Main API documentation missing"
 
     api_content = api_md.read_text()
-    assert (
-        "api-full.md" in api_content
-    ), "Main API guide doesn't reference auto-generated docs"
+    assert "api-full.md" in api_content, (
+        "Main API guide doesn't reference auto-generated docs"
+    )
 
     # Check auto-generated API docs
     api_full_md = docs_dir / "api-full.md"
     assert api_full_md.exists(), "Auto-generated API documentation missing"
 
     api_full_content = api_full_md.read_text()
-    assert (
-        "api.md" in api_full_content
-    ), "Auto-generated docs don't reference main API guide"
+    assert "api.md" in api_full_content, (
+        "Auto-generated docs don't reference main API guide"
+    )
 
 
 @pytest.mark.skipif(
@@ -124,13 +158,13 @@ def test_documentation_cross_references():
     reason="Skip integration test in CI to avoid circular dependency",
 )
 def test_scripts_directory_structure():
-    """Test that scripts directory has expected structure."""
-    scripts_dir = Path(__file__).parent.parent / "scripts"
+    """Test that dev directory has expected structure."""
+    scripts_dir = Path(__file__).parent.parent / "dev"
 
-    assert scripts_dir.exists(), "Scripts directory missing"
-    assert (
-        scripts_dir / "generate_api_docs.py"
-    ).exists(), "API generator script missing"
+    assert scripts_dir.exists(), "Dev directory missing"
+    assert (scripts_dir / "generate_api_docs.py").exists(), (
+        "API generator script missing"
+    )
 
     # Verify script is executable
     generator_script = scripts_dir / "generate_api_docs.py"
diff --git a/tests/test_blueprints.py b/tests/test_blueprints.py
index 3dbab18..490f0a8 100644
--- a/tests/test_blueprints.py
+++ b/tests/test_blueprints.py
@@ -1,24 +1,24 @@
 import pytest
-from ngraph.network import Network, Node, Link
 
 from ngraph.blueprints import (
-    DSLExpansionContext,
     Blueprint,
+    DSLExpansionContext,
     _apply_parameters,
-    _join_paths,
     _create_link,
+    _expand_adjacency,
     _expand_adjacency_pattern,
-    _process_direct_nodes,
-    _process_direct_links,
     _expand_blueprint_adjacency,
-    _expand_adjacency,
     _expand_group,
-    _update_nodes,
-    _update_links,
-    _process_node_overrides,
+    _join_paths,
+    _process_direct_links,
+    _process_direct_nodes,
     _process_link_overrides,
+    _process_node_overrides,
+    _update_links,
+    _update_nodes,
     expand_network_dsl,
 )
+from ngraph.network import Link, Network, Node
 
 
 def test_join_paths():
@@ -130,10 +130,10 @@ def test_expand_adjacency_pattern_one_to_one():
     _expand_adjacency_pattern(ctx, "S", "T", "one_to_one", {"capacity": 10})
     # We expect 2 links: S1->T1, S2->T2
     assert len(ctx_net.links) == 2
-    pairs = {(l.source, l.target) for l in ctx_net.links.values()}
+    pairs = {(link.source, link.target) for link in ctx_net.links.values()}
     assert pairs == {("S1", "T1"), ("S2", "T2")}
-    for l in ctx_net.links.values():
-        assert l.capacity == 10
+    for link in ctx_net.links.values():
+        assert link.capacity == 10
 
 
 def test_expand_adjacency_pattern_one_to_one_wrap():
@@ -151,7 +151,7 @@ def test_expand_adjacency_pattern_one_to_one_wrap():
     _expand_adjacency_pattern(ctx, "S", "T", "one_to_one", {"cost": 99})
     # Expect 4 total links
     assert len(ctx_net.links) == 4
-    pairs = {(l.source, l.target) for l in ctx_net.links.values()}
+    pairs = {(link.source, link.target) for link in ctx_net.links.values()}
     expected = {
         ("S1", "T1"),
         ("S2", "T2"),
@@ -159,8 +159,8 @@ def test_expand_adjacency_pattern_one_to_one_wrap():
         ("S4", "T2"),
     }
     assert pairs == expected
-    for l in ctx_net.links.values():
-        assert l.cost == 99
+    for link in ctx_net.links.values():
+        assert link.cost == 99
 
 
 def test_expand_adjacency_pattern_one_to_one_mismatch():
@@ -853,14 +853,14 @@ def test_adjacency_one_to_one():
     # 4 total nodes => 2 from each group
     assert len(net.nodes) == 4
     # one_to_one => 2 links
-    pairs = {(l.source, l.target) for l in net.links.values()}
+    pairs = {(link.source, link.target) for link in net.links.values()}
     expected = {
         ("GroupA/GroupA-1", "GroupB/GroupB-1"),
         ("GroupA/GroupA-2", "GroupB/GroupB-2"),
     }
     assert pairs == expected
-    for l in net.links.values():
-        assert l.capacity == 99
+    for link in net.links.values():
+        assert link.capacity == 99
 
 
 def test_adjacency_one_to_one_wrap():
@@ -884,7 +884,7 @@ def test_adjacency_one_to_one_wrap():
     assert len(net.nodes) == 6
     # wrap => 4 links
     assert len(net.links) == 4
-    link_pairs = {(l.source, l.target) for l in net.links.values()}
+    link_pairs = {(link.source, link.target) for link in net.links.values()}
     expected = {
         ("Big/Big-1", "Small/Small-1"),
         ("Big/Big-2", "Small/Small-2"),
@@ -892,8 +892,8 @@ def test_adjacency_one_to_one_wrap():
         ("Big/Big-4", "Small/Small-2"),
     }
     assert link_pairs == expected
-    for l in net.links.values():
-        assert l.cost == 555
+    for link in net.links.values():
+        assert link.cost == 555
 
 
 def test_adjacency_mesh():
@@ -1210,7 +1210,7 @@ def test_expand_adjacency_with_variables_zip():
     # (A->B), (B->C), (C->A)
     assert len(net.nodes) == 3
     assert len(net.links) == 3
-    link_pairs = {(l.source, l.target) for l in net.links.values()}
+    link_pairs = {(link.source, link.target) for link in net.links.values()}
     expected = {
         ("RackA/RackA-1", "RackB/RackB-1"),
         ("RackB/RackB-1", "RackC/RackC-1"),
diff --git a/tests/test_components.py b/tests/test_components.py
index 241fa63..bdf6eeb 100644
--- a/tests/test_components.py
+++ b/tests/test_components.py
@@ -1,6 +1,4 @@
 import pytest
-from copy import deepcopy
-from typing import Dict
 
 from ngraph.components import Component, ComponentsLibrary
 
diff --git a/tests/test_dsl_examples.py b/tests/test_dsl_examples.py
index 74c14a4..32360ed 100644
--- a/tests/test_dsl_examples.py
+++ b/tests/test_dsl_examples.py
@@ -263,8 +263,8 @@ def test_failure_policy_example():
 
     scenario = Scenario.from_yaml(yaml_content)
     assert scenario.failure_policy is not None
-    assert scenario.failure_policy.fail_shared_risk_groups == True
-    assert scenario.failure_policy.fail_risk_group_children == False
+    assert scenario.failure_policy.fail_shared_risk_groups
+    assert not scenario.failure_policy.fail_risk_group_children
     assert len(scenario.failure_policy.rules) == 1
     rule = scenario.failure_policy.rules[0]
     assert rule.entity_scope == "node"
@@ -313,7 +313,7 @@ def test_node_overrides_example():
   groups:
     my_clos1:
       use_blueprint: test_bp
-  
+
   node_overrides:
     - path: "^my_clos1/switches/switch-(1|3)$"
       disabled: true
@@ -344,7 +344,7 @@ def test_link_overrides_example():
     group2:
       node_count: 2
       name_template: "node-{node_num}"
-  
+
   adjacency:
     - source: /group1
       target: /group2
@@ -352,7 +352,7 @@ def test_link_overrides_example():
       link_params:
         capacity: 100
         cost: 10
-  
+
   link_overrides:
     - source: "^group1/node-1$"
       target: "^group2/node-1$"
@@ -386,7 +386,7 @@ def test_variable_expansion():
         node_count: 2
         name_template: "rack-{node_num}"
       plane2_rack:
-        node_count: 2  
+        node_count: 2
         name_template: "rack-{node_num}"
       spine:
         node_count: 2
diff --git a/tests/test_explorer.py b/tests/test_explorer.py
index a7316d1..93180cf 100644
--- a/tests/test_explorer.py
+++ b/tests/test_explorer.py
@@ -1,14 +1,13 @@
-import pytest
 import logging
 
+import pytest
+
+from ngraph.components import Component, ComponentsLibrary
 from ngraph.explorer import (
     NetworkExplorer,
     TreeNode,
-    TreeStats,
-    ExternalLinkBreakdown,
 )
-from ngraph.network import Network, Node, Link
-from ngraph.components import ComponentsLibrary, Component
+from ngraph.network import Link, Network, Node
 
 
 def create_mock_components_library() -> ComponentsLibrary:
diff --git a/tests/test_failure_manager.py b/tests/test_failure_manager.py
index 2161e99..72729b2 100644
--- a/tests/test_failure_manager.py
+++ b/tests/test_failure_manager.py
@@ -1,14 +1,15 @@
 """Tests for the FailureManager class."""
 
-import pytest
-from unittest.mock import MagicMock
 from typing import List
+from unittest.mock import MagicMock
+
+import pytest
 
+from ngraph.failure_manager import FailureManager
+from ngraph.failure_policy import FailurePolicy
 from ngraph.network import Network
 from ngraph.traffic_demand import TrafficDemand
-from ngraph.traffic_manager import TrafficManager, TrafficResult
-from ngraph.failure_policy import FailurePolicy
-from ngraph.failure_manager import FailureManager
+from ngraph.traffic_manager import TrafficResult
 
 
 @pytest.fixture
diff --git a/tests/test_failure_policy.py b/tests/test_failure_policy.py
index 2437a78..b212c3d 100644
--- a/tests/test_failure_policy.py
+++ b/tests/test_failure_policy.py
@@ -1,11 +1,9 @@
-import pytest
 from unittest.mock import patch
 
 from ngraph.failure_policy import (
+    FailureCondition,
     FailurePolicy,
     FailureRule,
-    FailureCondition,
-    _evaluate_condition,
 )
 
 
diff --git a/tests/test_network.py b/tests/test_network.py
index daf2e95..81b2814 100644
--- a/tests/test_network.py
+++ b/tests/test_network.py
@@ -1,12 +1,12 @@
 import pytest
+
 from ngraph.network import (
+    Link,
     Network,
     Node,
-    Link,
     RiskGroup,
     new_base64_uuid,
 )
-from ngraph.lib.graph import StrictMultiDiGraph
 
 
 def test_new_base64_uuid_length_and_uniqueness():
@@ -593,7 +593,7 @@ def test_find_links():
     # No filter => returns all
     all_links = net.find_links()
     assert len(all_links) == 2
-    assert set(l.id for l in all_links) == {link_a_c.id, link_b_c.id}
+    assert set(link.id for link in all_links) == {link_a_c.id, link_b_c.id}
 
     # Filter by source pattern "srcA"
     a_links = net.find_links(source_regex="^srcA$")
diff --git a/tests/test_readme_examples.py b/tests/test_readme_examples.py
index 22588c9..a0aa809 100644
--- a/tests/test_readme_examples.py
+++ b/tests/test_readme_examples.py
@@ -21,9 +21,9 @@ def test_max_flow_variants():
       - The flow along the shortest paths (expected flow: 3.0)
       - Flow placement using an equal-balanced strategy on the shortest paths (expected flow: 2.0)
     """
-    from ngraph.lib.graph import StrictMultiDiGraph
-    from ngraph.lib.algorithms.max_flow import calc_max_flow
     from ngraph.lib.algorithms.base import FlowPlacement
+    from ngraph.lib.algorithms.max_flow import calc_max_flow
+    from ngraph.lib.graph import StrictMultiDiGraph
 
     g = StrictMultiDiGraph()
     for node in ("A", "B", "C", "D"):
@@ -72,10 +72,10 @@ def test_traffic_engineering_simulation():
     - Each demand uses its own FlowPolicy, so the policy's global flow accounting does not overlap.
     - The test verifies that each demand is fully placed at 20 units.
     """
-    from ngraph.lib.graph import StrictMultiDiGraph
     from ngraph.lib.algorithms.flow_init import init_flow_graph
-    from ngraph.lib.flow_policy import FlowPolicyConfig, get_flow_policy
     from ngraph.lib.demand import Demand
+    from ngraph.lib.flow_policy import FlowPolicyConfig, get_flow_policy
+    from ngraph.lib.graph import StrictMultiDiGraph
 
     # Build the graph.
     g = StrictMultiDiGraph()
diff --git a/tests/test_result.py b/tests/test_result.py
index d7d1508..d8d21ca 100644
--- a/tests/test_result.py
+++ b/tests/test_result.py
@@ -1,4 +1,3 @@
-import pytest
 from ngraph.results import Results
 
 
diff --git a/tests/test_scenario.py b/tests/test_scenario.py
index 81f0935..b17bb72 100644
--- a/tests/test_scenario.py
+++ b/tests/test_scenario.py
@@ -1,17 +1,16 @@
-import pytest
-import yaml
-from typing import TYPE_CHECKING
 from dataclasses import dataclass
+from typing import TYPE_CHECKING
 
-from ngraph.scenario import Scenario
+import pytest
+
+from ngraph.failure_policy import FailurePolicy
 from ngraph.network import Network
-from ngraph.failure_policy import FailurePolicy, FailureRule, FailureCondition
-from ngraph.traffic_demand import TrafficDemand
 from ngraph.results import Results
+from ngraph.scenario import Scenario
 from ngraph.workflow.base import (
+    WORKFLOW_STEP_REGISTRY,
     WorkflowStep,
     register_workflow_step,
-    WORKFLOW_STEP_REGISTRY,
 )
 
 if TYPE_CHECKING:
diff --git a/tests/test_traffic_demand.py b/tests/test_traffic_demand.py
index b278e79..a981cbe 100644
--- a/tests/test_traffic_demand.py
+++ b/tests/test_traffic_demand.py
@@ -1,4 +1,3 @@
-import pytest
 from ngraph.traffic_demand import TrafficDemand
 
 
diff --git a/tests/test_traffic_manager.py b/tests/test_traffic_manager.py
index d742087..3d09c66 100644
--- a/tests/test_traffic_manager.py
+++ b/tests/test_traffic_manager.py
@@ -1,12 +1,10 @@
 import pytest
 
-from ngraph.network import Network, Node, Link
-from ngraph.traffic_demand import TrafficDemand
+from ngraph.lib.algorithms.base import MIN_FLOW
 from ngraph.lib.flow_policy import FlowPolicyConfig
 from ngraph.lib.graph import StrictMultiDiGraph
-from ngraph.lib.algorithms.base import MIN_FLOW
-from ngraph.lib.demand import Demand
-
+from ngraph.network import Link, Network, Node
+from ngraph.traffic_demand import TrafficDemand
 from ngraph.traffic_manager import TrafficManager
 
 
@@ -110,9 +108,9 @@ def test_place_all_demands_simple(small_network):
 
     # Check final placed_demand on each Demand
     for d in tm.demands:
-        assert (
-            abs(d.placed_demand - d.volume) < MIN_FLOW
-        ), "Demand should be fully placed"
+        assert abs(d.placed_demand - d.volume) < MIN_FLOW, (
+            "Demand should be fully placed"
+        )
 
     # Summarize link usage
     usage = tm.summarize_link_usage()
@@ -237,9 +235,9 @@ def test_place_all_demands_auto_rounds(small_network):
     total_placed = tm.place_all_demands(placement_rounds="auto")
     assert total_placed == 25.0, "Should place all traffic under auto rounds"
     for d in tm.demands:
-        assert (
-            abs(d.placed_demand - d.volume) < MIN_FLOW
-        ), "Demand should be fully placed"
+        assert abs(d.placed_demand - d.volume) < MIN_FLOW, (
+            "Demand should be fully placed"
+        )
 
 
 def test_combine_mode_multi_source_sink():
@@ -281,9 +279,9 @@ def test_combine_mode_multi_source_sink():
         for _, (src, dst, _, data) in tm.graph.get_edges().items()
         if src == d.src_node
     ]
-    assert (
-        len(edges_out_of_pseudo_src) == 2
-    ), "2 edges from pseudo-source to real sources"
+    assert len(edges_out_of_pseudo_src) == 2, (
+        "2 edges from pseudo-source to real sources"
+    )
 
     edges_into_pseudo_snk = [
         (src, dst)
@@ -375,9 +373,9 @@ def test_full_mesh_mode_self_pairs():
     # So we expect 2 demands, each with 10.0
     assert len(tm.demands) == 2, "Only N1->N2 and N2->N1 should be created"
     for d in tm.demands:
-        assert (
-            abs(d.volume - 10.0) < MIN_FLOW
-        ), "Volume should be evenly split among 2 pairs"
+        assert abs(d.volume - 10.0) < MIN_FLOW, (
+            "Volume should be evenly split among 2 pairs"
+        )
 
 
 def test_estimate_rounds_no_demands(small_network):
diff --git a/tests/transform/test_base.py b/tests/transform/test_base.py
index 54e824b..a47ff6b 100644
--- a/tests/transform/test_base.py
+++ b/tests/transform/test_base.py
@@ -1,8 +1,9 @@
 import pytest
+
 from ngraph.transform.base import (
     TRANSFORM_REGISTRY,
-    register_transform,
     NetworkTransform,
+    register_transform,
 )
 
 
diff --git a/tests/transform/test_distribute_external.py b/tests/transform/test_distribute_external.py
index 7c51193..875f243 100644
--- a/tests/transform/test_distribute_external.py
+++ b/tests/transform/test_distribute_external.py
@@ -1,10 +1,11 @@
 import pytest
+
+from ngraph.network import Network, Node
+from ngraph.scenario import Scenario
 from ngraph.transform.distribute_external import (
-    _StripeChooser,
     DistributeExternalConnectivity,
+    _StripeChooser,
 )
-from ngraph.network import Network, Node, Link
-from ngraph.scenario import Scenario
 
 
 def make_scenario_with_network(net):
diff --git a/tests/transform/test_enable_nodes.py b/tests/transform/test_enable_nodes.py
index 6cc41c2..8da0fcd 100644
--- a/tests/transform/test_enable_nodes.py
+++ b/tests/transform/test_enable_nodes.py
@@ -1,9 +1,8 @@
-import pytest
+import random
+
 from ngraph.network import Network, Node
 from ngraph.scenario import Scenario
 from ngraph.transform.enable_nodes import EnableNodesTransform
-import ngraph.transform.enable_nodes as en_mod
-import random
 
 
 def make_scenario(nodes):
diff --git a/tests/workflow/test_base.py b/tests/workflow/test_base.py
index 1fb4dd8..396d356 100644
--- a/tests/workflow/test_base.py
+++ b/tests/workflow/test_base.py
@@ -1,10 +1,11 @@
-import pytest
 from unittest.mock import MagicMock
 
+import pytest
+
 from ngraph.workflow.base import (
+    WORKFLOW_STEP_REGISTRY,
     WorkflowStep,
     register_workflow_step,
-    WORKFLOW_STEP_REGISTRY,
 )
 
 
diff --git a/tests/workflow/test_build_graph.py b/tests/workflow/test_build_graph.py
index ce2458e..ee3129a 100644
--- a/tests/workflow/test_build_graph.py
+++ b/tests/workflow/test_build_graph.py
@@ -1,9 +1,10 @@
-import pytest
 from unittest.mock import MagicMock
 
+import pytest
+
 from ngraph.lib.graph import StrictMultiDiGraph
+from ngraph.network import Link, Network, Node
 from ngraph.workflow.build_graph import BuildGraph
-from ngraph.network import Network, Node, Link
 
 
 @pytest.fixture
@@ -57,9 +58,9 @@ def test_build_graph_stores_multidigraph_in_results(mock_scenario):
     assert call_args[0][0] == "MyBuildStep"
     assert call_args[0][1] == "graph"
     created_graph = call_args[0][2]
-    assert isinstance(
-        created_graph, StrictMultiDiGraph
-    ), "Resulting object must be a StrictMultiDiGraph."
+    assert isinstance(created_graph, StrictMultiDiGraph), (
+        "Resulting object must be a StrictMultiDiGraph."
+    )
 
     # Verify the correct nodes were added
     assert set(created_graph.nodes()) == {
@@ -73,9 +74,9 @@ def test_build_graph_stores_multidigraph_in_results(mock_scenario):
     # Verify edges
     # We expect two edges for each link: forward ("L1") and reverse ("L1_rev"), etc.
     # So we should have 4 edges in total (2 from L1, 2 from L2).
-    assert (
-        created_graph.number_of_edges() == 4
-    ), "Should have two edges (forward/reverse) for each link."
+    assert created_graph.number_of_edges() == 4, (
+        "Should have two edges (forward/reverse) for each link."
+    )
 
     # Check forward edge from link 'L1'
     edge_data_l1 = created_graph.get_edge_data("A", "B", key="L1")
@@ -86,12 +87,12 @@ def test_build_graph_stores_multidigraph_in_results(mock_scenario):
 
     # Check reverse edge from link 'L1'
     rev_edge_data_l1 = created_graph.get_edge_data("B", "A", key="L1_rev")
-    assert (
-        rev_edge_data_l1 is not None
-    ), "Reverse edge 'L1_rev' should exist from B to A."
-    assert (
-        rev_edge_data_l1["capacity"] == 100
-    ), "Reverse edge should share the same capacity."
+    assert rev_edge_data_l1 is not None, (
+        "Reverse edge 'L1_rev' should exist from B to A."
+    )
+    assert rev_edge_data_l1["capacity"] == 100, (
+        "Reverse edge should share the same capacity."
+    )
 
     # Check forward edge from link 'L2'
     edge_data_l2 = created_graph.get_edge_data("B", "A", key="L2")
@@ -102,9 +103,9 @@ def test_build_graph_stores_multidigraph_in_results(mock_scenario):
 
     # Check reverse edge from link 'L2'
     rev_edge_data_l2 = created_graph.get_edge_data("A", "B", key="L2_rev")
-    assert (
-        rev_edge_data_l2 is not None
-    ), "Reverse edge 'L2_rev' should exist from A to B."
-    assert (
-        rev_edge_data_l2["capacity"] == 50
-    ), "Reverse edge should share the same capacity."
+    assert rev_edge_data_l2 is not None, (
+        "Reverse edge 'L2_rev' should exist from A to B."
+    )
+    assert rev_edge_data_l2["capacity"] == 50, (
+        "Reverse edge should share the same capacity."
+    )
diff --git a/tests/workflow/test_capacity_probe.py b/tests/workflow/test_capacity_probe.py
index 663eafd..262c42c 100644
--- a/tests/workflow/test_capacity_probe.py
+++ b/tests/workflow/test_capacity_probe.py
@@ -1,9 +1,10 @@
+from unittest.mock import MagicMock
+
 import pytest
-from unittest.mock import MagicMock, call
 
-from ngraph.network import Network, Node, Link
-from ngraph.workflow.capacity_probe import CapacityProbe
 from ngraph.lib.algorithms.base import FlowPlacement
+from ngraph.network import Link, Network, Node
+from ngraph.workflow.capacity_probe import CapacityProbe
 
 
 @pytest.fixture