diff --git a/AGENTS.md b/AGENTS.md
index 9f86e362..95100f68 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -37,8 +37,7 @@ cortex install nginx --dry-run
 ```bash
 python3 -m venv venv
 source venv/bin/activate
-pip install -e .
-pip install -r requirements-dev.txt
+pip install -e ".[dev]"
 pytest tests/ -v
 ```
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a2edaebf..3048d5dc 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -123,24 +123,19 @@ git remote add upstream https://github.com/cortexlinux/cortex.git
 python3 -m venv venv
 source venv/bin/activate  # On Windows: venv\Scripts\activate
 
-# Install dependencies
-pip install -r requirements.txt
-pip install -r requirements-dev.txt
-
-# Install in development mode
-pip install -e .
+# Install in development mode (includes all dependencies)
+pip install -e ".[dev]"
 
 # Run tests to verify setup
 pytest tests/ -v
 ```
 
-### Requirements Files
-
-If `requirements-dev.txt` doesn't exist, install these manually:
+### Dependencies
 
-```bash
-pip install pytest pytest-cov pytest-mock black pylint mypy bandit
-```
+All dependencies are defined in `pyproject.toml`. To install:
+- **Core dependencies**: `pip install -e .`
+- **With dev tools**: `pip install -e ".[dev]"`
+- **All extras**: `pip install -e ".[all]"`
 
 ### IDE Setup
 
diff --git a/Makefile b/Makefile
index 35aab6c9..0074bdd5 100644
--- a/Makefile
+++ b/Makefile
@@ -18,8 +18,7 @@ help:
 
 dev:
 	$(PYTHON) -m pip install -U pip
-	$(PYTHON) -m pip install -e .
-	$(PYTHON) -m pip install -r requirements-dev.txt
+	$(PYTHON) -m pip install -e ".[dev]"
 	@echo "✅ Dev environment ready"
 
 test:
diff --git a/docs/guides/Developer-Guide.md b/docs/guides/Developer-Guide.md
index 99e5ab7a..4a06cead 100644
--- a/docs/guides/Developer-Guide.md
+++ b/docs/guides/Developer-Guide.md
@@ -11,8 +11,7 @@ python3 -m venv venv
 source venv/bin/activate
 
 # Install dev dependencies
-pip install -r requirements.txt
-pip install -r requirements-dev.txt
+pip install -e ".[dev]"
 
 # Run tests
 pytest tests/
diff --git a/docs/guides/Getting-Started.md b/docs/guides/Getting-Started.md
index 89b84ce9..5984a413 100644
--- a/docs/guides/Getting-Started.md
+++ b/docs/guides/Getting-Started.md
@@ -12,8 +12,8 @@
 git clone https://github.com/cortexlinux/cortex.git
 cd cortex
 
-# Install dependencies
-pip install -r requirements.txt
+# Install Cortex
+pip install -e .
 
 # Configure API key
 export ANTHROPIC_API_KEY="your-key-here"
diff --git a/pyproject.toml b/pyproject.toml
index e59f5b83..5333fe48 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,21 +44,26 @@ requires-python = ">=3.10"
 dependencies = [
     "anthropic>=0.18.0",
     "openai>=1.0.0",
-    "rich>=13.0.0",
-    "pyyaml>=6.0.0",
+    "requests>=2.32.4",
+    "PyYAML>=6.0.3",
     "python-dotenv>=1.0.0",
+    "cryptography>=44.0.1",
+    "rich>=13.0.0",
+    "typing-extensions>=4.0.0",
 ]
 
 [project.optional-dependencies]
 dev = [
     "pytest>=7.0.0",
     "pytest-cov>=4.0.0",
-    "pytest-timeout>=2.0.0",
-    "black>=23.0.0",
-    "ruff>=0.1.0",
+    "pytest-asyncio>=0.23.0",
+    "pytest-mock>=3.12.0",
+    "pytest-timeout>=2.3.1",
+    "black>=24.0.0",
+    "ruff>=0.8.0",
     "mypy>=1.0.0",
     "pre-commit>=3.0.0",
-    "isort>=5.0.0",
+    "isort>=5.13.0",
 ]
 security = [
     "bandit>=1.7.0",
diff --git a/requirements-dev.txt b/requirements-dev.txt
deleted file mode 100644
index 2ccb0205..00000000
--- a/requirements-dev.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-# Development Dependencies
-pytest>=7.0.0
-pytest-cov>=4.0.0
-pytest-asyncio>=0.23.0
-pytest-mock>=3.12.0
-pytest-timeout>=2.3.1
-black>=24.0.0
-ruff>=0.8.0
-isort>=5.13.0
-pre-commit>=3.0.0
diff --git a/requirements.txt b/requirements.txt
deleted file mode 100644
index 166a777e..00000000
--- a/requirements.txt
+++ /dev/null
@@ -1,25 +0,0 @@
-# Cortex Linux - Core Dependencies
-
-# LLM Provider APIs
-anthropic>=0.18.0
-openai>=1.0.0
-requests>=2.32.4
-
-# Configuration
-PyYAML>=6.0.0
-
-# Environment variable loading from .env files
-python-dotenv>=1.0.0
-
-# Encryption for environment variable secrets
-cryptography>=42.0.0
-
-# Terminal UI
-rich>=13.0.0
-
-# Configuration
-pyyaml>=6.0.0
-
-# Type hints for older Python versions
-typing-extensions>=4.0.0
-PyYAML==6.0.3
diff --git a/setup.py b/setup.py
index 3a218042..63b9b318 100644
--- a/setup.py
+++ b/setup.py
@@ -5,20 +5,18 @@
 with open("README.md", encoding="utf-8") as fh:
     long_description = fh.read()
 
-# Try to read requirements from root, fallback to LLM directory
-requirements_path = "requirements.txt"
-if not os.path.exists(requirements_path):
-    requirements_path = os.path.join("LLM", "requirements.txt")
-
-if os.path.exists(requirements_path):
-    with open(requirements_path, encoding="utf-8") as fh:
-        requirements = [
-            line.strip()
-            for line in fh
-            if line.strip() and not line.startswith("#") and not line.startswith("-r")
-        ]
-else:
-    requirements = ["anthropic>=0.18.0", "openai>=1.0.0"]
+# Dependencies are now defined in pyproject.toml
+# This is kept for backward compatibility but pyproject.toml is the source of truth
+requirements = [
+    "anthropic>=0.18.0",
+    "openai>=1.0.0",
+    "requests>=2.32.4",
+    "PyYAML>=6.0.3",
+    "python-dotenv>=1.0.0",
+    "cryptography>=44.0.1",
+    "rich>=13.0.0",
+    "typing-extensions>=4.0.0",
+]
 
 setup(
     name="cortex-linux",