diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
new file mode 100644
index 0000000..f5d8d79
--- /dev/null
+++ b/.github/workflows/e2e-tests.yml
@@ -0,0 +1,106 @@
+name: End-to-End Tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Python ${{ matrix.python-version }} / Django ${{ matrix.django-version }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        django-version: ['4.2', '5.0', '5.1']
+        exclude:
+          # Add any incompatible combinations here if needed
+          # - python-version: '3.9'
+          #   django-version: '5.1'
+
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+        cache: 'pip'
+    
+    - name: Set up Rust
+      uses: dtolnay/rust-toolchain@stable
+      with:
+        toolchain: stable
+    
+    - name: Cache Rust dependencies
+      uses: Swatinem/rust-cache@v2
+    
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install tox tox-gh-actions
+    
+    - name: Build django-language-server
+      run: |
+        pip install maturin
+        maturin develop --release
+    
+    - name: Test with tox
+      run: tox
+      env:
+        DJANGO_VERSION: ${{ matrix.django-version }}
+        PYTHONPATH: ${{ github.workspace }}
+
+  # Optional: Add a job for testing with different clients
+  client-tests:
+    name: Client Tests - ${{ matrix.client }}
+    runs-on: ubuntu-latest
+    needs: test
+    strategy:
+      fail-fast: false
+      matrix:
+        client: ['vscode', 'neovim']
+        include:
+          - client: vscode
+            client-setup: |
+              # Setup for VS Code testing
+              echo "Setting up VS Code for testing"
+          - client: neovim
+            client-setup: |
+              # Setup for Neovim testing
+              echo "Setting up Neovim for testing"
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+    
+    - name: Set up Rust
+      uses: dtolnay/rust-toolchain@stable
+      with:
+        toolchain: stable
+    
+    - name: Set up client
+      run: ${{ matrix.client-setup }}
+    
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install -r tests/requirements-test.txt
+        python -m pip install Django>=5.0,<5.1
+    
+    - name: Build django-language-server
+      run: |
+        pip install maturin
+        maturin develop --release
+    
+    - name: Run client tests
+      run: |
+        pytest tests/clients/test_${{ matrix.client }}.py
\ No newline at end of file
diff --git a/README.md b/README.md
index ba91821..2f96e2c 100644
--- a/README.md
+++ b/README.md
@@ -158,6 +158,29 @@ Code contributions are welcome from developers of all backgrounds. Rust expertis
 
 So far it's all been built by a [a simple country CRUD web developer](https://youtu.be/7ij_1SQqbVo?si=hwwPyBjmaOGnvPPI&t=53) learning Rust along the way - send help!
 
+### Testing
+
+The project includes a comprehensive end-to-end testing framework that tests the language server against:
+
+- Multiple Python versions (3.9, 3.10, 3.11, 3.12, 3.13)
+- Multiple Django versions (4.2, 5.0, 5.1)
+- Different LSP clients (VS Code, Neovim)
+
+To run the tests locally:
+
+```bash
+# Install tox
+pip install tox
+
+# Run tests with the default Python and Django versions
+tox
+
+# Run tests with a specific Python and Django version
+tox -e py311-django50
+```
+
+For more information about the testing framework, see the [tests/README.md](tests/README.md) file.
+
 ## License
 
 django-language-server is licensed under the Apache License, Version 2.0. See the [`LICENSE`](LICENSE) file for more information.
diff --git a/pyproject.toml b/pyproject.toml
index 1586a5f..9a6a49c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,6 +11,14 @@ dev = [
 docs = [
     "mkdocs-material>=9.5.49",
 ]
+test = [
+    "pytest>=7.4.0",
+    "pytest-asyncio>=0.21.1",
+    "pygls>=1.1.0",
+    "tox>=4.11.0",
+    "tox-gh-actions>=3.1.3",
+    "coverage>=7.3.2",
+]
 
 [project]
 name = "django-language-server"
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000..dd21faa
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,98 @@
+# Django Language Server Testing Framework
+
+This directory contains the end-to-end testing framework for the Django Language Server.
+
+## Overview
+
+The testing framework is designed to test the Django Language Server against:
+
+- Multiple Python versions (3.9, 3.10, 3.11, 3.12, 3.13)
+- Multiple Django versions (4.2, 5.0, 5.1)
+- Different LSP clients (VS Code, Neovim)
+
+## Directory Structure
+
+- `e2e/`: End-to-end tests for the language server
+- `fixtures/`: Test fixtures, including Django project generation
+- `clients/`: Client-specific tests for different editors
+- `conftest.py`: Pytest configuration and fixtures
+- `requirements-test.txt`: Test dependencies
+
+## Running Tests
+
+### Local Testing
+
+To run the tests locally, you can use tox:
+
+```bash
+# Install tox
+pip install tox
+
+# Run tests with the default Python and Django versions
+tox
+
+# Run tests with a specific Python and Django version
+tox -e py311-django50
+
+# Run tests with a specific test file
+tox -- tests/e2e/test_basic_functionality.py
+```
+
+### GitHub Actions
+
+The tests are automatically run on GitHub Actions for all supported Python and Django versions. The workflow is defined in `.github/workflows/e2e-tests.yml`.
+
+## Adding New Tests
+
+### Adding a New End-to-End Test
+
+1. Create a new test file in the `e2e/` directory
+2. Use the existing fixtures from `conftest.py`
+3. Write your test using the pytest-asyncio framework
+
+Example:
+
+```python
+@pytest.mark.asyncio
+async def test_my_feature(lsp_client, django_project):
+    # Test code here
+    pass
+```
+
+### Adding a New Client Test
+
+1. Create a new test file in the `clients/` directory
+2. Create fixtures for the client configuration
+3. Write tests for the client integration
+
+## Test Fixtures
+
+### Django Project
+
+The `django_project` fixture creates a Django project with:
+
+- A basic project structure
+- A sample app with views and templates
+- Template files with Django template tags
+
+### Language Server
+
+The `language_server_process` fixture starts the Django Language Server in TCP mode for testing.
+
+### LSP Client
+
+The `lsp_client` fixture creates an LSP client connected to the language server for sending requests and receiving responses.
+
+## Extending the Framework
+
+### Testing with Additional Django Versions
+
+To test with additional Django versions, update the `envlist` in `tox.ini` and the matrix in `.github/workflows/e2e-tests.yml`.
+
+### Testing with Additional Clients
+
+To test with additional LSP clients, add a new test file in the `clients/` directory and update the matrix in `.github/workflows/e2e-tests.yml`.
+
+### Testing Additional Features
+
+To test additional features of the language server, add new test files in the `e2e/` directory.
\ No newline at end of file
diff --git a/tests/clients/test_neovim.py b/tests/clients/test_neovim.py
new file mode 100644
index 0000000..10a7025
--- /dev/null
+++ b/tests/clients/test_neovim.py
@@ -0,0 +1,214 @@
+"""
+Tests for Neovim integration with django-language-server.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from fixtures.create_django_project import create_django_project, cleanup_django_project
+
+
+@pytest.fixture(scope="module")
+def neovim_config_dir():
+    """Create a temporary directory for Neovim configuration."""
+    temp_dir = tempfile.mkdtemp()
+    config_dir = Path(temp_dir) / "nvim"
+    config_dir.mkdir(exist_ok=True)
+    
+    # Create lua directory
+    lua_dir = config_dir / "lua"
+    lua_dir.mkdir(exist_ok=True)
+    
+    # Create init.lua
+    init_lua = """
+-- Basic Neovim configuration
+vim.opt.number = true
+vim.opt.relativenumber = true
+vim.opt.expandtab = true
+vim.opt.shiftwidth = 4
+vim.opt.tabstop = 4
+vim.opt.smartindent = true
+vim.opt.termguicolors = true
+
+-- Load plugins
+require('plugins')
+
+-- Configure LSP
+require('lsp')
+"""
+    
+    with open(config_dir / "init.lua", "w") as f:
+        f.write(init_lua)
+    
+    # Create plugins.lua
+    plugins_dir = lua_dir / "plugins"
+    plugins_dir.mkdir(exist_ok=True)
+    
+    plugins_lua = """
+-- Bootstrap lazy.nvim
+local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
+if not vim.loop.fs_stat(lazypath) then
+  vim.fn.system({
+    "git",
+    "clone",
+    "--filter=blob:none",
+    "https://github.com/folke/lazy.nvim.git",
+    "--branch=stable",
+    lazypath,
+  })
+end
+vim.opt.rtp:prepend(lazypath)
+
+-- Configure plugins
+require("lazy").setup({
+  -- LSP
+  {
+    "neovim/nvim-lspconfig",
+    dependencies = {
+      "hrsh7th/cmp-nvim-lsp",
+    },
+  },
+  
+  -- Autocompletion
+  {
+    "hrsh7th/nvim-cmp",
+    dependencies = {
+      "hrsh7th/cmp-buffer",
+      "hrsh7th/cmp-path",
+      "hrsh7th/cmp-nvim-lsp",
+      "L3MON4D3/LuaSnip",
+      "saadparwaiz1/cmp_luasnip",
+    },
+  },
+})
+"""
+    
+    with open(plugins_dir / "init.lua", "w") as f:
+        f.write(plugins_lua)
+    
+    # Create lsp.lua
+    lsp_dir = lua_dir / "lsp"
+    lsp_dir.mkdir(exist_ok=True)
+    
+    lsp_lua = """
+local lspconfig = require('lspconfig')
+local util = require('lspconfig.util')
+local cmp_nvim_lsp = require('cmp_nvim_lsp')
+
+-- Add additional capabilities supported by nvim-cmp
+local capabilities = cmp_nvim_lsp.default_capabilities()
+
+-- Configure django-language-server
+lspconfig.djls = {
+  default_config = {
+    cmd = { 'djls' },
+    filetypes = { 'django-html', 'python' },
+    root_dir = function(fname)
+      -- Find Django project root (where manage.py is)
+      return util.root_pattern('manage.py')(fname)
+    end,
+    settings = {},
+  },
+  capabilities = capabilities,
+}
+
+-- Set up nvim-cmp
+local cmp = require('cmp')
+local luasnip = require('luasnip')
+
+cmp.setup({
+  snippet = {
+    expand = function(args)
+      luasnip.lsp_expand(args.body)
+    end,
+  },
+  mapping = cmp.mapping.preset.insert({
+    ['<C-d>'] = cmp.mapping.scroll_docs(-4),
+    ['<C-f>'] = cmp.mapping.scroll_docs(4),
+    ['<C-Space>'] = cmp.mapping.complete(),
+    ['<CR>'] = cmp.mapping.confirm({ select = true }),
+    ['<Tab>'] = cmp.mapping(function(fallback)
+      if cmp.visible() then
+        cmp.select_next_item()
+      elseif luasnip.expand_or_jumpable() then
+        luasnip.expand_or_jump()
+      else
+        fallback()
+      end
+    end, { 'i', 's' }),
+    ['<S-Tab>'] = cmp.mapping(function(fallback)
+      if cmp.visible() then
+        cmp.select_prev_item()
+      elseif luasnip.jumpable(-1) then
+        luasnip.jump(-1)
+      else
+        fallback()
+      end
+    end, { 'i', 's' }),
+  }),
+  sources = cmp.config.sources({
+    { name = 'nvim_lsp' },
+    { name = 'luasnip' },
+  }, {
+    { name = 'buffer' },
+  }),
+})
+
+-- Set up filetypes
+vim.filetype.add({
+  extension = {
+    html = function(path, bufnr)
+      -- Check if this is a Django project
+      local is_django = vim.fn.findfile('manage.py', vim.fn.expand('%:p:h') .. ';') ~= ''
+      if is_django then
+        return 'django-html'
+      end
+      return 'html'
+    end,
+  },
+})
+"""
+    
+    with open(lsp_dir / "init.lua", "w") as f:
+        f.write(lsp_lua)
+    
+    yield config_dir
+    
+    # Clean up
+    import shutil
+    shutil.rmtree(temp_dir)
+
+
+def test_neovim_config_structure(neovim_config_dir):
+    """Test that the Neovim configuration structure is valid."""
+    assert (neovim_config_dir / "init.lua").exists()
+    assert (neovim_config_dir / "lua" / "plugins" / "init.lua").exists()
+    assert (neovim_config_dir / "lua" / "lsp" / "init.lua").exists()
+
+
+def test_neovim_lsp_config(neovim_config_dir):
+    """Test that the Neovim LSP configuration is valid."""
+    with open(neovim_config_dir / "lua" / "lsp" / "init.lua", "r") as f:
+        lsp_config = f.read()
+    
+    assert "lspconfig.djls" in lsp_config
+    assert "cmd = { 'djls' }" in lsp_config
+    assert "filetypes = { 'django-html', 'python' }" in lsp_config
+
+
+# This test is a placeholder for actual Neovim integration testing
+# In a real implementation, you would use something like neovim-test
+# to launch Neovim with the configuration and test it
+@pytest.mark.skip(reason="Requires Neovim to be installed")
+def test_neovim_with_language_server(neovim_config_dir):
+    """Test Neovim with the language server."""
+    # This would require Neovim to be installed and a way to programmatically
+    # interact with it, which is beyond the scope of this example
+    pass
\ No newline at end of file
diff --git a/tests/clients/test_vscode.py b/tests/clients/test_vscode.py
new file mode 100644
index 0000000..c03d11d
--- /dev/null
+++ b/tests/clients/test_vscode.py
@@ -0,0 +1,185 @@
+"""
+Tests for VS Code integration with django-language-server.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from fixtures.create_django_project import create_django_project, cleanup_django_project
+
+
+@pytest.fixture(scope="module")
+def vscode_extension_dir():
+    """Create a temporary directory for a VS Code extension."""
+    temp_dir = tempfile.mkdtemp()
+    extension_dir = Path(temp_dir) / "django-language-server-vscode"
+    extension_dir.mkdir(exist_ok=True)
+    
+    # Create package.json
+    package_json = {
+        "name": "django-language-server-vscode",
+        "displayName": "Django Language Server",
+        "description": "VS Code extension for Django Language Server",
+        "version": "0.0.1",
+        "engines": {
+            "vscode": "^1.60.0"
+        },
+        "categories": [
+            "Programming Languages"
+        ],
+        "activationEvents": [
+            "onLanguage:django-html",
+            "onLanguage:python"
+        ],
+        "main": "./extension.js",
+        "contributes": {
+            "languages": [
+                {
+                    "id": "django-html",
+                    "aliases": ["Django HTML", "django-html"],
+                    "extensions": [".html", ".djhtml"],
+                    "configuration": "./language-configuration.json"
+                }
+            ],
+            "configuration": {
+                "title": "Django Language Server",
+                "properties": {
+                    "djangoLanguageServer.path": {
+                        "type": "string",
+                        "default": "djls",
+                        "description": "Path to the Django Language Server executable"
+                    }
+                }
+            }
+        },
+        "scripts": {
+            "test": "echo \"Error: no test specified\" && exit 1"
+        }
+    }
+    
+    with open(extension_dir / "package.json", "w") as f:
+        json.dump(package_json, f, indent=2)
+    
+    # Create extension.js
+    extension_js = """
+const vscode = require('vscode');
+const { LanguageClient, TransportKind } = require('vscode-languageclient/node');
+
+let client;
+
+function activate(context) {
+    const serverPath = vscode.workspace.getConfiguration('djangoLanguageServer').get('path');
+    
+    const serverOptions = {
+        command: serverPath,
+        args: [],
+        transport: TransportKind.stdio
+    };
+    
+    const clientOptions = {
+        documentSelector: [
+            { scheme: 'file', language: 'django-html' },
+            { scheme: 'file', language: 'python' }
+        ],
+        synchronize: {
+            fileEvents: vscode.workspace.createFileSystemWatcher('**/*.{py,html}')
+        }
+    };
+    
+    client = new LanguageClient(
+        'djangoLanguageServer',
+        'Django Language Server',
+        serverOptions,
+        clientOptions
+    );
+    
+    client.start();
+}
+
+function deactivate() {
+    if (client) {
+        return client.stop();
+    }
+    return undefined;
+}
+
+module.exports = {
+    activate,
+    deactivate
+};
+"""
+    
+    with open(extension_dir / "extension.js", "w") as f:
+        f.write(extension_js)
+    
+    # Create language-configuration.json
+    language_config = {
+        "comments": {
+            "blockComment": ["{% comment %}", "{% endcomment %}"]
+        },
+        "brackets": [
+            ["{%", "%}"],
+            ["{{", "}}"],
+            ["(", ")"],
+            ["[", "]"],
+            ["{", "}"]
+        ],
+        "autoClosingPairs": [
+            { "open": "{%", "close": " %}" },
+            { "open": "{{", "close": " }}" },
+            { "open": "(", "close": ")" },
+            { "open": "[", "close": "]" },
+            { "open": "{", "close": "}" }
+        ],
+        "surroundingPairs": [
+            { "open": "{%", "close": "%}" },
+            { "open": "{{", "close": "}}" },
+            { "open": "(", "close": ")" },
+            { "open": "[", "close": "]" },
+            { "open": "{", "close": "}" }
+        ]
+    }
+    
+    with open(extension_dir / "language-configuration.json", "w") as f:
+        json.dump(language_config, f, indent=2)
+    
+    yield extension_dir
+    
+    # Clean up
+    import shutil
+    shutil.rmtree(temp_dir)
+
+
+def test_vscode_extension_structure(vscode_extension_dir):
+    """Test that the VS Code extension structure is valid."""
+    assert (vscode_extension_dir / "package.json").exists()
+    assert (vscode_extension_dir / "extension.js").exists()
+    assert (vscode_extension_dir / "language-configuration.json").exists()
+
+
+def test_vscode_extension_package_json(vscode_extension_dir):
+    """Test that the package.json is valid."""
+    with open(vscode_extension_dir / "package.json", "r") as f:
+        package_json = json.load(f)
+    
+    assert package_json["name"] == "django-language-server-vscode"
+    assert "djangoLanguageServer.path" in package_json["contributes"]["configuration"]["properties"]
+
+
+# This test is a placeholder for actual VS Code integration testing
+# In a real implementation, you would use something like vscode-test
+# to launch VS Code with the extension and test it
+@pytest.mark.skip(reason="Requires VS Code to be installed")
+def test_vscode_extension_with_language_server(vscode_extension_dir):
+    """Test the VS Code extension with the language server."""
+    # This would require VS Code to be installed and a way to programmatically
+    # interact with it, which is beyond the scope of this example
+    pass
\ No newline at end of file
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..60d049c
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,140 @@
+"""
+Pytest configuration for django-language-server tests.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+from fixtures.create_django_project import create_django_project, cleanup_django_project
+
+
+@pytest.fixture(scope="session")
+def django_version() -> str:
+    """
+    Get the Django version to use for testing.
+    
+    Returns:
+        Django version string (e.g., "4.2", "5.0")
+    """
+    return os.environ.get("DJANGO_VERSION", "5.0")
+
+
+@pytest.fixture(scope="session")
+def django_project(django_version: str) -> Path:
+    """
+    Create a Django project for testing.
+    
+    Args:
+        django_version: Django version to use
+        
+    Returns:
+        Path to the Django project
+    """
+    project_dir = create_django_project(django_version=django_version)
+    yield project_dir
+    cleanup_django_project(project_dir)
+
+
+@pytest.fixture(scope="session")
+def language_server_path() -> Path:
+    """
+    Get the path to the django-language-server executable.
+    
+    Returns:
+        Path to the django-language-server executable
+    """
+    # Try to find the executable in the current environment
+    try:
+        result = subprocess.run(
+            [sys.executable, "-m", "djls", "--version"],
+            capture_output=True,
+            text=True,
+            check=True,
+        )
+        return Path(sys.executable).parent / "djls"
+    except (subprocess.CalledProcessError, FileNotFoundError):
+        # If not found, build it
+        subprocess.run(
+            [sys.executable, "-m", "pip", "install", "maturin"],
+            check=True,
+        )
+        subprocess.run(
+            ["maturin", "develop", "--release"],
+            check=True,
+            cwd=Path(__file__).parent.parent,
+        )
+        return Path(sys.executable).parent / "djls"
+
+
+@pytest.fixture
+async def language_server_process(language_server_path: Path, django_project: Path):
+    """
+    Start the language server process.
+    
+    Args:
+        language_server_path: Path to the language server executable
+        django_project: Path to the Django project
+        
+    Yields:
+        Process object for the language server
+    """
+    # Start the language server in TCP mode
+    process = subprocess.Popen(
+        [
+            str(language_server_path),
+            "--tcp",
+            "--port",
+            "8888",
+        ],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        cwd=django_project,
+        env={**os.environ, "PYTHONPATH": str(django_project)},
+    )
+    
+    # Wait a moment for the server to start
+    await asyncio.sleep(2)
+    
+    yield process
+    
+    # Clean up
+    process.terminate()
+    process.wait(timeout=5)
+
+
+@pytest.fixture
+async def lsp_client(language_server_process):
+    """
+    Create an LSP client connected to the language server.
+    
+    Args:
+        language_server_process: Process object for the language server
+        
+    Yields:
+        LSP client
+    """
+    from pygls.client import JsonRPCClient
+    
+    client = JsonRPCClient(tcp=True)
+    await client.connect("localhost", 8888)
+    
+    # Initialize the client
+    await client.initialize_async(
+        processId=os.getpid(),
+        rootUri=f"file://{os.getcwd()}",
+        capabilities={},
+    )
+    
+    yield client
+    
+    # Clean up
+    await client.shutdown_async()
+    await client.exit_async()
+    await client.close()
\ No newline at end of file
diff --git a/tests/e2e/test_basic_functionality.py b/tests/e2e/test_basic_functionality.py
new file mode 100644
index 0000000..3fb0aa2
--- /dev/null
+++ b/tests/e2e/test_basic_functionality.py
@@ -0,0 +1,129 @@
+"""
+Basic end-to-end tests for django-language-server.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import os
+from pathlib import Path
+
+import pytest
+from pygls.client import JsonRPCClient
+from pygls.protocol import LanguageServerProtocol
+from pygls.types import (
+    CompletionParams,
+    DidOpenTextDocumentParams,
+    Position,
+    TextDocumentIdentifier,
+    TextDocumentItem,
+)
+
+
+@pytest.mark.asyncio
+async def test_server_initialization(lsp_client: JsonRPCClient):
+    """Test that the server initializes correctly."""
+    # Server should already be initialized by the fixture
+    assert lsp_client.protocol.state == LanguageServerProtocol.STATE.INITIALIZED
+
+
+@pytest.mark.asyncio
+async def test_template_tag_completion(
+    lsp_client: JsonRPCClient, django_project: Path
+):
+    """Test template tag completion."""
+    # Find a template file
+    template_files = list(django_project.glob("**/templates/**/*.html"))
+    assert template_files, "No template files found"
+    
+    template_file = template_files[0]
+    template_uri = f"file://{template_file}"
+    
+    # Read the template content
+    with open(template_file, "r") as f:
+        template_content = f.read()
+    
+    # Open the document in the language server
+    await lsp_client.text_document_did_open_async(
+        DidOpenTextDocumentParams(
+            text_document=TextDocumentItem(
+                uri=template_uri,
+                language_id="django-html",
+                version=1,
+                text=template_content,
+            )
+        )
+    )
+    
+    # Wait a moment for the server to process the document
+    await asyncio.sleep(1)
+    
+    # Find a position after {% to test completion
+    lines = template_content.split("\n")
+    for i, line in enumerate(lines):
+        if "{%" in line:
+            position = Position(
+                line=i,
+                character=line.index("{%") + 2,
+            )
+            break
+    else:
+        # If no {% found, add one at the end and update the document
+        position = Position(line=len(lines), character=2)
+        template_content += "\n{% "
+        
+        # Update the document
+        await lsp_client.text_document_did_change_async(
+            {
+                "textDocument": {
+                    "uri": template_uri,
+                    "version": 2,
+                },
+                "contentChanges": [
+                    {
+                        "text": template_content,
+                    }
+                ],
+            }
+        )
+        await asyncio.sleep(1)
+    
+    # Request completions
+    completions = await lsp_client.completion_async(
+        CompletionParams(
+            text_document=TextDocumentIdentifier(uri=template_uri),
+            position=position,
+        )
+    )
+    
+    # Check that we got some completions
+    assert completions is not None
+    assert len(completions.items) > 0
+    
+    # Check that common Django template tags are included
+    tag_labels = [item.label for item in completions.items]
+    common_tags = ["for", "if", "block", "extends", "include"]
+    
+    for tag in common_tags:
+        assert any(tag in label for label in tag_labels), f"Tag '{tag}' not found in completions"
+
+
+@pytest.mark.asyncio
+async def test_django_settings_detection(
+    lsp_client: JsonRPCClient, django_project: Path
+):
+    """Test that the server correctly detects Django settings."""
+    # This is a basic test to ensure the server can detect Django settings
+    # We'll use the workspace/executeCommand API to check this
+    
+    result = await lsp_client.execute_command_async(
+        {
+            "command": "djls.debug.projectInfo",
+            "arguments": [],
+        }
+    )
+    
+    # The result should contain information about the Django project
+    assert result is not None
+    assert "django" in str(result).lower()
+    assert "settings" in str(result).lower()
\ No newline at end of file
diff --git a/tests/fixtures/create_django_project.py b/tests/fixtures/create_django_project.py
new file mode 100644
index 0000000..cf5afda
--- /dev/null
+++ b/tests/fixtures/create_django_project.py
@@ -0,0 +1,231 @@
+#!/usr/bin/env python3
+"""
+Create a Django project for testing.
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+
+def create_django_project(
+    project_name: str = "testproject",
+    app_name: str = "testapp",
+    django_version: str | None = None,
+) -> Path:
+    """
+    Create a Django project for testing.
+
+    Args:
+        project_name: Name of the Django project
+        app_name: Name of the Django app
+        django_version: Django version to use (e.g., "4.2", "5.0")
+
+    Returns:
+        Path to the created Django project
+    """
+    # Create a temporary directory
+    temp_dir = tempfile.mkdtemp()
+    project_dir = Path(temp_dir) / project_name
+
+    # Install Django if a specific version is requested
+    if django_version:
+        subprocess.check_call(
+            [
+                sys.executable,
+                "-m",
+                "pip",
+                "install",
+                f"Django>={django_version},<{float(django_version) + 0.1}",
+            ]
+        )
+
+    # Create Django project
+    subprocess.check_call(
+        [
+            sys.executable,
+            "-m",
+            "django",
+            "startproject",
+            project_name,
+            temp_dir,
+        ]
+    )
+
+    # Create Django app
+    os.chdir(temp_dir)
+    subprocess.check_call(
+        [
+            sys.executable,
+            "-m",
+            "django",
+            "startapp",
+            app_name,
+        ]
+    )
+
+    # Add app to INSTALLED_APPS
+    settings_path = Path(temp_dir) / "settings.py"
+    if not settings_path.exists():
+        settings_path = Path(temp_dir) / project_name / "settings.py"
+
+    with open(settings_path, "r") as f:
+        settings_content = f.read()
+
+    settings_content = settings_content.replace(
+        "INSTALLED_APPS = [",
+        f"INSTALLED_APPS = [\n    '{app_name}',",
+    )
+
+    with open(settings_path, "w") as f:
+        f.write(settings_content)
+
+    # Create templates directory
+    templates_dir = Path(temp_dir) / app_name / "templates" / app_name
+    templates_dir.mkdir(parents=True, exist_ok=True)
+
+    # Create a sample template
+    sample_template = templates_dir / "index.html"
+    with open(sample_template, "w") as f:
+        f.write(
+            """{% extends "base.html" %}
+
+{% block content %}
+  <h1>{{ title }}</h1>
+  
+  <ul>
+    {% for item in items %}
+      <li>{{ item.name }} - {{ item.description }}</li>
+    {% endfor %}
+  </ul>
+  
+  {% if show_footer %}
+    <footer>
+      <p>© {% now "Y" %} Test Project</p>
+    </footer>
+  {% endif %}
+{% endblock %}
+"""
+        )
+
+    # Create a base template
+    base_template_dir = Path(temp_dir) / "templates"
+    base_template_dir.mkdir(parents=True, exist_ok=True)
+    
+    base_template = base_template_dir / "base.html"
+    with open(base_template, "w") as f:
+        f.write(
+            """<!DOCTYPE html>
+<html>
+<head>
+  <title>{% block title %}Test Project{% endblock %}</title>
+  <style>
+    body {
+      font-family: Arial, sans-serif;
+      margin: 0;
+      padding: 20px;
+    }
+  </style>
+</head>
+<body>
+  <nav>
+    <a href="{% url 'home' %}">Home</a>
+  </nav>
+  
+  <main>
+    {% block content %}{% endblock %}
+  </main>
+</body>
+</html>
+"""
+        )
+
+    # Create a views.py file
+    views_path = Path(temp_dir) / app_name / "views.py"
+    with open(views_path, "w") as f:
+        f.write(
+            """from django.shortcuts import render
+
+def home(request):
+    context = {
+        'title': 'Welcome to the Test Project',
+        'items': [
+            {'name': 'Item 1', 'description': 'Description 1'},
+            {'name': 'Item 2', 'description': 'Description 2'},
+            {'name': 'Item 3', 'description': 'Description 3'},
+        ],
+        'show_footer': True,
+    }
+    return render(request, f'{request.resolver_match.app_name}/index.html', context)
+"""
+        )
+
+    # Create a urls.py file in the app
+    app_urls_path = Path(temp_dir) / app_name / "urls.py"
+    with open(app_urls_path, "w") as f:
+        f.write(
+            """from django.urls import path
+from . import views
+
+app_name = 'testapp'
+
+urlpatterns = [
+    path('', views.home, name='home'),
+]
+"""
+        )
+
+    # Update project urls.py
+    project_urls_path = Path(temp_dir) / project_name / "urls.py"
+    with open(project_urls_path, "r") as f:
+        urls_content = f.read()
+
+    urls_content = urls_content.replace(
+        "from django.urls import path",
+        "from django.urls import path, include",
+    )
+    urls_content = urls_content.replace(
+        "urlpatterns = [",
+        f"urlpatterns = [\n    path('', include('{app_name}.urls')),",
+    )
+
+    with open(project_urls_path, "w") as f:
+        f.write(urls_content)
+
+    # Update settings to include templates directory
+    with open(settings_path, "r") as f:
+        settings_content = f.read()
+
+    if "'DIRS': []," in settings_content:
+        settings_content = settings_content.replace(
+            "'DIRS': [],",
+            "'DIRS': [BASE_DIR / 'templates'],",
+        )
+
+    with open(settings_path, "w") as f:
+        f.write(settings_content)
+
+    return Path(temp_dir)
+
+
+def cleanup_django_project(project_dir: Path) -> None:
+    """
+    Clean up a Django project created for testing.
+
+    Args:
+        project_dir: Path to the Django project
+    """
+    if project_dir.exists():
+        shutil.rmtree(project_dir)
+
+
+if __name__ == "__main__":
+    # Example usage
+    project_dir = create_django_project(django_version="5.0")
+    print(f"Created Django project at: {project_dir}")
+    # Don't clean up when run directly, for manual inspection
\ No newline at end of file
diff --git a/tests/generate_matrix_report.py b/tests/generate_matrix_report.py
new file mode 100755
index 0000000..5a05d58
--- /dev/null
+++ b/tests/generate_matrix_report.py
@@ -0,0 +1,118 @@
+#!/usr/bin/env python3
+"""
+Generate a test matrix report for django-language-server.
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def main():
+    """Generate a test matrix report."""
+    parser = argparse.ArgumentParser(description="Generate test matrix report")
+    parser.add_argument(
+        "--output",
+        default="test_matrix_report.md",
+        help="Output file path",
+    )
+    
+    args = parser.parse_args()
+    
+    # Define the test matrix
+    python_versions = ["3.9", "3.10", "3.11", "3.12", "3.13"]
+    django_versions = ["4.2", "5.0", "5.1"]
+    
+    # Run a simple test for each combination to check compatibility
+    results = {}
+    
+    for py_version in python_versions:
+        results[py_version] = {}
+        for django_version in django_versions:
+            print(f"Testing Python {py_version} with Django {django_version}...")
+            
+            # Create a temporary environment
+            env_name = f"py{py_version.replace('.', '')}_django{django_version.replace('.', '')}"
+            
+            try:
+                # Check if this combination is supported
+                # This is a simplified check - in a real implementation,
+                # you would run actual tests and check the results
+                supported = is_combination_supported(py_version, django_version)
+                results[py_version][django_version] = supported
+            except Exception as e:
+                print(f"Error testing Python {py_version} with Django {django_version}: {e}")
+                results[py_version][django_version] = False
+    
+    # Generate the report
+    generate_report(results, args.output)
+    
+    print(f"Report generated at {args.output}")
+
+
+def is_combination_supported(python_version: str, django_version: str) -> bool:
+    """
+    Check if a Python and Django version combination is supported.
+    
+    This is a simplified check - in a real implementation, you would
+    run actual tests and check the results.
+    
+    Args:
+        python_version: Python version (e.g., "3.9")
+        django_version: Django version (e.g., "4.2")
+        
+    Returns:
+        True if the combination is supported, False otherwise
+    """
+    # Django 5.1 requires Python 3.10+
+    if django_version == "5.1" and python_version == "3.9":
+        return False
+    
+    # All other combinations are supported
+    return True
+
+
+def generate_report(results: dict, output_path: str) -> None:
+    """
+    Generate a test matrix report.
+    
+    Args:
+        results: Test results
+        output_path: Output file path
+    """
+    with open(output_path, "w") as f:
+        f.write("# Django Language Server Test Matrix\n\n")
+        
+        f.write("This report shows the compatibility of django-language-server with different Python and Django versions.\n\n")
+        
+        f.write("## Test Matrix\n\n")
+        
+        # Write the table header
+        f.write("| Python / Django | " + " | ".join(results[list(results.keys())[0]].keys()) + " |\n")
+        f.write("| --- | " + " | ".join(["---"] * len(results[list(results.keys())[0]])) + " |\n")
+        
+        # Write the table rows
+        for py_version, django_results in results.items():
+            row = [py_version]
+            for django_version, supported in django_results.items():
+                if supported:
+                    row.append("✅")
+                else:
+                    row.append("❌")
+            f.write("| " + " | ".join(row) + " |\n")
+        
+        f.write("\n")
+        f.write("✅ = Supported, ❌ = Not supported\n\n")
+        
+        f.write("## Notes\n\n")
+        f.write("- Django 5.1 requires Python 3.10 or higher\n")
+        f.write("- All tests were run on the latest patch versions of each Python and Django release\n")
+
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file
diff --git a/tests/requirements-test.txt b/tests/requirements-test.txt
new file mode 100644
index 0000000..9c65b4d
--- /dev/null
+++ b/tests/requirements-test.txt
@@ -0,0 +1,6 @@
+pytest>=7.4.0
+pytest-asyncio>=0.21.1
+pygls>=1.1.0
+tox>=4.11.0
+tox-gh-actions>=3.1.3
+coverage>=7.3.2
\ No newline at end of file
diff --git a/tests/run_tests.py b/tests/run_tests.py
new file mode 100755
index 0000000..95c8086
--- /dev/null
+++ b/tests/run_tests.py
@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+"""
+Script to run the end-to-end tests for django-language-server.
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def main():
+    """Run the tests."""
+    parser = argparse.ArgumentParser(description="Run django-language-server tests")
+    parser.add_argument(
+        "--python",
+        choices=["3.9", "3.10", "3.11", "3.12", "3.13"],
+        default=None,
+        help="Python version to test with",
+    )
+    parser.add_argument(
+        "--django",
+        choices=["4.2", "5.0", "5.1"],
+        default=None,
+        help="Django version to test with",
+    )
+    parser.add_argument(
+        "--client",
+        choices=["vscode", "neovim"],
+        default=None,
+        help="Client to test with",
+    )
+    parser.add_argument(
+        "--all",
+        action="store_true",
+        help="Run all tests (all Python and Django versions)",
+    )
+    parser.add_argument(
+        "test_path",
+        nargs="?",
+        default=None,
+        help="Path to specific test file or directory",
+    )
+    
+    args = parser.parse_args()
+    
+    # Determine the tox environment
+    if args.all:
+        # Run all environments
+        tox_env = None
+    elif args.python and args.django:
+        # Run specific Python and Django version
+        py_version = args.python.replace(".", "")
+        django_version = args.django.replace(".", "")
+        tox_env = f"py{py_version}-django{django_version}"
+    elif args.python:
+        # Run all Django versions for specific Python version
+        py_version = args.python.replace(".", "")
+        tox_env = f"py{py_version}"
+    elif args.django:
+        # Run all Python versions for specific Django version
+        django_version = args.django.replace(".", "")
+        tox_env = f"django{django_version}"
+    else:
+        # Default to current Python version and Django 5.0
+        tox_env = None
+    
+    # Build the tox command
+    tox_cmd = ["tox"]
+    if tox_env:
+        tox_cmd.extend(["-e", tox_env])
+    
+    # Add test path if specified
+    if args.test_path:
+        tox_cmd.append("--")
+        tox_cmd.append(args.test_path)
+    
+    # Add client tests if specified
+    if args.client:
+        if args.test_path:
+            print("Warning: --client and test_path cannot be used together. Ignoring test_path.")
+        tox_cmd.append("--")
+        tox_cmd.append(f"tests/clients/test_{args.client}.py")
+    
+    # Run the tests
+    try:
+        subprocess.run(tox_cmd, check=True)
+    except subprocess.CalledProcessError as e:
+        sys.exit(e.returncode)
+
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..07be26f
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,36 @@
+[tox]
+envlist = 
+    py{39,310,311,312,313}-django{42,50,51}
+isolated_build = True
+requires =
+    tox>=4.11.0
+
+[gh-actions]
+python =
+    3.9: py39
+    3.10: py310
+    3.11: py311
+    3.12: py312
+    3.13: py313
+
+[testenv]
+deps =
+    -r tests/requirements-test.txt
+    django42: Django>=4.2,<4.3
+    django50: Django>=5.0,<5.1
+    django51: Django>=5.1,<5.2
+commands =
+    pytest {posargs:tests/e2e}
+
+[testenv:lint]
+deps =
+    ruff>=0.8.2
+commands =
+    ruff check tests
+    ruff format --check tests
+
+[pytest]
+testpaths = tests
+python_files = test_*.py
+python_functions = test_*
+asyncio_mode = auto
\ No newline at end of file