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jordan macias
jordan macias

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Build Your Own AI Code Assistant: LocalLLM + Python Automation

Build Your Own AI Code Assistant: LocalLLM + Python Automation

Cloud-based AI code assistants are convenient, but they come with trade-offs. Your code snippets get sent to external servers, your usage patterns are tracked, and you're subject to rate limits and subscription fees. What if you could run a capable AI assistant locally on your machine, integrated directly into your development workflow?

In this tutorial, we'll build a privacy-first AI code assistant that runs entirely on your machine. You'll learn how to set up a local language model, wrap it with Python automation, and integrate it into your development environment. By the end, you'll have a tool that understands your codebase context and generates suggestions without ever leaving your machine.

Why Local LLMs Matter for Developers

Before diving into code, let's discuss why this matters. Local LLMs give you:

  • Privacy: Your code never leaves your machine. No cloud logging, no data retention policies to worry about.
  • Cost: Zero per-request fees. Run inference as much as you want.
  • Customization: Fine-tune models on your specific codebase or domain.
  • Offline capability: Work without internet connectivity.
  • Latency control: No network round-trips; responses are instantaneous.
  • Integration freedom: Direct programmatic access without API rate limits.

The trade-off? You need adequate hardware (GPU recommended but not required) and accept slightly lower performance compared to cutting-edge cloud models.

What You'll Need

  • Python 3.9+
  • 8GB+ RAM (16GB recommended)
  • GPU with 6GB+ VRAM (optional but significantly faster)
  • Ollama or LM Studio for running local models
  • About 30 minutes to set everything up

Step 1: Install and Run a Local LLM

We'll use Ollama because it's the most developer-friendly option for running local models. It handles model downloads, optimization, and provides a simple API.

Installing Ollama

Head to ollama.ai and download the installer for your OS. Installation is straightforward—it creates a background service that manages models for you.

Once installed, open a terminal and pull a model. For code tasks, I recommend starting with mistral or neural-chat, which are fast and capable:

ollama pull mistral
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This downloads the model (about 4GB for Mistral). You can also try smaller models like orca-mini (1.3GB) if space is constrained:

ollama pull orca-mini
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Test that it's working:

ollama run mistral "Write a Python function that reverses a string"
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You should see a response generated locally. Ollama runs on localhost:11434 by default.

Step 2: Create Your Python Wrapper

Now let's build a Python module that communicates with Ollama. This abstraction layer makes it easy to swap models or add features later.

First, install the required dependency:

pip install requests
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Create a file called local_assistant.py:


python
import requests
import json
from typing import Optional
import os

class LocalCodeAssistant:
    """
    A privacy-first code assistant powered by local LLMs.
    Runs entirely on your machine without external API calls.
    """

    def __init__(
        self,
        model: str = "mistral",
        base_url: str = "http://localhost:11434",
        temperature: float = 0.7,
        context_window: int = 4096
    ):
        """
        Initialize the local code assistant.

        Args:
            model: Name of the Ollama model to use
            base_url: URL where Ollama is running
            temperature: Creativity level (0.0-1.0)
            context_window: Maximum tokens to consider
        """
        self.model = model
        self.base_url = base_url
        self.temperature = temperature
        self.context_window = context_window
        self.conversation_history = []

        # Verify connection
        if not self._check_connection():
            raise ConnectionError(
                f"Cannot connect to Ollama at {base_url}. "
                "Make sure Ollama is running: `ollama serve`"
            )

    def _check_connection(self) -> bool:
        """Verify Ollama is accessible."""
        try:
            response = requests.get(f"{self.base_url}/api/tags", timeout=2)
            return response.status_code == 200
        except requests.exceptions.RequestException:
            return False

    def _build_prompt(
        self,
        user_query: str,
        context: Optional[str] = None,
        system_prompt: Optional[str] = None
    ) -> str:
        """
        Build a structured prompt with optional context.

        Args:
            user_query: The user's actual question
            context: Additional code or context (e.g., current file)
            system_prompt: Custom system instructions

        Returns:
            Formatted prompt string
        """
        if system_prompt is None:
            system_prompt = (
                "You are an expert code assistant. Provide concise, "
                "practical solutions. Include code examples when relevant. "
                "Explain your reasoning briefly."
            )

        prompt_parts = [system_prompt]

        if context:
            prompt_parts.append(f"\n## Context:\n{context}")

        prompt_parts.append(f"\n## Question:\n{user_query}")

        return "\n".join(prompt_parts)

    def generate(
        self,
        prompt: str,
        context: Optional[str] = None,
        system_prompt: Optional[str] = None,
        stream: bool = False
    ) -> str:
        """
        Generate a response from the local LLM.

        Args:
            prompt: The main prompt/question
            context: Optional code context
            system_prompt: Optional custom system instructions
            stream: If True, yield tokens as they arrive

        Returns:
            Generated response or generator if stream=True
        """
        full_prompt = self._build_prompt(prompt, context, system_prompt)

        payload = {
            "model": self.model,
            "prompt": full_prompt,
            "stream": stream,
            "temperature": self.temperature,
            "num_ctx": self.context_window
        }

        try:
            response = requests.post(
                f"{self.base_url}/api/generate",
                json=payload,
                timeout=300
            )
            response.raise_for_status()

            if stream:
                return self._stream_response(response)
            else:
                return self._parse_response(response)

        except requests.exceptions.RequestException as e:
            return f"Error communicating with Ollama: {str(e)}"

    def _parse_response(self, response: requests.Response) -> str:
        """Extract text from non-streaming response."""
        full_text = ""
        for line in response.iter_lines():
            if line:
                data = json.loads(line)
                full_text += data.get("response", "")
        return full_text

    def _stream_response(self, response: requests.Response):
        """Yield tokens from streaming response."""
        for line in response.iter_lines():
            if line:
                data = json.loads(line)
                yield data.get("response", "")

    def explain_code(self, code: str) -> str:
        """Explain what a code snippet does."""
        prompt = "Explain this code concisely, focusing on what it does and why:"
        return self.generate(prompt, context=code)

    def suggest_improvements(self, code: str) -> str:
        """Suggest improvements to a code snippet."""
        prompt = (
            "Review this code and suggest improvements for readability, "
            "performance, or best practices. Be specific."
        )
        return self.generate(prompt, context=code)

    def generate_tests(self, code: str, language: str = "python") -> str:
        """Generate unit tests for a code snippet."""
        prompt =

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