Local LLM Coding Agent: Aider + Ollama on Windows (No Cloud, No Token Limit, Full Privacy)

I just tried running Aider + Ollama locally on Windows (with Intel GPU) and it is promising! It edits files directly in my repo, auto-commits changes, handles multi-file refactors, adds features, fixes bugs, generates tests... basically anything I need in my .NET codebase.

Zero cloud dependency. Unlimited context. 100% private. $0 ongoing cost.

Here's the streamlined setup that got me productive fast. I used it to create unit tests.

1. (One-time) Prepare your xUnit test project (if using for tests)

dotnet new xunit -o YourProject.Tests
cd YourProject.Tests
dotnet add package Moq --version 4.20.70
dotnet add package Microsoft.AspNetCore.Mvc.Testing --version 8.0.0 # optional, great for API
dotnet add reference ../YourProject
dotnet sln add YourProject.Tests
dotnet restore

2. Install Aider

python -m pip install --user aider-install
aider-install

Windows: Add to User PATH (System → Environment Variables):

C:\Users\YourUsername\AppData\Roaming\Python\Python313\Scripts
C:\Users\YourUsername\.local\bin

Restart terminals / VS Code.

3. Grab a strong coding model small enough to run on your GPU

ollama pull qwen2.5-coder:14b

The coder variant excels at precise C# syntax, reasoning, and agent-like editing. Around 15s responses on decent hardware, perfect balance.

4. Launch Aider with your files (from solution root)

For auto-testing + fixing (great for unit tests):

aider ^
  "C:\Repo\YourProject\Api\Services\AuthorizationService.cs" ^
  "C:\Repo\YourProject\Api.Tests\Services\AuthorizationServiceTests.cs" ^
  --model ollama/qwen2.5-coder:14b ^
  --test-cmd "dotnet test YourProject.Tests" ^
  --auto-test

Or just for general coding (no auto-test):

aider --model ollama/qwen2.5-coder:14b "C:\Full\Path\To\YourFile.cs"

Windows tips

Full absolute paths in quotes (spaces break things)
Use ^ for line continuation in cmd/PowerShell

What you can do with it (beyond tests!)

/add File1.cs File2.cs → give context

Prompt examples:

"Refactor AuthorizationService to use proper DI and remove statics"
"Add a new endpoint for password reset with validation and email"
"Fix the null ref bug in this method, here's the stack trace"
"Generate CRUD controller for Product entity + repository pattern"

Aider edits files, shows diffs, commits to Git (with messages), and iterates automatically if you use --auto-test or ask it to fix failures.

The real wins

No API keys / data ever leaves your machine
Unlimited context, throw your whole repo at it
Works offline, no subscriptions
Auto-commits keep history clean
Feels like a real pair programmer for .NET/C# work

BTW I used IPEX-LLM Ollama for my Intel GPU.

Quick Update: Claude Code runs locally via latest Ollama (free/offline). Same models as Aider. Launch: ollama launch claude --model qwen2.5-coder:14b

Co-authored with Claude.

If this was useful, you can buy me a coffee.

New articles: follow via RSS.

Local LLM Coding Agent: Aider + Ollama on Windows (No Cloud, No Token Limit, Full Privacy)

Comments