# Local AI Coding Setup — Windows 11 (Aider + Ollama)

## Hardware
- GPU: RTX 5070 Ti, 12GB VRAM
- RAM: 32GB
- OS: Windows 11

---

## Prerequisites

### 1. Install Ollama
Download from https://ollama.com and install.

### 2. Pull a model
```powershell
ollama pull qwen3-coder:30b   # 18GB, strong coding model (MoE, VRAM+RAM split)
ollama pull gemma4:12b        # 12GB, responds in English more reliably
```

Confirm models are available:
```powershell
ollama list
```

Confirm Ollama is serving:
```powershell
curl http://localhost:11434/api/tags
```

---

## Install Aider

```powershell
pip install aider-chat
aider --version   # should print version number
```

---

## Project Config

Create `.aider.conf.yml` in your project root:

```yaml
model: ollama/gemma4:12b
openai-api-base: http://localhost:11434/v1
openai-api-key: ollama
edit-format: whole
map-tokens: 2048
no-auto-commits: true
system-prompt: "Always respond in English only. Never use Chinese or any other language."
```

**Config notes:**
- `edit-format: whole` — more reliable file writes for local models (avoids code showing in chat only)
- `map-tokens: 2048` — limits repo map size, important for smaller context windows
- `no-auto-commits: true` — review changes before they hit git
- `system-prompt` — forces English responses (important for Qwen3 which defaults to Chinese)

Switch models without editing the file:
```
/model ollama/qwen3-coder:30b
```

---

## Optional: Performance Tuning (if inference is slow)

Create a `Modelfile` in the project root:

```
FROM qwen3-coder:30b
PARAMETER num_ctx 8192
PARAMETER num_gpu 99
```

Register it:
```powershell
ollama create qwen3-coder-tuned -f Modelfile
```

Update `.aider.conf.yml`:
```yaml
model: ollama/qwen3-coder-tuned
```

**Why:** `num_gpu 99` maximizes VRAM usage. `num_ctx 8192` prevents the KV cache from
spilling too much into RAM. Recommended context range: 4096–16384.

---

## Daily Aider Workflow

Start Aider (reads config automatically):
```powershell
aider
```

| Command | What it does |
|---------|-------------|
| `/add src/foo.py` | Add file to context |
| `/drop src/foo.py` | Remove file from context |
| `/diff` | See pending changes |
| `/undo` | Revert last change |
| `/run pytest` | Run command, share output with model |
| `/run git rm --cached file.py` | Run git commands from inside Aider |
| `/clear` | Clear chat history (keep files) |
| `/settings` | Show loaded config (verify auto_commits, system_prompt) |
| `/model ollama/gemma4:12b` | Switch model on the fly |
| `/exit` | Quit |

---

## Known Issues & Fixes

### Model responds in Chinese
Cause: Qwen3 is a Chinese model and defaults to Chinese.
Fix: `system-prompt` in `.aider.conf.yml` (already included above). Restart Aider after config change.

### Aider shows code in chat but doesn't write files
Cause: Model didn't follow Aider's edit format.
Fix 1: `/add target_file.py` before asking — hints the target file to the model.
Fix 2: `edit-format: whole` in config (already included above).

### "File not found" / repo-map warnings for deleted files
Cause: File deleted from disk but still tracked in git index.
Fix:
```powershell
git rm --cached filename.py
```
Or from inside Aider:
```
/run git rm --cached filename.py
```

### Config changes not taking effect
Fix: Exit Aider (`/exit`) and restart. Config is only read at startup.

---

## Verify Everything Works

1. `ollama list` — model appears
2. `aider --version` — prints version
3. Start Aider, run `/settings` — confirm `auto_commits: False` and `system_prompt` present
4. Ask Aider to create a simple file — it should write to disk, not just chat
5. Response is in English