Aider AI Pair Programming

This skill helps you configure and use Aider, an AI pair programming tool that works directly with your codebase through the command line.

What This Skill Does

Aider is a command-line AI coding assistant that:

Configuration

Aider can be configured via a `.aider.conf.yml` file placed in your home directory or git repository root.

Essential Configuration Steps

1. **Choose Your LLM Model**

- Set the `model` field to specify which AI model to use

- Common options: `gpt-4o`, `claude-3-5-sonnet-20240620`, `vertex_ai/gemini-2.5-flash`

- Use `weak-model` for cheaper operations like commit messages

2. **Configure API Keys**

- OpenAI keys: set `openai-api-key` in config or `OPENAI_API_KEY` in `.env`

- Anthropic keys: set `anthropic-api-key` in config or `ANTHROPIC_API_KEY` in `.env`

- Other providers: use `.env` file (see Aider documentation)

3. **Set File Access**

- `file`: List of files to edit (Aider can modify these)

- `read`: List of read-only files for context (rules, docs, plans)

4. **Git Integration**

- `auto-commits: false` - Disable automatic commits if you want manual control

- `dirty-commits: true` - Allow commits even if repo has uncommitted changes

- `gitignore: true` - Automatically add `.aider*` files to `.gitignore`

5. **Performance Optimization**

- `cache-prompts: true` - Enable prompt caching to reduce costs

- `map-tokens: 1024` - Control repo map size (set to 0 to disable)

- `stream: true` - Enable streaming responses for faster feedback

6. **Code Quality**

- `lint-cmd` - Specify linting commands per language

- `auto-lint: true` - Automatically lint after changes

- `test-cmd` - Command to run your test suite

- `auto-test: false` - Set to true to run tests automatically

Usage Instructions

Step 1: Create Configuration File

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

```yaml

model: gpt-4o

cache-prompts: true

auto-commits: false

auto-lint: true

file: [

# Files you want Aider to edit

]

read: [

# Read-only files for context

"README.md",

"docs/architecture.md"

]

```

Step 2: Set API Keys

Create `.env` file in your repository root:

```bash

OPENAI_API_KEY=your-key-here

or

ANTHROPIC_API_KEY=your-key-here

```

Step 3: Start Aider

```bash

Launch with default config

aider

Launch with specific files

aider src/main.py tests/test_main.py

Launch with message and exit

aider --message "Add error handling to the login function"

```

Step 4: Work with Aider

**In interactive mode:**

**Common workflows:**

Step 5: Advanced Features

**Linting Integration:**

```yaml

lint-cmd:

python: "flake8 --select=E,W,F"

javascript: "eslint --fix"

auto-lint: true

```

**Testing Integration:**

```yaml

test-cmd: "pytest tests/"

auto-test: true

```

**Custom Edit Formats:**

```yaml

edit-format: diff # or whole, udiff, editor-diff

```

**Repo Mapping:**

```yaml

map-tokens: 2048 # Increase for larger context

map-refresh: always # or auto, files, manual

```

Examples

**Example 1: Quick fix with auto-commit**

```bash

aider --message "Fix the SQL injection vulnerability in user_search()" --commit

```

**Example 2: Interactive feature development**

```bash

aider src/api/routes.py src/api/handlers.py

Then in chat: "Add rate limiting to all API endpoints"

```

**Example 3: Test-driven development**

```yaml

.aider.conf.yml

test-cmd: "pytest tests/ -v"

auto-test: true

lint-cmd:

python: "black . && flake8"

auto-lint: true

```

**Example 4: Context-aware refactoring**

```bash

aider --read docs/architecture.md --read docs/style-guide.md src/legacy/

Then: "Refactor this code to match our current architecture patterns"

```

Important Notes

Constraints