# How to Start Using Aider

> Install Aider, point it at Claude or GPT with an API key, make your first edit, and control its git auto-commits. Copy-paste.

- Canonical: https://guides-ai.pages.dev/guides/aider-first-steps/
- Plate 14.02 · Topic: Other coding agents (https://guides-ai.pages.dev/topics/agents/)
- Published: 06 Sept 2026 · 3 min read
- Source site: guides-ai — https://guides-ai.pages.dev/

Aider is a terminal coding agent that works directly on a git repo. Its defining habit: it
commits every edit it makes, so every change is reviewable and reversible.

## 1. Install it

The recommended install, on any OS:

```bash
python -m pip install aider-install
aider-install
```

There are also one-line installers. macOS and Linux:

```bash
curl -LsSf https://aider.chat/install.sh | sh
```

Windows (PowerShell):

```powershell
powershell -ExecutionPolicy ByPass -c "irm https://aider.chat/install.ps1 | iex"
```

## 2. Launch it with a model

Aider is model-agnostic — you pick the model and supply the key:

```bash
aider --model sonnet --api-key anthropic=<key>
```

```bash
aider --model o3-mini --api-key openai=<key>
```

Run this from inside your repo. If the directory isn't a git repo, Aider asks to create one.
You can also keep keys out of your shell history by configuring them in your environment or
config file instead of `--api-key` — run `aider --help` for the exact names your version
accepts.

## 3. Make your first edit

Describe the change in plain English, one job at a time:

```text
Add input validation to parse_config() and raise a clear error for a missing "port" key.
```

Aider finds the relevant code, edits the files, and shows you what it did. Type `/help` inside
the session to see the in-chat commands your version supports.

## 4. The git part

Whenever Aider edits a file, it commits those changes with a descriptive commit message. That
means:

- **Don't like a change?** `/undo` discards the last one.
- **Want to keep control of history?** Start it with `--no-auto-commits`:

```bash
aider --no-auto-commits --model sonnet --api-key anthropic=<key>
```

Auto-commits are the safety net that makes an agent editing your files tolerable — leave them
on until you have a reason not to.

---

Next: [Codex CLI first steps](/guides/codex-cli-first-steps/) or
[giving a coding agent the right context](/guides/ai-coding-agent-context/).