$devvkit learn --librarie aider-guide

Aider Guide

[ai][coding][pair-programming][git]

AI / LLM Tools

Install

pip install aider-chat
# or: uv tool install aider-chat
# Set API key:
export ANTHROPIC_API_KEY=sk-ant-...
export OPENAI_API_KEY=sk-...

Aider is an AI coding assistant that runs in your terminal. Unlike generic chat UIs, Aider understands your git repo: it reads files context, suggests changes, and applies them directly to your code with proper git commits. It's like having a senior dev who never gets tired.

Aider supports multiple LLM backends: Claude 3.5 Sonnet (best for coding), GPT-4o, DeepSeek Coder, and local models via Ollama. It auto-commits before each change so you can always `git diff HEAD~1` or undo with `git reset`.

The `/add` command tells Aider which files to consider. The `/read-only` command adds files for context without allowing edits. Use `--model` to switch backends. Aider's "architect" mode has one model plan and another implement. GUI: Continue.dev (VS Code), Cursor (IDE) for editor-integrated AI.

Setup

Start chat· Launch aided coding session.

aider --model claude-sonnet-4-20250514
# Or set env:
export ANTHROPIC_API_KEY=sk-ant-...
aider --model claude-sonnet-4-20250514

# With GPT-4o:
export OPENAI_API_KEY=sk-...
aider --model gpt-4o

Basic Chat

Ask and edit· Request a code change.

# Aider will:
# 1. Read the added files
# 2. Edit them with your changes
# 3. Git commit with a descriptive message

# Example prompts:
"Add error handling to the file upload function"
"Refactor this into a class with type hints"
"Add unit tests for the UserService"
"Fix the off-by-one bug in the pagination"

File Management

Add files for editing· Tell Aider which files to edit.

# In chat:
/add src/main.py
/add src/utils/*.py
# Make files read-only (context only):
/read-only src/config.py

# Or from CLI launch:
aider src/main.py src/utils/*.py

Git Integration

Undo last change· Roll back AI edit.

/undo         # Undo the last AI change
/git diff     # See what changed
/git commit -m "fix: actually fix it"
/git diff HEAD~1  # Review last commit

# Aider auto-commits every change with:
# "aider: <description of change>"

Git workflows· Integration commands.

/commit      # Commit any uncommitted changes
/diff        # Show diff of pending changes
/run pytest  # Run tests and show results

# Aider uses the repo's git history to
# understand context and make better edits

Models

Use local models· Ollama with Aider.

aider --model ollama/llama3.2 \
  --ollama-base-url http://localhost:11434

# Best local coding models:
aider --model ollama/qwen2.5-coder:7b
# or:
aider --model ollama/deepseek-coder:6.7b

# For weaker models, add --weak-model flag

Tricks

Architect mode· Plan + implement split.

aider --model claude-sonnet-4-20250514 \
  --editor-model gpt-4o
# One model plans (architect)
# Another implements (editor)

# Or use Aider with --architect flag:
aider --architect --model claude-sonnet-4-20250514

Voice input· Speak your prompts.

aider --voice              # Uses microphone
# Requires: python -m pip install pyaudio
# Speaks: "Add a function to calculate fibonacci"
# Aider hears, transcribes, and implements

Lint & fix· Auto-fix lint errors.

aider --lint              # Lint repo and fix issues
# Or during session:
/lint                     # Lint current files

aider --test              # Run tests and fix failures
aider --test-cmd "npm test"  # Custom test command