Models and API keys
Aider needs to know which LLM model you would like to work with and which keys to provide when accessing it via API.
Defaults
If you don’t explicitly name a model, aider will try to select a model for you to work with.
First, aider will check which keys you have provided via the environment, config files, or command line arguments. Based on the available keys, aider will select the best model to use.
If you have not provided any keys, aider will offer to help you connect to OpenRouter which provides both free and paid access to most popular LLMs. Once connected, aider will select the best model available on OpenRouter based on whether you have a free or paid account there.
Specifying model & key
You can also tell aider which LLM to use and provide an API key.
The easiest way is to use the --model and --api-key
command line arguments, like this:
# Work with DeepSeek via DeepSeek's API
aider --model deepseek --api-key deepseek=your-key-goes-here
# Work with Claude 3.7 Sonnet via Anthropic's API
aider --model sonnet --api-key anthropic=your-key-goes-here
# Work with o3-mini via OpenAI's API
aider --model o3-mini --api-key openai=your-key-goes-here
# Work with Sonnet via OpenRouter's API
aider --model openrouter/anthropic/claude-3.7-sonnet --api-key openrouter=your-key-goes-here
# Work with DeepSeek Chat V3 via OpenRouter's API
aider --model openrouter/deepseek/deepseek-chat --api-key openrouter=your-key-goes-here
For more information, see the documentation sections: