Aider — A free, open-source terminal AI pair programmer that edits your codebase directly and auto-commits to git, using your own LLM API keys.

What is Aider?

Aider is a command-line AI pair-programming tool: it runs in a terminal inside a project's git repository, and a developer describes changes in plain language while Aider edits the relevant files directly and commits the result. It is model-agnostic, working with Anthropic's Claude, OpenAI's GPT models, DeepSeek, and local models run through Ollama or similar, so users are not locked into one AI vendor. A distinguishing design choice is Aider's repository map: rather than sending an entire codebase to the LLM, Aider analyzes the project's structure and sends a condensed map plus the most relevant files, which keeps token costs down on large codebases and lets the model reason about code it hasn't seen in full. Every accepted edit is committed to git automatically, so changes are inherently versioned and easy to roll back, and Aider can also accept images or web pages as additional context and take voice input for hands-free coding. Because Aider is Apache-2.0 licensed and free of any subscription fee, the only ongoing cost is API usage billed by whichever LLM provider a user configures, which can range from near-free with cheap models to significant spend with frontier models on large codebases.

Aider is an open-source, terminal-based AI coding assistant, released under the Apache-2.0 license, that pairs with large language models like Claude and GPT to write and edit code directly in an existing repository. It has no subscription cost of its own: users bring their own API keys for Anthropic, OpenAI, DeepSeek, or local models, so total cost depends entirely on token usage with the chosen provider. Aider builds a map of the codebase to give the LLM context on large projects, supports over 100 programming languages, and automatically creates git commits for each change so edits stay reviewable and revertible. The GitHub repository has 48.4k stars, and Aider reports 6.8 million weekly installs and roughly 15 billion tokens processed weekly across its user base, making it one of the most widely used open-source AI coding CLIs.

Standout feature: Model-agnostic design with an automatic codebase-mapping system that lets large repositories stay within context limits, combined with automatic git commits on every accepted edit.

Biggest weakness: There is no built-in GUI or IDE-native experience: Aider lives in the terminal, which is a barrier for developers who expect an editor-integrated assistant like Cursor or GitHub Copilot, and total cost is unpredictable since it scales directly with token usage on whatever LLM is configured.

Aider pricing

Free · verified undefined NaN, NaN from the vendor's pricing page

What reviewers say

• 5/5 on Product Hunt (1 reviews)

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