Aider is an open-source coding assistant that works in the terminal. You run it in your project folder, name the files you want, and write your request in plain language; Aider edits the code directly and commits each change to git with a clear message. What sets it apart is that it is designed around a git repository and works with many models, from cloud services to local ones.

What is Aider good for?#

  • Adding small to medium features: you ask for an email validation function, and the change is applied to the right file and committed.
  • Fixing bugs: you give it the output of a failing test and get a fix.
  • Refactoring: renaming and restructuring across several files at once.
  • Working with the model you like: you can pick a lighter or local model and keep costs under control.
  • Writing tests and documentation: it writes tests for existing functions.

Strengths and weaknesses#

Strengths:

  • Every change is committed to git, so undoing it is easy.
  • Open source and independent of any company or model.
  • Light and fast, suited to people comfortable with the terminal.
  • A repository map helps the model understand the project's structure.

Weaknesses:

  • No graphical interface, which is intimidating for beginners.
  • You need to name the relevant files yourself.
  • Quality depends on the model you pick.
  • For very long agent-style jobs, newer tools offer more features.

Free version and pricing#

Aider is free and open source. The real cost comes from the model: with a cloud key you pay that provider for usage, and with a local model you only need hardware.

Language support and access from Iran#

Aider depends on your model; Persian explanations are usually understood but English instructions are more precise. The software itself is installable, but many model services are restricted from Iran, so check access separately.

Aider alternatives#

  • Cline: an open-source agent inside VS Code with a graphical interface and approval at each step.
  • Claude Code: Anthropic's command-line agent for broader work across a project.
  • Cursor: a full editor with a more integrated experience, on subscription.
  • GitHub Copilot: code completion and chat in common editors.