Aider vs Claude Code: two terminal coding agents compared

What is the difference between aider and Claude Code?

Aider is an open source pair programmer that edits the files you add to the chat and commits each change to git, using almost any model you choose. Claude Code is Anthropic's coding agent that explores your codebase on its own, edits files, runs commands and connects to external tools, using Claude models. Both run in your terminal, but aider keeps you in charge of context while Claude Code takes on more of the work itself.

Cost follows the same split. Aider has no subscription, so you pay only for model usage. Claude Code needs a paid Claude plan, a Console account or a cloud provider. Everything below comes from the official docs as of 26 October 2026.

How does aider work?

The aider site calls it "AI pair programming in your terminal." You install it with Python, change into a git repository and start it with a model and API key:

python -m pip install aider-install
aider-install

cd your-project
aider --model sonnet --api-key anthropic=<key>

You add the files you want changed with /add, describe the change, and aider edits them. A repo map gives the model a compact view of the rest of your code, so you rarely need to add everything. The git docs say: "Whenever aider edits a file, it commits those changes with a descriptive commit message." /undo throws away the last change.

Aider has four chat modes: code (the default), ask, which "will discuss your code and answer questions about it, but never make changes," architect and help. In architect mode, "An architect model will propose changes and an editor model will translate that proposal into specific file edits," which lets you pair a strong reasoning model with a cheaper editor.

The source is on GitHub under Apache 2.0. The latest numbered release on the release history is v0.86.1, with newer model support on the main branch. Our aider guide covers install options and commands in more depth.

How does Claude Code work?

The Claude Code overview calls it "an agentic coding tool that reads your codebase, edits files, runs commands, and integrates with your development tools." You install it and run claude in a project:

# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# or Homebrew
brew install --cask claude-code

cd your-project
claude

You describe a task and Claude Code decides which files to read, plans the change, edits files and runs tests or other commands. It can commit, create branches and open pull requests when you ask. The same engine runs in a VS Code extension, a JetBrains plugin, a desktop app and the browser at claude.ai/code.

The setup docs say: "Claude Code requires a Pro, Max, Team, Enterprise, or Console account. The free claude.ai plan does not include Claude Code access." Amazon Bedrock, Google Cloud's Agent Platform and Microsoft Foundry are also supported. See the Claude Code setup guide for the full steps.

How do aider and Claude Code compare side by side?

How do they handle git, undo and permissions?

This is the clearest difference in day-to-day use.

Aider treats git as the safety net. Every edit becomes a commit with a message written by its weak model, and the git docs add that "Aider will first commit any preexisting changes with a descriptive commit message" so your own work stays separate. You review with /diff or normal git tools and roll back with /undo. If you prefer to commit yourself, --no-auto-commits turns this off.

Claude Code uses permission modes and checkpoints instead. The permission modes page says that "With Claude Code v2.1.283 or later, auto mode is the built-in starting permission mode for interactive terminal and VS Code sessions," where background safety checks review actions. Shift+Tab cycles to Manual, which asks before edits, to Edit automatically, or to Plan, which researches and proposes changes without editing your source. The checkpointing docs explain that every prompt creates a checkpoint and /rewind (or pressing Esc twice) restores code, conversation or both. Files changed only by shell commands are not tracked, so git is still your long-term history.

If you like reviewing a commit per change, aider gives you that by default. If you would rather let the agent work through a task and review at the end, Claude Code is built for that. The Claude Code checkpoints guide goes deeper.

How do rules, skills and MCP compare?

Rules. Claude Code reads CLAUDE.md at the start of every session, and the memory docs say it reads AGENTS.md "as your project instructions" when there is no CLAUDE.md. Aider's conventions page suggests a Markdown file loaded read-only with --read or /read, or a read: key in .aider.conf.yml. To share one file between both tools:

# .aider.conf.yml
read: [AGENTS.md]

Keep the shared rules in AGENTS.md and Claude Code picks them up as long as you have no CLAUDE.md, or through an @AGENTS.md import if you do.

Skills. Claude Code loads skills from .claude/skills/ in your project and ~/.claude/skills/ for your user, reading the full SKILL.md only when a task matches its description. Aider's docs do not describe skill folder discovery. You can load a SKILL.md for one session with /read.

MCP. Claude Code connects to MCP servers for things like issue trackers, docs and databases (see the Claude Code MCP guide). Aider's docs and release history do not describe MCP support. It stays focused on your files, the repo map and git, with built-in commands such as /run, /test and /web for shell output and web pages.

How do you run them in scripts and from your editor?

Both have a one-shot mode for scripts:

# aider: send one message, apply edits, exit
aider --message "add descriptive docstrings to all the functions" app.py

# Claude Code: print mode
claude -p "review the changes on this branch for security issues"

The aider scripting docs show --message in a shell loop over files. Claude Code's -p flag runs one task and exits, and it also has GitHub Actions and GitLab CI/CD integrations. The headless mode guide covers the flags.

In the editor, the approaches differ. Aider's watch mode runs with --watch-files and acts on one-line code comments marked with AI! (make a change) or AI? (answer a question), so it works with any editor. Claude Code ships its own VS Code extension, which also installs in Cursor, and a JetBrains plugin with diff views.

Which should you pick?

Start with how much you want to hand over.

Aider tends to fit when:

• You want to choose the model, including open weight or local models, and pay only for usage.
• You want to decide exactly which files the AI can edit.
• You like a git commit for every AI change and undo through git.
• You want a small, scriptable tool with architect mode for pairing two models.

Claude Code tends to fit when:

• You want to hand over a whole task and let the agent find the relevant files and run tests.
• You already pay for a Claude plan or want Anthropic's models.
• You need MCP servers, skills, hooks or subagents.
• You want the same agent in the terminal, your IDE, a desktop app and the browser.

Neither list is a verdict. Some developers run both: aider for small, controlled edits with a strict commit trail, and Claude Code for longer tasks. A shared AGENTS.md keeps their instructions in sync. If you are weighing other open source terminal agents, see OpenCode vs Claude Code.

Keep your prompts portable between agents

The prompts you write for either tool, review checklists, refactor requests, commit message rules, are worth keeping in one place. Kipt stores prompts and Agent Skills as Markdown in a private GitHub repo you own, with {{name}} blanks and Cmd+K search, and installs every skill into Claude Code with one npx skills add command. To turn a prompt you keep pasting into a skill folder for .claude/skills/, try the free SKILL.md generator.