Let an AI Agent complete coding tasks on its own in the terminal
You want to hand whole jobs like “fix this bug” or “add this feature” to an Agent and only do the review yourself.
Coding tasks handed to a terminal Agent, with you only reviewing
3 top picks
Reads and writes your whole codebase, runs commands and tests from the terminal.
Free: To be verified: needs a paid Claude subscription or API (see the official FAQ for which plans include it)
Comes with ChatGPT plans; usable in the terminal, editor and web.
Free: The official site says “Codex is included in your ChatGPT plan”; free-tier limits to be verified
Open source and free, works with any model, even local ones, so cost is the most predictable.
Free: Open source and free; bring your own model API
How to combine them
- 1
Write an AGENTS.md / instructions file in the project root: how to run, how to test, code conventions.
- 2
Give the Agent one clear, verifiable task at a time and ask it to run the tests.
- 3
Work on a separate git branch and merge only after review.
How far the free plans go
Aider and Cline are free themselves; you only pay model API fees. Claude Code and Codex need the matching subscriptions (exact allowances to be verified). Partly to be verified
Prices and limits change often. Data checked on 2026-10-27; the official sites are the final word.
Not for
- Projects with no tests and no version control (hard to roll back when the Agent breaks something)
- Shipping without ever looking at the code