AiderVS
OpenAI Codex CLI
Read from each vendor’s own pages last night, so it does not go stale the way a written comparison does.
- AIDER
- Free
- OPENAI CODEX CLI
- Not read
- CHANGES ON EITHER
- 2
- CAVEATS
- NONE
On the prices each vendor publishes about itself, Aider starts at Free and OpenAI Codex CLI at Not read. Both take your own API key, so on either one the subscription and the model bill are separate decisions. Both are open source, so neither can withdraw the thing you have already installed. Every figure on this page was read from the two vendors' own pages in last night's run rather than written down once, which is the only reason it is still the current answer. ToolDrift sells neither and takes no referral fee on either.
| COMPARED ON | AIDER | OPENAI CODEX CLI |
|---|---|---|
| ASSERTED · WHAT EACH VENDOR PUBLISHES ABOUT ITSELF | ||
| Category | CLI agent | CLI agent |
| Vendor | Aider AI | OpenAI |
| Status | Active | Active |
| How it charges | Free | Subscription |
| Entry price | Free | Not read |
| Default model | None, you choose | openai/gpt-5.5 |
| Your own key | Yes | Yes |
| Source | Open source · Apache-2.0 | Open source · Apache-2.0 |
| Plans | No named tier on Aider AI's pricing page could be read with a price beside it. | No named tier on OpenAI's pricing page could be read with a price beside it. |
| MEASURED · COUNTED ON THE LAST NIGHTLY RUN | ||
| Stars | 49.2K | 126.4K |
| Maintenance | 55/100 | 100/100 |
| Days since last push | 125 | 0 |
| Top model in it | Thinking Machines: Inkling (free) · Free | OpenAI: GPT-5.5 · $11.25 |
| Its volume | 10B tokens | not measured |
Is Aider or OpenAI Codex CLI cheaper?
On the cheapest option each vendor publishes: Aider is Free and OpenAI Codex CLI is Not read. Treat both as an allowance rather than a bill, every tool in this category meters model usage on top of the plan, and which one costs more in practice depends on the models you drive and how hard. The tier prices are the part that can be checked from outside, so they are the part this page prints.
Can I use my own API key with Aider or OpenAI Codex CLI?
Aider: yes. OpenAI Codex CLI: yes. It is the row that decides whether the subscription price is most of what you pay or a fraction of it: a tool that takes your own key charges for the software, and one that does not is reselling inference with a margin you cannot see.
Are Aider and OpenAI Codex CLI still maintained?
Active and Active as of last night's read. Aider's repository was last pushed 125 days ago and it scores 55/100 on maintenance; OpenAI Codex CLI's repository was last pushed 0 days ago and it scores 100/100 on maintenance. This is the question a written comparison cannot answer, because it was true on the day it was published and nobody went back.