Best open-source AI coding agents
Open-source coding agents let you read the code, pick your model provider and avoid lock-in. Every tool here is listed as open source in our data; check each project's license before you build on it.
Ranked by score on our 100-point rubric (how we score). Scores are initial editorial estimates from public information, not hands-on tests. Pricing is labeled verified (checked on the vendor's official pricing page, with date) or unverified.
Quick picks
| # | Tool | Tier | Score |
|---|---|---|---|
| 1 | OpenAI Codex Cloud and CLI coding agent from OpenAI | S | 88 |
| 2 | Gemini CLI Open-source terminal agent powered by Gemini | A | 81 |
| 3 | Cline Open-source autonomous coding agent for VS Code | A | 80 |
| 4 | OpenCode Open-source terminal coding agent | A | 77 |
| 5 | Aider Terminal pair programmer with git integration | A | 73 |
| 6 | Zed Fast native editor with AI agents | A | 71 |
The ranking
-
OpenAI's coding agent available as an open-source CLI, IDE extension and cloud task runner.
- Best for
- You have ChatGPT and want parallel cloud tasks plus a local CLI.
- Skip it if
- You are not in the OpenAI ecosystem.
- Pricing
- Included with ChatGPT Plus/Pro/Business; API usage also available unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- CLI · web · IDE extension · Mac · Linux · Win
-
Google's open-source CLI agent with a large context window, MCP support and a free usage tier.
- Best for
- You want a capable free terminal agent.
- Skip it if
- You need the very best code quality on hard refactors.
- Pricing
- Free tier with a personal Google account; paid via API keys unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- CLI · MCP
-
Open-source agent extension that plans and edits with your own model keys and supports MCP.
- Best for
- You want an open-source agent and full control of model choice and cost.
- Skip it if
- You want flat-rate pricing.
- Pricing
- Free and open source; pay your model provider unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- IDE extension · MCP
-
Terminal-first open-source agent with a polished TUI that works with 75+ model providers.
- Best for
- You want a Claude Code-style experience with any model.
- Skip it if
- You want a vendor-supported product.
- Pricing
- Free and open source; pay your model provider unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- CLI
-
Open-source CLI that edits code in your repo and auto-commits, working with most LLMs.
- Best for
- You like the terminal and clean git commits per change.
- Skip it if
- You want a GUI or a fully autonomous agent.
- Pricing
- Free and open source; pay your model provider unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- CLI
-
High-performance open-source editor written in Rust with built-in AI and support for external agents.
- Best for
- You want speed and a native editor that can host multiple agents.
- Skip it if
- You rely on a large VS Code extension ecosystem.
- Pricing
- Free forever editor; Pro $10/mo; Business $30/seat/mo ✓ verified on the official pricing page, Oct 18, 2026
- Platforms
- Mac · Linux · Win
Head-to-head comparisons
FAQ
What is the best AI tool for open-source coding agents?
OpenAI Codex ranks first with 88/100 (S-tier). Cloud and CLI coding agent from OpenAI. Use it when you have ChatGPT and want parallel cloud tasks plus a local CLI. Next in our ranking: Gemini CLI (81/100, A-tier) and Cline (80/100, A-tier).
Which AI tools for open-source coding agents have a free tier?
In our pricing data, Gemini CLI (unverified), Cline (unverified), OpenCode (unverified), Aider (unverified) and Zed (verified) list a free tier. "Unverified" means it is an editorial summary we have not yet confirmed on the vendor's official pricing page, so check the vendor before relying on it.
Are there open-source options for open-source coding agents?
Yes. OpenAI Codex, Gemini CLI, Cline, OpenCode, Aider and Zed are listed as open source or open weights. Check each project's license before commercial use.
How are these tools ranked?
Each tool is scored out of 100 on our public rubric: job fit (30), ease (15), value (15), momentum (15), openness and portability (10), trust and maturity (10) and a builder/gamer bonus (5). S-tier is 85+, A-tier 70–84, B-tier 55–69 and C-tier below 55. Current scores are initial editorial estimates from public information, not hands-on tests, and sponsors can't buy points.