Codex CLI vs. fx (by Vercel)

Feature	Codex CLI	fx (by Vercel)

Tagline	Lightweight coding agent that runs in your terminal	Tiny, open, embeddable, native coding agent by Vercel.
Website	https://openai.com/codex	https://fx.sh
Language	rust	zig
Release Date	April 30, 2025	August 17, 2026
Last Updated	June 29, 2026	August 19, 2026
Provider Type	AI Lab	Independent
MCP Support	Yes	Yes
Multi-Agent Support	Yes	No
Git Integration	deep	minimal
Multi-File Editing	Yes	Yes
Auto Test Running	Yes	No
Sandbox / Permissions	Yes	Yes
Image / Multimodal Input	Yes	Yes
Voice Mode	Yes	No
IDE Integration	VS Code, Zed (via ACP)
Hooks / Extensions	Yes	No
Web Search	Yes	Yes
Local Model Support	Yes	Yes
Context Window	Model-dependent	Model dependent
Terminal Bench 2.0	#6 · 82.0% ±2.2 ¹
Supported Models	All frontier GPT, Codex models: GPT-5.6 Sol / Terra / Luna, GPT-5.5, GPT-5.4 pro, GPT-5.3-Codex, optional custom models.	All Vercel AI Gateway supported models, including OpenAI, Anthropic, Google, DeepSeek, z.AI, Moonshot, etc
Supported Subscriptions	ChatGPT	—
Pricing Model	Subscription	Free, BYOK, Usage Based
Free Tier	No	No
Price Range	$20-200/mo	0 - $20 / mo / Custom (Vercel AI Gateway)
Source Code Availability	Open Source (Apache-2.0)	Open Source (Apache-2.0)
Source Code	https://github.com/openai/codex	https://github.com/vercel-labs/fx
Development State	active	active