A agentindex
Comparison

Gemini CLI vs OpenAI Codex

A like-for-like, spec-level comparison. Both entries are verified against their docs and repo.

Gemini CLI

Google's open-source terminal agent for Gemini.

  • + Open source and free to start
  • + Tight Gemini grounding (search, docs)
  • − Gemini models only
  • − Newer than incumbents

OpenAI Codex

OpenAI's open-source agentic coding CLI.

  • + Open-source CLI
  • + Sandboxed command execution
  • − OpenAI models only
  • − Newer, less battle-tested than incumbents
Spec Gemini CLI OpenAI Codex
Category coding-agent coding-agent
License Apache-2.0 Apache-2.0
Open source Yes Yes
Self-hostable No No
MCP support Yes Yes
Pricing freemium usage
Starting price Free tier with Gemini API Pay per token (OpenAI API)
Models gemini gpt
Languages typescript multi
GitHub stars 105.5k 93.6k
Last activity 2026-06-25 2026-06-25