Head to head / Harness
Codex CLI vs Grok Build
Codex CLI: OpenAI's open-source coding agent for the terminal, with cloud and app-server counterparts. Grok Build: xAI's terminal coding agent, with plan mode, parallel subagents, and MCP.
| Fact | Harness | Harness |
|---|---|---|
| Kind | Harness | Harness |
| Status | Active | Active |
| Source | Open source | Open source |
| License | Apache-2.0 | Apache-2.0 |
| Pricing | Freemium · Free · Go $8/mo · Plus $20/mo · Business Standard $25/mo · Pro $100/mo · Business Premium $125/mo · API Key Pay as you go | Freemium · Free · Plus $8/mo · Premium $30/mo · Super $100/mo · Ultra $200/mo |
| Model access | Your subscription, Your API key | Your subscription, Your API key |
| Platforms | macOS, Linux, Windows | macOS, Linux, Windows |
| Interfaces | CLI | CLI, TUI |
| Install | curl -fsSL https://chatgpt.com/codex/install.sh | sh | curl -fsSL https://x.ai/cli/install.sh | bash |
| GitHub | ★ 130k · checked 2026-10-18 | ★ 27.4k · checked 2026-10-18 |
| Last verified | 2026-10-18 | 2026-10-18 |
| Worktrees | ✓ | ? |
| Parallel agents | ✓ | ✓ |
| Subagents | ✓ | ✓ |
| MCP | ✓ | ✓ |
| Remote access | ✓ | ? |
| Cloud sandbox | ✓ | ✗ |
| Diff review | ✓ | ✓ |
| Plan mode | ✓ | ✓ |
✓ yes ✗ no ? not verified yet
How we check facts More head to heads