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OpenAINotable
Codex (cloud)
Released May 16, 2025
OpenAI's cloud software-engineering agent: runs many tasks in parallel, each in its own sandbox with the user's repo, and proposes pull requests.
- Domain
- Coding
- Access
- Generally available
- Plan
- Plus $20/mo
Strengths & weaknesses
Strengths
- Parallel cloud tasks in isolated sandboxes
- Available on web, CLI, IDE extension and iOS with one ChatGPT plan
- Token-based credit billing since 2026-04-02
Weaknesses
- Not available on Free/Go or API-key accounts
- OpenAI estimates ~$100–200 per developer per month average Codex cost
Notable: frontier-lab developer (OpenAI). Research preview 2025-05-16 on codex-1 (o3-based). underlyingModels are the models the current pricing page lists for Plus (GPT-6.1 Sol, GPT-6 Luna); GPT-6 Astra and others also listed for higher plans; GPT-5.5 retires from Codex 2026-10-14. Users choose among OpenAI models (vendor-only lineup). Codex CLI is a separate harness entry. GPT-6.1 Terra added to Codex 2026-10-26 for Plus, Pro, Business, Enterprise and Edu.