OpenAI

CLI agent

Codex

OpenAI's coding agent shipping as an Apache-2.0 CLI, IDE extension, desktop app, and cloud tasks started from web, GitHub, or Slack.

https://developers.openai.com/codex/↗ · source↗

Shape
CLI agent

Compare only what the shape makes comparable.

Released
2025-04 src↗as of 2026-08-20
Licence
Open source Apache-2.0 src↗
Self-hosting
yes src↗

The CLI is Apache-2.0 and "runs locally on your computer". The config reference supports custom model providers—"Built-in provider IDs (openai, ollama, and lmstudio) are reserved and cannot be overridden"—plus model_providers.<id>.base_url for an arbitrary API base URL, so the agent can be pointed at locally served models. The Codex cloud service itself is OpenAI-hosted.

Models
model-agnostic src↗

Named: gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna, gpt-5.3-codex-spark, gpt-5.5, gpt-5.4, gpt-5.4-mini

Pricing
  • Free$0 per user / month
  • Plus$20 per user / month
  • Pro$100 per user / month
  • Business$25 per user / month
  • Enterprise & Educontact
  • API key (pay-as-you-go)contact
pricing page↗as of 2026-08-20
Interfaces
terminal, ide-extension, web, mobile, chat-platform, api src↗
Capabilities
  • MCP support
    yes src↗mcp_servers config key, stdio and http
  • Plugins / custom tools
    yes src↗mcp_servers config, skills, slash commands
  • Subagents / parallel agents
    yes src↗subagent hook events, parallel cloud tasks
  • Hooks / lifecycle events
    yes src↗eleven events, PreToolUse through Stop
  • Persistent memory
    yes src↗AGENTS.md, global then project, concatenated
  • Background execution
    yes src↗isolated cloud tasks, scheduled runs
  • Sandboxing / permissions
    yes src↗seatbelt, bubblewrap, windows sandbox
  • Git / PR integration
    yes src↗cloud tasks open PRs, review feedback
as of 2026-08-20
Stated limits
  • gpt-5.4 and gpt-5.4-mini are "Being retired August 31, 2026". src↗

  • PR review inside the desktop app requires the GitHub CLI (gh) installed and authenticated via gh auth login; without it, PR details may not load in the sidebar or review pane. src↗

  • Built-in model provider IDs (openai, ollama, lmstudio) are reserved and cannot be overridden in config. src↗

What we could not source
  • first_release

    No OpenAI launch-announcement page was fetched with a dated Codex CLI release. 2025-04 is taken from the openai/codex repository creation date (2025-04-13T05:37:54Z via the GitHub API). Note that OpenAI previously used the name "Codex" for a 2021 code model, which is a different product from this agent.

  • pricing (Pro 20x)

    The pricing page states "From $100/month" for the 5x tier and "5x or 20x more Codex usage than Plus" but does not publish a separate dollar figure for the 20x tier.

  • interfaces

    Codex also ships a desktop app (codex app / ChatGPT desktop app on Windows, Linux, macOS), which has no matching value in the allowed interfaces enum.

  • model_support

    Recorded model-agnostic because the models page states Codex supports "any model and provider that supports either the Chat Completions or Responses APIs" and the config reference reserves ollama and lmstudio provider IDs. Every model named by OpenAI as recommended or available is an OpenAI model, so a stricter reading of "multi-vendor" vs "model-agnostic" is arguable.

  • capabilities.persistent_memory

    The docs feature index lists "Memories" under customization, but the dedicated Memories page was not fetched; the recorded evidence is the AGENTS.md layered-instructions mechanism.

Sentiment

What people say about Codex

+16

58 opinions · 2025-11-19 to 2026-08-19 · medium confidence

How this number was made

Counts are conservative estimates of distinct opinion-holders across the threads read, each tagged by overall polarity toward Codex; not a logged per-comment tally. Score is round(100*(26-17)/58) = 16.

Skew

The most comparative sample of the three: a large share of Codex opinion is expressed inside Claude Code threads by people explaining why they switched, which inflates the 'generous limits' and 'drop-in replacement' themes and undercounts complaints from people who only ever used Codex. The GitHub slice is concentrated in one incident (issue #28879, the June 2026 rate-limit burn) and so over-weights a single bad month. Only one blog in the sample. Praise skews toward price/limits rather than output quality, partly because the comparison is usually being made against Anthropic's pricing rather than on the merits.

  • hackernews+41
  • reddit+29
  • github-90

GitHub reads 131 points lower than the highest platform here. Issue trackers collect defects only, so that number measures activity more than opinion. Why we publish it anyway.

Trend

Codex is the only one of the three whose sentiment improved over the window, but not monotonically. Through late 2025 and early 2026 it was mostly praised as the generous-limits alternative, with 'slow but never cut off' as the accepted trade. The Codex app launch (Feb 2026) plus doubled limits pushed it further up, and it is the default recommendation in the August 2026 Reddit budget threads. The clear negative spike is June 2026: the rate-limit cost jump (issue #28879, 210 comments) and the July context-window reduction from 372k to 272k both read as the subsidy tightening, and produced the first real wave of switch-away-from-Codex posts, including one user saying Codex now felt more aggressive than Claude. By August 2026 recommendation sentiment had largely recovered. The persistent, non-cyclical weakness is UI and visual design work, which Codex users concede without argument across the entire window. The platforms also disagree sharply: Codex scores +41 on Hacker News and -90 on GitHub, a 131-point split that is mostly an artifact of the GitHub sample being drawn from one incident thread; people open issues when something breaks, not when it works.

Themes

Praised for

  • Generous rate limits for the price14×
  • Thorough context gathering, finds real fixes
  • Drop-in replacement when Claude limits hit
  • Async parallel cloud tasks
  • Codex app UX is thoughtful
  • Bundled value of the whole ChatGPT plan

Complained about

  • June 2026 rate-limit burn spike10×
  • Weak at UI and visual design
  • Slow compared to alternatives
  • Context window cut from 372k to 272k
  • Agentic scaffolding thinner than Claude Code
  • Banked limit resets quietly expiring
In their words

the true magical moment was codex pro letting me run swarms of agents day in day out without any worries about rate limits it truly felt unlimited

agentifysh · hackernews · 2025-11-19 · read it↗

ChatGPT 5 agentic functionality just sucks and wont chain workflows anywhere close to as long. The scaffolding is literally missing from Codex.

randombsname1 · reddit · 2025-12-16 · read it↗

Because Codex effectively rate limits you by being so slow.

The rate limit for my $20 OpenAI / Codex account feels 10x larger than the $20 claude account.

This week I’ve been hitting CC rate limits, and I switched to Codex with virtually no disruption to my workflow. It’s not good for Anthropic that I was able to do that!

jjfoooo4 · hackernews · 2026-04-06 · read it↗

I don't think it's as good at UI, but man is it thorough and able to gather the right context to find solutions.

carlgreene · hackernews · 2026-04-23 · read it↗

it's been frustrating how bad it is at UI.

I really like the codex app. just some really thoughtful user experience decisions

@лимонскокуче · youtube · 2026-05-26 · read it↗

Codex is the best at the difficult and intelligent stuff

@BenTECHofficial · youtube · 2026-05-26 · read it↗

I'm on the Pro plan and my quota suddenly vanishes in less than 5 hours now. Even with top-ups, it doesn't survive a single intense work session. This rate-limit spike completely breaks the entire workflow.

eva763057345-lab · github · 2026-06-18 · read it↗

I had to switch to Claude; now Codex seems like a more aggressive Claude

Aesthermortis · github · 2026-06-19 · read it↗

Before this change, I was never able to exhaust my 5-hour allowance, even during heavy Codex usage sessions involving large codebases and long-running tasks.

Its async cloud mode lets you queue several isolated tasks

I was going to explore paying for Codex since OpenAI seems to be a bit more generous with rate limits, but I'm now not sure - for the stuff I do limited context size would be a dealbreaker

KronisLV · hackernews · 2026-07-19 · read it↗

I switched from Claude to Codex recently and I like it. Only one thing I missing from Claude is Design.

@bibblebabl · youtube · 2026-07-24 · read it↗

Codex - new OpenAI models are really good, you also get ChatGPT plus in the web, image generation, research and whatnot. As a full self contained productivity package this is the best deal.

Right now Codex is the way to go. You have Sol which is a frontier model if you need it and Luna is probably the best model if you want a balance between intelligence and cost.

Ok-Elderberry739 · reddit · 2026-08-05 · read it↗

same split here honestly, opus plans better but 5.2 just executes. only thing is i keep runing into the codex weekly limit mid project and end up back on claude anyway

AdamSyakirin7_ · reddit · 2026-08-06 · read it↗