Grok Bot vs Codex: always-on bot or coding agent?

Codex is the better pick for writing code: it's OpenAI's coding agent in ChatGPT plans, with a desktop app, an open-source CLI and cloud tasks that keep working while your computer sleeps, while Grok Bot is xAI's always-on AI teammate for any job, with its own cloud computer, memory and routines. Grok Bot is the stronger fit for standing work around the code, and Reason lets you use both, running OpenAI models on the ChatGPT plan you already pay for.

  1. 1
    Open ReasonOn the web, or in the Reason app for Mac.
  2. 2
    Connect GitHubChoose the repositories it works in.
  3. 3
    Describe the taskReason does the work and opens a pull request.
Start with ReasonDownload for macOS

Reason works on its own cloud computer, on a Reason plan.

Always-on, or a coding agent? Both.

By The Reason Machines team

Grok Bot vs Codex side by side

Grok BotCodex
What it isxAI's always-on AI teammates for any jobOpenAI's coding agent: desktop app, CLI (open source, Apache-2.0), IDE extension, web and iOS
Where it runsOne persistent cloud computer per user, with a browser, terminal and filesystemYour computer, or Codex cloud, where each task has its own workspace and keeps working while your computer sleeps
Coding abilityWrites and runs code on its computer, and hands larger changes to Cursor cloud agents; not listed on public coding-agent benchmarksBuilt for coding; Codex on GPT-6 Astra scores 55 on Artificial Analysis's Coding Agent Index v2.0 (read Nov 2, 2026)
Always-on and schedulesYes: routines run in the cloud with your laptop closed, on a schedule at least five minutes apart or on eventsCodex cloud tasks run in the background; scheduled tasks on Plus, Pro, Business, Enterprise and API key, and local ones need the computer on and the app running
MemoryMemory per BotAGENTS.md instruction files in your repository
SlackTalk to a shared Bot in Slack; routines can start on a mention, a phrase, a reaction or any messageMention @ChatGPT; with Cloud delegation on, it sends repository work to a Codex cloud task (a workspace owner or admin sets it up)
Pricing and limitsIncluded on X Subscription Premium $30, Super $100 and Ultra $200 a month (Plus $8 doesn't include it); one weekly pool shared with Grok and Cursor, with the next reset date in your usage view; top-ups buy additional usageChatGPT Free and Go ($8) include Codex in the desktop app, subject to rollout; Plus $20; Pro $100, $200 or $500; Business $25 per user a month, or $20 billed annually. Plus and Business have five-hour windows, Pro has no five-hour limit, weekly limits may also apply, and Plus and Pro can buy credits
Best forA teammate that watches events, keeps routines and delegatesWriting code on OpenAI models, locally or in the cloud

US list prices and limits from each vendor's own pages, checked Nov 4, 2026. Codex shares usage with ChatGPT Work; Grok Bot's pool is shared across Grok, Grok Bot and Cursor.

Use ChatGPT and Grok together in Reason

  1. Open Reason on the web or the Mac app

    Sign in at reasonmachines.com, or download the Reason app for macOS from reasonmachines.com/download. Both open the same Sessions. Sending work to Reason needs a Pro or Max plan.

  2. Connect the plans you already pay for

    In Settings › Models, connect subscriptions such as Claude (Pro or Max), ChatGPT (Plus, Pro or Business), Grok (SuperGrok or X Premium+) or GitHub Copilot, or add API keys. Reason runs on your own accounts first; a Reason plan's credits cover the rest.

  3. Describe the task in the composer

    Name the repository and say what you want, for example "fix the failing checkout test and open a pull request". Reason works on its own cloud computer, runs the tests, and opens the pull request for you to review.

  4. Keep it working when you're away

    Mention Reason in Slack to hand it a task from a thread, and set up a Loop for work that repeats, such as a nightly dependency check or a morning CI sweep. Reason keeps memory across Sessions, so it remembers how your repository works.

Use them together

You don't have to choose. Codex writes the change; Grok Bot keeps the routines, watches Slack and email, and delegates. xAI's Grok Bot docs don't describe it running Codex, but it can add MCP servers by URL.

Reason works with both. In Settings › Models, choose Sign in with ChatGPT to connect your Plus, Pro or Business plan (and your Claude, Grok or Copilot accounts), and Reason runs OpenAI models on it, with its own cloud computer per Session, memory, Loops and Slack, and opens the pull request. Add the Reason MCP server (https://mcp.reasonmachines.com/mcp) to Grok Bot and your Bot can start Reason sessions, or message the Codex session on your own computer over Reason Network.

Reason: all your AI subscriptions in one coding agent

Use the subscriptions you already pay for (ChatGPT Plus/Pro/Business, Claude Pro/Max, SuperGrok or X Premium+, GitHub Copilot) or your own API keys in one coding agent. Hit your limit? Reason keeps going on your other connected accounts or Reason credits.

Reason is an always-on teammate that is also a coding agent: its own cloud computer per Session, memory across Sessions, Loops and Slack, with the model picked per task. Work that runs on your own subscription or API key is billed by that provider and keeps its limits; Reason's plans are Pro at $50 and Max at $200 a month, with no free plan, and it isn't open source.

Questions

Is Grok Bot better than Codex?

For coding, no: Codex is the dedicated agent, and on Artificial Analysis's Coding Agent Index v2.0, Codex on GPT-6 Astra scores 55, while Grok Bot isn't benchmarked as a coding agent (xAI's coding agent, Grok Build on Grok 4.7, scores 47). Grok Bot is the broader always-on teammate: routines, events, Slack and delegating.

Can Grok Bot use Codex?

Not by itself: xAI's docs say Grok Bot picks the model for each task and don't describe it running Codex. Through Reason Network it can: add the Reason MCP server to Grok Bot, put the Codex session on your computer on the same network, and Grok Bot can message it and read its replies.

Which is cheaper?

Codex: ChatGPT Free and Go ($8 a month) include it in the desktop app, subject to rollout, and Plus is $20 a month. Grok Bot starts at $30 a month with X Subscription Premium. Each plan has its own limits: Codex's five-hour and weekly windows, Grok Bot's weekly pool shared with Grok and Cursor.

Does Codex run in the background?

Codex cloud tasks do: OpenAI says each task has its own workspace and keeps working while your computer is asleep. OpenAI's pricing lists Codex cloud on Plus, Pro, Business and Enterprise.

Can I use my ChatGPT plan in Reason?

Yes. In Settings › Models, choose Sign in with ChatGPT to run OpenAI models on your Plus, Pro or Business plan. That plan's own usage limits still apply.

What happens when I hit a usage limit in Reason?

Hit your limit? Reason keeps going on your other connected accounts or Reason credits. When the account a turn runs on hits its limit, Reason moves the turn to the same model on your other connected accounts, then to Reason credits if your workspace can pay, and says so in the conversation.

Is Reason made by xAI?

No. Grok Bot is a product of xAI. Reason is built by Reason Machines and is not affiliated with or endorsed by xAI, Anthropic, OpenAI or Cognition. Facts about other products on this page come from their own pages, linked under Sources.

More guides

A teammate that ships code.

  1. 1
    Open ReasonOn the web, or in the Reason app for Mac.
  2. 2
    Connect GitHubChoose the repositories it works in.
  3. 3
    Describe the taskReason does the work and opens a pull request.
Start with ReasonDownload for macOS

Reason works on its own cloud computer, on a Reason plan.

Always-on, or a coding agent? Both.