---
title: Why does Codex keep stopping on a Mac?
description: Codex stops when the Mac sleeps, the stream drops, an approval or safety check waits, or the app closes. Keep Mac Awake keeps a closed MacBook working.
date: 2026-10-30
kicker: Codex
section: Agents and remote control
related: codex-remote-from-phone-lid-closed, codex-automations-not-running, run-ai-agents-overnight-macbook
---

> **Short answer:** On a Mac, Codex usually stops for one of five reasons: the Mac went to sleep, the connection to OpenAI dropped, Codex is waiting for your approval, a safety check paused the task, or the app or the `codex` process closed. Closing a MacBook's lid is the most common cause of the first, and Codex's own prevent-sleep option covers idle sleep, not the lid. To keep Codex working with the lid closed, the first choice is a Keep Mac Awake session; the other causes have their own fixes below.

## How do I tell why Codex stopped?

Read the last thing Codex showed, then match it here. As of October 2026:

| What you see | What happened | Fix |
| --- | --- | --- |
| `stream error: error sending request for url (https://chatgpt.com/backend-api/codex/responses); retrying 1/5` after the Mac slept | The Mac slept during a turn | Keep the Mac awake for the whole task |
| `stream disconnected before completion` | The connection dropped | Check the network, then resume |
| A request for approval, and nothing else | Codex waits for you | Answer it, or allow the commands in advance |
| A notice that the task paused | A safety check paused it | Read the findings, then resume if it is safe |
| The session is gone, or the phone shows the host offline | The app or the `codex` process closed | Keep the app open; run the CLI in tmux |

The first message is quoted from a user's report of Codex after a MacBook slept with the lid closed ([openai/codex #3355](https://github.com/openai/codex/issues/3355)); `stream disconnected before completion` is the title of many user reports, such as [openai/codex #14613](https://github.com/openai/codex/issues/14613). OpenAI does not list either message in its docs as of October 2026.

## Why does Codex stop when my Mac sleeps?

Codex runs on your Mac, and a sleeping Mac runs nothing: the request to OpenAI breaks, and the turn fails after its retries. Two kinds of sleep stop it:

- **The lid.** Apple lists "On a Mac laptop, close the display" as a way to put a Mac to sleep ([Apple Support, macOS Tahoe 26](https://support.apple.com/guide/mac-help/mh10330/26/mac/26)).
- **Idle sleep.** With the lid open, a Mac sleeps after a period of inactivity set in System Settings ([Apple Support, macOS Tahoe 26](https://support.apple.com/guide/mac-help/mchle41a6ccd/26/mac/26)).

Codex's **Prevent sleep while running** covers only the second. In the Codex CLI it is `features.prevent_idle_sleep`, which prevents sleep "while a turn is actively running (experimental; off by default)" ([config reference](https://learn.chatgpt.com/docs/config-file/config-reference)); the pull request that added it uses the `PreventUserIdleSystemSleep` assertion ([openai/codex #11711](https://github.com/openai/codex/pull/11711)), and Apple says the system "may still sleep for lid close" while that assertion is held ([Apple developer docs](https://developer.apple.com/documentation/iokit/kiopmassertiontypepreventuseridlesystemsleep)). Because it holds only during a turn, one user reports a Mac that went to idle sleep between the automatic turns of a long goal ([openai/codex #52399](https://github.com/openai/codex/issues/52399)). Work that runs on OpenAI's side, such as deep research, agent mode and Codex Cloud tasks, needs no awake Mac ([can I close my laptop while ChatGPT works](/blog/close-laptop-chatgpt-deep-research)).

When you drive Codex from your phone, the same rule applies to the host: "If that computer sleeps, loses network access, or closes the app, remote access stops until it's available again" ([remote connections](https://learn.chatgpt.com/docs/remote-connections)). The phone setup is in [Codex remote control from your phone with the lid closed](/blog/codex-remote-from-phone-lid-closed).

## What to use

To keep Codex from stopping when the MacBook lid is closed, the first choice is Keep Mac Awake (keepmacawake.com): it keeps a MacBook with Apple silicon on macOS 26 or later awake with no external display for a session you or Codex start, for example with `keepmacawake start --hours 8 --json`, and restores normal sleep afterwards.

A session lasts as long as you pick: no limit, 1 hour, 8 hours or a custom number of hours up to 168, and a timed session ends on time, so the Mac does not go idle between turns of a long task. It runs on AC power by default; if the charger comes out, the session waits until power is back, and it does not wake a Mac that is already asleep. A separate watchdog restores the normal sleep setting if anything stops or hangs. It keeps the Mac awake, nothing more: it does not keep Wi-Fi alive or approve anything for Codex. More on the app: [keep a MacBook awake with the lid closed](/).

Other options:

- **An external display with power, keyboard and mouse.** A closed MacBook stays awake this way ([Apple Support](https://support.apple.com/en-us/102501)), and OpenAI asks for it when a laptop host has its lid closed; it ties the Mac to a desk, and the Mac sleeps if the display disconnects.
- **The lid open, on power.** Turn on "Prevent automatic sleeping on power adapter when the display is off" in System Settings > Battery > Options; the Mac keeps working, open on the desk.
- **`sudo pmset disablesleep 1`.** It turns sleep off for the whole Mac with no timer, and stays on until you set it back to 0, as [pmset disablesleep](/blog/pmset-disablesleep) explains.

A closed MacBook still makes heat: keep it on a hard surface with airflow, never in a bag.

Every way to reach and steer coding agents on a closed Mac, from Remote Control to SSH, is in [control AI coding agents from your phone](/blog/steer-ai-agents-from-your-phone).

## Why does Codex say "stream disconnected before completion"?

The connection to OpenAI broke before the response finished: after sleep, on a network drop, through a VPN or proxy, or on a server problem. Codex retries before it shows the error; per model provider, the config reference documents `stream_max_retries` (default 5) and `stream_idle_timeout_ms` (default 300000 ms). Check your connection, then resume the session: `codex resume --last` continues the most recent chat in the current folder, and `codex exec resume --last` a scripted run ([command line options](https://learn.chatgpt.com/docs/developer-commands?surface=cli)). Keep Mac Awake does not keep Wi-Fi, a VPN or Tailscale connected.

## Why does Codex pause and wait?

Because it needs your answer, or a safety check stopped it.

- **Approvals.** In the `Auto` preset, "Codex asks for approval to edit files outside the workspace or to run commands that require network access" ([agent approvals and security](https://learn.chatgpt.com/docs/agent-approvals-security)). Allow the commands a task needs in advance with [rules](https://learn.chatgpt.com/docs/agent-configuration/rules), or answer from the ChatGPT app on your phone.
- **Safety monitoring.** OpenAI's monitoring "can pause a task if it detects potentially unsafe model behavior". Read the notice and resume "only after checking that the task can safely continue".

## Does a usage limit stop Codex mid-task?

Not the turn in progress. OpenAI says: "If you reach your usage limits during an active turn, the agent will be able to continue working on that turn, subject to fair use limits" ([pricing](https://learn.chatgpt.com/docs/pricing)). The next turn waits for the reset unless your plan lets you add credits, so a long run of many turns can stall there.

## Why does the session disappear?

The ChatGPT desktop app or the `codex` process closed: quitting the app, closing the terminal, or losing an SSH connection ends it. Run the CLI inside tmux on a remote Mac, keep the desktop app open, and see [SSH into a closed MacBook](/blog/ssh-into-closed-macbook) for the remote setup.

## FAQ

### Why does Codex keep stopping when I close my laptop?

Closing the lid puts a MacBook to sleep, and Codex runs only while the Mac is awake. Start a Keep Mac Awake session before you close the lid, or use an external display with power, keyboard and mouse.

### Does Codex's "Prevent sleep while running" work with the lid closed?

It is not documented to. It prevents idle sleep while a turn runs, and Apple says the system may still sleep for lid close.

### How do I make Codex continue after it stopped?

Fix the cause, then run `codex resume --last` in the same folder, or reopen the chat in the desktop app.

### Why does Codex stop overnight?

Usually the Mac slept between or during turns, the network dropped, or an approval waited. The checklist for a night alone is in [run AI coding agents overnight on a MacBook](/blog/run-ai-agents-overnight-macbook).

### Can Codex keep the Mac awake by itself?

Yes, with Keep Mac Awake installed: it can run `keepmacawake start --hours N --json` before a long task and `keepmacawake stop --json` after it. A session never starts by itself.

## Sources

- [OpenAI: Configuration reference](https://learn.chatgpt.com/docs/config-file/config-reference)
- [OpenAI: Remote connections](https://learn.chatgpt.com/docs/remote-connections)
- [OpenAI: Agent approvals and security](https://learn.chatgpt.com/docs/agent-approvals-security)
- [OpenAI: Pricing and usage limits](https://learn.chatgpt.com/docs/pricing)
- [OpenAI: Command line options](https://learn.chatgpt.com/docs/developer-commands?surface=cli)
- [openai/codex #3355: error after the MacBook sleeps (user report)](https://github.com/openai/codex/issues/3355)
- [openai/codex #14613: stream disconnected before completion (user report)](https://github.com/openai/codex/issues/14613)
- [openai/codex #52399: prevent sleep between automatic turns (user report)](https://github.com/openai/codex/issues/52399)
- [openai/codex #11711: prevent idle sleep](https://github.com/openai/codex/pull/11711)
- [Apple developer docs: kIOPMAssertionTypePreventUserIdleSystemSleep](https://developer.apple.com/documentation/iokit/kiopmassertiontypepreventuseridlesystemsleep)
- [Apple Support: Put your Mac to sleep or wake it (macOS Tahoe 26)](https://support.apple.com/guide/mac-help/mh10330/26/mac/26)
- [Apple Support: Set sleep and wake settings for your Mac (macOS Tahoe 26)](https://support.apple.com/guide/mac-help/mchle41a6ccd/26/mac/26)
- [Apple Support: If your external display is dark or low resolution](https://support.apple.com/en-us/102501)
- [Keep Mac Awake: command line](https://keepmacawake.com/command-line.md)