What is Luna Reserve (gpt-reserve) in Codex?
by vortwangUpdated
Luna Reserve is, in OpenAI's words, 'a fallback mode, not a separate model you need to buy. It doesn't restore regular usage or unlock our most capable models.' It 'gives selected accounts additional usage with GPT-5.6 Luna after regular usage is exhausted', is 'available to selected personal ChatGPT Plus and Pro accounts', and shows as 'a moon indicator in the usage warning'. Users report the Codex CLI cannot draw on it; the help center names the desktop app and web.
What the official docs say
Luna Reserve is a fallback mode, not a separate model you need to buy. It doesn't restore regular usage or unlock our most capable models.
Quoted from OpenAI Help Center: Luna Reserve in Codex and ChatGPT Work (article 20001499, read via Wayback snapshot dated 2026-09-04) Luna Reserve is available to selected personal ChatGPT Plus and Pro accounts.
Quoted from OpenAI Help Center: Luna Reserve in Codex and ChatGPT Work (article 20001499, read via Wayback snapshot dated 2026-09-04) Luna Reserve has its own usage limit and isn't unlimited.
Quoted from OpenAI Help Center: Luna Reserve in Codex and ChatGPT Work (article 20001499, read via Wayback snapshot dated 2026-09-04) look for a notice about Luna Reserve or a moon indicator in the usage warning.
Quoted from OpenAI Help Center: Luna Reserve in Codex and ChatGPT Work (article 20001499, read via Wayback snapshot dated 2026-09-04) Switching models does not restore allowance in a shared usage pool.
Quoted from OpenAI Help Center: Managing usage with GPT-6 Astra in Work and Codex (article 20001516, read via Wayback snapshot dated 2026-09-16)
How it is counted
Luna Reserve is a second allowance, not a refill of the first. 'Regular usage and Luna Reserve have separate allowances', 'Luna Reserve provides additional usage only with Luna after regular usage is exhausted', and 'Other models may be unavailable while your regular usage is exhausted.' It 'has its own usage limit and isn't unlimited', and 'Dismissing the notice doesn't turn off Luna Reserve or restore regular usage.'
It is not on every account. 'Luna Reserve is only available to select accounts, and is not available to every account. Availability can change.' It is 'available to selected personal ChatGPT Plus and Pro accounts' and 'isn't available in ChatGPT Business or Enterprise workspaces'. Reaching a limit does not grant it: 'Reaching a regular usage limit doesn't by itself guarantee access', and 'support cannot add Luna Reserve to your account if you never had the feature.'
Surfaces differ. The help center says to 'Open Codex or ChatGPT Work in the desktop app, or open ChatGPT Work on the web' and 'look for a notice about Luna Reserve or a moon indicator in the usage warning'. In the official Codex repository, issue #40939 (2026-08-26) reports that the CLI kept returning 'You've hit your usage limit.' while the app showed 'Luna Reserve: 100% remaining'; commenters there say /status lists the reserve under a model id 'gpt-reserve'. Those are user reports, not documentation. To get back to your plan's models you wait for regular usage or use 'upgrading, adding credits, or applying an available reset' as offered in your account.
| Question | What OpenAI says | Source |
|---|---|---|
| What is it? | A fallback mode: additional usage with GPT-5.6 Luna after regular usage is exhausted | [1] |
| Is it a reset? | No. "It doesn't restore regular usage or unlock our most capable models." | [1] |
| Who has it? | "selected personal ChatGPT Plus and Pro accounts"; not Business or Enterprise; availability can change | [1] |
| Is it unlimited? | No. "Luna Reserve has its own usage limit and isn't unlimited." | [1] |
| Where does it appear? | Desktop app (Codex or ChatGPT Work) and ChatGPT Work on web: a notice or moon indicator in the usage warning | [1] |
| Does it work in the Codex CLI? | Not published. Issue #40939 reports the CLI returns "You've hit your usage limit." while the app shows reserve remaining (user report) | [3] |
| Can support add it? | No: "support cannot add Luna Reserve to your account if you never had the feature." | [1] |
FAQ
Is Luna Reserve the same as a banked reset or a purchased reset?
No. A reset refreshes your regular windows; Luna Reserve 'doesn't restore regular usage'. It is a separate allowance for GPT-5.6 Luna only, used after your regular allowance is gone, and it has its own limit.
Why do I not see Luna Reserve when I hit my limit?
Because it is selective: 'If you don't see Luna Reserve, your account may not be included for access to this feature. Reaching a regular usage limit doesn't by itself guarantee access, and availability can change.' Support cannot add it if you never had it.
Can I use Luna Reserve from the Codex CLI?
OpenAI's help page names the desktop app and ChatGPT Work on web. Issue #40939 in the official repository reports the CLI failing with 'You've hit your usage limit.' while the same account had reserve remaining in the app; some commenters report invoking a 'gpt-reserve' model id, others report it not working. Treat CLI support as undocumented.
How do I get back to GPT-6 Astra or Sol after falling into Reserve?
Wait for regular usage to become available again, or use the options your account offers: 'upgrading, adding credits, or applying an available reset'. Open the Luna Reserve indicator to see which of these your account shows. Switching models by itself does not restore allowance.
Sources
- OpenAI Help Center: Luna Reserve in Codex and ChatGPT Work (article 20001499, read via Wayback snapshot dated 2026-09-04)verified 2026-09-18
- OpenAI Help Center: Managing usage with GPT-6 Astra in Work and Codex (article 20001516, read via Wayback snapshot dated 2026-09-16)verified 2026-09-18
- openai/codex issue #40939 (2026-08-26, user report): Codex CLI cannot use Luna Reserve after the standard usage limit is exhaustedverified 2026-09-18
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