How to Use GPT-6
Choose your model and product first. Sol and Luna are in Work and Codex; Free and Go users can use Luna in the desktop app. API billing is separate.
Access self-check
Check the route to GPT-6
Match a model to your product, plan and client. This checks published rules, not your account.
Model/plan rules checked 2026-09-24. Country or region lists checked 2026-09-11. Official GPT-6 and GPT-5.6 plan guidance. Codex CLI: 0.153.0+ for Astra; 0.156.1+ adds Sol/Luna. Sol/Luna access.
GPT-6 access at a glance
To use GPT-6, choose a model, open the right product, and select it in that product’s model picker. Chat, Work, Codex and API have different access rules. OpenAI’s Sol and Luna announcement lists Work and Codex access for Plus, Pro, Business, Enterprise and Edu, plus Luna desktop access for Free and Go. It does not offer Sol or Luna in ordinary Chat.
GPT-6 access requirements and entry points
| Model and product | Published eligibility | Next step |
|---|---|---|
| Astra as GPT-6 Pro in Chat | Pro, Business and Enterprise | Choose GPT-6 Pro in Chat; check managed workspace permissions |
| Astra in Work and Codex | Plus, Pro, Business and Enterprise | Choose Astra in the product’s model picker |
| Sol and Luna in Work and Codex | Plus, Pro, Business, Enterprise and Edu | Update the client, then select Sol or Luna |
| GPT-6.1 Sol in Work and Codex | Plus, Pro, Business, Enterprise and Edu, with staged rollout | Select GPT-6.1 Sol; check client and workspace settings |
| GPT-6 Astra Ultrafast in Work and Codex | Pro $500; eligible Enterprise/Edu arrangements | Confirm the Ultrafast entitlement and workspace controls |
| Luna in the desktop app | Free and Go also have access | Open Work or Codex in the latest desktop app; this is separate from ordinary Chat |
| Astra, Sol and Luna API | API organization with model access and billing | Use the exact model ID with a project key |
The checker above applies these published rules. It does not sign in to your account. Allowances and workspace controls still determine what you can run.
How to access GPT-6 in ChatGPT
Sign in to the intended account and workspace. For Astra in ordinary Chat, look for GPT-6 Pro. Plus access to Astra in Work or Codex does not grant GPT-6 Pro in Chat. In a managed workspace, ask an administrator to check model permissions if the selector is missing.
For Sol and Luna, open Work or Codex. Free and Go users should use the desktop app for Luna. The ChatGPT 6 guide explains these product names; the model directory explains what each model is designed for.
Access GPT-6 Astra in Work or Codex
Astra remains available through its established Work and Codex routes. To switch to Sol or Luna, use the same product’s model picker after updating the client. For coding work, start with a small repository task and a test that can confirm the result. For a structured task, provide the allowed labels and required fields.
OpenAI’s September 29 Codex changelog adds GPT-6.1 Sol as the default in the bundled catalog in CLI 0.159.1. CLI 0.159.2 fixes flashing console windows on Windows; use that version or newer for the updated catalog and fix. Original Sol and Luna entered the catalog in 0.156.1. In the desktop app, use Menu → Check for Updates, then reopen the model picker.
Signing in with ChatGPT uses your plan’s Work/Codex allowance. Using an API key uses API billing. The pricing guide separates those budgets.
Pro plans, allowances and Ultrafast access
Pro now has $100, $200 and $500 monthly USD tiers. New Pro $200 subscriptions are available again with a lower included allowance. Eligible existing subscribers keep the previous allowance through October 29, 2026, then move to the lower allowance at the same $200 price. Check OpenAI’s transition rules and your account notice before changing plans.
Among individual Pro tiers, Astra Ultrafast requires Pro $500. Credits on Pro $100 or $200 do not unlock it. Ultrafast consumes included usage before paid credits; speed modes also change how quickly allowance is consumed. The plan and credit tables explain that distinction. For GPT-6.1 Sol’s settings and migration checks, use its model page.
Access GPT-6 Astra through the API
The exact IDs are gpt-6-astra, gpt-6-sol and gpt-6-luna. Use the ID for the model you want; do not replace it with the family name gpt-6. Confirm the project, organization and billing state, then send a small request. The API guide contains a complete Responses example and error checks.
Use Responses for built-in tools. Sol and Luna support function calling through Chat Completions only at reasoning effort none; the model comparison makes endpoint restrictions visible.
Troubleshoot missing GPT-6 access
- Check the signed-in account and selected workspace.
- Confirm the product: ordinary Chat, Work, Codex or API.
- Match your model and plan to the table above.
- Update the desktop app or CLI; managed users should check administrator model controls.
- Read the current allowance, error or reset message. Save the wording if you need support.
OpenAI described a staged launch on September 22. It did not publish an activation time for each account. A missing model today needs the checks above; the launch notice cannot predict a waiting time.
Can I use GPT-6 for free?
Luna has a Free/Go desktop route. This does not make GPT-6 Pro in Chat or the GPT-6 API free. OpenAI’s model references list no Free API tier for Astra, Sol or Luna. Third-party trials have their own terms; the API access comparison records the separately dated offers.
A useful next task
Try the Sol coding guide or Luna structured-task guide. Each links to an actual worked example and reusable prompts. Choose a small input, state what a correct result must preserve, and check that result before expanding the task.