OpenAI

To get your OpenAI API key, you need to:

Go to https://platform.openai.com/account/api-keys
Create an account or log in with your existing one
Add a payment method to your account
Go to https://platform.openai.com/api-keys to get a key.
You will need to set the following environment variable to your key, or you can set it to user_provided for users to provide their own.

OPENAI_API_KEY=user_provided

Where users enter their own key

With user_provided, you supply no key at all: each user enters their own from the chat UI. Open the endpoint menu, and next to OpenAI there is a gear icon labelled Set API Key. Clicking it opens a dialog with a field for the key and a dropdown for how long it should be kept: 30 minutes, 2 hours, 12 hours (the default), 1 day, 7 days, 30 days, or never expire.

The key is encrypted and stored server-side against that user's account, so it is entered once rather than per conversation, and it is never shared with other users. The same dialog has a Revoke action, plus Revoke All to clear every key that user has stored.

If the endpoint menu is hidden, for example because a model spec disables modelSelect, the same dialog is reachable from Settings under Data controls, in the API keys section.

Until a user sets a key, the endpoint is visible but unusable for them.

You can determine which models you would like to have available with OPENAI_MODELS
- When OPENAI_API_KEY is set to user_provided → only the models put in this list will be available
  - ⚠️New models won't automatically show up; you'll need to add them to this list first
- When OPENAI_API_KEY is set to the actual API key value → as long as OPENAI_MODELS is left commented-out, it will do an API call to find out what models are available, which should include any new ones

OPENAI_MODELS=gpt-5.6,gpt-5.6-terra,gpt-5.6-luna,gpt-5.5,gpt-5.5-pro,chat-latest,gpt-5.4,gpt-5.4-pro,gpt-5.4-mini,gpt-5.4-nano,gpt-5.3-codex,gpt-5.2,gpt-5,gpt-5-codex,gpt-5-mini,gpt-5-nano,o3-pro,o3,o4-mini,gpt-4.1,gpt-4.1-mini,gpt-4.1-nano,o3-mini,o1-pro,o1,gpt-4o,gpt-4o-mini

Notes:

Internal OpenAI defaults include gpt-5.6, gpt-5.6-terra, and gpt-5.6-luna, followed by the existing GPT-5 catalog. gpt-5.6 is the Sol tier alias; LibreChat assigns all three GPT-5.6 tiers a 1,050,000-token context window and 128,000-token maximum output. Deprecated legacy defaults are no longer included unless you add them explicitly with OPENAI_MODELS.
GPT-5.6 supports the Responses API-only reasoning_mode values standard and pro, plus reasoning_context values auto, current_turn, and all_turns. These can be configured in model specs.
For a GPT-5.6 model with a non-none reasoning_effort, LibreChat defaults the canonical OpenAI endpoint to the Responses API so function tools remain compatible. An explicit useResponsesApi: false keeps Chat Completions. Azure OpenAI, OpenRouter, and custom or reverse-proxy base URLs are not switched automatically.
Selecting a vision model for messages with attachments is not necessary as it will be switched behind the scenes for you. If you didn't outright select a vision model, it will only be used for the vision request and you should still see the non-vision model you had selected after the request is successful
OpenAI Vision models allow for messages without attachments
OpenAI endpoint supports all Shared Endpoint Settings via the librechat.yaml configuration file, including streamRate, headers, titleModel, titleMethod, titlePrompt, titlePromptTemplate, and titleEndpoint