OpenAI (GPT)

All OpenAI functions share the same shape: a prompt, an optional system prompt and an optional ignore_cache flag. They need an OpenAI API key once you are licensed. Get one at platform.openai.com/api-keys and add it via Set API Keys → Insert OpenAI API Key.

Functions

Function	Model	Good for
`=GPT(prompt, [system_prompt], [ignore_cache])`	gpt-6.1-terra	the default: fast, strong at writing, good value
`=GPT6(prompt, [system_prompt], [ignore_cache])`	gpt-6-astra	the most capable model, hardest reasoning tasks
`=GPT61(prompt, [system_prompt], [ignore_cache])`	gpt-6.1-sol	near-Astra quality at a lower price
`=GPT61mini(prompt, [system_prompt], [ignore_cache])`	gpt-6.1-terra	same model as `=GPT()`
`=GPT6mini(prompt, [system_prompt], [ignore_cache])`	gpt-6-luna	cheapest current-generation model, classification and extraction
`=GPT56(prompt, [system_prompt], [ignore_cache])`	gpt-5.6-sol	GPT-5.6 flagship
`=GPT56mini(prompt, [system_prompt], [ignore_cache])`	gpt-5.6-terra	balanced quality and cost
`=OpenAI(prompt, [system_prompt], [model_name], [ignore_cache])`	any	pick any model by name

Parameters

prompt (required): the text sent as the user message. Reference a cell, a literal string, or a combination: "Summarize: " & A2.
system_prompt (optional): instructions that shape the answer. Defaults to “You are a helpful assistant.” Pass "" to skip it when you need the next argument.
model_name (=OpenAI() only, optional): any OpenAI chat model ID, for example "gpt-6-astra". Retired IDs are mapped to their replacement automatically.
ignore_cache (optional): TRUE forces a fresh API call. Default FALSE. See Caching.

Examples

=GPT("Write a two-sentence product description for " & A2)
=GPT6("Find the logical flaw in this argument: " & B2, "You are a rigorous editor. Be brief.")
=GPT6mini(A2, "Reply with the industry of this company in two words max")
=OpenAI("Explain photosynthesis to a 10-year-old", "", "gpt-6.1-sol")
=GPT("What changed in the news today?", "", TRUE)

Legacy function names

Older sheets keep working. These names run on current models:

Legacy function	Now runs on
`=GPT4o()`, `=GPT41()`	gpt-6-luna
`=GPT5()`, `=O1()`, `=O1PRO()`, `=O3()`, `=O3MINI()`	gpt-5.6-sol
`=GPT5mini()`, `=O4MINI()`	gpt-5.6-terra

Legacy model names in `=OpenAI()`

If you pass a retired model ID as model_name, it is replaced with the model OpenAI recommends:

You pass	Runs on
gpt-3.5-turbo, gpt-4o, gpt-4o-mini, gpt-4.1, gpt-4.1-mini	gpt-6-luna
gpt-4, gpt-4-turbo, chatgpt-4o-latest, gpt-5, gpt-5-pro, gpt-5-chat-latest, gpt-5.1/5.2/5.3-chat-latest, o1, o1-pro, o1-preview, o3, o3-mini, o3-pro	gpt-5.6-sol
gpt-5-mini, o1-mini, o4-mini	gpt-5.6-terra
gpt-4.1-nano, gpt-5-nano	gpt-5.6-luna

Errors

Errors are returned as text in the cell so a single bad row does not break the sheet.

Cell shows	Meaning
`Error: Free trial for OpenAI used up (10/10) ...`	Activate your license and add your own key.
`Error: OpenAI API key not set ...`	Add your key via Set API Keys → Insert OpenAI API Key.
`Error calling OpenAI API: OpenAI API returned 401 ...`	The key was rejected. Re-copy it from OpenAI.
`... returned 429 ...`	Rate limit or no credit on your OpenAI account.
`... returned 404 ...`	The model name does not exist or was retired. Use one from the table above.
`No prompt provided`	The prompt cell is empty.