A thread you can test
From Completion to Chat
4 notes move from the word to a real choice at work — understand it first, then decide whether to use it.
Each note stands alone, or becomes the next step in this thread.
THE QUESTION THIS PAGE ANSWERS
ANSWER FIRSTWhat is From Completion to Chat, and which AI decisions does it change?
It's clearly a conversation — so why is the API called "completions"? A typewriter animation explains This page keeps the related concepts, common mistakes, and practical notes in one reading thread.
First decide whether you are blocked by a definition, a choice, or verification; then choose the closest of the 4 notes below.
Start with “The chat/completions Mystery,” then restate the conclusion using your own task.
Do not treat every method in a topic as interchangeable. The answer changes with the input, risk, and acceptance bar.
THIS QUESTION THREAD
Put the word back inside the choice it changes.
The chat/completions Mystery
It's clearly a conversation — so why is the API called "completions"? A typewriter animation explains
Faking a Chat History
OpenAI's original experiment: turning a completion machine into a chatbot
Chat Template + SFT
Jinja formatting, instruction fine-tuning — LLMs finally learn to talk
The Context Window Is Key
Why are prompts powerful enough? Token truncation visualization — no retraining needed