Concepts Fondamentaux
System Prompt
An instruction block sent before the conversation that configures model behavior.
The system prompt is a privileged message — separate from the user turn — that sets the model's persona, constraints, and task context. It is consumed as input tokens on every request, so long system prompts can significantly increase costs at scale. Effective system prompts are concise but precise.
Termes Associés
Prompt Engineering
The practice of designing inputs to elicit optimal outputs from language models.
Completion
The text output generated by a language model in response to a prompt.
Token
The basic unit of text that language models process and are billed by.
Context Caching
A provider feature that stores a reusable prefix in memory to avoid re-processing repeated tokens.