Building and paying.
WHAT AN API GIVES YOU
Programmatic access. Your software sends requests and receives responses.
HOW PRICING USUALLY WORKS
Per token, for input and output separately.
Output is frequently more expensive than input.
WHAT DRIVES COST
Prompt length, sent every time Output length Model choice Volume
THE REPEATED PROMPT PROBLEM
A lengthy system prompt sent with every request costs on every request.
At volume, that dominates.
WHAT REDUCES COST
Shorter prompts Smaller models for simple tasks Caching, where supported Not sending more context than needed
WHAT TO ESTIMATE BEFORE BUILDING
Requests per day, average prompt and output length, model choice.
That gives you a cost figure. Most projects do not calculate it and are surprised.
RATE LIMITS
Requests per minute and tokens per minute. Plan for them.
WHAT TO MONITOR
Spend, daily. Costs can rise unexpectedly when usage changes.
