Prompt Caching in the API
What changed
Offering automatic discounts on inputs that the model has recently seen
Why it matters
A concrete addition to Practical AI: Tools, Models & Frameworks: it changes what's available to builders today rather than being general commentary.
How it compares
Related prior coverage to compare against:
- Introducing GPT-5.1 for developers
- Speeding up agentic workflows with WebSockets in the Responses API
- Introducing GPT-5 for developers
Sources
- Prompt Caching in the API (openai-blog)primary