Prompt Caching: Cut Latency and Cost on Repeated Context

Prompt caching lets the model store a stable prefix — a system prompt, style guide, or long document — so it isn't re-read on every call. On a cache hit you pay a fraction of the input cost (often around 10%) and get noticeably faster responses, because the expensive part of processing is reused rather than repeated.

The trick is ordering: put your unchanging content first and your variable content last. Keep the cached prefix identical byte-for-byte, mark the cache breakpoint after it, and remember caches are short-lived — typically a few minutes — so they pay off most under steady, repeated traffic like chat threads, batch jobs, or agent loops.

On CinderHub, caching a shared brand brief or storyboard spec across chat, image, and video calls means each new prompt only processes the small delta. Measure your cache-hit rate, stabilize the prefix, and you turn a costly long-context workflow into a cheap, snappy one.