Cache your repeated context to cut the API bill

Every single turn of your chat resends the same giant system prompt, and you keep paying full price for it again and again.

Beginner to intermediateRead 4 minDoing: about an hour6 steps

▶ Start

What you'll have at the end

The same feature at a lower cost, shown by comparing your token bill for ten calls before and after turning caching on.

Before you start

You need

You have a script or service that calls an LLM API and resends the same large block of content, a system prompt, a reference document, or tool definitions, on every call.

Not covered

Semantic caching, catching two differently worded but similar questions with a similarity check instead of an identical prefix, is a separate technique and isn't covered here.

Leans on

6 steps

Where to go next

Log the token count and dollar cost behind every API call you make

go there once you want a running log of every call's dollar cost over time; this recipe only proves the saving once, on ten calls

Checked 15 Aug 2026

Part of the Context Engineering cookbook