Cut Your Claude API Costs With Context Engineering — Reusable Scripts, Model Routing, and Token Pruning

Cut token spend with reusable scripts, model routing, and pruning

Context Engineering Guide

By the end of this guide, you'll have a context engineering strategy running inside Claude Code — reusable scripts replacing repeated rewrites, cheaper models handling simple tasks, and a pruning system keeping your context window lean so you run longer sessions for less money.

Who This Is For

  • You're running Claude Code sessions that are getting expensive and you're not sure why

  • You're hitting usage or budget limits mid-session on projects that should be well within your tier

  • Claude keeps rewriting the same code block to fix bugs instead of building a tool that handles it once

  • You're defaulting to Opus for every task — including simple ones that don't need it

  • You want longer, more productive dev sessions without increasing your API spend

What You'll Build

A three-part context engineering strategy for Claude Code:

  • Modular Script Skeletons — reusable terminal tools that replace repeated in-chat code rewrites

  • Model Routing Schema — a task-by-task breakdown of what routes to Sonnet or Haiku vs. Opus, keeping execution significantly cheaper without sacrificing output quality

  • Pruning Milestone System — a reminder framework that tracks when your context window is getting too heavy and triggers compaction before it starts costing you

What You'll Need

  • Claude Code CLI installed and running

  • An active development project with a defined working directory

  • Basic terminal comfort (you'll be running /compact and bash commands)

  • An Anthropic API key with access to multiple model tiers (Opus, Sonnet, Haiku)

Going Further

  • Apply model routing to a multi-agent swarm — Guide: Orchestrate a 60-Agent AI Swarm With Smart Task Routing Using Rooflow (AI Agent)

  • Evaluate which model tier fits which task type — Guide: How to Evaluate a New AI Model Before You Change Your Workflow (AI Agent)

  • Build reusable scripts into a persistent memory system — Guide: Build a Free Persistent AI Memory System Using Claude Code and Obsidian (AI Agent)