Prompt-caching MCP plugin automatically reduces Claude API costs by identifying stable context

Prompt-caching is an MCP plugin that automatically reduces Claude API costs by leveraging Anthropic's caching feature. When using Claude Code or Cursor/Windsurf/Zed with the Anthropic API, each turn typically re-sends the entire context from scratch, which means thousands of tokens get billed at full rate repeatedly during long debugging sessions.

How it works

Anthropic provides a caching feature that makes repeated reads cost 0.1× instead of 1×, but this requires manually marking what gets cached. The prompt-caching plugin runs in the background, identifies stable parts of your context (system prompts, tool definitions, large file reads), and automatically marks them before each API call.

Performance results

• 20-turn bug fix: 85% cheaper
• 15-turn refactor: 80% cheaper
• 40-turn coding session: 92% cheaper

Installation

For Claude Code users:

/plugin marketplace add https://github.com/flightlesstux/prompt-caching
/plugin install prompt-caching@ercan-ermis

For Cursor/Windsurf/Zed:

npm install -g prompt-caching-mcp

Then point your MCP configuration at it.

The tool is open source under the MIT license and available for free. The repository is at https://github.com/flightlesstux/prompt-caching.