MCP Plugin · Open Source · MIT

Built with Claude, for Claude.

Stop paying
full price
twice.

Automatic prompt caching for Claude Code. Detects stable content — system prompts, tool definitions, file reads — and marks them so you pay 90% less on every repeated turn.

Get started View on GitHub →

Claude Code

# One command. That's it.

/plugin install flightlesstux/prompt-caching

# No npm. No config file. No restart.
# Savings start on the next turn.

90% average token
cost reduction

90% token cost reduction

4 session modes

0 config required

MIT open source

How prompt-caching works

Anthropic's caching API stores stable content server-side for 5 minutes. Cache reads cost 0.1× instead of 1×. This plugin places the breakpoints automatically.

🐛

BugFix Mode

Detects stack traces in your messages. Caches the buggy file + error context once. Every follow-up only pays for the new question.

stack trace detected

♻️

Refactor Mode

Detects refactor keywords + file lists. Caches the before-pattern, style guides, and type definitions. Only per-file instructions re-sent.

refactor keywords + files

📂

File Tracking

Tracks read counts per file. On the second read, injects a cache breakpoint. All future reads cost 0.1× instead of 1×.

always on — all modes

🧊

Conversation Freeze

After N turns, freezes all messages before turn (N−3) as a cached prefix. Only the last 3 turns sent fresh. Savings compound.

turn count threshold

Benchmarks

Measured on real Claude Code sessions with Sonnet. Break-even at turn 2.

Session type	Turns	Without caching	With caching	Savings
Bug fix (single file)	20	184,000 tokens	28,400 tokens	85%
Refactor (5 files)	15	310,000 tokens	61,200 tokens	80%
General coding	40	890,000 tokens	71,200 tokens	92%
Repeated file reads (5×5)	—	50,000 tokens	5,100 tokens	90%

Cache creation costs 1.25× normal. Cache reads cost 0.1×. Every turn after the first is pure savings.

Install prompt-caching

One command for Claude Code. For Cursor, Windsurf, ChatGPT, Perplexity, Zed, Continue.dev, and any other MCP-compatible client — use the npm install path below.

Claude Code recommended

Run this inside Claude Code — no npm, no config file, no restart needed:

/plugin install flightlesstux/prompt-caching

Claude Code's plugin system handles everything automatically. The get_cache_stats tool is available immediately after install.

Cursor · Windsurf · ChatGPT · Perplexity · Zed · Continue.dev · any MCP client

Install globally via npm

npm install -g prompt-caching

Add to your client's MCP config

Cursor → .cursor/mcp.json · Windsurf → MCP settings · Any MCP client → stdio

{
  "mcpServers": {
    "prompt-caching": {
      "command": "prompt-caching"
    }
  }
}

Open source · MIT · Zero lock-in

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