mcptoon v0.1.0 — Token-efficient MCP CLI client

mcptoon v0.1.0

Token-efficient MCP CLI client for every AI agent.

What it does

mcptoon connects to any MCP server (stdio or HTTP) and outputs TOON (Token-Optimized Object Notation) instead of JSON — saving up to 97% tokens on tool discovery and 40-60% on tool results.

Key features

• TOON encoding — strips JSON syntax overhead, keeps real data
• Zero dependencies — pure Python stdlib, 50KB install
• Cross-platform — Windows, macOS, Linux
• Works with every agent — Claude Code, Codex, OpenCode, Cursor, CatPaw, anything that runs shell commands
• One config for all agents — ~/.mcptoon/config.json
• Safety features — dangerous operation blocking, no telemetry, no credential storage
• Schema cache — 5-min TTL, avoids re-discovery
• Usage tracking — local stats, never transmitted

Token savings

Operation	JSON	mcptoon TOON	Savings
Tool discovery (96 tools)	~2,000	~60	97%
Tool result (structured)	~800	~350	56%
Tool result (raw HTML)	~1,000	~900	10%

Install

pip install mcptoon

Quick start

mcptoon init
mcptoon add fetch --stdio npx -y @modelcontextprotocol/server-fetch
mcptoon manifest --toon
mcptoon call fetch fetch '{"url":"https://example.com"}' --toon

Full Changelog: https://github.com/activeing123/mcptoon/commits/v0.1.0