Hazumi News | Show HN: Mcp2cli – One CLI for every API, 96-99% fewer tokens than native MCP

Every MCP server injects its full tool schemas into context on every turn — 30 tools costs ~3,600 tokens/turn whether the model uses them or not. Over 25 turns with 120 tools, that's 362,000 tokens just for schemas.

mcp2cli turns any MCP server or OpenAPI spec into a CLI at runtime. The LLM discovers tools on demand:

    mcp2cli --mcp https://mcp.example.com/sse --list             # ~16 tokens/tool
    mcp2cli --mcp https://mcp.example.com/sse create-task --help  # ~120 tokens, once
    mcp2cli --mcp https://mcp.example.com/sse create-task --title "Fix bug"

No codegen, no rebuild when the server changes. Works with any LLM — it's just a CLI the model shells out to. Also handles OpenAPI specs (JSON/YAML, local or remote) with the same interface.

Token savings are real, measured with cl100k_base: 96% for 30 tools over 15 turns, 99% for 120 tools over 25 turns.

It also ships as an installable skill for AI coding agents (Claude Code, Cursor, Codex): `npx skills add knowsuchagency/mcp2cli --skill mcp2cli`

Inspired by Kagan Yilmaz's CLI vs MCP analysis and CLIHub.

https://github.com/knowsuchagency/mcp2cli

Summary

The article discusses mcp2cli, a command-line interface for controlling a Microchip MCP2221A USB-to-I2C bridge chip, which can be used to interface with I2C devices from a computer or single-board computer.

Story

Show HN: Mcp2cli – One CLI for every API, 96-99% fewer tokens than native MCP