Ruby

1.3x faster.
Less memory. Zero gems.

ZeroMCP vs fast-mcp — HTTP benchmarks.

Throughput
4.76K req/s ZeroMCP
vs.
3.73K req/s fast-mcp
Memory
33 MB ZeroMCP
vs.
48 MB fast-mcp

HTTP Performance — Head to Head

Same hello tool. Same methodology. 5-minute sustained load in Docker. Rack+Puma for ZeroMCP, fast-mcp with built-in server.

req/s p50 p99 Memory CPU
ZeroMCP (Rack+Puma) 4.76K 0.19ms 0.43ms 33 MB 0.06%
fast-mcp 3.73K 0.23ms 0.57ms 48 MB 0.02%

The tradeoff

Choose fast-mcp

If you want a Ruby DSL for rapid prototyping with a built-in server. Quick to start, familiar gem workflow.

  • Ruby DSL for rapid prototyping
  • Built-in server — quick to start
  • Familiar gem workflow
Choose ZeroMCP

If you want to run on infrastructure you already trust. Rack+Puma, zero gems, 1.3x faster, less memory.

  • 0 gems
  • File-based tools — drop a .rb file, it's live
  • Rack+Puma + Sinatra
  • Built-in sandbox with enforced permissions
  • 4.76K req/s on Rack+Puma

Drop a .rb file. It's an MCP tool.