Zod vs Valibot vs ArkType for MCP Tool Schemas | Waseem Anjum
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I wrote one MCP tool schema in Zod 4, Valibot and ArkType on MCP SDK 2.4: tools/list JSON Schema, datetime gotchas, parse speed, cold start, bundle size.

I wrote this (my own blog). I needed a schema lib for MCP tool inputs and kept seeing Zod vs Valibot vs ArkType takes with no numbers, so I timed the same schemas on Node 24 with tinybench and checked bundle size with esbuild.

Numbers and the MCP wiring are in the post. Short version: Valibot won the hot path for the shapes I use, ArkType was close, Zod 4 was fine but heavier. Bundle size mattered more than I expected once the schemas sat behind an MCP server.

Curious what people actually ship for tool schemas in production — Zod by default, or something lighter?

  • Artwork@lemmy.worldEnglish
    1·
    7 days ago

    Please just don’t make it always dependent on third parties as MCP/AI toolset/processing/vendors…

    All development toolset must be optimal and transparent for a human developer as mandatory, so that any developer will always be able to safely and accountably execute local tools and develop it safely in their own local workspace.

    These MCP/AI tools must always be supplementary and optional for anyone who use those sorrowful tools only, keeping it all possible to develop without them in the first place. Development must always stay independent on AI vendors and always focus on convenient and transparency between human developers.