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JSONShelf

by walkojas-boop · remote · no sign-in to list tools · v1.0.0 · published by GitHub user walkojas-boop

Deterministic JSON repair, validate, example-gen, schema-coerce for agents. Zero LLM, sub-10ms.

Changes · 3
CompareRegistry entry

4 tools: 3 change things and 1 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http jsonshelf https://jsonshelf.vercel.app/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

4 tools

Changes things 3Claude Code: ask
  • jsonshelf_coerceSoft-cast values to match a schema (string "42" → 42 for integer fields, etc.).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    Soft-cast values to match a schema (string "42" → 42 for integer fields, etc.).
  • jsonshelf_exampleGenerate a minimal valid example matching a JSON schema.No findings

    Why it is in this group

    • The description's first verb is "generate": a word for a change.
    Description, as the server wrote it
    Generate a minimal valid example matching a JSON schema.
  • jsonshelf_repairRepair malformed JSON.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    Repair malformed JSON. Returns valid JSON plus a diff of what was fixed.
Only reads 1Claude Code: allow
  • jsonshelf_validateValidate JSON against a schema.No findings

    Why it is in this group

    • The name "jsonshelf_validate" says "validate": a word for reading.
    Description, as the server wrote it
    Validate JSON against a schema. Returns structured errors with JSON Pointer paths and remedies.

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http jsonshelf https://jsonshelf.vercel.app/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__jsonshelf__jsonshelf_validate"
    ],
    "ask": [
      "mcp__jsonshelf__jsonshelf_repair",
      "mcp__jsonshelf__jsonshelf_example",
      "mcp__jsonshelf__jsonshelf_coerce"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as jsonshelf. Review it before you use it.