Json

io.github.rog0xPublished by GitHub account rog0xv1.0.1Updated Oct 24, 2026

JSON/YAML/CSV validate, diff, transform for AI agents

VerifiedSTDIODesktop onlyDeveloper ToolsData & Analytics

Overview

AI-generated overview

Lets an assistant validate, diff, transform, and convert JSON, YAML, and CSV data locally.

What you can do
Provides seven data-manipulation tools: json_validate checks JSON against a JSON Schema and returns errors with field paths; json_diff compares two JSON objects and reports added, removed, and changed values by dot-notation path; json_transform applies pick, rename, flatten, and unflatten operations; csv_to_json and json_to_csv convert between CSV text and JSON arrays; and yaml_to_json and json_to_yaml convert between YAML and JSON. All work is done on text passed to the tools.
When to use it
Useful when an assistant needs to check or reshape structured data during a task: validating config or API payloads against a schema, comparing two versions of a JSON document, extracting or renaming fields, or converting between JSON, YAML, and CSV formats.
Requirements
Runs as a local process over stdio. The README shows installing the npm package and building it, then registering it with a Node.js command pointing at the built entry file. No accounts, API keys, or environment variables are declared.
Before you install
The README's example configuration uses an absolute local path to the built file, which must be adjusted for the machine. The tools operate on text supplied in the request; no credentials or network access are declared.

Installation

In SourceWeft

  1. Open Json in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

mcp-json-tools

An MCP (Model Context Protocol) server that provides JSON and data manipulation tools for AI agents. Designed for use with Claude Code, Claude Desktop, and any MCP-compatible client.

Tools

ToolDescription
json_validateValidate JSON data against a JSON Schema, returning detailed errors with paths
json_diffCompare two JSON objects, showing additions, removals, and changes with paths
json_transformTransform JSON with pick, rename, flatten, and unflatten operations
csv_to_jsonConvert CSV text to a JSON array with configurable headers, delimiters, and type casting
json_to_csvConvert a JSON array of objects to CSV text
yaml_to_jsonConvert YAML text to JSON
json_to_yamlConvert JSON text to YAML

Installation

bash
npm installnpm run build

Usage with Claude Code

bash
claude mcp add json-tools -- node D:/products/mcp-servers/mcp-json-tools/dist/index.js

Usage with Claude Desktop

Add the following to your Claude Desktop configuration file:

Windows: %APPDATA%\Claude\claude_desktop_config.json macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

json
{  "mcpServers": {    "json-tools": {      "command": "node",      "args": ["D:/products/mcp-servers/mcp-json-tools/dist/index.js"]    }  }}

Tool Details

json_validate

Validate JSON data against a JSON Schema. Returns a valid boolean and an array of errors, each with the field path, message, and schema keyword that failed.

Parameters:

  • data (string) — JSON data to validate
  • schema (string) — JSON Schema to validate against

json_diff

Compare two JSON objects and produce a structured diff. Each difference includes the dot-notation path, the type of change (added, removed, or changed), and the old/new values.

Parameters:

  • original (string) — Original JSON object
  • modified (string) — Modified JSON object

json_transform

Apply transformations to JSON data. Supports four operations:

  • pick — Extract specific fields by dot-notation paths
  • rename — Rename top-level keys using a mapping object
  • flatten — Flatten nested objects into dot-separated keys
  • unflatten — Restore dot-separated keys into nested objects

Parameters:

  • data (string) — JSON data to transform
  • operation (string) — One of: pick, rename, flatten, unflatten
  • fields (string[]) — For pick: field paths to extract
  • mapping (object) — For rename: old-to-new key mapping
  • separator (string) — For flatten/unflatten: separator character (default: ".")

csv_to_json

Parse CSV text into a JSON array of objects.

Parameters:

  • csv (string) — CSV text to convert
  • hasHeaders (boolean) — Whether the first row is headers (default: true)
  • delimiter (string) — Column delimiter (default: ",")
  • castTypes (boolean) — Auto-cast numbers and booleans (default: false)

json_to_csv

Convert a JSON array of objects to CSV text. Headers are derived from the union of all object keys.

Parameters:

  • data (string) — JSON array to convert
  • delimiter (string) — Column delimiter (default: ",")
  • includeHeaders (boolean) — Include header row (default: true)

yaml_to_json / json_to_yaml

Convert between YAML and JSON formats.

Parameters:

  • yamlText / jsonText (string) — Text to convert
  • indent (number) — Indentation spaces (default: 2)

License

MIT

Source: README.md at commit bf22559

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v1.0.1LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts