A local tool for comparing two tables and showing what changed, including where those changes are concentrated in the data. It runs from the datadiffer Python package and requires a `DATADIFFER_CONFIG` environment variable.

Use it to diff table data and identify the slices where changes are concentrated.

It removes the need to manually inspect two table versions to find differences or the parts of the data most affected.

datadiffer — MCP server by gauthierpiarrette

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo

git clone --depth 1 https://github.com/gauthierpiarrette/datadiffer

Made for: Claude Code, Codex, Cursor, Gemini CLI, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/mcp/gauthierpiarrette/datadiffer/datadiffer/github.svg)](https://agentmods.dev/mcp/gauthierpiarrette/datadiffer/datadiffer)

Your own site

<a href="https://agentmods.dev/mcp/gauthierpiarrette/datadiffer/datadiffer"><img src="https://agentmods.dev/badge/mcp/gauthierpiarrette/datadiffer/datadiffer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/mcp/gauthierpiarrette/datadiffer/datadiffer"><img src="https://agentmods.dev/badge/mcp/gauthierpiarrette/datadiffer/datadiffer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured Not applicable: nothing here is loaded into a session.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

datadiffer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

server.json · 11 lines

What it actually says

{
  "datadiffer": {
    "command": "uvx",
    "args": [
      "datadiffer"
    ],
    "env": {
      "DATADIFFER_CONFIG": ""
    }
  }
}

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago First seen · 11 lines scan A 7b1b14f1762a

Subscribe to this mod's changes

datadiffer is an MCP server published in the GitHub repository gauthierpiarrette/datadiffer (0 stars, last pushed 2mo ago), licensed MIT. Its token cost is not measured: an MCP server costs its tool schemas, not its config file. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Analytics and metrics data-diff data-engineering data-quality duckdb mcp

datadiffer

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

What it actually says

What this file has done since we first saw it

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