Free MCP Plugins

Superpowers for the AI you already use. Open-source, no signup, no API key — and zero extra credits: they run on your own Claude or ChatGPT.

● 9 plugins · 29 tools live Claude + ChatGPT MIT licensed auto-updating
Step 1Copy a plugin's URL below.
Step 2Claude: Settings → Connectors → Add custom connector → paste. ChatGPT: Settings → Connectors → Advanced → Developer mode → paste.
Step 3Turn it on in a chat and ask away. That's it.

Semantic Diff

2 tools

What actually changed between two versions - the exact diff is computed, then analysed for meaning: rights gained or lost, protections removed, behaviour altered. Legal, privacy, code and prose lenses. Free MCP plugin for Claude and ChatGPT.

semantic_diffdiff_only
https://semantic-diff.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Open Data

3 tools

Grounds AI in real public data - Wikipedia summaries, live Open-Meteo weather, and official openFDA drug labels. All free, no API keys, every answer with a link you can check. Free MCP plugin for Claude and ChatGPT.

wikipediaweatherdrug_label
https://open-data.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Accessibility Auditor

3 tools

WCAG contrast ratios computed exactly with the real formula (not guessed), a contrast fixer that finds the nearest passing shade, and a full WCAG 2.2 audit protocol. Free MCP plugin for Claude and ChatGPT, zero extra credits.

check_contrastfix_contrastaudit_accessibility
https://accessibility-auditor.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

MCP Toolkit

8 tools

The basics AI keeps fumbling - real current time, exact math, word counts, regex actually tested, exact diff, token estimator, JSON/YAML validator, JWT decoder. Free MCP plugin for Claude and ChatGPT, zero extra credits.

get_current_timecalculateword_counttest_regexdiff_textestimate_tokensvalidate_datadecode_jwt
https://mcp-toolkit.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Pro Prompter

4 tools

Rewrites a rough request into a FAANG-grade prompt and runs it - 15 specialised task types. Free MCP plugin for Claude and ChatGPT, zero extra credits.

pro_promptrefine_promptrecall_promptsclear_memory
https://pro-prompter.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Learn Anything

1 tool

Turns any topic into a real lesson - prerequisites, intuition, worked example, misconceptions, practice and spaced repetition. Free MCP plugin for Claude and ChatGPT, zero extra credits.

curriculum
https://learn-anything.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Plain English

1 tool

Decodes contracts, leases, terms of service and policies into plain language - risks ranked, deadlines surfaced, questions to ask. Free MCP plugin for Claude and ChatGPT, zero extra credits.

decode
https://plain-english.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Thinking Tools

5 tools

Five rigorous reasoning protocols - debate, red team, argument audit, threat model, study sanity. Free MCP plugin for Claude and ChatGPT, zero extra credits.

debatered_teamaudit_argumentthreat_modelcheck_study
https://thinking-tools.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

Citation Guard

2 tools

Catches AI-hallucinated citations - verifies every DOI against live registries (doi.org, OpenAlex, Crossref) and flags fabricated, mismatched, retracted and duplicate references. Free MCP plugin for Claude and ChatGPT, zero extra credits.

verify_citationscheck_doi
https://citation-guard.mahendrakarpranay.workers.dev/mcp
Source ↗ Status ↗

How is this free?

These servers run no AI of their own. Each one returns either expert instructions or hard facts as plain text — and your Claude/ChatGPT does the thinking, on the plan you already pay for. There's no API key to buy and no bill to receive. The servers run on Cloudflare's free tier, so nothing costs anything to host either.

Add your own plugin to this page

This page isn't a hardcoded list — it reads GitHub. Tag any public repo with the mcp-plugin topic and set its homepage to the live /mcp URL, and it shows up here automatically within the hour.

gh repo edit <owner>/<repo> \
  --add-topic mcp-plugin \
  --homepage https://<your-worker>.workers.dev/mcp

Machine-readable list: /api/plugins