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MCP install guides

Pick your client, paste one block, then ask the test question. Each guide below is one server and one client: ChatGPT, Claude, Cursor, VS Code or Pi, with a tools/call posted to the live server and the date of that check.

CVE Risk Check in Claude Code

Add the cve server to Claude Code with one command, run from your project directory.

claude mcp add --transport http cve \
  https://cve.openkrill.app/mcp

Check it with claude mcp get cve. In the Claude app, paste the same URL as a custom connector instead.

Test it
How bad is CVE-2021-44228?
Expect tool
check_cve

Full steps: CVE Risk Check in Claude.

CVE Risk Check in Cursor

Add this entry to .cursor/mcp.json in the project, or to ~/.cursor/mcp.json for every project. Merge it with servers you already have.

{
  "mcpServers": {
    "cve": {
      "url": "https://cve.openkrill.app/mcp"
    }
  }
}

Save the file, then confirm the server is enabled in Cursor Settings, then MCP. Reload the window if it stays disconnected.

Test it
How bad is CVE-2021-44228?
Expect tool
check_cve

Full steps: CVE Risk Check in Cursor.

CVE Risk Check in VS Code

Add this entry to .vscode/mcp.json in the project. VS Code uses servers as the top-level key, with the type next to the url.

{
  "servers": {
    "cve": {
      "type": "http",
      "url": "https://cve.openkrill.app/mcp"
    }
  }
}

Save the file, select Start above the entry and confirm that you trust the server. Then ask in Chat, in Agent mode.

Test it
How bad is CVE-2021-44228?
Expect tool
check_cve

Full steps: CVE Risk Check in VS Code.

CVE Risk Check in ChatGPT

Turn on Developer mode in ChatGPT settings, then Security and login. Open ChatGPT plugins, select the plus button, choose the public endpoint and paste this URL.

https://cve.openkrill.app/mcp

No OAuth client and no key. Start a new conversation and add the connection from the tools menu.

Test it
How bad is CVE-2021-44228?
Expect tool
check_cve

Full steps: CVE Risk Check in ChatGPT.

Nothing is installed on your side for any client: no Python, no Node, no package and no API key. Every server is a remote MCP endpoint over streamable HTTP, and the same steps work for every server below with its own URL.

If it does not work

The tool does not show up

Check that the URL ends in /mcp and has no local command around it. Claude Code: run claude mcp list and start a new session. Cursor: open Cursor Settings, then MCP, and reload the window. VS Code: run MCP: List Servers and restart the server. ChatGPT: open the connection, select Refresh, and start a new conversation. Pi: run /reload, then /mcp.

429 or rate_limited

Each server takes 60 calls a minute from one network, and some tools take fewer. Past that the call comes back as a tool error that starts with rate_limited: wait a minute and ask again. daily_limit means the server reached its shared daily cap, which resets at 00:00 UTC. A limit is not an answer, so do not read it as no results. For higher limits, ask support@openkrill.app for a key.

Developer mode is missing in ChatGPT

Developer mode is in ChatGPT settings, then Security and login, on the web. In a Team or Enterprise workspace an admin can hide it, so ask the admin to allow custom connections first. Without developer mode ChatGPT cannot add a custom MCP server.

JSON entry has no type

Claude Code skips an entry in .mcp.json that has a url but no type. Add "type": "http" next to the url, or add the server with claude mcp add --transport http, which writes the type for you. The VS Code entry needs the same type field. Cursor and Pi read the url alone.

After an install, ask the "Test it" question under the server. If the client calls the tool named there, the setup works.

Building your own agent instead of using a client? The agent SDK snippets connect the OpenAI Agents SDK and LangChain to the same servers.

These pages are generated from the plugin listings, so the tool names match what tools/list returns. A combination with no checked call is left out. There is no sign-up and no key on the plugin hosts.

Not sure which server? Start with index_tools

Connect https://api.openkrill.app/mcp once. Its index_tools tool searches every server on this page by task in plain words and answers with the tool name, what it does and the MCP address to add. The servers below list only their own tools, so start here when you do not know which one you need. No key, no sign-up.

claude mcp add --transport http openkrill https://api.openkrill.app/mcp

In Cursor, VS Code, ChatGPT or Pi, add the same address as a remote MCP server; streamable HTTP, no headers. Test it with "Which OpenKrill tool tells me how bad a CVE is?". The agent should call index_tools and name check_cve on https://cve.openkrill.app/mcp.

To give an agent every tool on one server, connect the gateway at https://api.openkrill.app/gateway/mcp. Each tool is named <server>__<tool>, for example cve__check_cve, and each call runs on the owning server with its usual per-network limits. The full list has every tool of every server, about 200 KB, so a client that loads every tool into the model should pick a family with ?servers=, or name servers separated by commas.

claude mcp add --transport http openkrill-dev-security "https://api.openkrill.app/gateway/mcp?servers=dev-security"

The same tools work in Zapier without code: join the OpenKrill Tools integration with this invite link. It has 40 ready actions, such as Check VAT Number and Check CVE, and Run Any OpenKrill Tool for the rest. It is early and private until Zapier reviews it; every action is one gateway call and needs no key. How to use it.

Install every tool in one command

Add the openkrill marketplace to Claude Code once, then install the tool families you need. Each plugin brings the MCP servers and a skill that says when to use each tool. No key, no sign-up.

claude plugin marketplace add nguyenhieuec/agent-tools-plugins
claude plugin install dev-security@openkrill

dev-security brings CVE Risk Check, Package Health Check and Dev Facts Check. Start a new Claude Code session after an install and ask: "Is lodash 4.17.15 vulnerable, and which version fixes it?" Swap dev-security for any plugin name below. The source is the public agent-tools-plugins repository.

PluginTools
dev-securityCVE Risk Check, Dev Facts Check
web-emailSite SEO & AI Crawler Audit, SEO Audit, IndexNow Submit, Page Fetch, Domain Mail Check, Startup Name Check
commerceStore Price Tracker, Catalog QA Desk, Tariff & HS Code Duty Finder, CertPacket, Associate Product Finder
officeBusiness Days & Workday Calc, Tax Numbers, EU Business & VAT Checker, Document Tools, Send Out, Photo Sheet, BillPeak, Share Link Resolver
sales-hiringCompany Jobs Finder, Hiring Signals, Remote Jobs by Country, E-Commerce Store Enricher
researchCitation Checker, Regulation Reader, Belief Poll
marketsTrade Chart
consumerRecall Check, Car Check, Food Facts, Travel Check, Settlement Claim Finder
content-mediaPost Kit, Transcript Kit, Video Grab, Sound Vocabulary, Post Stats

Find a server

All 23 servers with a checked guide are listed below. Type a task, a tool name or a word such as CVE, VAT, recall or SEO to narrow the list.

Company Jobs Finder

Open jobs at named companies. Server: https://jobs.openkrill.app/mcp. Tools: find_company_jobs, rank_jobs_for_profile, job_fit_brief, profile_keyword_check.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What jobs is Stripe hiring for right now?" The client should call find_company_jobs.

Short questions this server answers: Open Jobs at Named Companies: Remote, Salary and Fit.

Startup Name Check

Is that name's domain taken?. Server: https://names.openkrill.app/mcp. Tools: check_domain_availability.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Is google.com available?" The client should call check_domain_availability.

Short questions this server answers: Check if a startup name's domain is taken.

Recall Check

US vehicle and product recalls. Server: https://recalls.openkrill.app/mcp. Tools: check_vehicle_recalls, decode_vin, search_product_recalls, search_food_drug_recalls, search_pet_food_recalls.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Does my 2018 Honda Accord have any recalls?" The client should call check_vehicle_recalls.

Short questions this server answers: Check US vehicle, product, food and pet food recalls.

Citation Checker

Check references and DOIs. Server: https://citations.openkrill.app/mcp. Tools: check_references.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Is this DOI correct? LeCun, Bengio & Hinton (2015), Deep learning, Nature 521, 436-444, doi:10.1038/nature14540." The client should call check_references.

Short questions this server answers: Check references and DOIs for real papers.

Store Price Tracker

Track an online store's prices. Server: https://stores.openkrill.app/mcp. Tools: check_store_prices, get_product_price_history, compare_store_prices.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Track competitor prices on allbirds.com." The client should call check_store_prices.

Short questions this server answers: Track an online store's prices and stock changes.

Business Days & Workday Calc

Workdays, holidays, SLA & PTO. Server: https://businessdays.openkrill.app/mcp. Tools: count_business_days, add_business_days, list_holidays.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "How many working days are there between 14 July 2026 and 18 August 2026 in Germany?" The client should call count_business_days.

Short questions this server answers: Count working days and business-day due dates.

Tariff & HS Code Duty Finder

HS codes, customs duty & tax. Server: https://tariffs.openkrill.app/mcp. Tools: find_tariff_codes, get_duty_rate.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What are candidate tariff codes for a lithium-ion battery imported into the US?" The client should call find_tariff_codes.

Short questions this server answers: HS Code Finder and US or UK Import Duty Rate Lookup.

EU Business & VAT Checker

Validate VAT, LEI & registries. Server: https://eubusiness.openkrill.app/mcp. Tools: company_from_domain, check_vat_number, find_company_lei, lookup_company_registry.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Which company is behind the domain doctolib.fr, and how big is it?" The client should call company_from_domain.

Short questions this server answers: Check EU VAT numbers, LEIs and company registers.

Regulation Reader

Read US federal regulations. Server: https://rules.openkrill.app/mcp. Tools: get_cfr_section, search_cfr, search_federal_register.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What does 21 CFR 11.10 say about controls for closed systems?" The client should call get_cfr_section.

Short questions this server answers: Look up US federal regulations and Federal Register rules.

Site SEO & AI Crawler Audit

SEO, AI citation, CRO, leaks. Server: https://sitecheck.openkrill.app/mcp. Tools: check_ai_crawler_access, check_page_tags, trace_redirects, product_page_seo, ai_readiness_check, link_sample_check, landing_page_check, exposure_check, ai_app_check.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Is https://www.allbirds.com/products/mens-tree-runners set up for search? Check the title, description and product data." The client should call product_page_seo.

Short questions this server answers: AI Crawler Access, Share Tags and Redirect Chain Check.

Travel Check

Travel advice and airports. Server: https://travel.openkrill.app/mcp. Tools: get_travel_advice, get_airport_status, compare_advisories.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What is the current travel advice for Thailand?" The client should call get_travel_advice.

Short questions this server answers: Check government travel advice and airport delays.

Food Facts

Look up food by barcode. Server: https://food.openkrill.app/mcp. Tools: lookup_barcode, search_products, compare_products, check_allergens.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What is in the product with barcode 3017620422003?" The client should call lookup_barcode.

Car Check

Recalls, ratings and mpg. Server: https://cars.openkrill.app/mcp. Tools: decode_vin, get_vehicle_report, list_recalls, get_fuel_economy.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What car is VIN 1HGCM82633A004353?" The client should call decode_vin.

Document Tools

Word count, translate, ICS/CSV. Server: https://docs.openkrill.app/mcp. Tools: count_text, make_calendar_file, make_csv_file, translate_page.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "How many words and characters is this sentence: 'The quick brown fox jumps over the lazy dog.'?" The client should call count_text.

Tax Numbers

US tax figures, VAT, sales tax. Server: https://tax.openkrill.app/mcp. Tools: get_tax_parameters, get_mileage_rate, tax_deadlines, estimate_federal_tax, tax_duty.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "What is the standard deduction for a single filer in 2026?" The client should call get_tax_parameters.

Short questions this server answers: 2026 Standard Deduction, Tax Brackets and Mileage Rate Lookup.

Catalog QA Desk

Check product CSVs and feeds. Server: https://catalogqa.openkrill.app/mcp. Tools: csv_import_preflight, merchant_feed_check, listing_text_audit, listing_fix_sheet, describe_product_photo.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Will this Shopify product CSV import cleanly?" The client should call csv_import_preflight.

Dev Facts Check

EOL, licences, browsers, RFCs. Server: https://devfacts.openkrill.app/mcp. Tools: get_eol_status, check_runtime_eol, check_license, check_browser_support, lookup_rfc, get_release_notes.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Is Node.js 20 still supported and when does it reach end of life?" The client should call get_eol_status.

Short questions this server answers: Runtime End of Life, License, Browser Support and RFC Lookup.

CVE Risk Check

CVE and dependency triage. Server: https://cve.openkrill.app/mcp. Tools: check_cve, check_cves, list_recent_kev, triage_dependencies, check_site_for_cve, list_cve_day_advisories, search_oss_security.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "How bad is CVE-2021-44228?" The client should call check_cve.

Short questions this server answers: CVE Exploit Status, EPSS and Patch Priority Lookup.

Domain Mail Check

Mail delivery and DNS check. Server: https://mailcheck.openkrill.app/mcp. Tools: launch_score, delivery_check, check_dns_hygiene, check_email_auth, check_dns_records, lookup_domain_registration.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Is acme-mail.com ready for cold email outreach?" The client should call launch_score.

Short questions this server answers: Email SPF, DKIM, DMARC and Domain Expiry Check.

SEO Audit

SEO audit, AI citation checks. Server: https://seoaudit.openkrill.app/mcp. Tools: audit_site, score_page_citation, find_ai_questions, compare_citations, audit_page, local_ai_readiness, check_ai_instructions, generate_ai_instructions, audit_ai_search.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Audit example.com for SEO problems." The client should call audit_site.

Page Fetch

Web page as Markdown or JSON. Server: https://pagefetch.openkrill.app/mcp. Tools: fetch_page, extract_page_json.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Read https://example.com as Markdown." The client should call fetch_page.

Post Stats

Public views of social posts. Server: https://poststats.openkrill.app/mcp. Tools: get_post_stats, compare_posts, list_channel_stats.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "How many views and likes does https://www.youtube.com/shorts/8bE_lGbtjyY have?" The client should call get_post_stats.

IndexNow Submit

Submit a sitemap to IndexNow. Server: https://indexnow.openkrill.app/mcp. Tools: indexnow_check, indexnow_submit.

Install in ChatGPT, Claude, Cursor, VS Code, Pi.

Test it: ask "Is my IndexNow key file set up right? Site tools.openkrill.app, key okindexnow20261005." The client should call indexnow_check.

If you already know the role rather than the server, start at the role guides for AI agents. Definitions of MCP, streamable HTTP and the other words on these pages are in the MCP and agent glossary.