Live tech-stack data for 887,540+ websites. Plug Claude, Cursor or Clay into our database. Find prospects by the tools they use, trigger outreach the moment their stack moves. No technical chops required.
REST API + native MCP server. Clay tables, AI SDR pipelines, Cursor agents pull live stack data programmatically. No headless browser automation, no per-site scraping.
Full-stack snapshot for any URL
CMS, hosting, JS framework, analytics, payment processor, fonts, AI tools, marketing stack. Built on a 3,854-tech open fingerprint catalog, extended with modern AI / SaaS coverage (Resend, Convex, Vapi, Retell, Anthropic SDK, Cal.com…).
Historical change signals
When did this site adopt Stripe ? Remove Drift ? Migrate from WordPress to Webflow ? 17 Common Crawl archives ingested, going back 18 months. Every stack change is a trigger event for outreach.
API + MCP for AI agents
Native MCP server for Claude Desktop, Cursor, Zed. Six tools : search_sites, get_site, get_adoption_signals + 3 more. Free tier 10 lookups/mo, Pro €99/mo unlimited.
Examples
Real queries you'll send.
Copy-paste these into Claude Desktop, Cursor, or your terminal. The agent or your script gets back JSON with the matching sites.
Plain English (MCP via Claude, Cursor, Zed)
"Find me 100 US-based SaaS websites using Stripe + Vercel + Anthropic SDK with at least 10k monthly visits. Add them to a list called 'AI-native Stripe targets'."
"Show me every site that adopted Anthropic SDK in the last 30 days. Export their domains + traffic estimates as CSV."
"Get the full tech stack for vercel.com and summarize the GTM-relevant tools (analytics, CRM, support)."
"Which companies removed Drift in the last 90 days ? Pin the top 50 by traffic to a list."
Full reference at /api/docs · MCP setup snippets at /mcp
How it works
From query to answer in under a second on warm cache.
1
Search any domain
Type any URL on the home page or hit GET /api/sites/{domain}. 887,540 sites already indexed, the rest queued on demand.
2
Get the stack
Every detected tech with first-seen / last-seen dates, detection source (HTML, JS, headers, cookies), category, links into the 3,854-tech catalog.
3
Plug into your workflow
10 free API + MCP lookups / month. Pro €99/mo unlimited, with exports, signal webhooks, and the full 18,898,811 detection event log.
Use cases
Built for the workflows you already run.
AI SDR
Trigger outreach on stack changes
Adopted Stripe last week ? Removed Drift ? Migrated to Vercel ? Each transition is a hand-raise event. Pipe signals into Clay, Apollo, Smartlead.
GTM
Target by exact tech stack
Find every Series-A B2B SaaS using both Anthropic SDK + Pinecone + Vercel. Build ICP segments from technology fingerprints, not headcount guesses.
Competitive intel
Audit competitor stacks
See what tools your competitor stopped paying for. Find migration patterns. Spot which tools their engineers added but PM never approved.
Devtools
Power your AI agent
Native MCP server. Claude Desktop, Cursor, Zed query the catalog directly. No Python wrapper, no scraping, no Wappalyzer headless-browser hell.
FAQ
Do I need to be technical to use this ?
No. Two ways to use it. (1) The website itself is a normal app : sign up, search by tech stack or country, click any site to see its full toolkit, export to CSV. Zero code. (2) For automation, you connect your AI agent (Claude Desktop, Cursor, Clay, etc.) once with copy-paste config and it queries the database for you in plain English : "Find me SaaS companies using Stripe in the US and pin them to a list." That's it.
What is MCP ?
Model Context Protocol. Anthropic released it in late 2024 as a standard way for AI agents to talk to external services. Instead of you copy-pasting data into ChatGPT or writing Python scripts, the agent connects directly to a service (like ours) and queries it natively. We expose 6 MCP tools : search by tech, get a site's stack, browse the catalog, get adoption signals, get removal signals, add sites to a list. Setup is 60 seconds : paste a JSON config into Claude Desktop / Cursor / Zed, restart, done.
Is the website technology checker free ?
Yes. The /sites/{domain} surface is open for every tracked site. Sign up for a free account to get 10 API + MCP lookups per month for programmatic access. Pro €99/mo unlocks unlimited queries, exports, and webhook signals.
How does this compare to Wappalyzer / BuiltWith / WhatRuns ?
Wappalyzer is a browser extension : one site at a time, no history, no API at this price point. BuiltWith starts at $295/mo. WhatRuns is the same browser-extension model. We built technologychecker.ai as a queryable database from day one : REST API + MCP server, signal events for adoptions and removals, 18 months of Common Crawl history, free tier for evaluation.
How accurate is the detection ?
We use the open-source enthec catalog (active fork of Wappalyzer, 7,537 fingerprints), extended with a custom catalog of modern AI / SaaS tools that mainstream catalogs miss (Resend, Convex, Vapi, Retell, Anthropic SDK, Cal.com, Polar…). Detection runs on HTML, JS, response headers, cookies, meta tags, and DOM selectors. Coverage : ~86% of techs detectable from a single page fetch.
Where does the data come from ?
Our crawler fetches the homepage of every site in our index. For historical signals (when a tech was added / removed), we ingest Common Crawl monthly archives going back 18 months. Both pipelines write into ClickHouse. The MySQL pivot keeps the current snapshot for the listing pages.
Can I use this in a commercial project ?
Yes. Free tier 10 lookups / mo for evaluation. Pro €99/mo per workspace, unlimited queries, full API + MCP, CSV / JSON export, webhook signals. No per-seat pricing, no annual lock-in, cancel anytime.
Can my AI agent query the catalog ?
Yes. MCP server at /api/mcp/technologychecker. Add the endpoint to your Claude Desktop or Cursor config. The agent gets 6 tools : search_sites, get_site, list_techs, get_adoption_signals, get_removal_signals, add_sites_to_list. Bearer-authed with the same token as the REST API.
The tech stack behind any website. Free to start.
10 free API + MCP lookups per month. Pro €99/mo for unlimited. Cancel anytime, no card on file for free.
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