web_techstack
Tech stack — detect what a website is built with. Fetches a public URL and fingerprints the web technologies it is built with — a BuiltWith / Wappalyzer-style detector. Returns a list of detected technologies, each with its categories, a confidence (high, medium, low), an optional version, and th...
This record as markdown: /tools/crawlora-mcp/web-techstack.md
What web_techstack does on Crawlora
AI agents call web_techstack to retrieve information from Crawlora without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
request | object | Yes | Target URL (and optional render strategy) |
Parameters from the server's own tool schema.
Why web_techstack is rated Low
Even though web_techstack only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
The rule that runs web_techstack safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Crawlora, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For web_techstack, this is the rule to start with:
web_techstack is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Crawlora, apply this rule, and every web_techstack call is checked against it from then on.
Questions about web_techstack
Tech stack — detect what a website is built with. Fetches a public URL and fingerprints the web technologies it is built with — a BuiltWith / Wappalyzer-style detector. Returns a list of detected technologies, each with its categories, a confidence (high, medium, low), an optional version, and the evidence that matched. Covers JavaScript frameworks and libraries (React, Vue.js, Angular, Svelte, jQuery), web frameworks / static site generators (Next.js, Nuxt.js, Gatsby, Remix, SvelteKit, Astro, Hugo), CMS and website builders (WordPress, Drupal, Joomla, Ghost, Wix, Squarespace, Webflow), e-commerce (Shopify, WooCommerce, Magento, BigCommerce), analytics, ad pixels, and tag managers (Google Analytics, Google Tag Manager, Meta Pixel, LinkedIn, Bing, TikTok/Pinterest/Reddit pixels, Segment, Hotjar, Microsoft Clarity), CDNs, UI frameworks and fonts, payments (Stripe, PayPal, Klarna), live chat, marketing automation, A/B testing, consent management, CAPTCHAs (reCAPTCHA, hCaptcha, Turnstile), video, and search. It also inspects response headers (from a plain HTTP fetch) to identify the web server (nginx, Apache, IIS), the CDN / hosting provider (Cloudflare, CloudFront, Fastly, Vercel, Netlify), and the server-side language / framework (PHP, ASP.NET, Ruby on Rails, Django, Laravel, Express). Results are directional, not exhaustive. The render fetch strategy is one of browser (headless browser that executes JavaScript — the default, so client-injected scripts like analytics, tag managers and pixels are detected), auto (Chrome-impersonated HTTP, escalating to a real browser only when blocked or JS-rendered), or http (HTTP only, no JavaScript — fastest, but sees only the server HTML); defaults to browser. Only public pages are supported; respect each site's terms of use and robots directives. It is categorised as a Read tool in the Crawlora MCP Server, which means it retrieves data without modifying state.
web_techstack accepts 1 parameter: request. Required: request. The full parameter table on this page comes from the server's own tool schema.
Register the Crawlora MCP server in PolicyLayer and add a rule for web_techstack: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Crawlora. Nothing to install.
web_techstack is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the web_techstack rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for web_techstack. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
web_techstack is provided by the Crawlora MCP server (crawlora-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Crawlora, and thousands of servers like it.
This server
Across the catalogue