DetectZeStack – REST API to detect any website's technology stack

Hi HN,

I built DetectZeStack, a REST API that identifies the technologies behind any website.

What it does: Give it a URL, get back a list of frameworks, CMS platforms, CDNs, analytics tools, and more — with confidence scores and metadata for each technology.

How detection works: - Wappalyzer fingerprinting (3,800+ signatures from HTML, headers, cookies, scripts) - DNS CNAME resolution (maps CNAMEs like *.cloudfront.net to CDN providers) - TLS certificate issuer analysis (identifies SSL providers like Let's Encrypt, Cloudflare, DigiCert) - Custom HTTP header matching (catches platforms like Railway that have unique headers)

Endpoints: - GET /analyze?url= — single URL analysis - POST /analyze/batch — up to 10 URLs concurrently, with CSV export - POST /compare — compare tech stacks between sites (shared vs unique) - GET /history — track how a site's stack changes over time - POST /webhooks — get notified when a domain is analyzed - GET /stats — your usage analytics (top domains, daily trends, cache hit rates)

Technical details: - Built in Go, deployed on Fly.io, SQLite for storage - Results cached 24 hours (cache hits don't count against quotas) - HMAC-signed webhook delivery, SSRF protection, AES-256-GCM encrypted secrets - Free tier: 100 requests/month, no credit card

Available on RapidAPI: https://rapidapi.com/mlugoapx/api/detectzestack

OpenAPI spec: https://detectzestack.fly.dev/openapi.yaml

I'd appreciate any feedback on the API design, detection accuracy, or use cases I haven't considered. Happy to answer questions about the implementation.