The positive-security alternative to Cloudflare WAF
Cloudflare is excellent at what it was built for. Two things worth knowing before you assume it has you covered: as a signature WAF it cannot see the application-logic attacks that actually breach apps, and Nemesis is not only an app SDK. Nemesis has its own network layer, Nemesis Edge, that runs on top of your CDN. Here is where each fits.
Two different models
Cloudflare's WAF is a managed-ruleset, signature-based firewall (the OWASP Core Rule Set plus Cloudflare's managed rules) applied globally in front of your origin. It is strong at DDoS, bot traffic and network-layer noise, and the same rules run for every customer.
Nemesis Shield is a positive-security platform that spans the whole request path. A one-line, open-source SDK (Sentinel) learns each app, API and LLM's own normal behavior per tenant and blocks the deviations a signature ruleset never sees: IDOR/BOLA, broken auth, business-logic abuse and zero-days. Nemesis Edge adds a per-tenant protective-DNS and optional inline-proxy layer at the network edge, running in front of or on top of your existing CDN, and it all correlates into one view. Free tier, observe-first, about two minutes to protect an app.
Side by side
| Cloudflare WAF | Nemesis Shield | |
|---|---|---|
| Detection model | Global signatures and managed rules, same for every customer | Positive security: learns your app's own normal behavior, per tenant |
| IDOR / BOLA and business logic | Not the design target (a well-formed request has no bad pattern) | Caught as a deviation from the learned baseline |
| Network and DNS layer | Global CDN, DDoS scrubbing, bot management, edge rules | Nemesis Edge: per-tenant protective DNS and optional inline proxy, on top of your CDN, catching the beaconing and per-tenant anomalies a global list misses |
| Application layer | Edge WAF rules only | Sentinel SDK in the app: app, API and LLM, learned per tenant |
| Getting started | Route DNS through Cloudflare, configure rules | Add one line, learn in observe mode, then enforce. Free tier |
| Scope | Web and network edge | App, API, LLM, network (Edge) and cloud, correlated into one incident |
When to choose which
If you mainly need a CDN, DDoS scrubbing and bot management at the network edge, Cloudflare is excellent, and Nemesis Edge layers on top of it rather than replacing it.
If you want per-tenant positive security at the app layer (IDOR/BOLA, broken auth, business logic, zero-days) plus a network layer of your own, with a one-line SDK and a free tier, that is Nemesis Shield and Nemesis Edge together.
Questions
Is Nemesis Shield a Cloudflare WAF alternative?
Yes, and often a complement. Cloudflare WAF and Nemesis Shield solve overlapping but different problems: Cloudflare WAF works at the level it was designed for, and Nemesis adds a positive-security layer that learns your app's own per-tenant behavior and blocks the logic-level attacks (IDOR/BOLA, broken auth, business-logic abuse) that a signature ruleset is not built to see.
Can I run Nemesis Shield together with Cloudflare WAF?
Yes. Nemesis is a one-line SDK inside your app (and an optional edge layer), so it runs happily behind or on top of Cloudflare WAF. Many teams keep Cloudflare WAF for what it is good at and add Nemesis for the application-logic layer.
What does Nemesis catch that a signature WAF does not?
Attacks that are well-formed. A request for an object that is not yours (IDOR/BOLA), a broken-auth flow, or business-logic abuse has no bad pattern to match, so a signature engine passes it. Nemesis flags it because it deviates from the app's learned normal, per tenant.
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