Cloudflare API Security

Secure your APIs at the edge — schema, rate limiting and bot defence

Independent Cloudflare API Shield setup for REST and GraphQL APIs. We help discover your endpoints, enforce schema and contract validation, validate JWT and mTLS, apply per-endpoint rate limits and reduce credential stuffing, scraping and abuse on auth and account APIs.

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Who this is for

SaaS products with public and private APIs
Mobile and partner APIs needing strong auth
Stores exposing REST or GraphQL endpoints
Teams worried about scraping and account abuse

API Shield

What Cloudflare API Shield gives you

A set of API-specific controls that enforce what a valid request looks like — and block the rest before it reaches your origin.

API discovery

Cloudflare learns the endpoints your traffic actually uses, so shadow and undocumented APIs become visible instead of silently exposed.

Schema & contract validation

Upload an OpenAPI schema and Cloudflare rejects requests that break the contract — wrong methods, missing fields or malformed parameters.

JWT validation

Validate JSON Web Tokens at the edge so unauthenticated or tampered requests are stopped before they ever reach your origin.

Mutual TLS (mTLS)

Pin trusted clients with client certificates for partner, mobile and machine-to-machine APIs, so only known callers can connect.

Sensitive-data detection

Cloudflare flags responses leaking PII, tokens or card-like data, giving you visibility into APIs that return more than they should.

Per-endpoint rate limiting

Apply request limits per route, token or client — capping abusive volume on auth, search and account APIs without throttling normal use.

Problems we solve

What does an API security problem actually look like?

If you recognise any of these, your APIs are already exposed to abuse, data loss or wasted origin capacity.

Credential stuffing on auth APIs

Bots replay leaked username/password lists against your login and token endpoints. We add rate limits, bot rules and challenges on the auth path.

Data scraping through APIs

Automated clients enumerate IDs and pull your catalogue, pricing or user data at scale. We make API scraping slow, costly and unreliable.

Broken-object-level-authorization abuse

Attackers swap object IDs to read records that are not theirs (BOLA / IDOR). Schema and auth checks help, but app-side authorization still matters.

Shadow and undocumented APIs

Old, internal or forgotten endpoints stay live with no rules on them. API discovery surfaces them so you can baseline and protect them.

Missing or inconsistent rate limits

Without per-endpoint limits, a single client can hammer search, login or export routes. We cap abusive volume where it actually happens.

No contract enforcement

APIs accept malformed, oversized or unexpected requests that waste origin capacity and widen your attack surface. Schema validation closes the gap.

Our process

How we secure your APIs: discover, baseline, enforce, monitor

Grounded in your real traffic and rolled out in stages, so enforcement never breaks legitimate clients.

1. Discover

We use Cloudflare API discovery and your traffic to map every endpoint — including shadow and undocumented APIs — across REST and GraphQL.

2. Baseline

We profile normal behaviour: methods, parameters, request volume and authentication patterns per route, so enforcement is grounded in real traffic.

3. Enforce schema & rate limits

We add schema validation, JWT/mTLS where appropriate and per-endpoint rate limits — rolled out in log-then-block stages to avoid breaking clients.

4. Monitor

We watch API analytics, sensitive-data alerts and abuse patterns, then tune rules as your endpoints and traffic change over time.

REST & GraphQL

Protecting auth, login and account APIs

Authentication and account endpoints are where the most damage happens — credential stuffing, token replay and enumeration of user records. We scope rate limits per route and per token, validate JWTs at the edge, apply bot management and Turnstile, and watch for the access patterns that signal abuse. GraphQL gets particular attention, since a single endpoint can hide expensive or abusive queries behind a valid-looking request.

See bot protection

How we harden the auth path

Per-endpoint and per-token rate limits
JWT validation and mTLS for trusted clients
Bot management and Turnstile on auth flows
GraphQL query and volume controls
Staged log → block rollout to protect clients

Honest scope

Edge API security is not a replacement for secure code

This distinction matters, so we make it plainly: Cloudflare hardens the edge and improves visibility, but some risks must be fixed in your application.

What edge API security does

Discovers endpoints, including shadow and undocumented APIs
Enforces schema, JWT and mTLS at the edge
Caps abusive volume with per-endpoint rate limits
Reduces credential stuffing, scraping and bot abuse

What it does not do

Fix broken-object-level-authorization (BOLA/IDOR) in your code
Replace secure development, code review and patching
Decide whether a given user may access a given object
Act as a full application penetration test

Edge enforcement vs. application authorization

Cloudflare API Shield enforces authentication, schema and rate limits at the edge and gives you visibility into shadow APIs and sensitive-data exposure — which reduces a large share of automated abuse. It is not a substitute for secure application code. Object-level authorization (whether a specific user may access a specific record) must be enforced in your application, and secure development, code review and timely patching remain essential. We configure Cloudflare as one strong layer alongside your application security, never as a replacement for it.

Scope

What is and isn’t included

Clear boundaries from the start, so expectations are honest.

What is included

API discovery and an endpoint inventory (REST & GraphQL)
Schema and contract validation from your OpenAPI spec
JWT validation and mTLS for trusted clients
Per-endpoint and per-token rate limiting
Bot management and Turnstile on auth and account APIs
Sensitive-data detection, monitoring and tuning

What is not included

Fixing BOLA/IDOR or other authorization flaws in your code
Application development, refactoring or bug fixes
Writing or maintaining your OpenAPI schema from scratch
Full application penetration testing or code review
Backups, hosting or origin server administration

When you need this

Your login or token API is hit by credential stuffing
Data is being scraped through public or private APIs
You suspect shadow or undocumented endpoints are live
APIs accept malformed requests with no contract enforcement
A single client can hammer search, export or account routes
You’re exposing a new REST or GraphQL API to partners

When Cloudflare is not enough

Edge API security is one strong layer. It does not replace:

Secure development, code review and timely patching of your application and plugins.
Backups, disaster recovery and a tested restore process.
A dedicated anti-fraud, chargeback or payment-risk platform.
Hosting, database administration and origin server maintenance.
Full incident response and forensics for large or regulated enterprises.

What Cloudflare can and cannot do

Cloudflare reduces risk, blocks a large share of malicious traffic, hardens critical endpoints and improves performance. No edge platform can make a website completely or permanently secure, and Cloudflare does not, on its own, stop payment fraud or replace secure development, patching, backups, anti-fraud platforms or proper hosting. We configure Cloudflare as one strong layer in a complete security posture.

Related services

Pair API security with the right layers

Cloudflare WAF SetupManaged and custom rules that protect API endpoints.Cloudflare Bot ProtectionReduce credential stuffing, scraping and API abuse.Zero Trust ConsultantIdentity-based access for admin and internal APIs.DDoS ProtectionPeak-traffic and attack readiness for your origin.Cloudflare AuditStart with an independent review of your setup.ContactTell us which APIs you need to protect.

Frequently asked questions

What is Cloudflare API Shield and what does it do?

API Shield is Cloudflare's set of API-specific security controls. It includes API discovery (finding endpoints in your real traffic, including shadow APIs), schema and contract validation against an OpenAPI definition, JWT validation and mutual TLS for authentication, sensitive-data detection on responses, and per-endpoint rate limiting. Combined with the WAF and bot management, it lets you enforce what a valid request to each endpoint looks like and block the rest before it reaches your origin.

Does Cloudflare protect both REST and GraphQL APIs?

Yes. Rate limiting, bot management, WAF rules and JWT/mTLS validation apply to REST and GraphQL endpoints alike. GraphQL needs particular care because a single endpoint can hide expensive or abusive queries, so we focus on rate limiting, query controls and abuse detection around that endpoint as well as schema enforcement where it fits.

Can Cloudflare stop credential stuffing on my login API?

It can substantially reduce it, not guarantee it away. We combine per-endpoint rate limiting, bot management scoring, Turnstile and custom rules on auth and token endpoints to make automated replay of leaked credentials slow and expensive. This raises the cost of credential stuffing, but secure password handling, breached-credential checks and multi-factor authentication in your application remain essential layers.

Will schema validation block my legitimate API clients?

Not if it is rolled out carefully. We first run schema validation and new rate limits in log-only mode, compare them against real traffic, and fix any mismatch between your documented schema and what clients actually send. Only once we are confident do we switch to blocking. This staged approach catches genuine drift between your spec and your clients before it can cause outages.

Does Cloudflare fix broken-object-level-authorization (BOLA) issues?

Only partially, and we are honest about this. Cloudflare can enforce schema, authentication and rate limits, and detect anomalous access patterns and sensitive-data exposure — which helps contain abuse. But BOLA/IDOR is fundamentally an application authorization flaw: deciding whether a given user may access a given object must be enforced in your code. We harden the edge and improve visibility, while your team fixes the underlying authorization logic.

Do I need a specific Cloudflare plan for API Shield?

Some controls — rate limiting, WAF rules, Turnstile and basic bot handling — are available on lower plans, while the full API Shield feature set (API discovery, schema validation, mTLS, sensitive-data detection and advanced Bot Management) typically requires higher Cloudflare plans or add-ons. During scoping we map what your current plan allows, what value you get without upgrading, and whether an upgrade is justified for your API traffic.

How this project is scoped — no hourly meter

Fixed scope, fixed timeline — priced by deliverable against an agreed Statement of Work, not by an hourly meter. Typically 2–4 weeks, delivered remotely.

What's included

Discovery & kick-off call to confirm goals and scope
Architecture & configuration review
Cloudflare setup for the agreed scope: DNS, SSL/TLS, WAF baseline, caching/performance and the products in your plan
Validation and a supervised go-live
Handover pack: runbook, configuration documentation and a team walkthrough
A 14-day post-go-live support window for fixes to what we configured

Not included (quoted separately)

Non-Cloudflare work (application/backend changes, third-party security tools)
Additional domains/zones beyond the agreed scope
Ongoing monthly management (that is a Care plan)
Anything not in the Statement of Work — handled as a separately quoted change order

Indicative “from” prices are a starting point. Your final price is confirmed in a written proposal after a free scoping call, and depends on the number of zones, the Cloudflare products in scope and environment complexity.

Harden your APIs against abuse

Tell us which REST or GraphQL APIs you need to protect. You’ll get an independent, vendor-neutral plan to discover, baseline and enforce schema, rate limits and bot defence.

Request a Cloudflare Audit Talk to a Cloudflare Specialist