/waf

name: waf
description: >-
  Configures AWS WAF to filter web traffic: creating web access control lists (web ACLs) on
  CloudFront, Application Load Balancers, API Gateway, and AppSync; AWS Managed Rules tuned in Count
  mode; rate-based rules for HTTP floods; IP set and geographic match rules; Bot Control (Common and
  Targeted); turning bot labels into a confidence signal; stripping spoofed inbound x-amzn-waf-*
  headers; recovering the real client IP behind a CDN; Fraud Control (account takeover and account
  creation fraud prevention); and logging and request sampling. Use when the user wants to protect a
  web application or API from common exploits, bots, credential stuffing, fake-account creation, or
  HTTP floods at the application layer (layer 7). Routes to the right per-task procedure in
  references. Do NOT use for L3/L4 DDoS protection (shieldadvanced skill), multi-account WAF rollout
  (firewallmanager skill), CloudFront configuration (cloudfront skill), or Route 53 health checks or
  records (route53 skill).
version: 1

AWS WAF

Overview

Domain expertise for configuring AWS WAF, the web application firewall that filters HTTP and HTTPS traffic to CloudFront distributions, Application Load Balancers, API Gateway REST APIs, and AppSync GraphQL APIs. Covers web ACL creation and association, AWS Managed Rules, rate-based rules, match rules (IP set and geographic), Bot Control and the signal-forwarding workflows built on top of it, Fraud Control for logins and signups, AI and LLM crawler management, and the logging that every tuning workflow depends on.

This skill is a router. Each customer task maps to a procedure file under `references/`. Read the matching reference in full before acting, then follow its constraints and steps. The reference files are self-contained: each carries its own decision tables, constraints, procedure, and troubleshooting.

Execute commands using the AWS MCP server when connected (sandboxed execution, audit logging, observability). Fall back to the AWS CLI otherwise. A web ACL's scope is fixed at creation: a CloudFront web ACL must be created in `us-east-1` with `CLOUDFRONT` scope, while a regional web ACL (Application Load Balancer, API Gateway, AppSync) is created in the resource's Region with `REGIONAL` scope.

Which WAF task do you need?

| Goal | Reference | | --- | --- | | Create a web ACL and attach it to a resource | [creating a web ACL and associating it with a resource](references/creating-a-web-acl-and-associating-it-with-a-resource.md) | | Set up logging and sampling before tuning anything | [setting up logging and request sampling](references/setting-up-logging-and-request-sampling.md) | | Add AWS Managed Rules and tune false positives | [adding managed rules and tuning with count mode](references/adding-managed-rules-and-tuning-with-count-mode.md) | | Throttle HTTP floods and brute force | [adding rate-based rules](references/adding-rate-based-rules.md) | | Allow or block by IP range or country | [using ip sets and geographic match rules](references/using-ip-sets-and-geographic-match-rules.md) | | Detect and control bots (the on-ramp) | [protecting against bots with bot control](references/protecting-against-bots-with-bot-control.md) | | Collapse bot labels into one confidence signal | [turning bot control labels into a confidence signal](references/turning-bot-control-labels-into-a-confidence-signal.md) | | Forward all signals to the origin with one rule | [forwarding signals with dynamic label interpolation](references/forwarding-signals-with-dynamic-label-interpolation.md) | | Decide what the app does with the forwarded signal | [adaptive mitigation playbook for forwarded signals](references/adaptive-mitigation-playbook-for-forwarded-signals.md) | | Stop attackers from spoofing forwarded headers | [stripping inbound waf headers before trusting them](references/stripping-inbound-waf-headers-before-trusting-them.md) | | Recover the real client IP behind a CDN | [recovering the real client ip behind a cdn](references/recovering-the-real-client-ip-behind-a-cdn.md) | | Protect logins and signups from fraud | [protecting logins and signups with fraud control](references/protecting-logins-and-signups-with-fraud-control.md) | | See and manage AI and LLM crawler traffic | [seeing and managing ai crawler traffic](references/seeing-and-managing-ai-crawler-traffic.md) |

Routing notes

• **Logging comes before tuning.** Every Count-mode tuning workflow assumes logging and request

sampling are on. If the customer has not set up logging, run that reference first; otherwise Count-mode tuning has nothing to read.

• **Web ACL scope is fixed at creation.** A CloudFront web ACL is `CLOUDFRONT` scope in

`us-east-1`; a regional resource needs a `REGIONAL` web ACL in its own Region. Scope cannot be changed later, so the creating reference settles it before anything is built.

• **Bot Control is a chain, not one task.** Protecting against bots is the on-ramp (turn on, choose

Common vs Targeted, observe). Turning labels into a confidence signal, forwarding that signal, and deciding what the application does with it are three separate references that build on it in that order. The header-stripping reference is the mandatory safety companion whenever a signal is forwarded to the origin.

• **Common vs Targeted is not a soft choice.** Common only catches self-identifying bots and

known-bad IPs. For login, checkout, or any high-value endpoint facing evasive bots, Targeted with the application integration SDK is required. The bots reference pushes Targeted for real bot threats rather than presenting it as optional.

• **Rate limiting vs Fraud Control.** Rate-based rules blunt volumetric HTTP floods. Credential

stuffing and fake-account creation are account-based abuse that rate limiting misses; those go to the Fraud Control reference (ATP and ACFP), not the rate-based reference.

• **Forwarded headers need the strip rule.*