Ladder is a self-hosted HTTP web proxy written in Go, designed for testing and analyzing paywall implementations, content delivery, and access control behavior on modern websites. It intercepts client requests, applies domain-specific YAML rulesets to modify request headers, URLs, and response content (e.g., removing CORS/CSP headers, injecting scripts, rewriting relative URLs), then fetches the target site and returns the modified response. The proxy exposes a web form, a JSON API, a raw HTML endpoint, and a ruleset endpoint, and supports optional FlareSolverr integration for bypassing Cloudflare challenges. It is deployable as a binary, Docker container, or Helm chart, and is configured via environment variables and CLI flags. The architecture is a single Go binary using the Fiber web framework. The main entry point (cmd/main.go) sets up routing, basic auth, and middleware. Core logic lives in handlers/proxy.go, which handles URL extraction, ruleset application, HTTP fetching, HTML rewriting, and FlareSolverr integration. The pkg/ruleset package provides a clean, reusable ruleset loader supporting local files, directories, remote URLs, and gzip-compressed YAML. The codebase is generally well-structured with some global state and a few misnamed test files (e.g., proxy.test.go instead of proxy_test.go) that are not executed by Go's test runner. Despite these minor issues, the project is actively maintained, uses current dependencies, and demonstrates solid engineering practices for a focused tool.