CSP Reporting
CSP reporting collects browser telemetry when a Content-Security-Policy blocks a resource or inline script. Directives such as report-uri or Report-To send JSON violation reports to your endpoint so you can tune policies before enforcing strict blocks.
Technical Architecture & Deep-Dive
Start in report-only mode with Content-Security-Policy-Report-Only to observe real traffic. Violations reveal forgotten analytics domains, rogue inline handlers, or compromised third-party scripts.
Reports may contain URLs and snippets: treat endpoints as sensitive and rate limit them. When SPAs call APIs via connect-src, ensure your BFF host appears in policy before switching to enforcement.
Key Architectural Benefits
Implement CSP Reporting at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:Does CSP reporting block attacks by itself?
Reporting modes log violations without blocking. Enforcement mode blocks; use reporting first to validate rules.
Related Architecture Concepts
Content Security Policy (CSP) is an HTTP response header that tells browsers which sources of scripts, styles, images, and network connections a page is allowed to use. By blocking unapproved sources, CSP reduces the impact of cross-site scripting and data exfiltration.
Cross-site scripting (XSS) is a class of vulnerabilities where attackers inject malicious JavaScript into pages other users view. Injected script runs in the victim browser with access to that origin, enabling theft of cookies, tokens, and private API responses.
HTTP security headers are response directives that tell browsers how to handle your site: enforce HTTPS, restrict script sources, block clickjacking, and limit powerful features. They complement API auth because many attacks target how browsers mix your UI with cookies and third-party scripts.
Cross-Origin Resource Sharing (CORS) is a browser security mechanism that controls whether a web page on one origin may read responses from another origin. Servers advertise permitted caller origins and methods using HTTP response headers such as Access-Control-Allow-Origin.
Ready-to-Use Edge Recipes
Webflow is a purely static and frontend visual builder with no backend server. To call private APIs from Webflow custom code without revealing secrets in the browser inspector, route requests through RealComposer. RealComposer stores your API keys in an AES-256-GCM vault, injects credentials at the edge, and handles CORS headers automatically.
To use OpenAI in a client-side React app without leaking your secret key, never include OPENAI_API_KEY or REACT_APP_OPENAI_API_KEY in frontend .env files. Instead, route your fetch calls through a RealComposer edge endpoint that injects your secret key server-side on Cloudflare Workers and enforces CORS origin whitelisting.
To solve fix cors error in webflow api call, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.