Monitor from the Edge Without Touching Application Code
See network failures your servers can't. Configure HTTP headers at your reverse proxy — NEL, CSP, and more — and route browser-side alerts to your existing NOC tools. No application deployments. No developer involvement.
The Situation
Your Visibility Ends at the Edge
Infrastructure teams manage the reverse proxies, load balancers, and DMZ that sit in front of dozens — or hundreds — of applications. You're responsible for availability and network security. But your visibility ends at the edge.
Once traffic leaves your infrastructure, you're blind. You see the requests that arrive at your servers. You don't see the ones that never make it — the DNS resolution failures, the TCP timeouts, the TLS handshake errors that happen between the user's browser and your edge.
When users report "the site is down," your dashboards are green. Your servers are healthy. But somewhere between the user and your infrastructure, something went wrong — and you have no data to prove it's not your fault.
For managed service providers and outsourced infrastructure teams, this blind spot is especially acute. You're responsible for availability but often have no access to application code — no way to add monitoring without developer involvement.
What the edge actually looks like in 2024
- of TCP connections to Cloudflare end before useful data flows Cloudflare Radar 2024
- 20.7%
- median MTTD for high-impact outages New Relic Observability Forecast 2024
- 37 min
- mobile vs desktop pages with “good” LCP HTTP Archive 2024
- 59% / 72%
- of sites send any browser-reporting header today HTTP Archive 2024
- 14%
The Complication
Network Issues Your Servers Can't See
Traditional monitoring has a fundamental blind spot: if requests never reach your servers, you have no visibility.
During a regional ISP routing issue, 50% of users from a specific ASN couldn't connect. Server-side metrics showed zero errors — because the traffic never arrived. The infrastructure team had no data to diagnose the problem, let alone prove it was an ISP issue and not their infrastructure.
The network issues that happen in the "last mile" — DNS failures, BGP route leaks, ISP outages, TLS certificate problems — are invisible to server logs. Research from Google's NEL deployment shows that 80% of network problems happen in the last 20% of the network path.
Adding application-level monitoring requires developer involvement, code changes, and deployment cycles that infrastructure teams don't control. Header misconfiguration (CSP, CORS, COOP/ COEP) can break websites entirely — and without visibility into what the browser is actually experiencing, diagnosing these issues can take hours.
The Solution
HTTP Headers You Already Control
The W3C Reporting API is configured entirely via HTTP headers — which infrastructure teams already control at the reverse proxy layer.
-
Network Error Logging (NEL)
- See DNS failures, TCP timeouts, and TLS errors that servers can't detect. Google has used NEL across all domains since 2014 to detect BGP route leaks and DNS hijacking. Learn more
-
Header-Only Deployment
- Configure Reporting-Endpoints at your reverse proxy, CDN, or load balancer. nginx, HAProxy, Cloudflare, AWS CloudFront — all support header injection without application changes.
-
One Config, All Apps
- Deploy once at the edge and every application behind your proxy gains browser-side monitoring. Perfect for platform teams managing 50+ applications or MSPs monitoring multiple client sites.
-
Existing NOC Integration
- Route browser-side alerts to Splunk, PagerDuty, ServiceNow, or any webhook endpoint. No new dashboards — browser visibility flows into your existing incident workflow.
Report Types
What You'll See
01 · NEL
Network Errors (NEL)
DNS resolution failures, TCP connection errors, TLS handshake problems. The network issues your servers can't see — measured from the browser, not the origin.
02 · CSP
CSP Violations
Blocked resources and policy misconfigurations before they become outages.
03 · ISOLATION
Cross-Origin Isolation
COOP/COEP header issues that break OAuth flows and cross-origin integrations.
04 · CRASH
Crash Reports
Browser crashes and out-of-memory errors across your entire application portfolio. Aggregated across user-agents and regions.
Deploy Edge Monitoring in Minutes
Add two HTTP headers to your reverse proxy configuration. Start seeing network failures your servers can't.