# Signalhouse > Inspect DNS, TLS, mail, CDN and routing of all your domains — and see what changed. Signalhouse turns usefulweb’s network explorers into one inspection workspace. Add a portfolio of domains, pick a suite of checks — multi-region uptime and response headers, DNS and certificates, mail security, HTTP stack, CDN caching, IPv6, global DNS propagation, Certificate Transparency, domain history, BGP routing, outage signals, accessibility and AI readiness — and run them as a paced batch. A scorecard, merged findings with triage, run-to-run diffs, A/B comparisons and a renewal calendar turn the results into decisions; projects stay in your browser. Signalhouse (Website & internet infrastructure inspector) is a premium app of usefulweb.site (https://usefulweb.site/): a full program that runs in the browser. Its engine is deterministic and the same functions are exposed as tools, so an agent can compute exactly what the app shows. ## Use it - Landing page: https://signalhouse.usefulweb.site/ - Workspace (browser app): https://signalhouse.usefulweb.site/app - open a project with https://signalhouse.usefulweb.site/app#project= or a template with https://signalhouse.usefulweb.site/app#template= - Project file format (JSON Schema): https://signalhouse.usefulweb.site/project.schema.json - Tutorials: https://signalhouse.usefulweb.site/tutorials - JSON API: POST https://signalhouse.usefulweb.site/api/v1/tools//calculate (catalog: https://signalhouse.usefulweb.site/api/v1/tools) - OpenAPI: https://signalhouse.usefulweb.site/openapi.json - MCP (Streamable HTTP): https://signalhouse.usefulweb.site/mcp ## Engine tools - [HeaderLens](https://headerlens.usefulweb.site/): Is a website down? Multi-region status, redirects, TLS and security headers. API: POST https://signalhouse.usefulweb.site/api/v1/tools/headerlens/calculate · MCP tool `headerlens` - [DNS + Certificate Explorer](https://dnscertificateexplorer.usefulweb.site/): DNS records, e-mail security, CAA, live TLS certificate and CT history for a domain. API: POST https://signalhouse.usefulweb.site/api/v1/tools/dns-certificate-explorer/calculate · MCP tool `dns_certificate_explorer` - [E-mail Infrastructure Explorer](https://emailinfrastructureexplorer.usefulweb.site/): MX, SPF lookups, DMARC, DKIM, MTA-STS, TLS-RPT and BIMI for a domain, scored with fixes. API: POST https://signalhouse.usefulweb.site/api/v1/tools/email-infrastructure-explorer/calculate · MCP tool `email_infrastructure_explorer` - [Security Configuration Scanner](https://securityconfigurationscanner.usefulweb.site/): Passive, graded check of a domain's TLS, security headers, DNS security and security.txt. API: POST https://signalhouse.usefulweb.site/api/v1/tools/security-configuration-scanner/calculate · MCP tool `security_configuration_scanner` - [HTTP Technology Explorer](https://httptechnologyexplorer.usefulweb.site/): Headers, compression, caching, HTTP/2-3 hints, redirects, security and tech stack for a URL. API: POST https://signalhouse.usefulweb.site/api/v1/tools/http-technology-explorer/calculate · MCP tool `http_technology_explorer` - [CDN Behaviour Explorer](https://cdnbehaviorexplorer.usefulweb.site/): Which CDN serves a URL, whether it caches it (HIT/MISS, Age, TTL) and how, from two requests. API: POST https://signalhouse.usefulweb.site/api/v1/tools/cdn-behavior-explorer/calculate · MCP tool `cdn_behavior_explorer` - [IPv6 Readiness Explorer](https://ipv6readinessexplorer.usefulweb.site/): Is a domain reachable over IPv6? Web, DNS and mail checks, address classes and a scored report. API: POST https://signalhouse.usefulweb.site/api/v1/tools/ipv6-readiness-explorer/calculate · MCP tool `ipv6_readiness_explorer` - [Global DNS Explorer](https://globaldnsexplorer.usefulweb.site/): Ask every authoritative name server and public resolvers: records, propagation, DNSSEC, mistakes. API: POST https://signalhouse.usefulweb.site/api/v1/tools/global-dns-explorer/calculate · MCP tool `global_dns_explorer` - [Certificate Transparency Explorer](https://certificatetransparencyexplorer.usefulweb.site/): Every logged certificate for a domain: history, issuers, subdomains, wildcards and expiry. API: POST https://signalhouse.usefulweb.site/api/v1/tools/certificate-transparency-explorer/calculate · MCP tool `certificate_transparency_explorer` - [Domain History Graph](https://domainhistorygraph.usefulweb.site/): Registration, DNS, hosting networks, certificates and Wayback captures of a domain as a timeline. API: POST https://signalhouse.usefulweb.site/api/v1/tools/domain-history-graph/calculate · MCP tool `domain_history_graph` - [BGP Route Explorer](https://bgprouteexplorer.usefulweb.site/): Who announces an IP or prefix in BGP: origin ASes, RPKI validity, visibility and origin changes. API: POST https://signalhouse.usefulweb.site/api/v1/tools/bgp-route-explorer/calculate · MCP tool `bgp_route_explorer` - [ASN Relationship Explorer](https://asnrelationshipexplorer.usefulweb.site/): An autonomous system at a glance: holder, country, BGP neighbours and announced prefixes. API: POST https://signalhouse.usefulweb.site/api/v1/tools/asn-relationship-explorer/calculate · MCP tool `asn_relationship_explorer` - [Internet Outage Atlas](https://internetoutageatlas.usefulweb.site/): Correlate public outage signals (IODA, RIPEstat BGP, live probe) for a country, ASN or domain. API: POST https://signalhouse.usefulweb.site/api/v1/tools/internet-outage-atlas/calculate · MCP tool `internet_outage_atlas` - [AI Website Readiness Explorer](https://aiwebsitereadinessexplorer.usefulweb.site/): Can ChatGPT, Claude, Perplexity and AI agents read your website? Explainable score. API: POST https://signalhouse.usefulweb.site/api/v1/tools/ai-website-readiness-explorer/calculate · MCP tool `ai_website_readiness_explorer` - [Accessibility Snapshot](https://a11ysnapshot.usefulweb.site/): Static WCAG 2.2 snapshot of a page: findings by severity, evidence and manual checks. API: POST https://signalhouse.usefulweb.site/api/v1/tools/a11y-snapshot/calculate · MCP tool `a11y_snapshot` - [Website Change Explainer](https://websitechangeexplainer.usefulweb.site/): Compare two versions of a page and see which changes matter: prices, terms, dates, links. API: POST https://signalhouse.usefulweb.site/api/v1/tools/website-change-explainer/calculate · MCP tool `website_change_explainer` - [Scam Signal Checker](https://scamsignalchecker.usefulweb.site/): Check a message or link for common scam and phishing warning signs — without clicking. API: POST https://signalhouse.usefulweb.site/api/v1/tools/scam-signal-checker/calculate · MCP tool `scam_signal_checker` - [Browser Compatibility Checker](https://browsercompatibilitychecker.usefulweb.site/): Which browsers support a CSS property, JS API or HTML element? MDN data + Baseline status. API: POST https://signalhouse.usefulweb.site/api/v1/tools/browser-compatibility-checker/calculate · MCP tool `browser_compatibility_checker` - [Network Speed Tester](https://networkspeedtester.usefulweb.site/): Measure latency, jitter, download and upload speed between your browser and our server. API: POST https://signalhouse.usefulweb.site/api/v1/tools/network-speed-tester/calculate · MCP tool `network_speed_tester` - [Explorer of Everything](https://explore.usefulweb.site/): Search transactions, contracts, domains, packages, advisories, MCP servers and websites in one box. API: POST https://signalhouse.usefulweb.site/api/v1/tools/explore/calculate · MCP tool `explore` ## Formats - Import: Signalhouse project (.signalhouse.json), Domain lists (one per line, CSV/TSV with a domain or URL column, free text with links), Project link (#project=…), App Bridge: text and tables with domains - Export: Signalhouse project (.signalhouse.json), Printable report (PDF via print), Markdown report, CSV: scorecard, findings, fix plan, changes, renewals, JSON results, iCalendar renewal calendar (.ics) with reminders, SVG and PNG of the scorecard, renewal timeline and connection log ## Limits - No unattended monitoring: runs happen while the workspace is open; reminders come from the calendar export. - Network checks are rate-limited to about 15 per minute per visitor, so a run over 100 targets with 6 checks takes around 40 minutes. - Live checks run from one server location; CDN behaviour, DNS answers and reachability can differ elsewhere. - The accessibility snapshot reads the static HTML only; it cannot replace a manual audit with assistive technology. - Private networks and hosts behind a login can only be analysed from pasted headers, records or HTML. - Tool findings and summaries are shown in English when a translation is not available. - Projects keep a compact summary of each result, not the full raw tool output; open the tool page for every detail.