# Certack — Extended Summary (llms-full.txt)

> Certack provides proactive monitoring of SSL certificates, DNS records, and domain expiry for production websites. Lightweight, set-up-in-minutes monitoring with adaptive check frequency near expiry, multi-channel alerting, and a REST API. See https://certack.com/llms.txt for the compact index.

## What it does
- SSL/TLS monitoring: expiry date, issuer, chain, SANs, days remaining, plus CT log monitoring for unauthorized certificate issuance; alerts at configurable lead times (60/30/14/7/1 days or custom).
- DNS monitoring: A/AAAA/MX/NS/TXT record tracking with change detection.
- Domain monitoring: WHOIS/RDAP-based expiry tracking and registrar info.
- Certificate change monitoring: alerts when a certificate for your domain is issued, replaced, or renewed by an unrecognized CA.
- Alert channels (paid plans): Email, Slack, Discord, Teams, Telegram, DingTalk, Feishu, PagerDuty, Custom Webhook (HMAC-signed events).

## Plans
- Free (Free): 2 sites, dashboard alerts only, 1 API key(s), 100 API calls/mo at 1 QPS.
- Starter ($9.9/mo, $99/yr): 10 sites, 9 alert channels, 3 API key(s), 2,000 API calls/mo at 5 QPS.
- Pro ($15.9/mo, $159/yr): 20 sites, 9 alert channels, 5 API key(s), 10,000 API calls/mo at 10 QPS.
- SSL/TLS, DNS, and domain expiry monitoring are included on every plan. Paid plans add external alert channels, more sites, larger API quotas and priority support.
- Payments are processed by Creem (merchant of record). Cancel anytime from the dashboard; refunds are handled in accordance with our Terms of Service and applicable consumer law.

## REST API (summary)
- Base URL: https://api.certack.com/v1 — full reference at https://certack.com/docs/api, OpenAPI spec at https://certack.com/openapi.yaml.
- Auth: Bearer API keys (format ct_…), created in the dashboard.
- Key endpoints: GET/POST /sites (PATCH/DELETE /sites?id=SITE_ID), GET /checks, GET /alerts, GET/POST /api-keys (DELETE /api-keys?id=KEY_ID), maintenance-window management, public no-auth GET /public/check-ssl?domain=example.com.
- Rate limits: per-plan QPS (sliding window) + monthly call quota; responses include X-RateLimit-* and X-MonthlyLimit-* headers.

## Integrations
- Webhooks: HMAC-SHA256 signed JSON events (ssl.expiring, site.down, incident.created/resolved, site.added/removed).
- MCP server for AI assistants (no authentication required, rate limited): https://api.certack.com/v1/public/mcp — exposes check_ssl, check_dns and check_domain. An authenticated endpoint with full site management is available at https://api.certack.com/v1/mcp.
- Service status: https://certack.com/status.

## Support & Legal
- Support (all inquiries): support@certack.com
- Terms: https://certack.com/terms — Privacy: https://certack.com/privacy