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 # arcline-uptime — Lightweight Uptime Monitor
 
-Polls HTTP/TCP endpoints on a schedule, stores results in SQLite, sends alerts
-via webhook (Discord, Slack) and/or email. Single binary, no external services.
+Polls HTTP/TCP/TLS/DNS endpoints on a schedule, stores results in SQLite, sends alerts
+via webhook (Discord, Slack), email, ntfy, or Gotify. Single binary, no external services.
 
 ## Stack
 - Language: Go
 - Storage: SQLite (via modernc.org/sqlite — pure Go, no CGO)
 - Config: YAML
-- Alerts: HTTP webhook (Discord/Slack compatible), SMTP email
-- Optional UI: embedded web dashboard (net/http + Go templates)
+- Alerts: Discord/Slack webhook, SMTP email, ntfy.sh, Gotify
+- UI: embedded web dashboard (net/http + Go templates)
 
-## Config format (uptime.yaml)
-```yaml
-global:
-  check_interval: 60      # seconds
-  timeout: 10             # seconds per check
-  alert_cooldown: 300     # seconds between repeat alerts for same monitor
+## Done
+- [x] Project scaffold
+- [x] YAML config parser
+- [x] HTTP monitor (status code, body contains, response time threshold)
+- [x] HTTP POST/PUT with custom body and headers
+- [x] TCP monitor (dial timeout)
+- [x] TLS certificate expiry monitor
+- [x] DNS resolution monitor (optional expected IP assertion)
+- [x] Per-monitor interval and timeout overrides
+- [x] Scheduler (ticker per monitor, immediate first check)
+- [x] SQLite schema (checks, alerts_sent)
+- [x] Result storage with configurable retention / auto-pruning
+- [x] Discord / Slack webhook alerter
+- [x] SMTP email alerter (multiple recipients)
+- [x] ntfy.sh alerter
+- [x] Gotify alerter
+- [x] Per-monitor alert routing (named alerters)
+- [x] Maintenance windows (suppress alerts on a schedule)
+- [x] Alert cooldown logic (don't spam on sustained outage)
+- [x] Recovery alert ("Main Website is back up, was down 12m 34s")
+- [x] Web dashboard — current status page (24h / 7d / 30d uptime)
+- [x] Web dashboard — history / SVG sparkline graph with down markers
+- [x] Web dashboard — incident log
+- [x] Public status page (no auth)
+- [x] /metrics Prometheus endpoint (up, response_ms, uptime_24h, uptime_7d)
+- [x] Basic auth for dashboard
+- [x] systemd unit file example
+- [x] README with self-hosting guide
+- [x] Cross-compile Makefile
+- [x] Structured logging (slog, text or JSON)
+- [x] `start`, `check`, `list`, `version` CLI subcommands
 
-alerts:
-  - type: discord
-    webhook_url: "https://discord.com/api/webhooks/..."
-  - type: email
-    smtp_host: mail.arclineit.com
-    smtp_port: 587
-    from: alerts@arclineit.com
-    to: blake@arclineit.com
-
-monitors:
-  - name: "Main Website"
-    type: http
-    url: "https://arclineit.com"
-    expected_status: 200
-    contains: "[arcline]"        # optional string check in body
-
-  - name: "Control Panel"
-    type: http
-    url: "https://cp.arclineit.com"
-    expected_status: 200
-
-  - name: "SSH"
-    type: tcp
-    host: "server1.arclineit.com"
-    port: 22
-
-  - name: "Mail Server"
-    type: tcp
-    host: "mail.arclineit.com"
-    port: 587
-```
-
-## Web dashboard
-- `/` — current status of all monitors (live, auto-refresh)
-- `/history` — response time graph (ASCII sparklines or simple SVG)
-- `/metrics` — Prometheus-compatible text endpoint (optional)
-- Protected by basic auth (config: dashboard.username / dashboard.password)
-
-## Alert format (Discord example)
-```
-[DOWN] Main Website
-Expected 200, got 503
-Checked at 2026-03-03 14:32:01 UTC
-Response time: 8043ms (timeout)
-```
-
-## Tasks
-- [ ] Project scaffold
-- [ ] YAML config parser
-- [ ] HTTP monitor (status code, body contains, response time)
-- [ ] TCP monitor (dial timeout)
-- [ ] Scheduler (ticker per monitor, respect interval)
-- [ ] SQLite schema (monitors, checks, alerts_sent)
-- [ ] Result storage
-- [ ] Discord webhook alerter
-- [ ] SMTP email alerter
-- [ ] Alert cooldown logic (don't spam on sustained outage)
-- [ ] Recovery alert ("Main Website is back up, was down 12m 34s")
-- [ ] Web dashboard — current status page
-- [ ] Web dashboard — history / sparkline graph
-- [ ] /metrics Prometheus endpoint
-- [ ] Basic auth for dashboard
-- [ ] systemd unit file example
-- [ ] README with self-hosting guide
-- [ ] Cross-compile Makefile
+## Ideas
+- [ ] ICMP/ping monitor
+- [ ] HTTP response header assertion
+- [ ] HTTP JSON path check
+- [ ] SSH command check
+- [ ] Generic webhook alerter (configurable template body)
+- [ ] Telegram alerter
+- [ ] PagerDuty alerter
+- [ ] Escalation policy (alert A immediately, alert B after N minutes still down)
+- [ ] `test-alert` subcommand
+- [ ] `validate` subcommand (parse config, print summary, exit non-zero on errors)
+- [ ] `--dry-run` flag for start (run checks, no alerts)
+- [ ] Per-monitor detail page with full history and time-axis chart
+- [ ] Uptime calendar heatmap (GitHub-style, per day)
+- [ ] CSV / JSON export of check history
+- [ ] JSON API (/api/v1/monitors, /api/v1/monitors/{name}/checks)
+- [ ] Environment variable substitution in config (${VAR})
+- [ ] Config hot-reload on SIGHUP
+- [ ] TLS for the dashboard itself
+- [ ] Database backup command