A minimal alternative to Uptime Kuma: HTTP, Prometheus and push checks, notifications and status pages, configured in plain key = value files.

• One static binary, Go standard library only (go.mod), in the spirit of nobloat.org
• No database: one append-only CSV audit log per monitor
• Config as code: one file per monitor, notifier and status page, checked with up -check, reloaded on change

Features

HTTP checks	status codes, body regex, JSON match, headers, basic auth, redirects, TLS expiry
Prometheus checks	one metric of a /metrics endpoint, or a PromQL query (Thanos, Mimir, VictoriaMetrics work too)
Push monitors	dead man switch for cron jobs and backups; Uptime Kuma and healthchecks.io compatible URLs
Notifications	Slack / Mattermost webhooks, mail, ilert; reminders while red
Status pages	public, per tag, custom templates
Web UI	live updates, filters, search, keyboard shortcuts, pause with reason and end, dark mode, phone friendly, installable on the home screen
Heartbeat	pings an external URL so something notices when up itself is down

Not included: editing monitors in the UI (the files are the source of truth), graphs, users and roles.

Deployment

compose.yaml with Caddy for TLS:

services:
  up:
    image: ghcr.io/nobloat/up:latest
    restart: unless-stopped
    environment: {TZ: Europe/Vienna}
    volumes: [./config:/config:ro, ./data:/data]
  caddy:
    image: caddy:2
    restart: unless-stopped
    ports: ["80:80", "443:443", "443:443/udp"]
    volumes: [./Caddyfile:/etc/caddy/Caddyfile:ro, caddy:/data]
volumes:
  caddy:

Caddyfile:

up.nobloat.org {
	reverse_proxy up:7493
}

• ./data must be writable by uid 65534: sudo chown 65534:65534 data
• up -check -config <dir> validates a config, e.g. in CI (exit code 1 on any error)
• A damaged audit log stops startup instead of being reset: back it up and repair it

Configuration

A directory (-config, /config in the image): up.conf plus one file per entity, named <name>.<kind>.conf. Start from example/config, or see config for every feature (make run).

config/
  up.conf
  website.monitor.conf
  prod/api.monitor.conf
  ops-chat.notifier.conf
  public.page.conf

• One key = value per line, # starts a comment, lists are comma separated, nested keys are dotted (headers.X-Api-Key)
• Durations: Go syntax plus days (30s, 1h, 7d, 1d12h)
• Unknown keys are errors. A broken entity file is skipped and logged; only a broken up.conf stops startup
• The directory holds credentials: treat it as secret

up.conf

listen = :7493
base_url = https://up.nobloat.org
data_dir = /data
auth.user = admin
auth.password = secret
heartbeat.urls = https://hc-ping.com/<uuid>

Option	Default
base_url	required	public URL, for links in notifications
data_dir	required	audit logs
auth.user, auth.password	required	basic auth for the UI and API
listen	:7493	plain HTTP, put a TLS proxy in front
proxy		HTTP proxy for all checks and notifications
evaluation_interval	30s	how often notifications are evaluated and batched
heartbeat.urls, heartbeat.interval	1m	URLs to GET while up runs

Monitors

type = http
description = Home page answers with 2xx
tags = public
interval = 1m
retry_count = 2
notifiers = ops-chat
url = https://example.com/health
cert_min_valid_days = 14

Type	Checks	Options
http	an HTTP(S) endpoint	HTTP options
metric	one metric of a Prometheus text format endpoint	HTTP options, metric, labels.<name>, value (< 80, ops > >= < <=); every matching series must pass, none fails
promql	an instant query; url is the API base	HTTP options, query, value; every series must pass, empty fails
push	something reports in	token (16+ characters, unique), see push monitors

Option	Default
type, interval	required	interval: between checks, or expected between pushes
description		public, shown on status pages
tags		UI filters and status pages
retry_count	0	failures after the first before red; yellow until then
retry_interval	interval	between checks while yellow
timeout	10s	per check
grace		push only: extra time before a missing push fails
notifiers		notifier names; unknown ones are skipped and logged

HTTP options

For http, metric and promql (promql always uses GET).

Option	Default
url	required
method	GET	GET, POST, HEAD
headers.<name>		Host overrides the host header
basic_auth.user, basic_auth.password
body		request body
accepted_status	any 2xx	e.g. 200, 204
body_regex		RE2 syntax
json_match.path, json_match.equals		data.0.status = ok; 1 is a number, "1" a string
max_redirects	10
skip_verify	false	skip TLS verification
cert_min_valid_days		red without retries when the certificate expires sooner

• Redirects never downgrade HTTPS. With credentials, headers, a body or a query string only same-origin redirects are followed
• Secrets are masked on the detail page; errors never contain the URL

Push monitors

curl -fsS https://up.nobloat.org/push/backup/<token>
curl -fsS -d '{"files": 12}' "https://up.nobloat.org/push/backup/<token>?status=down"

curl -fsS "https://up.nobloat.org/api/push/<token>?status=down&msg=disk%20full"

some-job > job.log 2>&1; rc=$?; curl -fsS --data-raw "$(tail -c 4000 job.log)" https://up.nobloat.org/ping/<token>/$rc

No push within interval + grace is a failure; the token is the only auth.

Notifiers

Sent when a monitor turns red or recovers, batched every evaluation_interval. Failed deliveries retry, also after a restart.

type = webhook
url = https://chat.example.com/hooks/xyz
reminder_interval = 1h

Type	Options
webhook	url, headers.<name>; Slack / Mattermost format
smtp	host, port, tls (starttls · tls · none), user, password, from, to, subject_prefix ([up])
ilert	integration_key of an "API" alert source; red opens an alert, recovery resolves it

All but ilert take reminder_interval; ilert escalates on its own.

Status pages

public.page.conf serves /status/public with every monitor tagged public:

title = Example Status
tag = public

template points to a custom html/template (relative to the config directory) receiving StatusPage{Title, State, Monitors}, e.g. config/templates/minimal.html.

Development

make run
make mailpit
make test
make build
make package
make screenshots