# Build brief — a focused alternative to Cronitor

> **Verdict:** Yes, for personal use · **Buildability:** 71/100 · **Category:** Cron
> **Source:** https://www.canitbevibecoded.com/cronitor
> Independent editorial assessment from Can It Be Vibe Coded? Not affiliated with, endorsed by, or derived from Cronitor. Verify current pricing and capabilities before acting.

## Context

**Cronitor** — Heartbeat endpoint plus dead-man's-switch alerts. It currently costs $10/mo.

Heartbeat endpoint plus dead-man's-switch alerts. A hundred lines of code wearing a SaaS badge.

This brief describes a focused, single-operator replacement for the part of Cronitor that is genuinely reproducible. It is deliberately narrower than the product it replaces, and it says so in writing. Build the useful core; do not pretend to have rebuilt the rest.

## What you are building

A focused, single-user version of Cronitor's main workflow.

- Build a focused single-user workflow with real persistence, search, and export.
- A responsive interface with real empty, loading, success, and error states.

## Requirements

### Non-functional

- Accessibility: semantic markup, labelled controls, visible focus, and reduced-motion support.
- Security: server-side secrets, validated input, and no credentials in the client bundle.
- Reliability: retries with backoff on external calls, and a clear failure state when a provider is down.
- Portability: the operator can export their data and leave without losing it.

## Implementation brief

Build me a cron-job monitor like Cronitor / Healthchecks. Requirements:

- Each monitored job gets a unique ping URL (/ping/:uuid). The job's crontab
  line just appends `&& curl -fsS <url>` · document this.
- Define jobs in SQLite via a basic-auth /admin page: name, expected period
  (e.g. every 60 min) and grace time. Store every ping with timestamp.
- A scheduler loop checks each job: if now > last_ping + period + grace, the job
  is LATE → send one alert webhook (Discord/Slack/Telegram, URL in .env) with
  the job name and how late it is. Alert again on recovery. No alert spam ·
  one per state change.
- /admin dashboard: each job as a row with green/amber/red status dot, last ping
  time ("7 min ago"), and a 24h ping histogram as inline SVG.
- Support /ping/:uuid/fail for explicit failure reports with an optional body
  shown in the alert.
- Python or Node, single process, systemd unit included.

## Delivery standard

- Inspect the repository first, then write a short implementation plan before writing code.
- Deliver the smallest complete end-to-end workflow first; every primary control must work against persisted data.
- Use real validation and storage; never substitute fake dashboards, decorative controls, hard-coded success states, or mock integrations.
- Include responsive layouts plus genuine empty, loading, success, validation, and failure states.
- Keep secrets server-side in environment variables, provide .env.example, and never commit credentials or user data.
- Add structured logs around every external call and return actionable errors without leaking sensitive details.
- Write unit tests for the core logic and one automated test of the main user journey.
- Finish with a README covering setup, architecture, data location, backups, tests, deployment, and known limitations.

## Acceptance criteria

- [ ] A clean install starts the app using only the README and .env.example.
- [ ] The primary journey works from first visit through saved result, reload, edit, export, and deletion where applicable.
- [ ] Invalid input, missing configuration, provider failure, and an empty database each have a usable state.
- [ ] The interface works at 390px and 1440px, is keyboard navigable, and shows visible focus on every control.
- [ ] Tests, type checking, linting, and a production build all pass with no ignored failures.
- [ ] No part of the interface implies a live integration, security guarantee, or scale capability that was not actually built and verified.

## Non-goals

Do not build these, and do not claim to have replaced them:

- Their status pages and team features.
- Alert routing (SMS, PagerDuty).
- Cron expression insights.
- Reliability at the vendor's scale is an operations problem, not a prompt.
- Connectors, OAuth flows, and vendor API changes require constant upkeep.

## What you still own after launch

- Run migrations, backups, restores, and dependency updates.
- Test the critical journey after every model, API, or hosting change.
- Monitor failures and fix the edge cases a first prompt will miss.
- Maintain every third-party integration as APIs and OAuth rules change.

## Risk

**Operational risk.** The code is achievable; dependable data, integrations, and ongoing operations are the real cost.

Editorial confidence in this assessment: high. No independent one-shot implementation is linked yet.

## Prior art

Working open-source software you can read, fork, or borrow from before starting:

- [Healthchecks](https://github.com/healthchecks/healthchecks) — excellent open-source cron monitoring

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Generated by [Can It Be Vibe Coded?](https://www.canitbevibecoded.com) · Full report: https://www.canitbevibecoded.com/cronitor