use-cases / heartbeat-for-silent-jobs / hero

CRON · NOTIFICATIONS · SILENCE-ALARM

A heartbeat for the silent jobs

Most monitoring watches what happened. You needed something that watches what didn't. Two cron entries — one beats, one listens for the absence of a beat — and the page that finds you on a beach.

Read the cron docs

ops · heartbeats

https://ops.containers.hoody.com/heartbeatslive

Monitored jobs · last 24 beats

6 of 6

backup-prod-dbMISSED · 2h overdue
2h 06m ago
@daily · 02:00
rotate-api-keys
6m ago
0 4 * * 0 · weekly
cleanup-stale-snapshots
3m ago
0 * * * * · hourly
export-stripe-ledger
11h 04m ago
@daily · 03:30
renew-letsencrypt
1h 12m ago
0 1 * * * · daily
vacuum-postgres
2m ago
*/15 * * * *

Silence watcher

# Pages on missing beat*/15 * * * *curl /silence-check

channels

push · ios
sms · twilio
email · ops@

ok late missedwindow: 24 beats

two cron entries · zero new services · the alert finds you when nothing happens

use-cases / heartbeat-for-silent-jobs / mechanism

Two cron entries. One says I'm alive. The other listens for nothing.

The job you already had keeps doing its work. After it finishes, it adds one curl: a heartbeat row to a notifications endpoint. A second cron entry runs on its own cadence and checks for silence — if no fresh beat, it pages your phone. The job's success is silent. Its absence is loud.

worker.cron · the job

POST · heartbeat

schedule0 2 * * *

# After the nightly export finishes,# the job pings its own heartbeat.0 2 * * * /usr/local/bin/export.sh \ && curl -fsS -X POST \ https://notify.containers.hoody.com/heartbeats/backup-prod-db

the absence is the signal

watcher.cron · the listener

GET · silence-check

schedule*/15 * * * *

# Every 15 minutes, ask: was there a beat?# If silent for >1h, the API pages all channels.*/15 * * * * curl -fsS \ https://notify.containers.hoody.com/silence-check?\ job=backup-prod-db&max_age=1h

Two POSTs to /users/root/entries with five-field expressions. The first runs after each scheduled job and posts its heartbeat. The second runs on its own cadence, asks the notifications endpoint whether the last beat is fresh enough, and triggers the page if not. No queue, no agent, no daemon — just two crontab lines that already had to exist.

use-cases / heartbeat-for-silent-jobs / powers

Why watching absence is different

Most monitoring tools watch the success path: they alert when something happens. This shape alerts when nothing does — and that's the case the silent jobs always lose.

FAILURE MODES

Catches the silent crash

If the worker process never starts — the box rebooted, the script was deleted, a quota expired — there is nothing to log and nothing to alert on. The watcher cron runs anyway and notices that the heartbeat row is stale. The thing that catches the silent crash is exactly the thing that doesn't depend on the silent thing.

ZERO SURFACE

No new service to babysit

The monitor is one extra crontab line, not a Healthchecks.io account or a CloudWatch alarm. It's bound to the same container as the work, expires with `expires_at` if you want it to, and reads from the same notifications API the rest of your stack already uses.

REACHES YOU

Loud when it matters

The notifications endpoint fans the page across push, SMS, and email — the channels you already trust. You don't watch the dashboard. The dashboard watches itself, and finds you on the beach in Bali only when the silence has gone on too long.

use-cases / heartbeat-for-silent-jobs / capacity

Real cron, real notifications

The mechanism is plain Hoody Cron and Hoody Notifications. The numbers come from the documented API surface, not from a demo runtime.

ALL CRON SYNTAX@daily
Standard 5-field expressions plus macros — `@hourly`, `@daily`, `@weekly`, `@monthly`, `@yearly`. The watcher and the worker can have completely different cadences.
AUTO-EXPIRYexpires_at
Managed entries support `expires_at`, so a temporary heartbeat (a one-week migration window, say) cleans itself up. The watcher disappears with the work.
ISOLATIONper-user
Each container gets its own crontab. The heartbeat for one tenant cannot mute the watcher for another, and disabling a job is a single PATCH `enabled: false`.

Limits per the Hoody Cron API: 5-field expressions plus the `@hourly`/`@daily`/`@weekly`/`@monthly`/`@yearly` macros, optional `expires_at` on managed entries, per-user crontab isolation, enable/disable via PATCH.

use-cases / heartbeat-for-silent-jobs / punchline

Silence is now an alert.

BEFORE · WATCHING THE LOGopen dashboard · search for last export · sigh · forgetyou only notice the missing job on Monday

AFTER · WATCHING THE QUIET*/15 * * * * curl /silence-check?job=backup-prod-dbthe page reaches you while the silence is still small

Read the cron docs

use-cases / heartbeat-for-silent-jobs / replaces

What this replaces

The standard reach-for-it tools when you want a cron-monitor with paging. Each one is a separate account, a separate bill, a separate API. Two crontab lines and the notifications endpoint do the same job.

custom orchestratorsWhole orchestration services for what is two crontab lines
Healthchecks.ioA SaaS account just to receive an HTTP heartbeat
CronitorPer-monitor pricing for a thing your container already does
Dead Man's SnitchThe exact pattern, sold as a subscription
AWS CloudWatch alarms for cronLambda + alarms + IAM policies for one stale row
custom heartbeat collection scriptsA microservice to log a value the cron could just POST

use-cases / heartbeat-for-silent-jobs / cta

Stop watching the success path. Watch the absence of success — it's the only place the silent failures live.

Read the cron docs

use-cases / heartbeat-for-silent-jobs / related

Read the others

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One bare-metal box runs dozens to hundreds of Hoody containers. KSM and BTRFS dedup make the marginal cost near zero.

Containers·Snapshots

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Snapshots·Containers·Terminal·Files

API endpoints that materialize on demand

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Exec·Agent·Code·Files

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Snapshots·Containers

Real VS Code on your phone

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Display·Terminal·Files·Containers+1

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Agent·Exec·Containers

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Containers·Snapshots·Exec·Files

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Agent·Snapshots·Containers·Browser+2

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Terminal·Snapshots·Network

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Pipe

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Pipe

Watch your agent think from the coffee shop

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Pipe·Agent

Move 200GB between clouds with two curls

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Pipe

Send a teammate a database state in one line

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Pipe

Stream LLM tokens to anything that reads HTTP

Step 3 streams tokens with curl -T -. Step 4 curls the same path. Tokens move generator to consumer at line speed. No SSE plumbing, no broker.

Pipe·Agent

A progress bar your boss can spectate without joining

Append ?progress to the pipe URL. Anyone who opens it gets a live HTML dashboard — bytes, speed, ETA, state. Up to fifty spectators, none consuming a receiver slot, none touching the stream.

Pipe

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Pipe·Exec

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tar | zstd | curl puts node_modules into a pipe. Twenty downstream jobs curl | zstd -d | tar x. No S3 bucket, no cache action, no egress bill.

Pipe·Containers

Drag-drop uploads into your script

hoody-pipe serves a web upload form at every path. Drag a file onto the page, your script reads the bytes from stdin. Zero upload code, no S3 bucket, no presigned URLs.

Pipe·Exec

Broadcast a workshop to 200 viewers from your laptop

ffmpeg streams your screen to a pipe path with ?n=200. Each attendee curls the URL into a browser tab. No platform, no logins, no upload.

Pipe

Inter-container IPC without the message broker

Container A writes to a pipe path. Container B reads from the same path. Backpressure is the connection. No Redis, no queue, no broker.

Pipe·Containers

Tail your agent on the train, get pinged when it lands

The agent streams its trace to a pipe path you can curl from your phone. When it finishes, its last act hits hoody-notifications and your phone buzzes. Two URLs and a buzz — no SDK, no client app, no dashboard.

Pipe·Agent·Notifications

A microphone over HTTP, in two terminals

ffmpeg captures the mic, pipes to a URL. The other end curls and plays the audio. No Zoom, no SDK, no signaling server.

Pipe

Five agents, five pipes, one verdict

A panel of five models reviews the same input. Each runs in its own container and streams its verdict to its own pipe path. A judge process curls all five in parallel and tallies the result.

Pipe·Agent·Containers

Replay this morning's incident to the whole team

Snapshot the incident-time logs in hoody-files. Replay them through a Hoody Pipe URL with ?n=8. Eight engineers curl the same path and watch the cascade fire in lockstep — the post-mortem is a synchronized stream, not a Confluence doc.

Pipe·Files

The fastest 'send me that file' you've ever typed

A teammate pings for a 4 GB dump. Slack rejects it, Drive needs a share request. You type curl -T file …; they type curl … > file. The bytes move directly between disks — no upload bar, no link to share.

Pipe

Run a local LLM, serve it to your whole fleet

One GPU runs llama.cpp. Its tokens stream into a pipe path with ?n=50. Fifty containers curl the same URL and split the stream.

Pipe·Daemon

A live metrics dashboard with no metrics backend

Each container's monitoring loop curls a metric to a pipe URL. The dashboard curls the same URL with ?progress and renders the SSE stream.

Pipe

The cron job that deletes itself when you're done

POST a managed cron entry with expires_at set 48 hours out. The job runs on schedule, then removes itself — no reminder, no cleanup PR, no stale entry.

Cron

Snapshot the container right before the nightly migration

A hoody-cron entry that fires at 02:55 UTC, curls the snapshots URL, and names the artifact pre-migration-2026-05-04. Five minutes later the migration runs. If it succeeds, the snapshot sits idle and costs nothing. If it fails, you restore in 30 seconds with a single PATCH.

Cron·Snapshots

A separate crontab for every customer, automatically

Each tenant gets their own container and their own hoody-cron service. Customer A's 9am digest fires on time even when customer B's job hangs for 40 minutes, because they aren't on the same crontab.

Cron·Containers

Wake an agent at 3am, retire it at 4

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Cron·Agent·Containers

Daily rollups without an orchestrator

Raw events pile up in a sqlite URL. Every night a cron entry curls an exec endpoint, the script runs the rollup SQL, writes the daily table back. No DAG, no Airflow Postgres, no scheduler dashboard.

Cron·SQLite·Exec

A crontab per branch, deployed with the code

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Cron·Containers

On-call escalation that ages out with the shift

POST a cron entry with expires_at = shift end. When the shift ends, the entry deletes itself. The next on-call posts their own.

Cron·Notifications

Hourly scrape, daily digest, weekly archive — one container

Three lines in one crontab: hourly browser scrape into SQLite, daily exec digest, weekly archive to files. Flat-rate server, three rhythms, no scheduler service.

Cron·Browser·SQLite·Files

Let your customers BYO their own cron schedule

Customers POST their own 5-field expressions; their crontab lives in their container, isolated. You don't validate against a global queue.

Cron·Containers

Schedule the agent, not the script

A 5-field cron entry curls hoody-agent with a prompt instead of running a fixed script. Today is the last day of the month — the agent figures it out. The data shape changed — the agent figures it out.

Cron·Agent

Keep the last 24 hours as 24 snapshots

An hourly cron POSTs a snapshot named with the hour. After 24 hours each new snapshot overwrites yesterday's at the same hour. The 24-floor time machine.

Cron·Snapshots

Replay this morning's webhooks at the same time tomorrow

You captured 30 minutes of real Stripe traffic into a hoody-files folder. One cron entry replays it against staging at 9am every weekday — same volume, same payloads, same time-of-day pressure.

Cron·Files·Exec

Edit your crontab from a phone, in the airport

Open the cron URL on your phone in the gate area. Tap a row, change a single field of the cron expression, hit Save. PATCH lands. The job fires tonight on the new schedule. No SSH session, no jump box, no laptop.

Cron·Terminal

A scheduled digest that fans out to 200 inboxes

Cron at 9am POSTs to an exec script that builds the digest and curls a pipe URL with ?n=200. Two hundred recipients hit the same URL once.

Cron·Exec·Pipe

Mute the flaky job without losing it

PATCH /entries/[id] [ enabled: false ]. The job stays in your crontab waiting to be fixed. No deletion, no rewrite, no lost context.

Cron

An agent that grades yesterday's agents

A nightly cron POSTs to the supervisor agent with yesterday's agent traces from SQLite. The supervisor scores each one. Cron is the supervisor.

Cron·Agent·SQLite

Cleanup jobs that schedule their own retirement

The cleanup script checks if there's anything left to clean. When the directory is empty, it DELETEs its own cron entry. Job's done, job's gone.

Cron·Files

Roll your TLS certificates without an SSH session

Cron weekly: POST to an exec script that runs certbot, posts the new cert to the proxy via PATCH. No shell session, no key, no jump host.

Cron·Exec

A weekly canary that tries to break production

Sunday 7am cron wakes a Hoody Agent in a fresh container against a snapshot of prod. It runs the OWASP top twenty, fuzzes the API, and writes a findings report to a URL by 9am. Container retires.

Cron·Agent·Browser·Snapshots

The hobby-project graveyard you can afford to keep alive

Eleven half-finished side projects on Heroku is eleven dynos at $5–7 each. On Hoody it's eleven containers on one $29 bare-metal box. Idle costs zero, the URL wakes the container in milliseconds, and the chess engine nobody uses still runs.

Containers

A preview environment per pull request, all month

Each open PR gets its own clone of a snapshot. The container wakes when reviewers click the link; idle PRs cost nothing.

Containers·Snapshots

Run a 12-product portfolio from one bare-metal box

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Containers

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Containers·Snapshots

Forty client sites, one rent, one dashboard

Each client site lives in its own container; you bill them per-site, you pay the host once. The math finally works for agencies.

Containers·Workspaces

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Containers·Agent·Exec

Idle staging costs nothing, so staging stops getting deleted

Staging used to die because it was expensive to keep around. When idle is free, staging gets to live — even the one a teammate touched 90 days ago.

Containers·Snapshots

Per-customer sandboxes at fleet scale

Eight hundred isolated customers on three bare-metal servers — one flat-rate monthly bill, no per-tenant meter. Each tenant gets a real container with its own kernel namespace, filesystem, and URL. Idle containers cost nothing on top of the server you already pay for.

Containers·Snapshots·Exec

The CI cache that's not an S3 line item

Cache files live in /files on the box you already rent. Workers PUT and GET tarballs over HTTP. No S3 bucket, no egress, no third vendor — the bytes never leave the box.

Files·Containers

Fifty demo environments for fifty sales calls

Each prospect gets a real, isolated copy of your product seeded with their data. Cloned from a snapshot. Theirs to keep for a week.

Containers·Snapshots

A heartbeat for the silent jobs

Two cron entries. One says I'm alive. The other listens for nothing.

Why watching absence is different

Catches the silent crash

No new service to babysit

Loud when it matters

Real cron, real notifications

What this replaces

Read the others

Sixty containers on one server

Onboard a developer with one link

API endpoints that materialize on demand

Branch computers like Git

Real VS Code on your phone

AI agents that spawn other AI agents

One sandbox per customer, automatically

Wake up to a finished prototype

Emergency production fix from your phone

Tail production logs to a URL anyone can curl

Push one build to thirty CI workers at once

Watch your agent think from the coffee shop

Share your screen with a URL, not a meeting invite

Move 200GB between clouds with two curls

Send a teammate a database state in one line

Stream LLM tokens to anything that reads HTTP

A progress bar your boss can spectate without joining

The webhook fan-out you didn't have to build

A CI cache that's just two curl commands

Drag-drop uploads into your script

Broadcast a workshop to 200 viewers from your laptop

Inter-container IPC without the message broker

Tail your agent on the train, get pinged when it lands

A microphone over HTTP, in two terminals

Five agents, five pipes, one verdict

Replay this morning's incident to the whole team

The fastest 'send me that file' you've ever typed

Run a local LLM, serve it to your whole fleet

A live metrics dashboard with no metrics backend

The cron job that deletes itself when you're done

Snapshot the container right before the nightly migration

A separate crontab for every customer, automatically

Wake an agent at 3am, retire it at 4

Daily rollups without an orchestrator

A crontab per branch, deployed with the code

On-call escalation that ages out with the shift

Hourly scrape, daily digest, weekly archive — one container

Let your customers BYO their own cron schedule

Schedule the agent, not the script

Keep the last 24 hours as 24 snapshots

Replay this morning's webhooks at the same time tomorrow

Edit your crontab from a phone, in the airport

A scheduled digest that fans out to 200 inboxes

Mute the flaky job without losing it

An agent that grades yesterday's agents

Cleanup jobs that schedule their own retirement

Roll your TLS certificates without an SSH session

A weekly canary that tries to break production

The hobby-project graveyard you can afford to keep alive

A preview environment per pull request, all month

Run a 12-product portfolio from one bare-metal box

Kill the staging-server tax

Forty client sites, one rent, one dashboard

Replace the E2B bill with the bare metal you already rent

Idle staging costs nothing, so staging stops getting deleted

Per-customer sandboxes at fleet scale

The CI cache that's not an S3 line item

Fifty demo environments for fifty sales calls