Vigil Core — free and open source under the AGPL-3.0

Start with the free one. Most people should.

A complete uptime monitor, not a trial.

Vigil Core is the same codebase under the AGPL-3.0: HTTP checks with keyword assertions, automatic incidents, a public status page, team roles and an audit trail. 161 tests. No licence key, no telemetry, no expiry.

Read the source on GitHub Compare with the commercial edition git clone → docker compose up → live in 10 min
The split

Exactly what is in each edition.

No asterisks. If a row is in Core, it is in Core forever — the free edition is not a funnel with a timer on it.

Vigil Core — free, AGPL-3.0Included
MonitoringHTTP(S) checks — interval, timeout, expected status, degraded threshold
AssertionsBody contains / does not contain — catches the 200 that serves an error page
IncidentsOpened and resolved automatically, immutable timeline, postmortem field
Status pageOne public page, 90-day uptime bars, incident history
AlertsEmail, plus HMAC-signed webhooks that auto-format for Slack and Discord
TeamOwner, admin, responder, viewer — viewers never see signing secrets
AuditEvery mutation recorded with actor, target and metadata
Tests161, plus lint, typecheck and Docker images for app and worker
Commercial — $149 onceAdds
RecoveryVerifies the failure, fires your signed restart hook, verifies the fix — bounded and recorded
Multi-tenantMany client organizations in one install, each with its own branded status page
On-callRotations and escalation ladders, with SMS and voice through your own Twilio account
Check typesTCP/port monitors and TLS-certificate expiry warnings
Status pagesPrivate and password-protected pages, plus internal-only incident notes
SubscribersDouble opt-in email subscriptions on public status pages
LicenceNo copyleft obligation — modify and serve clients without publishing changes
Full terms ↗Every word readable before you pay
When to upgrade

Three walls. If you never hit one, stay free.

Stated in advance so the decision is yours rather than a surprise four weeks in.

You have clients
The multi-tenant wall

Core runs one organization per install. Fine for a team watching its own systems. If you monitor for clients and each needs their own branded status page and isolated data, you would be running one install per client — which is when the commercial edition's multi-tenancy pays for itself immediately.

You want the restart, not the page
The recovery wall

Core tells you something is down. It does not act on it. Automatic recovery — verify the failure, call your restart hook with a signed payload, verify the fix, hold the alert while it tries — is the commercial edition's reason to exist. If a human is going to run the same restart command anyway, that loop is what you are buying.

The AGPL is in your way
The licensing wall

Run Core internally, modified or not, and the AGPL asks nothing of you. Modify it and serve that modified version to other people over a network and your changes must be published under the same licence. For an agency shipping a customised monitor to clients, that is usually the blocker — and the commercial licence removes it.

None of these apply to you? Then Core is the right answer and this page has done its job.

Why it is built this way

Open source as evidence, not as marketing.

An unknown company asking $149 for software you cannot inspect is asking for trust it has not earned. Publishing the engine under a real licence is the only answer to that which costs the seller something.

So Core is not a stripped shell. It is the checker, the incident state machine, the status page and the role system — the parts you would need to read to judge whether the paid edition is competent. Reading them is the point.

The line between the editions is drawn where the value is genuinely different, not where it would hurt most to lose. That is a commercial choice, and it is the one Sikur intends to keep applying to future products.

The rules Sikur holds its products to
No licence key, no activation, no phone-home in either edition
Same schema in both — upgrading is a migration, not a re-platform
Core cannot be withdrawn: it is published under the AGPL already
Issues and pull requests welcome on the public repository
If Core is enough for you, that is the intended outcome — not a lost sale
Questions

Asked by people deciding whether to trust this.

No. Nothing is gated behind a licence key, there is no telemetry, nothing expires and no feature stops working after a while. Core is a complete uptime monitor. If Core is all you need, that is the intended outcome.

If you run Core internally — modified or not — the AGPL asks nothing of you. The obligation triggers when you modify it and offer that modified version to other people over a network: then your changes have to be published under the same licence. Running unmodified Core for your own company is not affected.

Agencies serving clients over a network want to modify the product without the copyleft obligation, and the commercial licence removes it. And the features that only matter at that scale — automatic recovery, many client organizations in one install, on-call rotations, TCP and TLS checks — are what fund the maintenance of both editions.

Yes. Same codebase, same database schema, so it is a migration rather than a re-platforming — your monitors, incidents and history come with you. The upgrade guide covers taking updates after you have customised the code.

Core is AGPL-3.0 and already published, so it cannot be withdrawn — you can fork it, run it and modify it regardless of what happens to the company. Commercial licences are perpetual for the versions you already hold, and there is no licence server that could switch anything off.