SignalFlare watches your Cloudflare spend and fires a flare in your team's Slack the moment it goes sideways — so a runaway bug costs you pocket change, not a mortgage payment. And you finally see where every dollar goes.
Read-only token · 2-minute setup · No card
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The problem
Usage-based billing is wonderful until something starts spending on your behalf.
A developer on a $5/month plan watched two buggy Workers write 4.8 billion rows to D1 over one weekend. The invoice landed at $4,586.64 — later waived, after 18 days of tickets. Nothing on the platform flinched while it was happening.
Read the write-upWorkers, R2, KV and D1 bill per use with no ceiling. A retry loop writing to KV at $5 per million writes doesn't stop until you notice. Nothing in the platform will stop it for you.
Cloudflare shipped budget alerts in April 2026: an email, account-wide, PAYG only. No Slack. No per-service rules. No projections. Nothing pauses. Better than silence, but an email about the whole account is not what saves your weekend.
What you get
FinOps dashboards tell you what happened. SignalFlare is a tripwire: it tells you while it's happening — and shows you exactly where the money went.
"R2 alone crosses $10" is a rule, not a wish. Budget the services that can hurt you individually, on top of the account total.
We alert on trajectory: when the math says you'll blow the budget by the 24th, you hear about it on the 17th — while it's still a small number.
Slack, Discord, email, or a signed webhook into your own tooling — not another inbox you check on Mondays.
Cloudflare's analytics forget after a month. We keep your usage history, so month-over-month trends actually exist.
Agencies and multi-org teams: connect all your client accounts and watch every bill from a single dashboard.
Setup
One scope: Account Analytics: Read. We show you exactly where to click.
About 60 seconds, and the token can't modify a thing.
$20 a month? $200? Add per-service rules ("R2 alone crosses $10") and thresholds at 50, 80 and 100%.
Slack, Discord, email or a signed webhook. Including when the projection says you'll blow the budget, not just when you already have.
The honest comparison
Cloudflare's built-in Budget Alerts are free and better than nothing — run both. SignalFlare is the half they left out.
| Cloudflare Budget Alerts | SignalFlare | |
|---|---|---|
| Delivery | Email only | Slack, Discord, email, signed webhooks |
| Scope | Whole account, one number | Per-service budgets + account totals |
| Projections | Alerts after you spend | Forecast alerts before you cross the cap |
| Billing plans | Pay-as-you-go only | Any billing type |
| Usage history | ~31 days, then gone | Kept for month-over-month trends |
| Multiple accounts | One at a time | Roll-ups across accounts |
| Can it stop the spend? | No | Kill switch — opt-in, early access |
Security
Analytics-read-only scope. It can't touch DNS, Workers, or settings. We encrypt it with AES-256-GCM at rest, decrypt it only in memory to poll, and never log it. Revoke it in the Cloudflare dashboard any time and we go blind immediately.
Early access — in the product today
The emergency brake: when a hard cap breaches 100%, SignalFlare removes a Worker route or flips on a blocking WAF rule — automatically. Opt-in with a separate write token, born in dry-run mode, armed only after you type the confirmation, every execution audited. Because an alert at 3am is only useful if someone's awake.
Pricing
That's the whole pitch.
$0
$19/mo
Custom
Monitoring runs on Cloudflare Workers, naturally. We watch our own bill with SignalFlare.
FAQ
Close, not exact. Cloudflare samples its analytics, so our dollar figures can drift a few percent from your invoice. That's fine for the job: what you need at 3am is direction and timing (spend doubled in the last hour, you'll cross your cap on Thursday), not cent-level accounting. We label every number in the app as an estimate.
Use both, honestly. But Cloudflare's alerts (shipped April 2026) send an email, cover the whole account in one number, and only work on pay-as-you-go billing. No Slack or webhooks, no per-service rules, no projections. SignalFlare tells you R2 specifically is on fire, in the channel your team actually reads, before the cap is hit rather than after.
The token you give us is analytics-read-only. It cannot change DNS, deploy Workers, or touch settings; the worst a leaked one could do is read usage numbers. We encrypt it with AES-256-GCM at rest, decrypt it only in memory to poll, and never write it to logs. You can revoke it in the Cloudflare dashboard at any time and we're instantly blind.
Workers, R2, KV, D1 and Durable Objects at launch. Queues, Images and Stream are next. If the service that bit you is missing, email us; the polling layer is the same, so adding one is usually quick.
Yes, and that matters more than it sounds. Cloudflare's analytics only retain about 31 days, so by the time you want to compare this month's R2 spend to last month's, the raw data is gone. We keep your history so month-over-month trends survive. Delete your account and the history goes with it.
Yes — if you arm it. The kill switch (auto-remove a Worker route or flip a blocking WAF rule when a hard cap is breached) ships today in early access: opt-in, powered by a separate write token you grant explicitly, born in dry-run mode so you can see exactly what it would have done before you let it do anything, and armed only after a typed confirmation. Every execution is audited.
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