Costs less than the waste it finds.

Paid plans buy capacity and history, not features, so you can count what you owe before you agree to it: how many people, how many projects, how far back.

One honest exception: the activity log needs a paid plan. On Free the account has a single person, so every line in it would name whoever is reading it. Everything else runs in full on the free plan.

Free

For side projects and proofs of concept
$0
1 person · 1 project
  • Every screen, every SDK, every alert
  • Cost per customer and per feature
  • Budgets and anomaly alerts
  • Deploy markers, CI check, MCP server
  • 7 days of history
Start free
RECOMMENDED

Pro

For products with AI in production
$49 /mo
Unlimited people · unlimited projects
  • Everything in Free, nothing removed
  • Your whole team, at no cost per seat
  • 90 days of history
  • Activity log: who changed rates, budgets and keys
Get Pro

Scale

For the team that signs the month off
$249 /mo
Unlimited people · unlimited projects
  • Everything in Pro
  • 395 days (13 months) of history, events and activity log
  • A full year of closed months to reconcile and sign off, not just the last quarter
  • Every screen reaches the same month last year
  • Priority support
Get Scale

Prices in USD. Cancel from the billing screen at any time. No per-seat charge, no per-trace charge, no per-gigabyte charge.

What you get that the console cannot give you

Providers meter their infrastructure. You need to measure your business.

OpenAI, Anthropic and Google bill you by organization, key and model, which are the dimensions of their system. Your questions are about yours.

The question Provider console KostLens
Which customer of mine costs the most? No Yes
Which feature costs the most? No Yes
Every provider on one screen No Yes
Claude Code, Cursor and Copilot seats in the same total No Yes
What will this month's invoice be, across every provider? No Yes
One budget for every provider, not one per console No Yes
What would this month have cost on another model? No Yes
Which deploy made spend jump? No Yes
Who changed a budget or a rate, on any provider, and when? No Yes
The invoice you legally owe Yes No

The last row is not a slip. KostLens does show every single call, with its cost, on a screen of its own. What it does not hold is the authority: your provider issues the invoice and applies your discounts and credits, and we read usage. When the two disagree, theirs is the one you pay. Plans are not metered by volume, though a fair-use ceiling on stored data does exist and is described in the terms.

Billing

Before you put a card in.

Is Free a trial?

No. Free is free forever, and it runs the product: all six screens, all three SDKs, budgets, alerts, the CI check and the MCP server. What it limits is capacity, one person and one project, and how far back you can look. The one thing that needs a paid plan is the activity log, because on a single-person account every line in it would name the person reading it. Nothing switches off on day 15.

Why not charge per event, per trace or per gigabyte?

Because you could not predict the bill before agreeing to it, and a company that sells cost predictability should not send surprise invoices. Capacity is something you can count in your head: how many people, how many projects, how far back. You know the number before you pay it.

Do you charge per seat?

No. On a paid plan your whole team is included at no extra cost, and so is every project. Per-seat pricing quietly punishes you for inviting the person who most needs to see the spend, which is usually whoever is paying for it.

What happens when I hit a limit on Free?

The action is refused with a clear message, not silently dropped. Inviting a second person or creating a second project asks you to upgrade. Your data keeps being collected the whole time, so nothing is lost while you decide.

What happens to my history if I downgrade?

Nothing is deleted on the spot. The plan sets how far back you can READ, not how much we keep, and there is a grace period before the shorter window applies. Go back up and the older months are there again.

Do the numbers match my provider invoice?

Closely, and rather than ask you to take that on faith the product measures it: the Overview puts our total for the month next to what the provider's own usage API reports, per provider, and names the gap. Cost is computed from token counts and published prices, versioned by effective date, including the parts nobody models: batch and flex halve the rate, priority and fast mode multiply it, and writing to cache costs more than reading from it. What we cannot see is your private discount or your credits, so the provider's invoice stays the source of truth for payment.

Can I cancel whenever?

Yes, from the billing screen, and you keep the paid plan until the period you already paid for ends. No call, no email, no retention flow.

Start on the free plan.

One person, one project, the whole product. Wired into your app before your coffee cools.

Start free