Your API key

Thank you for subscribing. Your key is shown below and works on your very next request. It stays retrievable on this page for 24 hours after checkout — so if you close the tab by accident, come back to the same link and it will still be here. We do not email keys. For that window we hold a copy of your key so this page can show it again. After the window closes it cannot be retrieved, the copy is deleted automatically, and we keep only a SHA-256 hash of the key, so nobody can produce it again, including us.

Your subscription key

This page needs the checkout reference that is added to the link when your payment completes. Open it from the link you were sent to after checkout — it looks like /mcp/key/?checkout_id=… — and your key will appear here. The reference is removed from your address bar as soon as the page loads, because it is what unlocks your key; keep the original link if you need to retry.

Looking for a free key instead? You can create one yourself in a single click on the pricing page. No card, no email address, no waiting.

Use it on your next request

Send the key as a standard bearer credential. Nothing else about your integration changes — same endpoint, same tools, same math:

curl -X POST https://mcp.digitalcalculator.info/mcp \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer <YOUR_KEY_HERE>' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"mortgage_monthly_payment","arguments":{"principal":300000,"annualRatePercent":6.5,"termYears":30}}}'

Responses are byte-identical to what the anonymous tier returns for the same inputs, per the anonymous-parity invariant in our versioning contract. What your subscription buys is allowance, per-key attribution, and a support channel — never different numbers. Client-by-client setup notes are in onboarding step 4.

Store it before you leave this page

Treat this key the way you would any server-side secret:

Put it in a secrets manager — AWS Secrets Manager, 1Password, HashiCorp Vault, or your CI vault — rather than in a config file
Keep it server-side. A subscription key carries paid capabilities, so it does not belong in browser JavaScript or a public repository. If you need a key that is safe to publish in an embed, that is what the free key is designed for
Do not commit it. Our own repository scans for this key format on every commit; yours probably should too

If the 24-hour window has closed

After 24 hours this page stops showing your key and it cannot be retrieved again. The copy we held for the window is then deleted automatically, and once it is gone we keep only a one-way hash of the key, so nobody can recover it, including us. That is deliberate: a credential that stays recoverable forever is a credential that stays stealable forever.

If you missed the window, or you lose the key later, email admin@markcolabs.com from the address you subscribed with and we will revoke the old key and issue a replacement. Your subscription is unaffected — only the key changes.

Managing your subscription

Billing, payment method, invoices and cancellation are handled by our payment provider, who is the merchant of record for the transaction. Use the customer portal link on your receipt for those. If you cancel, your key keeps working until the end of the period you have already paid for — it is switched off when that period ends, not when you click cancel.

To change tier, email admin@markcolabs.com or change the plan in the customer portal; your key stays the same and only its allowance changes.

References

Pricing — the published rate card and what each tier includes
Onboarding — the full flow from checkout to first authenticated call
Quickstart — first call in under 5 minutes
API Reference — input schemas and output shapes for all 10 tools
Versioning contract — SemVer policy, deprecation window, anonymous-parity invariant