When billing changes, product access doesn't always follow.
Refunds process, but access stays live. Cancellations go through in Stripe, and users keep premium features. You usually notice later.
API preview — entitlement check
Confirm a user's access state from your source of truth
POST https://api.keyfox.io/v1/entitlements/check Headers: x-api-key: YOUR_API_KEY Body: subject: user_123
{ "hasAccess": true, "subject": "user_123", "entitlement": "premium" }
Where things break
A payment fails, and the user keeps premium access.
A user cancels or downgrades, but the system keeps premium access.
A refund is processed, and the user's access never gets revoked.
A billing webhook is delivered, but your app does not update access state.
Repetition
Cancellations, refunds, and plan changes happen all the time. Each product or pricing update means rewriting the same billing boilerplate.
Fragility
Ad-hoc fixes often fail silently. One missed webhook or script error means a canceled user keeps access, or a paying user loses it, and no one sees it.
Maintenance
Custom billing and entitlement sync code gets harder to maintain, test, and trust as it grows. Each hotfix for a corner case adds debt and more bugs.
These issues often go unnoticed for weeks. Support ends up fixing them by hand.
From “it should have updated” to a single entitlement check.
Keep Stripe as your billing system. Use Keyfox to resolve the user's current access state, plan, features, and grace in one place. It stays correct when events arrive late, retry, or arrive out of order.
BEFORE. Custom, fragile validation logic
const key = getUserLicenseKey()
if (!key) return console.error("No license found!")
const expired = checkIfExpired(key)
const valid = !expired && validateKey(key)
if (!valid) {
renewKey(key)
const renewed = validateKey(key)
if (!renewed) return console.error("License invalid.")
}
console.log("License valid!")AFTER. One clean Keyfox API call
const client = new Keyfox({
apiKey: process.env.KEYFOX_API_KEY
});
// Validate a license key with a single API call
const result = await client.verify("KFX-XXXX-XXXX");
if (result.valid) {
console.log("License valid!");
// Continue with your application logic
}No manual fixes. No one-off scripts. No missed cancellations. One API keeps access state in sync.
API Examples
Preview real Keyfox responses — mocked during early access while we finalize the API.
Active Access
Access check example
{
"hasAccess": true,
"subject": "user_123",
"entitlement": "premium"
}Expired Access
Access check example
{
"hasAccess": false,
"subject": "user_456",
"reason": "subscription_expired"
}Revoked Access
Access check example
{
"hasAccess": false,
"subject": "user_789",
"reason": "refund_processed"
}Built for developers, not legacy vendors.
A modern entitlement platform built to remove boilerplate, ensure consistency, and give you clean, predictable control — without the bloat or black boxes of traditional vendors.
Modern Entitlement API
Check access, sync billing state, and manage user entitlements via a simple REST API that integrates with Stripe, Paddle, or any payment provider. No SDK lock-in. No proprietary formats.
Zero Boilerplate
No more custom cancellation handlers, refund scripts, or 'does this user still have access?' checks. Keyfox handles the lifecycle complexity so you don't have to write any glue code.
Auditable by Default
Every access event is logged and traceable, providing a clear audit trail of user entitlements. Always know exactly when access was granted or revoked — no more guesswork or surprises.
Self-Hosted or Cloud
Run Keyfox anywhere — your infrastructure or ours. Control regions, data, and scaling with a fully portable API.
Get early access
to the Keyfox API
Get API preview access, sample code, and early feature updates.
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Early members get priority when API keys are released.