MonetizeKit vs Flexprice

import { FlexPrice } from "@flexprice/sdk";

const flexprice = new FlexPrice({ apiKeyAuth: process.env.FLEXPRICE_API_KEY! });

// Entitlements are aggregated across the customer's subscriptions
const { features } = await flexprice.customers
  .getCustomerEntitlementsByExternalID("cust_123");
const apiCalls = features?.find((f) => f.feature?.lookupKey === "api_calls");
const enabled = apiCalls?.entitlement?.isEnabled ?? false;
const limit = apiCalls?.entitlement?.usageLimit; // compare with usage yourself

// Send a usage event; it is metered asynchronously (202 Accepted)
await flexprice.events.ingestEvent({
  eventName: "api.calls",
  externalCustomerId: "cust_123",
  properties: { endpoint: "/v1/chat" },
});

import { MonetizeKit } from "@monetizekit/node";

const mk = new MonetizeKit({ apiKey: process.env.MONETIZEKIT_SECRET_KEY! });

// Gate a feature with an explainable decision
const decision = await mk.entitlements.check("cust_123", "api_access");
if (!decision.allowed) {
  // decision.reasonCode: "not_in_plan" | "limit_reached" | ...
  // decision.grantedByPlans: plans that would grant access
  // decision.resetsAt: when a reached limit's window resets
}

// Hold credits for work with unknown cost, capture the actual cost
const { value } = await mk.credits.withReservation(
  { customerId: "cust_123", amount: 100, description: "agent run" },
  async () => {
    const output = await runAgent();
    return { value: output, cost: output.tokensUsed * 0.01 };
  },
);