Node.js and Bun

npm i @atrix.dev/analytics-node      # or: bun add @atrix.dev/analytics-node

import { Atrix } from "@atrix.dev/analytics-node";

const atrix = new Atrix(process.env.ATRIX_PUBLIC_KEY ?? "");   // atx_pk_eu_production_…

atrix.capture({
  distinctId: "user_42",                                       // your user id, never an email or phone number
  event: "subscription_renewed",
  properties: { plan: "growth", amount: 14900, currency: "USD" },   // money: integer minor units + ISO currency
  groups: { company: "acme" },
});

// Link the browser or app visitor to the account at sign-in (anonId comes from the client SDK).
atrix.identify({ distinctId: "user_42", anonId: "0190f2a4-5b6c-7d8e-9f01-23456789abcd", set: { plan: "growth" } });

// Link a billing customer so provider webhooks are attributed to this user.
atrix.setRevenueCustomer({ distinctId: "user_42", customerId: "cus_Nffrfeu", provider: "stripe" });

// Company or team profiles.
atrix.groupIdentify({ groupType: "company", groupKey: "acme", properties: { name: "Acme", seats: 40 } });

// Before the process exits (in serverless handlers: at the end of every invocation).
await atrix.shutdown();

import { Atrix } from "@atrix.dev/analytics-node";

const atrix = new Atrix(process.env.ATRIX_PUBLIC_KEY ?? "", {
  flagsSecretKey: process.env.ATRIX_FLAGS_SECRET,   // atx_svc_…: evaluate locally
});

const enabled = await atrix.isFeatureEnabled("new-checkout", "user_42", { personProperties: { plan: "pro" } });
const variant = await atrix.getFeatureFlag("pricing", "user_42");          // "test" | "control" | false | undefined
const config = await atrix.getFeatureFlagPayload("pricing", "user_42");