FlexPrice TypeScript / JavaScript SDK

Type-safe TypeScript/JavaScript client for the FlexPrice API: billing, metering, and subscription management for SaaS and usage-based products.

Requirements

• Node.js 18+ (or see RUNTIMES.md for supported runtimes)

Installation

npm i @flexprice/sdk

With pnpm, bun, or yarn:

pnpm add @flexprice/sdk
bun add @flexprice/sdk
yarn add @flexprice/sdk

The package supports both CommonJS and ESM.

Then in your code:

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

All generated modules (shared models, enums, errors, operation types, SDK types) are re-exported from the package root so you can import everything from one place. Run npm run build before publishing so both ESM and CommonJS entry points (dist/esm/index.js and dist/commonjs/index.js) include these re-exports; then import and require("flexprice-ts-temp") both expose types/enums from the root.

import {
  FlexPrice,
  FeatureType,
  Status,
  FlexpriceError,
  CreateCustomerRequest,
  createPageIterator,
} from "@flexprice/sdk";
// No need for: .../dist/sdk/models/shared, .../errors, .../operations, .../types

Runnable samples are in the examples/ directory.

Quick start

Initialize the client with your server URL and API key, then create a customer and ingest an event:

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

// Always include /v1 in the base URL; no trailing space or slash.
const flexPrice = new FlexPrice({
  serverURL: "https://us.api.flexprice.io/v1",
  apiKeyAuth: process.env.FLEXPRICE_API_KEY ?? "YOUR_API_KEY",
});

async function main() {
  // Create a customer
  const customer = await flexPrice.customers.createCustomer({
    externalId: "customer-123",
    email: "user@example.com",
    name: "Example Customer",
  });
  console.log(customer);

  // Ingest an event (use snake_case for request body fields where required by the API)
  const eventResult = await flexPrice.events.ingestEvent({
    eventName: "Sample Event",
    externalCustomerId: "customer-123",
    properties: { source: "ts_sdk", environment: "test" },
    source: "ts_sdk",
  });
  console.log(eventResult);
}

main();

For more examples and all API operations, see the API reference and the examples in this repo.

Property names (snake_case)

For request bodies, the API often expects snake_case field names. The SDK may accept camelCase and serialize to snake_case; if you see validation errors, use the API shape:

• Prefer: event_name, external_customer_id, page_size
• Avoid using only camelCase in raw payloads if the API spec uses snake_case

Check the API reference for the exact request shapes.

TypeScript

The package ships with TypeScript definitions. Use the client with full type safety:

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

const flexPrice = new FlexPrice({
  serverURL: "https://us.api.flexprice.io/v1",
  apiKeyAuth: process.env.FLEXPRICE_API_KEY!,
});

const result = await flexPrice.events.ingestEvent({
  eventName: "usage",
  externalCustomerId: "cust_123",
  properties: { units: 10 },
  source: "backend",
});

Authentication

• Set the API key via apiKeyAuth when constructing FlexPrice. The SDK sends it in the x-api-key header.
• Use environment variables (e.g. FLEXPRICE_API_KEY) and never expose keys in client-side or public code. Get keys from your FlexPrice dashboard or docs.

Features

• Full API coverage (customers, plans, events, invoices, payments, entitlements, etc.)
• TypeScript types for requests and responses
• Built-in retries and error handling
• ESM and CommonJS support

For a full list of operations, see the API reference and the examples in this repo.

Troubleshooting

• Missing or invalid API key: Ensure apiKeyAuth is set and the key is active. Use server-side only.
• Wrong server URL: Use https://us.api.flexprice.io/v1. Always include /v1; no trailing space or slash.
• Validation or 4xx errors: Confirm request body field names (snake_case vs camelCase) and required fields against the API docs.
• Parameter passing: Pass the request object directly to methods (e.g. ingestEvent({ ... })), not wrapped in an extra key, unless the SDK docs say otherwise.

Documentation

• FlexPrice API documentation
• TypeScript SDK examples in this repo