loops

Developer-friendly & type-safe Typescript SDK specifically catered to leverage loops API.

Summary

Loops Public API: A standalone Fastify server that provides checkout session APIs

Table of Contents

• loops
  • SDK Installation
  • Requirements
  • SDK Example Usage
  • Authentication
  • Available Resources and Operations
  • Standalone functions
  • Retries
  • Error Handling
  • Server Selection
  • Custom HTTP Client
  • Debugging
• Development
  • Maturity
  • Contributions

SDK Installation

The SDK can be installed with either npm, pnpm, bun or yarn package managers.

NPM

npm add @loops-fi/sdk

PNPM

pnpm add @loops-fi/sdk

Bun

bun add @loops-fi/sdk

Yarn

yarn add @loops-fi/sdk

[!NOTE] This package is published with CommonJS and ES Modules (ESM) support.

Requirements

For supported JavaScript runtimes, please consult RUNTIMES.md.

SDK Example Usage

Example

import { Loops } from "@loops-fi/sdk";

const loops = new Loops({
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  const result = await loops.v1.checkoutSessions.create({
    paymentLinkId: "pl_1234567890abcdef",
    externalCustomerId: "cust_12345",
    metadata: {},
  });

  console.log(result);
}

run();

Authentication

Per-Client Security Schemes

This SDK supports the following security scheme globally:

| Name | Type | Scheme | Environment Variable | | -------- | ---- | ----------- | -------------------- | | apiKey | http | HTTP Bearer | LOOPS_API_KEY |

To authenticate with the API the apiKey parameter must be set when initializing the SDK client instance. For example:

import { Loops } from "@loops-fi/sdk";

const loops = new Loops({
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  const result = await loops.v1.checkoutSessions.create({
    paymentLinkId: "pl_1234567890abcdef",
    externalCustomerId: "cust_12345",
    metadata: {},
  });

  console.log(result);
}

run();

Available Resources and Operations

checkoutSessions

• create - Create a new checkout session
• list - List all checkout sessions
• get - Retrieve a checkout session
• update - Update a checkout session
• expire - Expire a checkout session

customerPortal

• create - Create a customer portal session

paymentLinks

• create - Create a new payment link
• list - List payment links with optional filtering
• get - Get a specific payment link by ID
• update - Update a payment link
• delete - Delete a payment link

products

• create - Create a new product (Stripe only)
• list - List products with optional filtering (database optimized)
• get - Get a specific product by ID (database optimized)
• update - Update a product (Stripe only)
• delete - Delete a product (Stripe only)

subscriptions

• list - List all subscriptions
• get - Get a subscription
• delete - Cancel a subscription
• update - Update a subscription

v1.checkoutSessions

• create - Create a new checkout session
• list - List checkout sessions
• get - Get checkout session by ID
• update - Update checkout session
• delete - Delete checkout session

v2.checkoutSessions

• create - Create a new checkout session
• list - List checkout sessions
• get - Get checkout session by ID
• update - Update checkout session
• delete - Delete checkout session

v2.paymentLinks

• create - Create a new payment link
• list - List payment links with optional filtering
• get - Get a specific payment link by ID
• update - Update a payment link
• delete - Delete a payment link

v2.products

• create - Create a new product
• list - List products with optional filtering
• get - Get a specific product by ID
• update - Update a product
• delete - Delete a product

Standalone functions

All the methods listed above are available as standalone functions. These functions are ideal for use in applications running in the browser, serverless runtimes or other environments where application bundle size is a primary concern. When using a bundler to build your application, all unused functionality will be either excluded from the final bundle or tree-shaken away.

To read more about standalone functions, check FUNCTIONS.md.

• checkoutSessionsCreate - Create a new checkout session
• checkoutSessionsExpire - Expire a checkout session
• checkoutSessionsGet - Retrieve a checkout session
• checkoutSessionsList - List all checkout sessions
• checkoutSessionsUpdate - Update a checkout session
• customerPortalCreate - Create a customer portal session
• paymentLinksCreate - Create a new payment link
• paymentLinksDelete - Delete a payment link
• paymentLinksGet - Get a specific payment link by ID
• paymentLinksList - List payment links with optional filtering
• paymentLinksUpdate - Update a payment link
• productsCreate - Create a new product (Stripe only)
• productsDelete - Delete a product (Stripe only)
• productsGet - Get a specific product by ID (database optimized)
• productsList - List products with optional filtering (database optimized)
• productsUpdate - Update a product (Stripe only)
• subscriptionsDelete - Cancel a subscription
• subscriptionsGet - Get a subscription
• subscriptionsList - List all subscriptions
• subscriptionsUpdate - Update a subscription
• v1CheckoutSessionsCreate - Create a new checkout session
• v1CheckoutSessionsDelete - Delete checkout session
• v1CheckoutSessionsGet - Get checkout session by ID
• v1CheckoutSessionsList - List checkout sessions
• v1CheckoutSessionsUpdate - Update checkout session
• v2CheckoutSessionsCreate - Create a new checkout session
• v2CheckoutSessionsDelete - Delete checkout session
• v2CheckoutSessionsGet - Get checkout session by ID
• v2CheckoutSessionsList - List checkout sessions
• v2CheckoutSessionsUpdate - Update checkout session
• v2PaymentLinksCreate - Create a new payment link
• v2PaymentLinksDelete - Delete a payment link
• v2PaymentLinksGet - Get a specific payment link by ID
• v2PaymentLinksList - List payment links with optional filtering
• v2PaymentLinksUpdate - Update a payment link
• v2ProductsCreate - Create a new product
• v2ProductsDelete - Delete a product
• v2ProductsGet - Get a specific product by ID
• v2ProductsList - List products with optional filtering
• v2ProductsUpdate - Update a product

Retries

Some of the endpoints in this SDK support retries. If you use the SDK without any configuration, it will fall back to the default retry strategy provided by the API. However, the default retry strategy can be overridden on a per-operation basis, or across the entire SDK.

To change the default retry strategy for a single API call, simply provide a retryConfig object to the call:

import { Loops } from "@loops-fi/sdk";

const loops = new Loops({
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  const result = await loops.v1.checkoutSessions.create({
    paymentLinkId: "pl_1234567890abcdef",
    externalCustomerId: "cust_12345",
    metadata: {},
  }, {
    retries: {
      strategy: "backoff",
      backoff: {
        initialInterval: 1,
        maxInterval: 50,
        exponent: 1.1,
        maxElapsedTime: 100,
      },
      retryConnectionErrors: false,
    },
  });

  console.log(result);
}

run();

If you'd like to override the default retry strategy for all operations that support retries, you can provide a retryConfig at SDK initialization:

import { Loops } from "@loops-fi/sdk";

const loops = new Loops({
  retryConfig: {
    strategy: "backoff",
    backoff: {
      initialInterval: 1,
      maxInterval: 50,
      exponent: 1.1,
      maxElapsedTime: 100,
    },
    retryConnectionErrors: false,
  },
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  const result = await loops.v1.checkoutSessions.create({
    paymentLinkId: "pl_1234567890abcdef",
    externalCustomerId: "cust_12345",
    metadata: {},
  });

  console.log(result);
}

run();

Error Handling

LoopsError is the base class for all HTTP error responses. It has the following properties:

| Property | Type | Description | | ------------------- | ---------- | --------------------------------------------------------------------------------------- | | error.message | string | Error message | | error.statusCode | number | HTTP response status code eg 404 | | error.headers | Headers | HTTP response headers | | error.body | string | HTTP body. Can be empty string if no body is returned. | | error.rawResponse | Response | Raw HTTP response | | error.data$ | | Optional. Some errors may contain structured data. See Error Classes. |

Example

import { Loops } from "@loops-fi/sdk";
import * as errors from "@loops-fi/sdk/models/errors";

const loops = new Loops({
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  try {
    const result = await loops.v1.checkoutSessions.create({
      paymentLinkId: "pl_1234567890abcdef",
      externalCustomerId: "cust_12345",
      metadata: {},
    });

    console.log(result);
  } catch (error) {
    // The base class for HTTP error responses
    if (error instanceof errors.LoopsError) {
      console.log(error.message);
      console.log(error.statusCode);
      console.log(error.body);
      console.log(error.headers);

      // Depending on the method different errors may be thrown
      if (error instanceof errors.BadRequestError) {
        console.log(error.data$.error); // string
        console.log(error.data$.details); // Detail[]
      }
    }
  }
}

run();

Error Classes

Primary errors:

• LoopsError: The base class for HTTP error responses.
  • UnauthorizedError: Status code 401. *

Network errors:

• ConnectionError: HTTP client was unable to make a request to a server.
• RequestTimeoutError: HTTP request timed out due to an AbortSignal signal.
• RequestAbortedError: HTTP request was aborted by the client.
• InvalidRequestError: Any input used to create a request is invalid.
• UnexpectedClientError: Unrecognised or unexpected error.

Inherit from LoopsError:

• InternalServerError: Status code 500. Applicable to 31 of 40 methods.*
• NotFoundError: Status code 404. Applicable to 27 of 40 methods.*
• BadRequestError: Status code 400. Applicable to 19 of 40 methods.*
• ResponseValidationError: Type mismatch between the data returned from the server and the structure expected by the SDK. See error.rawValue for the raw value and error.pretty() for a nicely formatted multi-line string.

* Check the method documentation to see if the error is applicable.

Server Selection

Select Server by Index

You can override the default server globally by passing a server index to the serverIdx: number optional parameter when initializing the SDK client instance. The selected server will then be used as the default on the operations that use it. This table lists the indexes associated with the available servers:

| # | Server | Description | | --- | ------------------------------ | ------------------ | | 0 | https://api.loops.fi | Production server | | 1 | https://staging-api.loops.fi | Staging server | | 2 | http://localhost:3001 | Development server |

Example

import { Loops } from "@loops-fi/sdk";

const loops = new Loops({
  serverIdx: 0,
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  const result = await loops.v1.checkoutSessions.create({
    paymentLinkId: "pl_1234567890abcdef",
    externalCustomerId: "cust_12345",
    metadata: {},
  });

  console.log(result);
}

run();

Override Server URL Per-Client

The default server can also be overridden globally by passing a URL to the serverURL: string optional parameter when initializing the SDK client instance. For example:

import { Loops } from "@loops-fi/sdk";

const loops = new Loops({
  serverURL: "http://localhost:3001",
  apiKey: process.env["LOOPS_API_KEY"] ?? "",
});

async function run() {
  const result = await loops.v1.checkoutSessions.create({
    paymentLinkId: "pl_1234567890abcdef",
    externalCustomerId: "cust_12345",
    metadata: {},
  });

  console.log(result);
}

run();

Custom HTTP Client

The TypeScript SDK makes API calls using an HTTPClient that wraps the native Fetch API. This client is a thin wrapper around fetch and provides the ability to attach hooks around the request lifecycle that can be used to modify the request or handle errors and response.

The HTTPClient constructor takes an optional fetcher argument that can be used to integrate a third-party HTTP client or when writing tests to mock out the HTTP client and feed in fixtures.

The following example shows how to use the "beforeRequest" hook to to add a custom header and a timeout to requests and how to use the "requestError" hook to log errors:

import { Loops } from "@loops-fi/sdk";
import { HTTPClient } from "@loops-fi/sdk/lib/http";

const httpClient = new HTTPClient({
  // fetcher takes a function that has the same signature as native `fetch`.
  fetcher: (request) => {
    return fetch(request);
  }
});

httpClient.addHook("beforeRequest", (request) => {
  const nextRequest = new Request(request, {
    signal: request.signal || AbortSignal.timeout(5000)
  });

  nextRequest.headers.set("x-custom-header", "custom value");

  return nextRequest;
});

httpClient.addHook("requestError", (error, request) => {
  console.group("Request Error");
  console.log("Reason:", `${error}`);
  console.log("Endpoint:", `${request.method} ${request.url}`);
  console.groupEnd();
});

const sdk = new Loops({ httpClient: httpClient });

Debugging

You can setup your SDK to emit debug logs for SDK requests and responses.

You can pass a logger that matches console's interface as an SDK option.

[!WARNING] Beware that debug logging will reveal secrets, like API tokens in headers, in log messages printed to a console or files. It's recommended to use this feature only during local development and not in production.

import { Loops } from "@loops-fi/sdk";

const sdk = new Loops({ debugLogger: console });

You can also enable a default debug logger by setting an environment variable LOOPS_DEBUG to true.

Development

Maturity

This SDK is in beta, and there may be breaking changes between versions without a major version update. Therefore, we recommend pinning usage to a specific package version. This way, you can install the same version each time without breaking changes unless you are intentionally looking for the latest version.

Contributions

While we value open-source contributions to this SDK, this library is generated programmatically. Any manual changes added to internal files will be overwritten on the next generation. We look forward to hearing your feedback. Feel free to open a PR or an issue with a proof of concept and we'll do our best to include it in a future release.