Square Java Library

The Square Java library provides convenient access to the Square API from Java.

Requirements

Use of the Square Java SDK requires:

• Java 8+

Installation

Gradle

Add the dependency in your build.gradle:

dependencies {
    implementation 'com.squareup:square:44.0.0.20250319'
}

Maven

Add the dependency in your pom.xml:

<dependency>
    <groupId>com.squareup</groupId>
    <artifactId>square</artifactId>
    <version>44.0.0.20250319</version>
</dependency>

Usage

Instantiate and use the client with the following:

package com.square.examples;

import com.squareup.square.SquareClient;
import com.squareup.square.types.CashPaymentDetails;
import com.squareup.square.types.CreatePaymentRequest;
import com.squareup.square.types.CreatePaymentResponse;
import com.squareup.square.types.Currency;
import com.squareup.square.types.Money;

public class QuickStart {

    public static void main(String[] args) {
        SquareClient square = SquareClient.builder().build();
        CreatePaymentResponse response = square.payments()
                .create(CreatePaymentRequest.builder()
                        .sourceId("CASH")
                        .idempotencyKey("4935a656-a929-4792-b97c-8848be85c27c")
                        .amountMoney(Money.builder()
                                .amount(100L)
                                .currency(Currency.USD)
                                .build())
                        .tipMoney(Money.builder()
                                .amount(50L)
                                .currency(Currency.USD)
                                .build())
                        .cashDetails(CashPaymentDetails.builder()
                                .buyerSuppliedMoney(Money.builder()
                                        .amount(200L)
                                        .currency(Currency.USD)
                                        .build())
                                .build())
                        .build());
    }
}

Instantiation

To get started with the Square SDK, instantiate the SquareClient class as follows:

import com.squareup.square.SquareClient;

SquareClient square = SquareClient.builder().token("SQUARE_TOKEN").build();

Alternatively, you can omit the token when constructing the client. In this case, the SDK will automatically read the token from the SQUARE_TOKEN environment variable:

import com.squareup.square.SquareClient;

SquareClient square = SquareClient.builder().build();

Environment and Custom URLs

This SDK allows you to configure different environments or custom URLs for API requests. You can either use the predefined environments or specify your own custom URL.

Environments

import com.squareup.square.SquareClient;
import com.squareup.square.core.Environment;

SquareClient square = SquareClient.builder().environment(Environment.PRODUCTION).build();

Custom URL

import com.squareup.square.SquareClient;

SquareClient square = SquareClient.builder().url("https://custom-staging.com").build();

Enums

This SDK wraps enums for forward compatibility. We define enum properties as constant type instances with String properties and use valueOf to specify custom enum types that may not yet be included as constants.

Example Usage

Supported Property

import com.squareup.square.types.InvoicePaymentRequest;
import com.squareup.square.types.InvoiceRequestType;

InvoicePaymentRequest paymentRequest = InvoicePaymentRequest.builder()
        .requestType(InvoiceRequestType.BALANCE)
        .build();

Custom Property

import com.squareup.square.types.InvoicePaymentRequest;
import com.squareup.square.types.InvoiceRequestType;

InvoicePaymentRequest paymentRequest = InvoicePaymentRequest.builder()
        .requestType(InvoiceRequestType.valueOf("CUSTOM"))
        .build();

Versioning

By default, the SDK is pinned to the version 2025-03-19. If you would like to override this version you can simply pass in a request option.

client.cards().create(..., RequestOptions.builder()
    .version("2024-05-04")  // override the version used
    .build());

Automatic Pagination

Paginated requests will return an Iterable<T>, which can be used to loop through the underlying items.

import com.squareup.square.SquareClient;
import com.squareup.square.core.SyncPagingIterable;
import com.squareup.square.types.Payment;
import com.squareup.square.types.PaymentsListRequest;

SquareClient square = SquareClient.builder().token("YOUR_TOKEN").build();

SyncPagingIterable<Payment> payments =
        square.payments().list(PaymentsListRequest.builder().total(100L).build());

for (Payment payment : payments) {
    System.out.printf(
            "payment: ID: %s Created at: %s, Updated at: %s\n",
            payment.getId(), payment.getCreatedAt(), payment.getUpdatedAt());
}

or stream them:

square.payments()
        .list(PaymentsListRequest.builder().total(100L).build())
        .streamItems()
        .map(item -> ...);

or calling nextPage() to perform the pagination manually:

// First page
List<Payment> pagePayments = payments.getItems();
for (Payment payment : pagePayments) {
    // ...
}

// Remaining pages
while (payments.hasNext()) {
    pagePayments = payments.nextPage().getItems();
    for (Payment payment : pagePayments) {
        // ...
    }
}

Retries

The SDK is instrumented with automatic retries with exponential backoff. A request will be retried as long as the request is deemed retriable and the number of retry attempts has not grown larger than the configured retry limit (default: 2).

A request is deemed retriable when any of the following HTTP status codes is returned:

• 408 (Timeout)
• 429 (Too Many Requests)
• 5XX (Internal Server Errors)

Use the maxRetries request option to configure this behavior.

square.cards().create(..., RequestOptions.builder()
  .maxRetries(1)
  .build());

Timeouts

The SDK defaults to a 60 second timeout. You can configure this with a timeout option at the client or request level.

square.cards().create(..., RequestOptions.builder()
  .timeout(10)
  .build());

Exception Handling

When the API returns a non-success status code (4xx or 5xx response), a SquareApiException will be thrown.

import com.squareup.square.SquareClient;
import com.squareup.square.core.SquareApiException;

try {
    square.payments().create(...);
} catch (SquareApiException e) {
    System.out.println("Square API exception occurred: " + e.getMessage());
    System.out.println("Status code: " + e.statusCode());
    System.out.println("Response body: " + e.body());
}

Webhook Signature Verification

The SDK provides utility methods that allow you to verify webhook signatures and ensure that all webhook events originate from Square. The WebhooksHelper.verifySignature method can be used to easily verify the signature like so:

import com.squareup.square.utilities.WebhooksHelper;

boolean isValid = WebhooksHelper.verifySignature(
        requestBody,
        headers.get("x-square-hmacsha256-signature"),
        "YOUR_SIGNATURE_KEY",
        "https://example.com/webhook" // The URL where event notifications are sent.
);

Legacy SDK

While the new SDK has a lot of improvements, we at Square understand that it takes time to upgrade when there are breaking changes. To make the migration easier, the new SDK also exports the legacy SDK as com.squareup.square.legacy.... Here's an example of how you can use the legacy SDK alongside the new SDK inside a single file:

import com.squareup.square.SquareClient;
import com.squareup.square.core.Environment;

SquareClient square = 
        SquareClient.builder()
                .environment(Environment.PRODUCTION)
                .token("YOUR_TOKEN")
                .build();

com.squareup.square.legacy.SquareClient legacyClient = 
        new com.squareup.square.legacy.SquareClient.Builder()
                .environment(com.squareup.square.legacy.Environment.PRODUCTION)
                .accessToken("YOUR_TOKEN")
                .build();

We recommend migrating to the new SDK using the following steps:

1. Include the following dependencies in your project

Gradle:

dependencies {
    implementation 'com.squareup:square:44.0.0.20250319'
    implementation 'com.squareup:square-legacy:44.0.0.20250319'
}

Maven:

<dependency>
    <groupId>com.squareup</groupId>
    <artifactId>square</artifactId>
    <version>44.0.0.20250319</version>
</dependency>
<dependency>
    <groupId>com.squareup</groupId>
    <artifactId>square-legacy</artifactId>
    <version>44.0.0.20250319</version>
</dependency>

2. Search and replace all imports from com.squareup.square to com.squareup.square.legacy
3. Gradually move over to use the new SDK by importing it from the com.squareup.square import

Advanced

Custom HTTP Client

This SDK is built to work with any instance of OkHttpClient. By default, if no client is provided, the SDK will construct one. However, you can pass your own client like so:

import com.squareup.square.SquareClient;
import com.squareup.square.core.Environment;
import okhttp3.OkHttpClient;

OkHttpClient customClient = ... ;

SquareClient square =
        SquareClient.builder()
                .environment(Environment.PRODUCTION)
                .token("YOUR_TOKEN")
                .httpClient(customClient)
                .build();

Receive Additional Properties

Every response type includes the getAdditionalProperties method, which returns an array that contains any properties in the JSON response that were not specified in the returned class. Similar to the use case for sending additional parameters, this can be useful for API features not present in the SDK yet.

You can access the additional properties like so:

CreatePaymentResponse payments = square.payments().create(...);
Map<String, Object> additionalProperties = payments.getAdditionalProperties();

Contributing

While we value open-source contributions to this SDK, this library is generated programmatically. Additions made directly to this library would have to be moved over to our generation code, otherwise they would be overwritten upon the next generated release. Feel free to open a PR as a proof of concept, but know that we will not be able to merge it as-is. We suggest opening an issue first to discuss with us!

On the other hand, contributions to the README are always very welcome!