Lob SDKs & Libraries: Official & Community Integrations (2026)

SDKs overview

Lob provides a suite of Software Development Kits (SDKs) designed to streamline the integration of its print and mail services and address verification capabilities into various applications. These SDKs abstract the underlying RESTful API, allowing developers to interact with Lob's services using native language constructs rather than direct HTTP requests and JSON parsing. The primary goal of these SDKs is to accelerate development cycles and reduce the boilerplate code required for common operations such as sending postcards, letters, or validating addresses programmatically.

The official SDKs are maintained by Lob and are kept up-to-date with the latest API versions and features. They typically include methods for all major API endpoints, handling authentication, request serialization, and response deserialization. This enables developers to focus on application logic rather than the intricacies of API communication. In addition to official offerings, the developer community sometimes contributes unofficial libraries, which can offer alternative approaches or support for languages not officially covered. However, official SDKs are generally recommended for stability and ongoing support, as detailed in the Lob developer documentation.

Using an SDK often results in more maintainable and readable code because it maps API concepts to familiar programming language objects and functions. For example, instead of constructing a complex JSON payload for a new postcard, a developer can simply call a function like lob.postcards.create() with structured arguments. This approach is consistent with best practices for integrating third-party services, as highlighted by various API providers, including Stripe's guidance on using client libraries for their own API.

Official SDKs by language

Lob maintains official SDKs for several popular programming languages, ensuring robust and supported access to their API endpoints. These SDKs are available through standard package managers for each respective ecosystem, simplifying dependencies and updates.

Installation

Installing Lob's official SDKs typically involves using the standard package manager for your chosen programming language. This ensures that all necessary dependencies are resolved and the library is correctly integrated into your project. Below are common installation commands for the officially supported languages:

Node.js

npm install lob --save

This command adds the lob package to your project's node_modules directory and includes it in your package.json dependencies. For more specific instructions, developers can refer to the Lob Node.js SDK documentation.

Python

pip install lob-python

This command uses Python's package installer, pip, to download and install the lob-python library. It is recommended to install it within a virtual environment to manage project dependencies effectively. Further details are available in the Lob Python SDK guide.

Ruby

gem install lob-ruby

This command installs the lob-ruby gem, making it available for use in Ruby applications. If you are using Bundler, you would add gem 'lob-ruby' to your Gemfile and then run bundle install. Consult the Lob Ruby SDK installation instructions for best practices.

PHP

composer require lob/lob-php

For PHP projects, Composer is the dependency manager of choice. This command adds the Lob PHP client to your composer.json file and installs it. The Lob PHP SDK documentation provides complete setup details.

Java

For Maven projects, add the following dependency to your pom.xml file:

<dependency>
    <groupId>com.lob</groupId&n;    <artifactId>lob-java</artifactId>
    <version>X.Y.Z</version> <!-- Replace with the latest version -->
</dependency>

Replace X.Y.Z with the latest Lob Java SDK version. For Gradle or other build systems, equivalent dependency declarations would apply.

Go

go get github.com/lob/lob-go

This command fetches the Lob Go module and adds it to your project's dependencies. Go modules manage dependencies directly. Refer to the Lob Go SDK documentation for usage examples.

C#

dotnet add package Lob.Net

For .NET projects, use the dotnet add package command to include the Lob.Net NuGet package. Alternatively, you can install it via the NuGet Package Manager in Visual Studio. The Lob C# SDK guide offers comprehensive integration instructions.

Quickstart example

This example demonstrates how to use the Node.js SDK to create and send a postcard. The process involves initializing the Lob client with your API key, defining the postcard's content and recipients, and then making the API call. Similar logic applies across other SDKs, with syntax adjusted for the respective language.

Node.js Postcard Creation

const Lob = require('lob')(process.env.LOB_API_KEY);

async function createPostcard() {
  try {
    const postcard = await Lob.postcards.create({
      description: 'My First Postcard',
      to: {
        name: 'Jane Doe',
        address_line1: '123 Test Street',
        address_city: 'San Francisco',
        address_state: 'CA',
        address_zip: '94107'
      },
      from: {
        name: 'Lob',
        address_line1: '210 King St',
        address_city: 'San Francisco',
        address_state: 'CA',
        address_zip: '94107'
      },
      front: 'tmpl_4120803c7e7591e',
      back: 'tmpl_08d172e25d97f88'
    });
    console.log('Postcard created successfully:', postcard);
  } catch (error) {
    console.error('Error creating postcard:', error);
  }
}

createPostcard();

In this example:

• process.env.LOB_API_KEY represents your confidential API key, which should be loaded from environment variables for security.
• The to and from objects specify the recipient and sender addresses, respectively. Lob also provides an Address Verification API to ensure address validity before sending mail.
• front and back refer to template IDs for the postcard's design. Lob supports custom templates or pre-designed options for various mail pieces.
• The await keyword is used to handle the asynchronous nature of API calls, ensuring the application waits for the response before proceeding.

Before running this code, ensure you have set up your Lob API key and have valid template IDs. The Lob pricing page details costs associated with creating and sending physical mail items.

Python Address Verification

import os
from lob import Lob

Lob.api_key = os.environ.get('LOB_API_KEY')

def verify_address():
    try:
        address = Lob.us_verifications.verify(
            address_line1='123 Main St',
            address_city='San Francisco',
            address_state='CA',
            address_zip='94107'
        )
        print("Address verification successful:", address)
    except Exception as e:
        print("Error verifying address:", e)

verify_address()

This Python snippet demonstrates how to use the lob-python SDK to verify a US address. The Lob.us_verifications.verify method sends the address details to Lob's API, which then returns a standardized and validated address, along with other metadata like deliverability information. This is particularly useful for reducing mail returns and ensuring data quality, as described in the Lob Address Verification API reference.

Community libraries

While Lob provides a strong set of official SDKs, the broader developer community occasionally creates and maintains additional libraries or integrations. These community-driven projects can sometimes offer experimental features, support for less common programming languages, or integrations with specific frameworks. However, it is important to note that community libraries may not offer the same level of support, maintenance, or feature parity as the officially supported SDKs.

Developers considering a community-maintained library should evaluate its active development, documentation quality, and community support before integrating it into production systems. Resources like GitHub often host these projects, where developers can check commit history, issue trackers, and pull request activity to gauge the project's health. For example, a search on GitHub for "Lob API client" might reveal various third-party wrappers, though Lob's official documentation primarily directs users to their official SDKs and guides for reliable integration paths.

As of this writing, most standard integrations are well-covered by the official SDKs. For niche use cases or languages not officially supported, checking community forums or public code repositories is a common practice. Always consider the long-term maintainability and security implications when choosing a non-official client library for any critical API integration, a principle generally applicable across the API ecosystem, as discussed in Google's guidance on API client libraries.