Expedia Group Java SDK

The Expedia Group Java SDK Foundations provides the core components and tools for building and maintaining our SDK libraries. These foundations enable developers to create consistent, high-quality Java SDKs that interact with the Expedia Group platform.

Note

Previous versions of the SDK core modules are available in maintenance mode in the legacy branch.

Key Features

• Pluggable Architecture: Modular design with interchangeable HTTP transports and authentication mechanisms
• Async & Sync Support: Built-in CompletableFuture-based async transport alongside traditional synchronous APIs
• Auth Support: Different authentication models (OAuth 2.0, Basic Auth) with automatic token management
• Observability: Logging, request/response masking, and custom pipeline steps for monitoring or custom authentication models
• Type-Safe Code Generation: Automatic SDK generation from OpenAPI specifications and GraphQL schemas

Core Modules

Module	Purpose	Key Features
expediagroup-sdk-core	SDK foundation and utilities	HTTP abstractions, authentication, logging, pipeline architecture
expediagroup-sdk-rest	REST API client framework	Request/response handling, operation patterns, REST-specific utilities
expediagroup-sdk-graphql	GraphQL client framework	Apollo integration, type-safe operations
expediagroup-sdk-transport-okhttp	HTTP transport layer	OkHttp-based transport, supporting both sync and async executions
expediagroup-sdk-openapi-plugin	Code generation plugin	Gradle plugin for generating SDKs from OpenAPI specifications
exemplar	Complete reference implementation	Full-featured demo with server, generated SDKs, and usage examples

Quick Start

This repository provides the foundational modules to build Product SDKs for REST/GraphQL APIs in EG. Once you have initiailized a new SDK project for your API, you can add dependency on these foundational modules.

All product SDKs projects have to use Gradle as the main build tool. Most of the generation tasks are built for Gradle.

Adding Dependencies

Add the core SDK modules to your project:

dependencies {
    implementation 'com.expediagroup:expediagroup-sdk-rest:{latest-version}' // For REST SDK
    implementation 'com.expediagroup:expediagroup-sdk-graphql:{latest-version}' // For GraphQL SDK

    // HTTP transport (OkHttp-based)
    implementation 'com.expediagroup:expediagroup-sdk-transport-okhttp:{latest-version}'
}

Getting Started

1. Choose your API type: REST or GraphQL
2. Review the exemplar: Complete working examples with server and client implementations
3. Follow module guides: Each module contains detailed setup and usage instructions
4. Explore demos: Check out the playground examples for practical patterns

Architecture Highlights

Pluggable Transport Layer

Swap HTTP implementations without code changes - see transport documentation for details.

Currently, only OkHttp transport is supported. You may implement your own Transport interface using a different HTTP client. See exemplar-playground-java for custom transport examples.

Pipeline-Based Processing

Extensible request/response processing with custom steps - explore pipeline examples.

SDK Generation

From OpenAPI Specification

Use the OpenAPI plugin to generate type-safe REST clients from your API specifications.

From GraphQL Schema

Integrate with GraphQL module and Apollo Kotlin for type-safe GraphQL operations and schema-first development.

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.