--- title: HB.js url: https://www.broadcom.com/products/mainframe/application-development-testing-devops/hostbridge description: Mainframe API creation, orchestration and optimization --- # HB.js ## Mainframe API creation, orchestration and optimization Transform CICS applications into hybrid, multi-modal applications. [View Product Brief](https://docs.broadcom.com/docs/HB-JS-PB) [What's Up, Mainframe #23: HB.js and API Generation for CICS](https://players.brightcove.net/6415665063001/Vh8ALpkmx_default/index.html?videoId=6401640444112) ## Overview Developers use the HostBridge Javascript Engine (HB.js) to create highly-efficient business integrations to trusted z/OS-based applications. Integrations run natively within CICS, meaning all API requests and data exchanges are processed locally and securely behind existing mainframe controls. The Mainframe DevOps Suite includes HB.js so adoption is easy and straightforward. ![HB.js Interface Types](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/blt0ea937bdf6cad522/6a5e7b1816166f4da20c3cd2/MSD_FY26_Hostbridge_Three-Key-Interface-Types-of-HB.js.jpg) ## Benefits ![Risk-managed modernization](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/blt7cba71491a23fe83/6a5e7e13f61eb3d069106374/MSD_Risk-managed-icon_100x100.png) ### Risk-managed modernization Extend the value of CICS applications to upstream and customer-facing processes without the risk of source code changes. ![Intelligent integration](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/blt750eb55266e23053/6a5e7e139e4a6b696bf52213/MSD_intelligent-integration-icon_100x100.png) ### Intelligent integration Consolidates multiple API calls into a single one saving valuable processing cycles (MIPs/MSUs). ![Business Agility](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/bltabd00ffb8a21f1dd/6a5e7e13d47080ffe982ad8f/MSD_business_agility-icon_100x100.png) ### Business Agility Accelerate application integration by equipping developers with a compelling Code4z-based experience. ## FAQ ### What is HB.js? A: HB.js (HostBridge JavaScript Engine) is a tool for creating highly-efficient business integrations with z/OS-based applications. Developers use HB.js to easily transform complex CICS transactions into reusable REST/JSON APIs. The APIs, which are written in JavaScript and run cost-effectively in CICS, require no changes to the application source enabling teams to safely drive additional business value from their trusted mainframe applications. ![MSD_FY26_Hostbridge_HB.js-Solution-Architecture.jpg](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/bltf74644d1b183eb46/6a5e875500401781fc954838/MSD_FY26_Hostbridge_HB.js-Solution-Architecture.jpg) ### Who is it for? A: Teams that require secure access to business logic and data residing in CICS applications. For example, developers of cloud and mobile applications that need access to logic and data in their systems of record use HB.js to replace legacy approaches, like screen scraping. ### How does it work? A: Instead of screen scraping, which may need to be updated whenever the application changes, HB.js uses the key-value pairs from BMS maps or interacts directly via COMMAREA/channels to navigate applications. This ensures that changes to the visual appearance (screens/fields) of an app won't break the HB.js API services. ### What’s the UI? A: Developers typically use HB.js’s convenient [VS Code extension](https://marketplace.visualstudio.com/items?itemName=broadcomMFD.hbjs), enabling them to run commands (Make/Put/Run), generate objects from COBOL copybooks and OpenAPI files, access the Application Explorer (AE) and Playback, and generate and run automated tests. ### Can it help with testing? A: Yes, HB.js can automate integration and regression testing by simulating user and system interactions with CICS applications. Teams can use it to validate business workflows, reduce manual QA effort, and verify that the application changes do not impact critical business functionality. ### Is it secure? A: Yes, HB.js operates natively within CICS, meaning all API requests and data exchanges are processed locally and securely behind existing mainframe controls. Furthermore, it integrates with standard mainframe security frameworks, such as ACF2, TopSecret, and RACF, to enforce strict user authorization and authentication. ### What are the license costs? A: The Broadcom Mainframe DevOps Suite includes HB.js, so these customers already have access (contact your account team). ### What is the impact on mainframe resource usage? A: HB.js is highly efficient. For example, instead of forcing a web or mobile application to make dozens of separate network requests to fetch piece-of-concept data, it consolidates multiple API calls into a single one by serving as an orchestration layer. Eliminating multiple round-trips saves valuable cycles (MIPs/MSUs). Also, it runs directly within CICS to minimize network overhead and redundancy, and it is fully zIIP-enabled to shift processing workloads off standard engines, lowering overall mainframe costs. ### Is there a way for me to try it? A: Yes, register for a hands-on, facilitator-led [workshop](https://engage.broadcom.com/mainframe-code4z-workshops), which provides access to a sandbox environment, sample applications, and scripts. Alternatively, contact your account team to arrange a personalized demo and/or PoC engagement. ## Testimonials HostBridge is perfect – it’s exactly what we need for our upcoming integration projects. — Lead Architect, Government Institution Why would anyone with CICS not want this? — Developer, Global Systems Integrator ## Customer Success: Large, US-based Insurance Provider ### Challenge The company needed a modern, standardized way to grant both internal teams and external partners access to data and processes housed in their mainframe applications. Traditional access methods like screen scraping were not scalable or sustainable. This limitation made it difficult to deliver essential services in an efficient and secure manner across their hybrid IT environment. ### Solution By adopting the HB.js, the company was empowered to rapidly develop robust web service APIs to meet the evolving requirements of business units and partners. These APIs enabled external applications—such as self-service portals—to securely interact with core systems like CICS, thereby improving service access, integration speed, and operational efficiency across the enterprise. ### Benefits Successfully deployed production-grade APIs for claims, membership, and partner access, improving the user experience for tens of millions of customers Reduced reliance on centralized development teams by enabling service teams to manage and deploy APIs via a shared GitHub repo Implemented automated deployment using Jenkins pipelines with smoke testing for efficient production rollout ## Related Products [Code4z](https://www.broadcom.com/products/mainframe/application-development-testing-devops/code4z) Empower developers with a contemporary, hybrid experience using Visual Studio Code (VS Code) and compatible cloud development environments (CDEs). ![Application Development](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/blt9bec74bc8388c1cd/6035497278be6d3f5c17895b/Application_Development) [Mainframe DevOps Suite](https://www.broadcom.com/products/mainframe/application-development-testing-devops/mainframe-devops-suite) Accelerate application software delivery with a suite of hybrid development tools and enablers. ## Resources ### Technical Documentation Installation, getting started, release notes, and more. - [View Team Build Documents](https://techdocs.broadcom.com/content/dam/broadcom/techdocs/us/en/pdf/ca-mainframe-software/devops/hostbridge-javascript-engine/baseline-80/hostbridge-javascript-engine-8.pdf) ### Related Blogs Stay up-to-date with insights, trends, and best practices. - [Read the Blogs](https://medium.com/modern-mainframe/subpage/f05af723b9a2) ## Work Smarter. Not Harder. ### Education and Training ![Education & Training](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/bltbc585e58ca29cd6e/6051c98891c90f4740ec8b5c/online-training.png) Transform your company and build your career with Broadcom training, certifications, and resources. ### Mainframe Integration Portal Your hub for creating seamless integrations that tap into the full capabilities of mainframe services. - [Explore Integration Resources](https://integration.mainframe.broadcom.com) ### Support Get more from your software investment, leverage the knowledge of Broadcom services and support professionals. - [Mainframe Software Support](https://support.broadcom.com/mainframe-software) ### Community ![Community](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/blta25aa8e36ce17207/6051bd0f0a20382deb90a6c6/community.png) Join the conversation at Broadcom's Mainframe Software Community, where members can go to collaborate with Broadcom products and solutions in an online setting. - [Join the Conversation](https://community.broadcom.com/mainframesoftware/home) ### Services Leverage the knowledge of Broadcom Services professionals to get more from your mainframe solution. ### Documentation ![Documentation](https://www.broadcom.com/media/blt4ac44e0e6c6d8341/blt7ac0ea7616016375/6051bba400b4d402d3f33945/paper.png) Find the answers by leveraging Broadcom Mainframe's online knowledge center. - [Documentation](https://techdocs.broadcom.com/us/en/ca-mainframe-software.html) ### Work Smarter. Not Harder. - [Mainframe Education Community](https://www.broadcom.com/support/education/mainframe) - [Mainframe Professional Services](https://www.broadcom.com/support/services/mainframe) ## Also of Interest - [Mainframe Software Rationalization and Conversion](https://www.broadcom.com/products/mainframe/product-portfolio/core-systems-consulting-program) - [Mainframe Software Solutions](https://www.broadcom.com/solutions/mainframe) - [Mainframe Open Software Architecture](https://www.broadcom.com/solutions/mainframe/open-software-architecture)