# Custom Extensions Starting from **ONEWEB version 4.0.19.10**, the platform introduces a powerful extensibility mechanism called **Custom Extensions**.\ Custom Extensions allow developers to create their own **activity nodes** and use them seamlessly inside **Microflows** and **Process Flows**. Once installed, Custom Extension nodes behave **exactly like built‑in nodes** and can encapsulate both simple logic and complex, proprietary integrations—extending ONEWEB beyond its default capabilities. *** ### Purpose of Custom Extensions Custom Extensions are designed to: * Extend ONEWEB beyond built‑in integration nodes * Encapsulate proprietary or highly specialized logic * Promote reuse of common integration capabilities * Share domain‑specific functionality across applications * Enable ecosystem growth through reusable components #### Typical Examples * A reusable node for querying an internal legacy database * A proprietary connector to a blockchain or third‑party platform * A standardized integration node required across multiple projects *** ### Reusability and Sharing Once created and packaged, a **Custom Extension** can be: * Installed into any ONEWEB application * Reused across multiple Microflows and Process Flows * Shared with other ONEWEB users or teams * Distributed internally as a standard integration component In future platform capabilities (ONEWEB Marketplace), Custom Extensions will also support: * Publishing extensions * Public sharing * Monetization through marketplace distribution This enables teams to treat Custom Extensions as **reusable platform assets** rather than project‑specific implementations. *** ### Important Note > **Important**\ > The process to create a Custom Extension is **identical for both**: > > * **Microflow Designer** > * **Process Designer** Once an extension is packaged as a JAR file, **the same JAR can be used in both designers** without modification. For detailed, step‑by‑step instructions on: * Creating Custom Extensions * Packaging Extension JARs * Installing Extensions into applications > Please refer to the official documentation:\ > **Custom Extensions**\ > *** ### Using Custom Extensions in Microflow Designer After a Custom Extension is installed in an application: * The extension appears as a new **Activity Node** in Microflow Designer * Developers can **drag and drop** the extension node onto the Microflow canvas * The node can be **configured like any standard built‑in activity** * The extension integrates naturally into Microflow orchestration and execution From a designer’s perspective, Custom Extensions are **indistinguishable from native nodes**, ensuring a consistent development experience.
*** ### Key Benefits of Custom Extensions Using Custom Extensions allows teams to: * Enforce architectural and integration standards * Centralize complex or sensitive logic * Reduce duplication across Microflows * Improve consistency and long‑term maintainability * Scale integration capabilities across teams and applications Custom Extensions provide a balanced middle ground between: * **Low‑code visual integration**, and * **Full‑code extensibility** *** ### Best Practices To maximize reliability and reuse: * Design extensions with a **single, clear responsibility** * Keep extension interfaces stable and well documented * Use Custom Extensions only for logic that cannot be expressed cleanly using standard nodes * Version extensions carefully to avoid breaking existing flows * Treat extensions as reusable **platform components**, not ad‑hoc project solutions *** ### Summary **Custom Extensions** provide ONEWEB with a powerful mechanism to extend Microflow integration capabilities beyond built‑in nodes. With Custom Extensions, developers can: * Build reusable, domain‑specific activity nodes * Share integration logic across applications and teams * Encapsulate complex or proprietary logic cleanly * Prepare for future ecosystem and marketplace‑based reuse Custom Extensions are a key enabler for building **enterprise‑scale, extensible, and future‑proof integrations** using **ONEWEB Microflow Designer**. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.onewebstack.com/designer-reference/microflow-designer/custom-extensions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.