> You are reading the Docusign Developer Documentation. For clean Markdown of any page, append .md to the page URL.
>
> Documentation indexes by section:
> - APIs and SDKs: https://docusign.docs.buildwithfern.com/docs/llms.txt
> - Platform 101: https://docusign.docs.buildwithfern.com/platform/llms.txt
> - Extension Apps: https://docusign.docs.buildwithfern.com/extension-apps/llms.txt
> - Docusign CLI: https://docusign.docs.buildwithfern.com/docusign-cli/llms.txt
>
> Authentication (OAuth, JWT Grant, M2M): https://docusign.docs.buildwithfern.com/platform/auth
> Webhooks and Connect: https://docusign.docs.buildwithfern.com/platform/webhooks
>
> OpenAPI specifications: https://docusign.docs.buildwithfern.com/openapi.json
> MCP server: https://docusign.docs.buildwithfern.com/_mcp/server

# Extension apps 101

> Learn what extension apps are and how you can use them to extend your Docusign workflows.

An *extension app* is a type of application that enables you to extend the Docusign platform by integrating external functionalities (such as Google Drive or Stripe).

Extension apps work by setting [actions](/extension-apps/extension-apps-101/concepts/actions) and, optionally, [capabilities](/extension-apps/extension-apps-101/concepts/capabilities) that are triggered at specific points in your Docusign agreement process. When these actions and capabilities trigger, the extension app calls an external API and the response is integrated back into your Docusign agreement process:

![Image showing the basic flow of an extension app.](/_fern-files/_img/0f1e36b73ae1839612b3ff8247dc812e2f97940463397c310f446f19f4382733.webp)

Compared to [API integrations](/extension-apps/extension-apps-101/extension-app-vs-api-integrations), extension apps provide the following benefits for developers:

* Simplify the process of integrating Docusign and external platform functionality.
* Use the [Workflow Builder API](/docs/workflow-builder-api) to define customized Docusign workflows of individual, modular steps where you can enable and trigger your extension actions and capabilities.
* Increase user productivity by providing an out-of-the-box solution for integrating external functionalities with Docusign at different points in the agreement journey.

Once you’ve built your extension app, you will be able to publish it to the [Docusign App Center](/extension-apps/extension-apps-101/app-center).

## Next steps

* Visit the [Docusign Developer Community](https://community.docusign.com/developer-59) with any questions or feedback.
* See [Extension app use cases](/extension-apps/extension-apps-101/use-cases) for examples of how extension apps can extend Docusign functionality.
* Learn about [How extension apps work](/extension-apps/extension-apps-101/how-extension-apps-work) to understand their structure and behavior.
* See [What's inside an extension app registration](/extension-apps/extension-apps-101/inside-an-extension-app) for details on how to register an extension app in the [Docusign Developer Console](/extension-apps/developer-console-overview).
* Review [Extension app concepts](/extension-apps/extension-apps-101/concepts) to understand the key elements of an extension app.
* Take the Docusign University course: [Build Extension Apps for the Docusign App Center](https://dsudevelopers.docusign.com/build-extension-apps-for-the-docusign-app-center).