> 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).

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

## Docs

- [Extension app use cases](https://developers.docusign.com/extension-apps/extension-apps-101/use-cases.md): See how extension apps can help you simplify document preparation, signing, and post-signing tasks.
- [How extension apps work](https://developers.docusign.com/extension-apps/extension-apps-101/how-extension-apps-work.md): See an overview of extension app elements and how they fit together to extend Docusign functionality.
- [What's inside an extension app registration](https://developers.docusign.com/extension-apps/extension-apps-101/inside-an-extension-app.md): Learn the basics about the different pieces of an extension app registration
- [Supported extensions](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions.md): See a list of the supported extensions for Docusign extension apps.
- [Connected fields extension overview](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/connected-fields.md): Get an overview of an extension that performs real-time custom data verification against a system of record.
- [Data IO extension overview](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/data-io.md): Lean how the data IO extension works, where it is used, and how it executes.
- [Define related objects in a data model](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/data-io/related-objects.md): Learn how to define related objects in the data model for a data IO extension app.
- [Data model](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/data-model.md): Learn about the data model that Docusign extension apps use.
- [File input cloud storage extension overview](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-input-cloud-storage.md): Import agreements from a cloud storage service to the Docusign Navigator smart repository.
- [File input system of record extension overview (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-input-system-of-record.md)
- [File output cloud storage extension overview](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-cloud-storage.md): Learn about how files generated from Docusign workflows can be written to cloud storage in real time.
- [File output system of record extension overview (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-system-of-record.md): Learn about how files generated from Docusign workflows can be written to a system of record in real time.
- [Identify destination records (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-system-of-record/identify-destination-records.md): Review the options for identifying records to which files will be written.
- [Identify the file source (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-system-of-record/identify-file-source.md): Review the options for the source of files to write to a system of record.
- [Workflow configuration for file output scenarios (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-system-of-record/workflow-configuration.md): Review workflow configuration options for various file output scenarios.
- [Extensions and actions (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-system-of-record/extensions-and-actions.md): Review the extensions and actions associated with file output to system of record.
- [Plan an implementation (beta)](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-system-of-record/plan-implementation.md): Learn about important considerations when planning a file output to system of record implementation.
- [File output tabular format extension overview](https://developers.docusign.com/extension-apps/extension-apps-101/supported-extensions/file-output-tabular-format.md)
- [How extension apps differ from API integrations](https://developers.docusign.com/extension-apps/extension-apps-101/extension-app-vs-api-integrations.md): Learn about the differences between extension apps and API integrations.
- [App Center](https://developers.docusign.com/extension-apps/extension-apps-101/app-center.md): Learn how to publish your extension apps to the App Center and make them available for Docusign users to find, purchase, and use.
- [Choosing private distribution instead of public](https://developers.docusign.com/extension-apps/extension-apps-101/choosing-private-distribution.md): Learn about the difference between private extension apps and public extension apps.
- [Globalization](https://developers.docusign.com/extension-apps/extension-apps-101/globalization.md): Learn how to prepare your extension app for distribution in different regions.
- [Extension app concepts](https://developers.docusign.com/extension-apps/extension-apps-101/concepts.md): Learn extension apps concepts.
- [Extension app manifest](https://developers.docusign.com/extension-apps/extension-apps-101/concepts/extension-app-manifest.md): Learn what an extension app manifest is, what it does, and how it is organized.
- [Actions](https://developers.docusign.com/extension-apps/extension-apps-101/concepts/actions.md): Learn about the actions that you can trigger in an extension app.
- [Capabilities](https://developers.docusign.com/extension-apps/extension-apps-101/concepts/capabilities.md): Learn about optional extension app actions that enhance an extension's base functionality.
- [Connections](https://developers.docusign.com/extension-apps/extension-apps-101/concepts/connections.md): Learn about defining a connection for your extension app manifest file.
- [Extensions and extension points](https://developers.docusign.com/extension-apps/extension-apps-101/concepts/extensions-and-extension-points.md): Learn what extensions are and when their actions are triggered.