> 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

> Learn how to build custom functionality into Docusign and publish your apps in the App Center to enhance your workflows & e-Signature experiences.

Bring your own custom functionality into Docusign. Publish your apps in the App Center to scale your solution’s reach.

## Learn what’s possible

![Diagram showing an extension app development and publishing pattern.](/_fern-files/_img/6306582244456f08499a53f4be6a8626dde2a15d7a90cb323b305aff8fd190dd.webp)![An image of a smartphone screen showing a document vault.](/_fern-files/_img/1b0e5c04113d82529d61f5e61c44bbe87742b032471dbe4d0c85e7c2c7ddcbdc.webp)

### Prisidio builds an Extension App to automatically update your digital vault!

You can enable your customers to incorporate the Prisidio extension app into their workflows by providing them with Prisidio digital vaults. This automatically and securely archives signed documents into their vaults.

Tags: eSignature, Workflow Builder, extension app, File archive extension

### Know before you build

#### Extension Types

Before you build, explore the different extension types, their JSON contracts, and the business use cases they support.
[Learn more](/extension-apps/extension-app-reference/extension-contracts)

![Image of the developer center documentation page for extension contracts.](/_fern-files/_img/9913e4821a9ac2ba05f89a6e427a7913c73145bf0f10fdcce758093a6b0417b8.webp)

#### Developer Console

Login to the Developer Console using your free developer account to build, test and publish your extension apps.
[Launch Developer Console](https://devconsole.docusign.com/apps)

![An image of the Docusign developer console UI.](/_fern-files/_img/4b59e3228ced610118f4e42a9bb9c0aef3863fee5c0edbcedb7ac91d9550f486.webp)

#### Extension Points

An extension point is a predefined location in the Docusign user interface where your extension app’s custom functionality gets invoked. The Docusign eSignature UI and Workflow Builder workflows are two examples of extension points.
[Learn more](/extension-apps/extension-apps-101/concepts/extensions-and-extension-points)

![An image of the docusign tagger UI.](/_fern-files/_img/c94a831594cd367171beb87f50e2c9be8579b8045b1bc9a28d397912d409a677.webp)

#### Public or Private Publishing

Distribute your extension app publicly on the Docusign App center to be discovered by 1.6 million customers. Alternatively, share your app privately to select production accounts.
[Learn more](/extension-apps/extension-apps-101/choosing-private-distribution)

![Image of the Docusign extension apps UI.](/_fern-files/_img/6e8c40cd86aa7ca5c57b589758e5f7c9cde3687d8d5764b7cca0b263c85f5f3b.webp)

### Everything you need to build an extension app with Docusign

Use our Starter Kit to accelerate your proof of concept.

[Get Your Starter Kit](/get-started/extension-app/toolkit)