EasyLink Technical Guide

Take your EasyLinks to the next level.

Under the hood, EasyLinks are actually just a faster way to create business transactions with an API key. Note the presence of an API key within an EasyLink URL:

The API key for an EasyLink is a client-only API key, meaning it can only be used to create transactions, and not delete or modify them. In essence, EasyLinks are client-only API keys with permission to create POST requests at this endpoint: https://app.proof.com/easy-link.

This allows you to achieve much more customization with your EasyLink, both at the transaction level via query parameters, and at the API key level.

Accepted EasyLink Query Parameters

By providing query parameters in the EasyLink URL, you can achieve a similar level of transaction customization offered by the Business API, without needing to fully integrate. Instead, you can build dynamic URLs to provide to your signers. But keep in mind there is only a limited amount of customization available.

Below are the allowed query parameters for EasyLink:


On a Signer Upload EasyLink, you can provide a document as a query parameter. This is a good option to consider if the document template may vary at runtime, or if the document is pre-filled with PII.

Single Document
Here's a test Signer-Upload EasyLink:

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT

Here's an example of providing a document permalink as a query parameter on that EasyLink:

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT&document=https://static.proof.com/Example.pdf

Additionally, you can provide a reference to a document template:

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT&document=foobar

Multiple Documents
Provide each document as a separate query parameter with the key documents (plura):

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT&documents=https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf&documents=https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf

The same approach applies when referencing document templates:

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT&documents=foobar&documents=foobar


If you have internal tracking information you'd like to associate with your Proof transactions, you can provide this as an external_id on the transaction, much like you would in the Business API, but as a query parameter on the EasyLink:

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT&external_id=abc123


If you know who the signer is at the time of building the URL, you can provide the signer's email address as well:

  • https://app.fairfax.proof.com/easy-link?ApiKey=ZbPDguLqVc5iTAEBsPggt5ZT&signer[email][email protected]

They'll have a chance to modify this email before creating their account and proceeding.

API Key Level Customization

Want to redirect your signers to a specific URL after they complete signing? Read more about Post-signing Redirects and other API Key Settings.

What’s Next

Still want to do more than EasyLink allows you? Try diving into a full integration.