Skip to main content
No items found.
logo dropboxsign
Why Dropbox Sign?
Expand or collapse accordion

What you can do

Sign documents online
Create electronic signatures
Choose or create templates
Fill and sign PDFs
Complete online contracts
Document management
Explore features
icon arrow right

Use cases

Sales and business development
Human resources
Startups
Financial technology
Real estate
On-demand services
Products
Expand or collapse accordion
icon dropbox
Sign
Make it easy to send and sign
icon dropbox
Sign API
Integrate eSign in your workflow
icon dropbox fax
Fax
Send faxes without a fax machine
icon dropbox integrations
Integrations
We meet you where you work
Resources
Expand or collapse accordion
Blog
Workflow expertise & product news
Customer stories
Real-world stories with real results
Help center
In-depth guidance for our products
Resource library
Reports, videos, and info sheets
Developers
Pricing
Expand or collapse accordion
Dropbox Sign pricing
Find the right plan for you
Dropbox Sign API pricing
Real-world stories with real results
Contact sales
Sign up
Contact Sales
Sign in
Expand or collapse accordion
Dropbox Sign
Dropbox Forms
Dropbox Fax
Free trial
Blog
/
Developers

Using Dropbox Sign API Callbacks

by 
Ana Orozco
December 13, 2019
3
minute read
"Using Dropbox Sign API Callbacks" header image
icon tooltip

New look, same great product! HelloSign is now Dropbox Sign.

icon close

Let’s start by defining callbacks (otherwise known as webhooks). There are two ways two apps can communicate with each other to share information: polling and callbacks. Polling is like going on a roadtrip and asking the driver “are we there yet?” every 5 minutes. Callbacks are like falling asleep and having the driver wake you up once you are finally there.

‍

Callbacks are automated messages sent from apps to notify that something happened. They have a payload (or body) and are sent to a unique URL.

‍

The Dropbox Sign API sends callbacks for the life cycle of a signature request. Instead of calling the API to check the status of a request, you can listen for these callbacks to build a reliable flow in your application.

‍

Let’s take the example of creating a simple signature request. After you call the “signature_request/create_embedded” endpoint, you receive a response from the API with a status (“200” if it was successful. Otherwise, learn our error messages) and a JSON containing information pertinent to the call you made. This response is useful because it gives you basic information about the request, lets you know that our server received it successfully and there were no issues with the parameters you passed in.

‍

Here is what is happening behind the scenes:

A diagram showing a callback with Dropbox Sign API

‍

If, for example, there was an issue during document processing because the uploaded document has a text tag that is malformed, this is flagged as an error and our API will want to notify you that this happened through a callback event. Wouldn’t it be nice for you to know there was an issue with your file right away instead of having to figure it out the hard way?

‍

This is why it is a best practice to wait for the “signature_request_sent” callback (which only fires once document processing is complete) before attempting to open a sign url in the iFrame. In the case of the error we used as an example, a “file_error” callback will be sent instead. This is how an example of the “file_error” callback event will look like in the API Dashboard:

Screenshot of the "file_error" callback event in the Dropbox Sign API dashboard
Note: to see something like the above, you need to make sure to be logged in with the  Dropbox Sign account that owns the app the requests are being made with.

‍

Another example of when you can benefit from callbacks is downloading the final (signed) document. The “signature_request_all_signed” callback will trigger only after all the signers have completed the document and it’s ready for download. In this case, a best practice is to wait for the “signature_request_all_signed” callback event and then trigger the document download. This ensures that you will get the final copy of the document with all signatures and the “completed” status on the audit trail.

Responding to callbacks

The Dropbox Sign API will send callbacks to whatever URL you tell it to. You can set your account callback by using the account API call or manually on the settings page.

‍

Your endpoint will need to return a 200 HTTP code and a response body containing the following text: “Hello API Event Received.” Otherwise, the callback will be considered a failure and will be retried later. Refer to the “Events and Callbacks” article for more information on this. To illustrate the workflow:

‍

Diagram showing how to respond to callbacks using the Dropbox Sign API

‍

Other resources on this topic:

Example Dropbox Sign API Callback Event

The difference between signature_request_signed and all_signed callback events.

Example Java Callback Handler

Simple PHP Callback Handler

A Simple Python Callback Handler

Example of how to use ngrok (or other localhost tunneling software) to test callback handlers

Tools for Testing the API and Callbacks Locally

Stay in the loop

Done! Please check your inbox.

Thank you!
Thank you for subscribing!

Lorem ipsum

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

Lorem ipsum
icon arrow right
icon close

Up next:

Close-up illustration of a handwritten signature, representing modern digital signing solutions.
Developers
15
minute read

Integrating Dropbox Sign with Ruby on Rails: A Step-by-Step Tutorial

Close-up illustration of a handwritten signature, representing modern digital signing solutions.
Developers
15
minute read

Dropbox Sign vs. SignNow for developers

eBook

Built to scale: How Great Processes Drive Business Growth

Products
Dropbox SignDropbox Sign APIDropbox FaxIntegrations
Why Dropbox Sign
Electronic signaturesSign documentsSign and Fill PDFsOnline contractsCreate electronic signaturesSignature editorSign word documents
Support
Help centerContact salesContact supportManage cookiesGetting started: Dropbox SignGetting started: Dropbox Sign API
Resources
BlogCustomer storiesResource centerLegality guideTrust center
Partners
Strategic PartnersPartners locator
Company
CareersTermsPrivacy
icon facebookicon youtube

Accepted payment methods

Mastercard logoVisa logoAmerican Express LogoDiscover logo
CPA Compliance BadgeHIPAA compliance badgeSky High Enterprise Ready badgeISO 9001 Certified badge

Dropbox Sign electronic signatures are legally binding in the United States, European Union, United Kingdom, and in many countries around the world.
For more information, please view our Terms and Conditions and Privacy Policy