The Witness API

A Digital Witness™ from iDefendo can help you protect IP rights, demonstrate corporate compliance and prove data existence and provenance.

Not sure if this is for you? Read our One-Minute Witness Primer and our One-Minute API Primer.

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{{witness.timestamp | momentFormat:'lll' }} {{witness.visibility}}
Witness ID {{witness.witnessId | formatHash}}
Content ID {{witness.contentId | formatHash}}
Auxillary data
File Witnesses
File witnesses
Text Witnesses
Type: {{hash.type}}
Content ID: {{hash.contentId | formatHash}}
Advanced settings

All you really need to create a witness is a piece of content and a signature. But more data can be added if you like. Some of that data – like metadata – can help you find your witnesses more easily later, but is not encoded into the actual witness. Other data fields – like salt – actually changes the witnesses that are created, and can be used as a security or privacy measure. You can also add auxillary data that gets encoded into the witness and can be used to create chains of multiple witnesses, for example to document the steps in a multi-step process.

Private or public
  • {{key}} = {{value}}
Auxillary data
  • {{key}} = {{value}}
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Get started for free. Our free plan includes:

  • 1 user
  • 1 signature
  • 1 access key
  • Public witnesses
  • 3,000 new witnesses per month
  • One year retention time
  • Commerical use allowed


Created for small and medium businesses, our Starter plan includes:

  • All Free features +
  • Unlimited users
  • Unlimited signatures
  • 10 access keys
  • Public or private witnesses
  • Witness metadata
  • Witness auxillary data
  • Custom witness invalidation
  • 100,000 new witnesses per month
  • 1,000,000 witness storage
  • Unlimited retention time


Optimized for volume, our Business plan includes:

  • All Starter features +
  • 1,000 access keys
  • 1,000,000 new witnesses per month
  • 1,000,000,000 witness storage

Get exactly what you need. Our Enterprise plan is whatever you need it to be since it's taylor made for each customer.


Offer Digital Witnesses to your users. Our Reseller plan comes in all shapes and sizes. Contact us for more information.

Access Key

In the text box below is your access key. That key is sent by your app or browser to our servers, and is used to uniquely identify you. Please keep it to yourself, because anyone who has access to it can manage your witnesses.

Access key
Digital Witnesses in 60 seconds(ish)

A witness is someone who have seen something, and who can attest to that. A witness does not take sides, it does not in itself prove anything. But it helps YOU prove things by corroborating what you say.

Our Digital Witnesses are exactly the same. They certify that a document with a cartain content existed at a certain point in time, and that your your signature was connected to that document at that time. You can use our digital witnesses to help prove any number of things, from IP-related claims to stated intentions to agreements between parties.

Digital Witnesses are usually created in the background with no human interaction, as silent observers of everything that transpires. You can create as many of them as you like for little or no extra cost; our basic idea has always been that it's better to log everything now than to realize too late that you're missing some key evidence that could pivot the whole case.

APIs in 60 seconds(ish)

An API is a method that lets computers talk to other computers. You can think of it as a language that lets one computer system ask another to perform specific tasks.

iDefendo's Witness API allows other systems to create Digital Witnesses for whatever it is you need to prove. Since it's an API, it is built in into other systems, and human users normally won't even notice that it's there.

The iDefendo Witness API is a RESTful API. That means it uses standardized HTTP requests over the Internet, just like the web browser you're using now. It also means that the API is accessible anywhere your browser works; there is no need for specialized hardware or software, firewall configuration or any other potentially complicated or expensive setup. As long as you can communicate over encrypted HTTPS – and every programming language supports that – you're good to go.

Console | Sent: {{ctrl.outDataLength}} bytes N/A | Received: {{ctrl.inDataLength}} bytes N/A
Outgoing request
  • "{{key}}": "{{value}}"
Incoming response