Use the power of the blockchain to manage contracts and signatures.

Mantle Sealer is a blockchain-powered e-Signature solution. Sealer provides a simple and powerful API you need to manage contracts and signers, without having to worry about the authenticity of the documents.

Use cases

  • Employment contracts and other legal agreements: A system that ensures contract integrity across signing parties.


You can find detailed use cases on Mantle Sealer in our Insights section.

Additional use cases are added on a weekly basis.


The idea behind Sealer is pretty straightforward. You can add contracts (or agreements), signatures and templates in Sealer. This will create a cryptographic representation of the documents and store their fingerprints in the blockchain backed by Keeper. When we want to sign a contract, we will go fetch the contract on the blockchain and compare it to the uploaded contract to sign. If they do not match, we do not let you sign the contract. We want to make sure that the contract you are about to sign is exactly the one you were supposed to sign.


ContractA contract is a document uploaded by a user that needs to be signed.
SignatureA signer uploads a signature, which is normally a picture of its signature, and use it to sign a contract.
TemplateA template is what the contract was based on. You can regroup contracts by a template. This is optional for a contract.
Signature RequestSignature requests are created when a contract is added without signatures. For each signer of the contract, a signature request will be created, which is the link between the signer email and the contract.

How to use it?

You can use our API to integrate it into your solution. You can start by taking a look at our guide or directly access our API documentation.

You can also use our hosted solution by connecting into it at

Inside our platform, if you have this product enable, Sealer admin will have access to all the sub-menus and Sealer users will only have access to their signatures and contracts they have signed. Let's take go forth on which is your contracts and how you will be able to secure, seal and manage them on the blockchain.

What’s Next