Announcing New, Lower, Dynamic Docproof Fees

Tue, 26 June 2018

PoEx announces a reduction in Proof of Existence Docproof Certifications Fees from 0.5 to 0.25 mBTC

While changes in the USD-BTC exchange rate tend to capture all the headlines, the more important figure for purely Bitcoin-based services is the accepted fee rate per byte of data. As miners give priority to transactions with higher fees, the average fee rate can rise and fall based on demand.


When we embed your docproof in the Bitcoin blockchain, we rely on a median fee estimate that aims to give your transaction priority without being excessively high. Up until now we have relied on adjusting the Docproof Certification Fee manually to stay in line with average Bitcoin fees.

Dynamic Fees

For the latest release of our open-source Proof of Existence software, we’ve switched to a dynamic fee calculation. The software determines the certification fee automatically based on the current estimated transaction fee rate, rounded up to the nearest 0.25 mBTC (0.00025 BTC). Please consult the Proof of Existence home page for the latest fees.

For Developers

If you’re currently running an instance of our software, then after upgrading: simply remove the documentPrice setting from your configuration file to take advantage of the new dynamic fees feature.

Proof of Existence is Open Source

Did you know Proof of Existence is Open Source software? The code to run your own instance, compare to our public service, add your own ideas or request features is all available on the Proof of Existence website. If you have ideas for features, please let us know here: Proof of Existence.

POEX sponsoring ETH Buenos Aires

Tue, 22 May 2018

We are proud to announce that Poex is supporting the ETH Buenos Aires community and their global hackathon to be held from May 25th to 27th, 2018 in Buenos Aires, Argentina.

We will be there for the intense schedule of coding and workshops for the 3 days!

Follow #ETHbuenosaires to get the updates.

Get in touch with us @poexio and let’s meet in Buenos Aires! Announcement

Tue, 1 May 2018 has been released as a public service !

The original Proof of Existence project was first released as a personal, open-source project by Manuel Araoz and Esteban Ordano in 2013. In 2016, Manuel began a rewrite of the core software using Node.js, in order to connect it to the growing ecosystem of Bitcoin and cryptocurrency-related packages and libraries written in JavaScript.

In December 2017, the PoEx team took up the development mantle to improve the codebase. The goal was to work toward a larger and more stable open source release.

Today, we are announcing the release of, as the first open-source public service to certify documents in the BTC blockchain.

The proofofexistence organization will continue to improve the software and surrounding services. We focus on the ease-of-use and quality of the core functionalities to make data and metadata from the Bitcoin blockchain more availabile.

You can start testing it today at

Any feedback or questions can be sent at!

Stay tuned for more!

Onwards, The Poex Team

PoEx on NPM

Mon, 26 February 2018

We have long made use of free and open source software, programming languages, and blockchain libraries and tools. Now it’s our chance to give back.

We’ve staked our claim on with the @poexio organization scope, which will be our conduit for releasing software for the JavaScript and Node.js ecosystems.

We’ve just released @poexio/blockcypher, a flexible Node.js client for the BlockCypher API and a fork of the official SDK, updated to use native JavaScript ES6 promises, and with a configurable URL endpoint. The code is available under a generous MIT License.

Watch for us on and at our home on GitHub.

Price status info for our API users

Mon, 15 January 2018

As Bitcoin transaction fees have increased sharply in the past year, we have been careful to set a sufficient docproof price so that a proof of existence can be confirmed in the blockchain as quickly as possible, ideally in the next block.

We display the fee denominated in mBTC on the docproof web page (including in a QR code), and in satoshis for our API users when they register a hash. However, the exact price was missing when checking the status of a docproof via our API. This has been remedied in our most recent update.

While we are committed to keeping version 1 of our API stable, we haven’t stopped working on new features to bring you in 2018.

Happy New Year from the PoEx Team!