The Hedera previewnet is now live
Jul 23, 2020
by Hedera Hashgraph Team
Hedera is a decentralized public network upon which developers can build fast, fair, and secure applications.

The Hedera developer community and our ecosystem partners have expressed interest in early access to Hedera codebase features and functionality, prior to their release on the Hedera testnet and mainnet. In response to this feedback, we started looking into the idea of a second testnet that would run a development version of the Hedera codebase.

We’re excited to announce that the Hedera preview testnet (previewnet) is now publicly available, and running the same version of the Hedera codebase on the testnet (v0.6.0). Moving forward, the previewnet will run the latest development version of the Hedera codebase, prior to its subsequent stable release on the testnet and mainnet.

You can create a Hedera previewnet account and access your keys by visiting https://portal.hedera.com/ and selecting “previewnet” from the network drop-down menu. Once you’ve created an account on the previewnet, you can find the address book for previewnet nodes, as well as some getting started instructions, in the official Hedera documentation: https://docs.hedera.com/guides/testnet/testnet-nodes#preview-testnet-nodes

Differences between testnet and previewnet

There are now two independent testnets run by Hedera: the stable testnet that you’ve always used and the new previewnet. Here are the differences and additional information about both:

  • The testnet runs the same codebase as the Hedera mainnet, and is designed to provide a pre-production environment for developers to test their applications prior to moving them into production on the mainnet.
  • The previewnet (preview network) will run a codebase still under development by the Hedera team. It’s designed to offer developers early exposure to features coming down the pipe. It’s not always stable and accounts / data are likely to be lost when the network codebase is upgraded.

Both the testnet and previewnet are composed of four nodes operated by Hedera in Google Cloud, publicly accessible, and using the same throttles as the mainnet. A Hedera-managed mirror node (REST API) is available for both networks. Accounts can be created for the previewnet in the Hedera developer portal at https://portal.hedera.com.

SDK support

As of right now, you’ll need to use the latest version of the SDK in the language of your choice to interact with the previewnet. You can find all of the Hedera SDKs in our documentation, here: https://docs.hedera.com/guides/docs/sdks. We plan to support a previewnet version of the officially supported SDKs in the future, but do not have a timeline for this yet. Features in certain versions of the previewnet codebase will not be accessible through the SDK.

Previewnet network status

The source of truth for Hedera network, mirror node, and planned network upgrades for Hedera’s mainnet, testnet, and, now, previewnet, will always be available at https://status.hedera.com/. You can email subscribe, follow us on Twitter, or use the RSS feed link for live status updates. Hedera also provides network status updates in the #network-status channel in the Hedera developer Discord.

Whenever upgrades occur on the testnet or previewnet, developers who created their account through the Hedera Portal will receive an email notice of the network upgrade. In some cases (more likely on the previewnet), this means old account IDs are purged and you’ll receive a new account ID and associated keys — the email notice will contain your new account ID, public key, and private key to get back up and running more smoothly. Those keys will also be available in the Hedera Portal, after logging in.

Submitting bugs & issues for previewnet

Once the Hedera services codebase is open sourced by the end of 2020, we will be accepting issues and pull requests for any bugs found in the codebase running on the previewnet. Until then, if you have a new feature request that you’d like to see as part of the Hedera services codebase, the Hedera improvement proposal (HIP) program continues to be open and we strongly recommend submitting your feature request there. The Hedera engineering team doesn’t currently have an SLA in place for responding to community contributions, but we expect to learn and get better at accommodating these requests over time.