Ephemery is an automatically reset testnet, a novel approach to public testnets. It enables a single testing infrastructure consisting of ephemeral networks with deterministic parameters. Each network iteration is created by a specified function which deterministically generates new genesis states.
This kind of testnet can provide an alternative environment for short-term testing of applications, validators and also breaking changes in client implementations. It avoids issues of long running testnets which suffer from state bloat, lack of testnet funds or consensus issues. Periodically resetting the network back to genesis cleans the validator set, returns funds back to faucets while keeping the network reasonably small for easy bootstraping.
Test your applications, validators, client implementations or contribute to the testnet at ephemery.dev.
It has been running since December 2022 and is maintained only by community. Testnet is described in EIP-6916 and currently being implemented in Ethereum clients.