In Polkadot, Kusama and other parachains, RPC is the interface between DApp and the network. As the Polkadot network continues to expand, more and more parachains will be online, and more and more parachains will support smart contract functions. Faced with more and more parallel chains, developers need to build and maintain multiple blockchain nodes in order to interact with them, which will be a huge development cost for them. Whether it is facing the development and testing needs of developers or users' online DApp usage requirements, a convenient, fast and stable network access is one of the necessary conditions, and it is also the infrastructure of the Polkadot ecosystem. Elara is inspired by Infura from the Ethereum ecosystem, named after Jupiter’s seventh moon. Elara's goal is to build a similar infrastructure and network public access services to provide developers with a unified access layer based on Substrate multi-chain. In addition, Elara will be used as part of the smart contract development service, and will be integrated with other components of the Patract toolchain in the future, in terms of contract development environment support, development tools component, contract deployment and DApp release. Elara will be Polkadot’s infrastructure, allowing developers to focus on building upper-level applications.