A blockchain indexer is a software tool — often available as a service — that organizes and provides access to blockchain data more efficiently. They are usually accessible through hosted services in the form of API routes or can be self-hosted and highly customizable.
Indexers are often necessary as reading data from the blockchain can be time-consuming and very difficult. While not impossible to do on the fly, it is generally more efficient. It provides a better User Experience to index the data and then serve data that has already been parsed and transformed as needed.
Covalent offers a unified API for over 100+ blockchains, including active support for seven (7) different SKALE Chains. The unified API gives endpoints for token balances, transaction data, nfts, security, core chain information, and more.
The Graph is a self-hosted solution that enables highly-customizable indexing for any SKALE Chain. The Graph operates on Subgraphs that index for a specific subset of information from a given blockchain network e.g., token balances for all user wallets.
Subsquid is a highly configurable hosted indexing solution that allows developers to create customizable squids that can be deployed on their Aquarium service. Subsquid currently supports both SKALE Calypso and SKALE Nebula Mainnet and Testnet chains.