Subsquid

What is Subsquid?

Susquid is a query node framework for Substrate-based blockchains.In very simple terms, Subsquid can be thought of as an ETL tool, with a GraphQL server included.

Subsquid's multi-layer approach aims to pre-process and decode raw chain data and store it for easier access by the query nodes, providing increased performance over direct RPC calls.

A Squid Archive can constantly synchronize raw data with the chain and by simply defining the custom data model and Event handlers in the Squid project, it is possible to perform complex queries on top of it.

For example, expired Kusama Treasury spending proposals are pruned from the state of the Kusama blockchain, so querying one-year-old proposals would be problematic. With the traditional approach, it would be necessary to track the evolution of the state by sequentially applying the Treasury events and extrinsics in each historical block.

Thanks to Subsquid, that's no longer the case and the complexity is vastly reduced.

On top of that, you get a batteries-included GraphQL server with comprehensive filtering, pagination, and even full-text search capabilities.