This section is for listing some useful projects and tools that are relevant for node operators and developers. A community maintained Awesome Substrate is a more detailed general list.
Open source GraphQL indexing of any Substrate network (including EVM and WASM smart contract data) directly from the RPC node. SubQuery does not require any preprocessed data making it suitable for fast changing testnets
The main use case of this application consits of a scanner that can be configured to start from a configured block number, and then it keeps monitoring the on-chain situation delivering alerts to a notifier.
The watcher is a nodeJs application meant to be connected with a substrate based node through a web socket. It can then monitor the status of the node, leveraging on mechanisms such as the builtin heartbeat.