Hydra Chain Observer

A lightweight executable designed to connect to a blockchain, such as the hydra-node, and streams chain observations as traces to stdout.

It supports two modes of operation: Direct connection to a node via socket, and connection through Blockfrost API.

In both modes, reporting observations to a hydra-explorer can be enabled.

Direct Mode

To run the observer directly connected to a cardano-node, use the --node-socket option and specify the network id via --mainnet or --testnet-magic. Optionally, you can specify a starting point to observe usin --start-chain-from:

hydra-chain-observer \
  --node-socket testnets/preprod/node.socket \
  --testnet-magic 1 \
  --start-chain-from "41948777.5d34af0f42be9823ebd35c2d83d5d879c5615ac17f7158bb9aa4ef89072455a7"

Blockfrost Mode

To run a chain observer using blockfrost, use the --blockfrost-project-path option to point to a file containing your Blockfrost project API token (e.g. testnetA3C2E...). Optionally, you can specify a starting point to observe usin --start-chain-from:

hydra-chain-observer blockfrost \
  --blockfrost-project-path $PROJECT_TOKEN_PATH \
  --start-chain-from "41948777.5d34af0f42be9823ebd35c2d83d5d879c5615ac17f7158bb9aa4ef89072455a7"

Report to hydra-explorer

Using the --explorer argument we can specify a hostname / port for a hydra-explorer instance to report observations to. For example using a direct observer:

hydra-chain-observer \
  --node-socket testnets/preview/node.socket \
  --testnet-magic 2 \
  --start-chain-from "49533501.e364500a42220ea47314215679b7e42e9bbb81fa69d1366fe738d8aef900f7ee" \
  --explorer http://0.0.0.0:8080