Custom networks

Connecting to a network other than mainnet, testnet, preprod, or preview? The [chain] block gives Oura the parameters it needs to make sense of that network.

Context

Oura requires certain information about the chain it is reading from. In a way, this is similar to the json config files required to run the Cardano node. These values are used for procedures such as encoding bech32 addresses, computing wall-clock time for blocks, etc.

Since mainnet, testnet, preprod and preview are well-known, heavily used networks, Oura hardcodes these values as part of the binary release so that the user is spared from having to manually specify them. On the other hand, custom networks require the user to configure these values manually for Oura to establish a connection.

Feature

By adding a [chain] section in the daemon configuration file, users can provide the information required by Oura to connect to a custom network.

The [chain] section has the following properties:

Name	DataType	Description
type	string	types of network (mainnet, testnet, preprod, preview, custom)
magic	integer	the network number
byron_epoch_length	integer	the length (in seconds) of a Byron epoch in this network
byron_slot_length	integer	the length (in seconds) of a Byron slot in this network
byron_known_slot	integer	the slot of a Byron block known to exist in this network
byron_known_hash	string	the hash of the known Byron block
byron_known_time	integer	the unix timestamp of the known Byron block
shelley_epoch_length	integer	the length (in seconds) of a Shelley epoch in this network
shelley_slot_length	integer	the length (in seconds) of a Shelley slot in this network
shelley_known_slot	integer	the slot of a Shelley block known to exist in this network
shelley_known_hash	String	the hash of the known Shelley block
shelley_known_time	integer	the unix timestamp of the known Shelley block

Examples

Chain information for mainnet

This example shows the values for mainnet. Since these are hardcoded in Oura’s release you’d never enter them by hand, but they’re a good illustration of what a [chain] section looks like.

daemon.toml

[chain]
type = "custom"
magic = 764824073
byron_epoch_length  = 432000
byron_slot_length = 20
byron_known_slot = 0
byron_known_time = 1506203091
byron_known_hash = "f0f7892b5c333cffc4b3c4344de48af4cc63f55e44936196f365a9ef2244134f"
shelley_epoch_length = 432000
shelley_slot_length = 1
shelley_known_slot = 4492800
shelley_known_hash = "aa83acbf5904c0edfe4d79b3689d3d00fcfc553cf360fd2229b98d464c28e9de"
shelley_known_time = 1596059091