Ouroboros

Dolos exposes a unix socket implementing Cardano’s node-to-client Ouroboros mini-protocols. This provides drop-in compatibility with tools that normally connect to a Cardano full node, such as cardano-cli, Ogmios, and other ecosystem tooling.

Note

The Ouroboros endpoint is only available on Unix-based systems (Linux, macOS). It is not supported on Windows.

Supported Mini-protocols

Dolos implements the following node-to-client mini-protocols:

Mini-protocol	Description
ChainSync	Follow the chain tip and receive new blocks in real time
LocalStateQuery	Query the current ledger state

LocalStateQuery Coverage

The following local state queries are supported:

Query	Description
GetSystemStart	Get the system start time
GetChainBlockNo	Get the current chain block number
GetChainPoint	Get the current chain tip point
GetCurrentEra	Get the current era index
GetInterpreter	Get the era history / interpreter summary
GetCurrentPParams	Get the current protocol parameters
GetLedgerTip	Get the ledger tip point
GetEpochNo	Get the current epoch number
GetUTxOByAddress	Query UTxOs for a set of addresses
GetStakePools	List all registered stake pools
GetStakePoolParams	Get parameters for specific stake pools
GetPoolState	Get detailed state for specific pools
GetStakeSnapshots	Get stake snapshots for specific pools
GetAccountState	Get the global account state (treasury/reserves)

Usage

If enabled via configuration, Dolos will create a unix socket file accepting Ouroboros node-to-client connections. The default socket path is dolos.socket in the working directory, but this can be changed via configuration.

Using with cardano-cli

Point cardano-cli to the Dolos socket using the CARDANO_NODE_SOCKET_PATH environment variable:

export CARDANO_NODE_SOCKET_PATH=./dolos.socket
cardano-cli query tip --testnet-magic 1

Using with Ogmios

Start Ogmios pointing to the Dolos socket:

ogmios --node-socket ./dolos.socket --node-config config.json

Configuration

The serve.ouroboros section controls the options for the Ouroboros endpoint.

property	type	example
listen_path	string	”dolos.socket”

• listen_path: the file path for the unix socket that will listen for Ouroboros node-to-client mini-protocols.

This is an example of the serve.ouroboros fragment within a dolos.toml configuration file.

[serve.ouroboros]
listen_path = "dolos.socket"

Check the Configuration Schema for detailed info on how to set this up.