This tool synthesizes a valid ChainDB, replicating cardano-node's UX

Usage: db-synthesizer --config FILE --db PATH [--byron-delegation-certificate FILE] [--byron-signing-key FILE] [--shelley-kes-key FILE | --shelley-kes-agent-socket PATH] [--shelley-vrf-key FILE] [--shelley-operational-certificate FILE] [--bulk-credentials-file FILE] ((-s|--slots NUMBER) | (-b|--blocks NUMBER) | (-e|--epochs NUMBER)) [-f | -a]

Available options: --config FILE Path to the node's config.json --db PATH Path to the Chain DB -s,--slots NUMBER Amount of slots to process -b,--blocks NUMBER Amount of blocks to forge -e,--epochs NUMBER Amount of epochs to process -f Force overwrite an existing Chain DB -a Append to an existing Chain DB

The credential options are cardano-node's own (they come from cardano-config), so --help documents them the way the node does.