Command line

hippodatamus-cli --config customers.yaml

Using seed 20260822 (from config)
Generating 1000 rows to customers.csv
Done. 1000 rows in 0.31s (3,225 rows/s) -> customers.csv

Options

Required:
  -c, --config <path>   YAML schema describing the columns to generate, or a
                        .hippo bundle. A bundle is unpacked to a temporary
                        folder and run from there, so it needs nothing else
                        present.

Options:
  -o, --output <path>   Output file. Format is inferred from the extension
                        (.csv, .json, .xlsx, .xls). Defaults to the config's
                        output.path.
  -r, --rows <n>        Override the schema's row count. Must be > 0.
  -s, --seed <n>        Override the seed. Falls back to the config's seed, then
                        to a random seed, which is printed.
  -q, --quiet           Print only errors.
  -v, --verbose         Include stack traces on failure.
  -h, --help            Show this help.
      --version         Show the version.

Exit codes

Code	Meaning
0	Generation completed
1	Generation failed
2	Invalid arguments

Distinguishing 1 from 2 matters in a script: a 2 means the command was wrong, and retrying will not help.

In CI

hippodatamus-cli --config fixtures/orders.yaml --output "$ARTIFACTS/orders.csv" --quiet

Because output is byte-identical for a fixed configuration and seed, you can check a hash of the result and detect an unintended change to your fixtures:

hippodatamus-cli --config fixtures/orders.yaml --output orders.csv --quiet
sha256sum -c fixtures/orders.csv.sha256

Note that generated files use the platform's line ending, so a hash taken on Windows will not match one taken on Linux. Normalise first, or take the hash on one platform.

Overriding rows and seed

hippodatamus-cli --config orders.yaml --rows 50 --seed 7

Useful for a quick look at a schema without editing it. Remember that a different seed means different data - if you want the dataset the file describes, do not pass --seed.