In Prefect 3.x, you can pass a full JSON object of parameters with

--params

when running a deployment. Basic usage (inline JSON):

prefect deployment run <FLOW_NAME>/<DEPLOYMENT_NAME> --params '{"name":"Alice","count":42,"enabled":true}'

Read JSON from stdin (handy for files or generators):

# From a file
cat params.json | prefect deployment run <FLOW_NAME>/<DEPLOYMENT_NAME> --params -

# Construct JSON dynamically (jq)
jq -n '{name:"Alice", count:42, enabled:true}' | \
  prefect deployment run <FLOW_NAME>/<DEPLOYMENT_NAME> --params -

Notes: - Wrap the JSON in single quotes in bash/zsh to avoid escaping double quotes. -

--params

accepts one complete JSON object. If you prefer setting individual keys, you can use

-p/--param key=value

repeatedly; if both are provided,

--param

entries override keys from

--params

. - Add

--watch

if you want to stream logs until the run finishes:

prefect deployment run <FLOW_NAME>/<DEPLOYMENT_NAME> --params '{"foo":"bar"}' --watch