Neither --field nor --raw-field accept JSON arrays right now. To pass a JSON array or a nested object, one needs to construct the JSON payload outside of gh and pass it in via --input. E.g.

jq -n '...' | gh api repos/:owner/:repo/deployments --input -

I propose a new array syntax for fields:

# array of strings
-f labels[]=one labels[]=two

# empty array
-f required_contexts[]

# other value types
-F foo[]=true -F bar[]=null

This syntax would allow passing values of any type, including an empty array, and is fully backwards-compatible. The only theoretical drawback is that it would be impossible to pass a parameter name that includes the literal [] characters, but since no API parameters ever have [] characters in their name, I think this is not a concern.

Originally posted by @mislav in #921 (comment)