Curl -F

curl --help
-F, --form <name=content> Specify multipart MIME data
    --form-string <name=string> Specify multipart MIME data

Slack API

 curl -F token=xoxp-... -F team_id=T1234 -F user_id=U1234 https://slack.com/api/admin.users.remove

OAuth
  curl -F code=1234 -F client_id=3336676.569200954261 -F client_secret=ABCDEFGH https://slack.com/api/oauth.v2.access

See also

• cURL, curl -s, -X, -x, curl -T, curl --help, curl -L, curl -o, curl -X POST, curl -d, curl --header, curl -I, curl --silent, curl -Is, curl -k or curl --insecure, curl -XPUT, curl -d, ~/.curlrc, curl -i, curl --version, curl --help