Strangely, you need the ONLY the CREATE permission for Computers for this particular API call to work. Nothing else.

curl -su "api_user1:pass" https://jss.url/JSSResource/fileuploads/computers/id/# -F "name=@/localcomputer/path/to/file" -X POST

Now I'd like to know how to delete all those attachments with the API to reduce DB bloat. 

check out this script 

#!/usr/bin/env bash



# Script to delete all the attachment on a single device.

# Created by macstuff.dev - Melwin Moeskops 

#

# Will delete from 1 till 450 with a sleep to keep the server from being overloaded.



# --------------    edit the variables below this line    ----------------



# API username

username=""



# API password

password=""



# JSS URL without trailing slash

jamfProURL="https://url.jamfcloud.com"



# Device ID (Example where to find: https://URL.jamfcloud.com/computers.html?id=2523&o=r) ID 2523 in example.

deviceID="2227"



# ------------------  do not edit below this line  -------------------



# Create base64-encoded credentials

encodedCredentials=$( printf "${username}:${password}" | /usr/bin/iconv -t ISO-8859-1 | /usr/bin/base64 -i - )



# Generate an authorization bearer token

authToken=$( /usr/bin/curl "${jamfProURL}/uapi/auth/tokens" --silent --request POST --header "Authorization: Basic ${encodedCredentials}" )



# Clean up token to omit expiration details

token=$( /usr/bin/awk -F \\" '{ print $4 }' <<< "${authToken}" | /usr/bin/xargs )



# Start deletion loop (adjust 450 to desired amount)

for attachmentId in {1..450}

  do

    # Wait 1 second to prevent the server from overloading

  sleep 1

  # Delete attachement

  curl -X DELETE "${jamfProURL}/api/v1/computers-inventory/${deviceID}/attachments/${attachmentId}" -H "accept: */*" -H "Authorization: Bearer ${token}"

done



# Expire our authorization token

curl "${jamfProURL}/uapi/auth/invalidateToken" \\

--silent \\

--request POST \\

--header "Authorization: Bearer ${token}"



exit 1

I cleaned up this part of the script ,but otherwise it looks to be good:

# Create base64-encoded credentials
encodedCredentials=$( printf "${username}:${password}" | /usr/bin/iconv -t ISO-8859-1 | /usr/bin/base64 -i - )

# Generate an authorization bearer token
authToken=$( /usr/bin/curl "${jamfProURL}/uapi/auth/tokens" --silent --request POST --header "Authorization: Basic ${encodedCredentials}" )

# Clean up token to extract just the token value from JSON response
token=$( echo "${authToken}" | /usr/bin/grep -o '"token":"[^"]*"' | /usr/bin/awk -F'"' '{print $4}' )