And of course now that I test it again, it's working.

code API is still messed up for me.

curl --insecure -u "me@mailserver.com:<my password>" https://screeps.com/api/user/code?branch=sim > sim.json

This works fine but then

curl --insecure -u "me@mailserver.com:<my password>" -X "POST" -H "Content-Type: application/json" --data @sim.json

returns

{"error":"TypeError: Cannot read property 'length' of undefined"}