Hello Magnus:

It looks like I changed it from input to input_payload because
the "input" variable was shadowing the built-in input function.

It is definitely a bug in the docs. I pushed a fix for the
rest documentation few minutes ago in changeset:   8563:909cf30c01c1.
I also need to update the upgrading guide so people can change their
endpoints.

Thank you for reporting this.

Sorry I missed it in the docs.

-- rouilj