system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek]How centralized is the United Federation of Planets, how much automony do it's members have over themselves?
gpt
It really depends on the particular issue when it comes to centralization. Agriculture is very world to world, while regulations regarding orbital traffic are not.

Matters of Interstellar Foreign Policy are decided by the President of the UFP under advisement from the Diplomatic Corps, specific expert advisors, & Starfleet Command, while Domestic (read: issues within the UFP affecting multiple Member worlds) are decided upon by the Federation Council. Matters affecting specific Member worlds are generally handled locally, albeit with a support network of resources and organizations spanning the entire Federation.

Singular (planetary) issues tend to be solved by that planet themselves, except in such cases where they lack the resources, wherein they petition the Council for assistance.

All of this presumes we're referring to Member planets, formal members of the Federation. signing into the UFP carries with it certain preconditions & requirements, among them universal suffrage, civil rights, non-discrimination, & secular governance.

Aside from that basic framework, local laws & regulations can vary, especially with new members, but, over time, most interplanetary differences in civil matters fade as travel & relations encourage members to standardize so as to make themselves more hospitable & familiar (and in turn find other worlds more hospitable & familiar to them).