while there are several good resources for pre written NAP agreements that you can check out, look at it this way.

A NAP is an agreement between to players, usually brought about by a discussion between the parties as to what each of them want from said peace agreement, this may include or exclude many things & every NAP has the flexibility to be whatever you want it to cover, of course you have to get the other guy to agree & this is generally what keeps NAP agreements sensible.

Some players will want to be very detailed while other will be very casual, it may be as simple as "want a NAP?"

So what is a basic NAP then?

A basic NAP would include things like:
1. you don't attack each other ;) 2. not casting spells that effect your NAP partner without asking 1st. 3. not allow anyone to access your NAP partner through your regions.

Other things you should consider.
Duration, how long is it, 3, 5 or GL, you may want to include fury farm or temple swap agreements, mutual enemy agreements (seen more in team games than Indy games) you might want to include an inactivity clause? ie: If you go inactive for 3 ticks, the nap will become void & must be renegotiated should you return.

Also be aware that while most players will honour their word, should you intentionally or mistakenly attack or effect a NAP partner, they may decide that you have breached your NAP & may further declare war upon you.

Allow honest mistakes.