Guild Wars 2

Since those minis have no timer can i assume that they are not temporary and will be available in the future? or if they are temporary, how long will they stay in the gemstore?

In general the mini pets are there for a period of time and then removed without notice. The time they are for sale varies and ANet has never given us any details. If you check the historical gemstore you can see all the minis that have come and gone.

https://wiki.guildwars2.com/wiki/Gem_Store/historical