The Buddha and the Gods realm So according to Buddhism , the gods realm is part of the cycle of existence.
What are the references of this  , according to all buddhists canons?
the gods realm is part of the cycle of existence.

Correct, while devas' lifespan is much longer than ours and they enjoy a lot more bliss/pleasure, they too will die eventually:

This was said by the Blessed One, said by the Arahant, so I have heard:
&quot;When a deva is about to pass away from the company of devas, five omens appear: his garlands wither, his clothes get soiled, sweat comes out of his armpits, a dullness descends on his body, he no longer delights in his own deva-seat. The devas, knowing from this that 'This deva-son is about to pass away,' encourage him with three sayings: 'Go from here, honorable sir, to a good destination. Having gone to a good destination, gain the gain that is good to gain. Having gained the gain that is good to gain, become well-established.'&quot; ~~ Iti 76 ~~