You can copy the cornychat repo on github and host it, not sure about Nests. nostr:nprofile1qqsggfwsgcqnvaf2xtmhuvg526hf02ykqnkce26eht0x7s3yz463a6cpr4mhxue69uhkummnw3ezumt4w35ku7thv9kxcet59e3k7mf0qy88wumn8ghj7mn0wvhxcmmv9uq32amnwvaz7tmjv4kxz7fwv3sk6atn9e5k7tcvnz0yz did for a while. Cornychat uses Jam Systems, i think Nests uses Jitsi but not 100%.