CXPLAY on Nostr: Blossom 没有设计这个规范, ...

Blossom 没有设计这个规范, 在外部服务器发现和保存文件是一些服务端实现里单独加的功能:

quoting
nevent1q…9ch2

Discovering and downloading (or streaming) blobs from other servers isn't part of the blossom spec but its something I added to my blossom-server implementation
By default the example config has it setup to check cdn.satellite.earth and nostr 1063 events to find blobs, but if you want you can turn it off in the config https://github.com/hzrd149/blossom-server/blob/master/config.example.yml#L15-L30

I don't know if there are any security implications of downloading a blob. but its possible an attacker could flood a server by asking it to download everything from another server