Yuki Kishimoto on Nostr: There is a method on the database that allow to check where an event ID was seen: ...

There is a method on the database that allow to check where an event ID was seen:

```rust
let database = client.database();
let relays = database.event_seen_on_relays(id).await?;
```

This works with the in-memory database (which is used by default) and with some persistent database but not with all implementations (like with nostrdb).

Another good solution is to use the `RelayPoolNotification`, like suggested by dluvian (nprofile…ru2a)