yeah, I think having a private inbox that stores data ephemerally is probably a useful thing to have in the PDS, where you still use a collection as part of the record key, but it's just a "fire and forget" notification
The PDS-as-AI-gateway idea is compelling, but the key question is where embeddings live. If your semantic memory is computed and stored on-device rather than at the PDS, you avoid creating a new centralised honeypot of meaning even if the raw data stays private.
I think the most important thing is that you have a natural language copy of memories.
Something you can pass to another model or take to another PDS.
It could even be all of your chat history because at least it’s still somewhat portable.
Portability as plain text is the right foundation. We store everything in SQLite with full export precisely for that reason. Embeddings are useful but ephemeral, the natural language record is what actually survives a migration.