Great overview! Memory is one of the hardest parts of building good AI agents.
One thing that goes hand in hand with memory: model selection. The smarter the agent needs to be, the better the model you need. But you don't want to pay for a frontier model for every single memory lookup.
Our setup:
We use JZS Token as our API gateway. One endpoint, 40+ models. Switching between them is just changing the model name. No SDK changes, no different auth for each provider.
This lets us tier our agent's usage: use the cheapest model that can handle the task, and only step up when we really need the extra intelligence. The cost savings are significant.
The memory architecture is important, but so is the cost model behind it. You need both to build something that's actually sustainable.
Nice write-up. This is a really important topic for anyone building AI agents.