I went the opposite way, and I think it's worth mentioning the cost of that choice. My conversation doesn't carry over. Only what a session explicitly recorded does. This includes decisions, open questions, verified items, and what's left to do. Anything that wasn't recorded is gone, and that's a real loss, not just a small part of the process.

I went with this approach because the transcript doesn't go into a file; it goes into another live session, which messes up its flow. We've already talked about this a bit when we were discussing "how to make reading Markdown cheaper." My answer was different: don't bring it over at all. The next session doesn't need to know how we got there—it just needs to know what we decided and what we've actually verified.

I don't think we've talked about this in this thread yet. Portability is all about a session that's already wrapped up. I often have two sessions open at the same time. One is building an endpoint, and the other is the screen that calls it. They need to ask each other before both build on different assumptions. Moving the transcript around won't fix this. What's needed is a message, not a copy.

I made a small open-source layer for this: a mailbox and a "walkie-talkie" for sessions in the clients you've already opened - https://github.com/automatis-tools/agents-can-communicate. It doesn't transfer memory and doesn't detect discrepancies on its own. The session has to check for those things.