I want to challenge the thin-client / remote backend architecture that's mainstream in the software industry. I think its authority boundaries are WRONG. Thought experiment: why can't I own the money transfer log in my own (old school, non DeFi) bank account? I want that log replicated securely between my phone and the bank. All outgoing money transfers must be signed by my key on request, and by the bank on execution. Incoming money is signed by whatever entity sent the transfer, their bank upon execution, and my bank on reception. The concept of downloading your bank extract is moot - it lives on your device. And for cancelling a subscription, you just change your phone settings so it doesn't sign its debits anymore. In general, why do we need thin clients at all? I think we're closing on an arc that started 20 years ago, and could align the authority boundaries in our software platforms with our expectations. I want to share the idea of a Co-transactional database: a content-addressable, self-verifiable, coordination-free database for our collective decentralized future. Powered by Monotone View Types. Ergonomic, down to Earth and easy to use.