You're right that I asked an XY question, but the reason is Y is a general solution/tool that will let me apply it to a large set of specific X's. The general X is: ``` IPC without a server, message bus, or another process to receive messages. You have two processes, one writes to a SQLite file using vanilla SQLite. The other process must respond and run a function based on certain create/update/delete operations. ``` I do not have control over the first process, but I can use any code in the second process. As an example, the first process could be a GUI database tool, and the second process could be something updating a remote store. The user deletes a row in the GUI, the second process detects this from the file, and deletes something in a remote store. Using vanilla SQLite is important in the first process as it would allow any SQLite library to write to the file. I think the issue is that unless the first process records the change event, the second process will not know what changed so will need to run an expensive diff operation by checking all the rows against the older snapshot. This is mostly an experiment.