OpenCode history: reviewing an incident

Which change caused this, and why did it look correct at the time?

Why this is hard

Git answers the first half of an incident question. The second half — what the author was trying to do, what constraint they gave the model, what the model quietly worked around — is in the conversation, and it is the half that stops the same failure recurring.

What OpenCode specifically does to you here

Session diffs are kept in a storage directory outside the database, so reconstructing what changed means joining two places. Both survive or neither does, and people back up the database alone.

du -sh ~/.local/share/opencode/storage

Where OpenCode keeps this in the first place: ~/.local/share/opencode/opencode.db. One database holds every session, it grows without limit, and nothing else has a copy.

What a working answer looks like

A working answer means going from a line of code to the prompt that produced it, months later, without depending on anyone's memory.

Start by measuring what you have. npx promptwake doctor reports what every AI tool on the machine is holding and how much of it sits inside a deletion window — no account, writes nothing, sends nothing anywhere. If the conclusion is that the record should not depend on one laptop, that is what PromptWake captures: prompt, response and the resulting diff, local by default and synced into a shared timeline on the paid tiers.