Build notes on Xerum

Same-origin bought us a lot, and charged us one path space

Mon, 31 Aug 2026 14:00:00 +0000

The web app is split by plane: account pages served by the control plane on its own origin, your instance’s pages served by your instance on its. Each app is same-origin with the data it reads.

That buys a lot. No CORS on any data call. The browser is an ordinary OAuth client rather than a privileged one — it ends up holding exactly what an agent holds, which means we did not invent a second auth mechanism for the UI. And opening the app does not wake a sleeping container, because the shell is served from the edge.

The deploy artefact that had never once built

Mon, 31 Aug 2026 09:00:00 +0000

task backend:build:linux had never worked. Not once, since the day it was written.

Nothing noticed, because nobody had run it. Every developer build is a darwin build, and a darwin build takes a different path that succeeds. The task that produces the thing we would actually deploy had been quietly broken for as long as it had existed.

The failure

Building the tenant with GOOS=linux CGO_ENABLED=0 failed on undefined symbols.

We reversed our biggest design decision, and it cost almost nothing

Thu, 27 Aug 2026 10:00:00 +0000

The design said git was the system of record. A change was a commit, a revision a commit id, a proposal a ref kept alive. It was written down, argued for, and — for a while — right.

We reversed it. Sqlite is the system of record now: an append-only changes log plus a content-addressed blobs table, with everything else a derived index. This is the note about why, and about the thing that made the reversal affordable.