Files
platform/docs/file-sync.md
T
pastilhas 027b10bd6e step 4/4: the docs say permissions too, and capability means one thing again
44 files of prose — CLAUDE.md, AGENTS.md, TODO.md, 20 docs, both plugin design
documents, and the comment surface the earlier steps could not reach.

Applied against an explicit keep-list, not swept, because the word turned out to
have SIX meanings in this repository rather than the three the offscale doc
recorded:

  permissions          renamed (steps 1–2)
  $OFFICER_ROOT/capabilities/  KEPT — the item store, and now the only thing
                               the word means that is ours
  sidecar routing keys renamed to `handles` (step 3)
  Lightning wallet     KEPT — a domain term, and on the wire to the mobile apps
  terminfo queries     KEPT — XTGETTCAP, in the pty sidecar
  InvoiceShelf         KEPT — per-resource { write, bulkDelete } flags

The sweep still falsified two things, both caught by checking rather than by
review, and both in prose that discusses more than one meaning at once:

CLAUDE.md began claiming the item store lives at `$OFFICER_ROOT/permissions`.
It does not; that directory is on disk and full of skills and tools.

And the offscale doc's own note about the collision became
"Named `permissions`, NOT `permissions`" — a sentence that had eaten the thing
it existed to warn about.

Both restored, and the note rewritten to say what is now true: capability means
one thing of ours, and three that belong to somebody else's vocabulary.

Verified live after restart: self and admin permission endpoints 200, gated
route 200, agent-status 200, 9 grants intact with 6 permissions offered.
tsgo clean, 797 tests, 787 pass, same 7.

The rename is done. Four steps, no data lost, no client break that survived
the step it was introduced in.
2026-08-15 16:31:11 +00:00

7.1 KiB

File sync

Written 2026-08-04. The "final boss" of the NextCloud replacement — separated from nextcloud-replacement.md because the answer is genuinely different from calendar and contacts, and conflating them is how this becomes a six-month project.

The ask: "the synced files functionality that I can run on each computer and phone", with the same acceptance test as the rest — it has to just work.


The distinction that decides everything

A mount is not a sync.

Mount (WebDAV, SMB, sshfs) Sync (NextCloud client, Syncthing, Dropbox)
Offline Nothing works Everything works
Open a 2 GB file Streams over the network Local disk read
Flaky connection Failed saves, hung apps Queues, retries
Conflicts Last writer wins, silently Detected and surfaced
Cost to build Days The rest of the year

What NextCloud's desktop client actually gives you is a local-first replica: a full copy on every device, a local database of file state, change detection via filesystem watching, transfer scheduling, and explicit conflict handling. That is the thing being asked for, and it is a genuinely hard, well-studied distributed-systems problem.


Decision: run Syncthing, do not write a sync engine

Same reasoning as choosing Radicale over writing CalDAV, only more so.

Option Verdict
Syncthing Chosen. Mature (since 2013), open source, peer-to-peer, real clients on Linux/macOS/Windows/Android, explicit conflict files, block-level transfer, no server account model to build.
WebDAV from the caldav sidecar Radicale is calendars and contacts only, so this would be a second server anyway — and it solves "see my files remotely", not "have my files offline". Complementary, not a substitute. Cheap to add later.
Reimplement NextCloud's sync protocol Chunked upload, ETag bookkeeping, a local state DB, conflict resolution, and a client on three platforms. The single largest item on the whole list, to arrive at something worse than what exists.

Why Syncthing fits this platform specifically

It is peer-to-peer, so there is no server-side account model to build — devices authenticate each other by device ID. That removes the entire class of work that a Dropbox-alike would need. Officer's job shrinks to: run it, own its config, show its state, and point the file browser at the folder.

It also composes with what is already here: the machine already runs Headscale, so devices are already on a private network and Syncthing's discovery/relay layer can be turned down or off entirely.


Shape of the work

officer-syncthing sidecar

Same pattern as officer-caldav (supervise a real server) crossed with officer-memos (hold a credential, proxy an API).

  • Supervise the syncthing binary on a loopback port, like Radicale.
  • Generate its config at boot rather than hand-maintaining it — same reasoning as caldav/radicale.ts: config is derived state, and a hand-edit that disagrees with what the code believes is very hard to debug.
  • Syncthing's own REST API is authenticated with an API key it writes into its config; the sidecar reads that key and holds it. The platform never sees it.
  • Storage under DATA_PATH/sync/, so it is inside the existing backup story.

Platform side

Sixteen lines of createSidecarProxy at /api/sync, exactly like memos and transmission. No sync knowledge in the platform, ever.

UI — replicate Syncthing's own UI first

Per the standing rule: reproduce what the service already ships, then extend. Syncthing's own web UI covers folders, devices, sync status/percentage, and conflicts. Those are the four panels. The extension Officer can add that Syncthing cannot is the interesting part: the synced tree is just a directory, so the existing file browser, code editor and file viewer all work on it for free. That is the integration nothing else offers.

Build order

  1. Sidecar supervising syncthing + config generation + registration.
  2. /api/sync proxy.
  3. Status panel (folders, devices, completion) — read-only.
  4. Add/remove folder and device pairing from the UI.
  5. Surface the synced root in the file browser as a first-class location.

The honest problem: iOS

There is no good Syncthing on iOS, and there will not be one. iOS does not allow a general-purpose background daemon doing continuous filesystem work; the only always-on sync clients that exist there are ones Apple grants entitlements for. This is also why NextCloud's own iOS app is a manual, foreground, tap-to-upload experience rather than a real sync client — the platform, not the software, is the limit.

So "on each computer and phone" splits:

  • Linux/macOS/Windows — solved by Syncthing, properly, today.
  • Android — solved by Syncthing (there are maintained forks; verify which is current before recommending one).
  • iOSnot solvable as continuous sync. The realistic shape is a WebDAV mount for browsing and on-demand download, plus explicit upload from the Officer mobile app. That is a different feature with a different backend, and it is a decision for the owner rather than something to assume.

This is worth deciding before step 1, because "iOS matters" changes the answer: if it does, a WebDAV server becomes a first-class part of the design rather than an optional later addition, and it may be worth serving both from one place.


What this does NOT do

  • It is not a replacement for the file browser. Officer already has one, and it already reaches the whole filesystem. Syncthing adds replication, not access.
  • It is not backup. Sync propagates deletions. A synced folder is not a backup of itself, and anyone who believes otherwise finds out at the worst moment. Versioning (Syncthing has several strategies) should be enabled and surfaced in the UI precisely so this is not confused.
  • It is not sharing. Files is an execution permission — the owner's disk, never grantable — so there is still nobody to share with, whatever the account list says since 2026-08-07.

Status

Design only. Nothing built — this was written before implementation on the night of 2026-08-04 and the implementation ran out of night. The two things to settle before writing code are the iOS question above and whether the synced root should live under DATA_PATH or somewhere the owner picks.