Customizing Harness Maxxing

Your server, your product: you can change anything, and updates keep your changes. Just ask Claude ("put a snake game on my dashboard", "allow 20 sessions per topic") - it picks the right level below, records what it did and carries it over every update.

Three levels

Claude always tries the first two before touching the product code. The web interface itself cannot be customized (it is shipped pre-built): visual additions are extensions. See Dashboard widgets and Page extensions.

Customizations

A customization is a change to the code directory (/opt/claude-maxxing) saved as a git commit with a title and the reason:

maxxing custom save "Allow 20 sessions per topic" --why "I run many research threads in parallel"
maxxing custom                 # list, unsaved changes, pending update
maxxing custom drop <id>       # remove one

Every customization is listed in <workspace>/CUSTOMIZATIONS.md (title, reason, files) and exported as a patch in <workspace>/customizations/. Both are part of the memory backup.

Smart updates

Before: Settings -> System shows what the next update does to your server - tested on a throw-away copy, nothing changed yet (maxxing update --preflight on the server). Each customization carries over, carries over on code that changed (checked after), is now included in the product (Harness offers to drop it), or must be adapted. Unsaved edits, edits of the interface files and extensions the new version no longer supports are listed too.

• Everything compatible: Update does it all. After the restart, your extensions and customizations are checked automatically, and Harness applies the version's workspace novelties in a session of system/harness.
• Something to adapt: Update with Harness opens a session that adapts each change to the new code from what it is for (recorded with it), tests, then updates. The current version keeps running until everything works.

After: "Checked after the update: your extensions and changes work" - or what stopped working, with Fix with Harness. Check any time with maxxing update --verify (or "Check now").

Give each customization a check - a command that succeeds while it works - and it is tested after every update: maxxing custom save "..." --why "..." --check "<command>", or later maxxing custom check <id> "<command>". Extensions declare the version of the extension contract they use ("api": 1 in manifest.json): a version that stops supporting it is announced before you update.

Careful updates

maxxing update (or the topic system/harness (system/update on older servers), or Settings -> System) keeps you safe:

1. Unsaved edits of the code are saved as a customization first - nothing is ever lost. Edits of the pre-built interface (web/) cannot be customizations: they are set aside (git stash) instead of blocking the update, and Harness rebuilds what they did as an extension.
2. Your customizations are replayed on top of the new version.
3. No conflict: the update finishes ("N customizations carried over").
4. Conflict (the new version changed the same lines): nothing changes, the current version keeps running, and Settings -> System shows "Update waits for Harness". In the topic system/harness (system/update on older servers), Claude reads CUSTOMIZATIONS.md, adapts each customization to the new code, and finishes the update (maxxing update --resume). If a customization is no longer needed (the product now does it), Claude tells you and drops it.
5. The new version does not start: it is rolled back automatically to the previous one (and to the previous branch after --branch).

maxxing update --rollback returns to the version (and the branch) that ran before the last update. It refuses to run while the code directory has unsaved changes (nothing is changed): put them aside first (git stash), run the rollback, then put them back (git stash pop). A customization saved just before would be undone by the rollback.

Automatic updates

Off by default. Settings -> System -> Update by itself when nobody is here: when a new version is out, nobody is on the interface and nothing runs (no turn, no queued message, no scheduled job, nothing for 10 minutes), and the update is "simple" (no customization to adapt, no unsaved change, no upgrade note asking for something), Harness runs maxxing update by itself and restarts for a few seconds. Otherwise it waits and tells you in the notifications. It never touches a server whose code is on a branch under test (detached HEAD) or an update that already waits for you (conflict, rolled-back version), and tries a given version at most once a day.

New server

Restore your memory backup on the new server (RESTORE_FROM=owner/name at install): the installer re-applies your customizations. Otherwise run maxxing custom restore.

See also: maxxing custom --help and the skill maxxing-customize (what Claude follows).