# Exapp Operations

> Installs, operates and troubleshoots Nextcloud AppAPI and External Apps (ExApps) with occ: set up the HaRP deploy daemon on Docker, Kubernetes, a remote GPU host or Nextcloud AIO, route /exapps/ on the reverse proxy, install, enable, disable, update and remove ExApps, manage daemon registries and ExApp config, and diagnose daemon or routing failures symptom-first. Use for AppAPI admin questions and day-2 ExApp operations on development or production instances.

- Skill: `nextcloud/exapp-operations` (Agent Skill, multi-file: 5 files)
- Install (CLI): `npx skillmds@latest add nextcloud/exapp-operations`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nextcloud/exapp-operations/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- License: AGPL-3.0-or-later
- Author: nextcloud (https://skillmd.com/u/nextcloud)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/nextcloud/exapp-operations

---


# AppAPI and ExApp operations

AppAPI is the Nextcloud component that runs External Apps: services living outside the PHP process, usually
as Docker containers, deployed and managed through a deploy daemon (HaRP is the recommended one). This skill
is the operator's view: getting a daemon working on a real instance, the full occ command surface, and what
to check when something breaks.

## How to work

Start in [references/operations.md](references/operations.md); it is the hub:

- New instance, no daemon yet: follow its **Quickstart** (section 2), an eight-step golden path from
  `occ app:enable app_api` to a running ExApp.
- Choosing or registering a daemon: sections 3 to 5 (deploy types, topologies, the full
  `daemon:register` flag table).
- Managing installed ExApps: section 6 (lifecycle commands and their semantics) and section 7 (config,
  registries, certificates, maintenance mode).
- Something is broken: section 10 (symptom-first troubleshooting) plus section 11 (which capability exists in
  which Nextcloud version).

Special topologies have their own runbooks, same directory:

- [references/kubernetes.md](references/kubernetes.md): ExApps in a Kubernetes cluster (NC34+); HaRP runs
  off-cluster, expose types are the core decision.
- [references/remote-daemon.md](references/remote-daemon.md): ExApp containers on a different machine than
  Nextcloud, for example a GPU server.
- [references/aio.md](references/aio.md): Nextcloud AIO, where the daemon is auto-managed and the main
  failure mode is fighting it.

## Facts that save hours

- The number one failure is a shared-key mismatch: `--harp_shared_key` must be byte-identical to HaRP's
  `HP_SHARED_KEY`.
- `daemon:register` is a silent no-op when a daemon with that name exists; `daemon:unregister` first to change
  anything.
- Green daemon checks do not prove the ExApp path. Without a working `/exapps/` reverse-proxy rule (with
  WebSocket upgrade) no ExApp can even be installed on a HaRP daemon: AppAPI polls the heartbeat at
  `<nextcloud_url>/exapps/<appid>`, so the install fails while `DaemonCheck` stays green.
- Never paste real secrets into shared files or commands you log; placeholders in the runbooks are in angle
  brackets.
- Destructive flags need explicit human approval: `app:unregister --rm-data` deletes the app's data volume.

## Files

- [references/operations.md](references/operations.md): concepts, Quickstart, daemon and lifecycle command
  references, operating notes, app store, runtime contract, troubleshooting, version notes.
- [references/kubernetes.md](references/kubernetes.md), [references/remote-daemon.md](references/remote-daemon.md),
  [references/aio.md](references/aio.md): topology runbooks.
- The HaRP service itself (probes, logs, upgrades, load):
  [harp-operations](../harp-operations/SKILL.md). AI features on top of AppAPI:
  [nextcloud-ai-stack](../nextcloud-ai-stack/SKILL.md).
- Building the app side of the contract: [exapp-development](../exapp-development/SKILL.md). Changing an
  installed app: [exapp-maintenance](../exapp-maintenance/SKILL.md). Local dev environment:
  [nextcloud-dev-setup](../nextcloud-dev-setup/SKILL.md).