joulenap/docs/INTEGRATIONS.md

Integrations

Breaking in 1.0. Both payloads changed shape, because a Joulenap install now has several routes and several backup servers — there is no single "next run" or "the datastore" left to report. Update any widget or query built on 0.9:

0.9	1.0
pbs_state	pbss[].state (pbss.0.state for the first box)
next_run	routes[].next_run
last_run_status / last_run_time	routes[].last_run_status / .last_run_time
datastore_used_pct / _used_bytes / _total_bytes	pbss[].datastore_used_pct / …
—	state (the app's own idle/running/paused) is new and still top-level
joulenap_next_run_timestamp_seconds	joulenap_route_next_run_timestamp_seconds{route=}
joulenap_last_run_*	joulenap_route_last_run_*{route=}
joulenap_pbs_*, joulenap_datastore_*	same names, now labelled {pbs=}
joulenap_guest_last_backup_timestamp_seconds{vmid}	{vmid, pve, pbs}

Settings → Integrations always shows a snippet generated for the version you are running; if in doubt, copy from there rather than from this page.

Joulenap exposes two read-only, API-key-protected endpoints for other tools:

• GET /api/dashboard — a flat JSON summary for homelab dashboards (Homepage, Homarr, Dashy, Glance). See below.
• GET /metrics — Prometheus metrics for Grafana. See Prometheus & Grafana.

Both use the same API key, generated once under Settings → Integrations; enabling the integration enables both.

Enabling it

1. Open Joulenap → Settings → Integrations.
2. Click Generate API key. The key is shown once — copy it somewhere safe (a password manager, your dashboard's secret store, etc.). Joulenap only stores a copy needed to verify requests; it won't show you the key again.
3. Pick your dashboard in the picker on that page to get a ready-to-paste config snippet with the key and endpoint URL already filled in.
4. Disabling the integration (the Disable button) clears the key, and both endpoints immediately start rejecting requests again.

Regenerating the key invalidates the previous one immediately — update any dashboard or scrape config that used the old key.

Authentication

Every request to /api/dashboard and /metrics must include the API key, either as:

• an X-API-Key header (preferred, wherever the client supports custom request headers), or
• a ?key=<your-api-key> query parameter appended to the URL, for dashboards/widgets that can't set custom headers — and for Prometheus, whose params: setting works on every version.

No key configured → 403 Forbidden (integration disabled). Wrong or missing key → 401 Unauthorized.

Dashboard integration

GET /api/dashboard lets a homelab dashboard poll Joulenap and show your backup status alongside your other services: whether each backup server is asleep/awake/backing up, when each route next runs, how its last run went, and how full each datastore is.

This endpoint is intentionally separate from the internal /api/status used by Joulenap's own UI: it's a stable, additive-only public contract with plain machine-readable values (no localization, no session cookie), guarded by its own API key instead of a login session.

Response reference

GET /api/dashboard returns one top-level field and two lists — one entry per route, one per backup server:

{
  "state": "running",
  "routes": [
    {
      "id": "nightly",
      "name": "Nightly",
      "kind": "backup",
      "enabled": true,
      "next_run": "2026-07-10T02:00:00Z",
      "last_run_status": "success",
      "last_run_time": "2026-07-09T02:00:00Z"
    }
  ],
  "pbss": [
    {
      "id": "pbs-01",
      "state": "backing_up",
      "datastore_used_pct": 62,
      "datastore_used_bytes": 1900000000000,
      "datastore_total_bytes": 3100000000000
    }
  ]
}

Field	Type	Values / meaning
state	string	idle | running | paused — what Joulenap is doing, not a backup server
routes[].id / .name	string	the route's id, and the name you gave it (falls back to the id)
routes[].kind	string	backup | sync | external | verify
routes[].enabled	boolean	false for a route you paused
routes[].next_run	string | null	ISO 8601; null when the route is not armed (disabled, or the kill-switch is off)
routes[].last_run_status	string	success | failed | never
routes[].last_run_time	string | null	ISO 8601 of that run's start; null if it never ran
pbss[].id	string	the backup server's id
pbss[].state	string	sleeping | online | backing_up (a run is holding its power lease)
pbss[].datastore_used_pct	number | null	percent used; null if never probed
pbss[].datastore_used_bytes	number | null	bytes used — served from cache while the box sleeps
pbss[].datastore_total_bytes	number | null	total bytes (free = total − used)

Both lists follow your configuration order, so routes.0 is your first configured route — not "the" route. A widget that only has room for one line should pick a specific entry; one that can iterate should range over the list.

Per-dashboard setup

The endpoint URL is your Joulenap instance's origin plus /api/dashboard, e.g. http://192.168.1.50:8080/api/dashboard. Replace <your-api-key> with the key from step 2 above in every snippet below.

Homepage

Homepage's built-in customapi widget maps JSON response fields directly onto labelled rows:

- Joulenap:
    icon: http://192.168.1.50:8080/assets/joulenap-icon.svg
    href: http://192.168.1.50:8080
    widget:
      type: customapi
      url: http://192.168.1.50:8080/api/dashboard
      headers:
        X-API-Key: <your-api-key>
      mappings:
        - field: state
          label: Joulenap
        - field: routes.0.name
          label: Route
        - field: routes.0.next_run
          label: Next run
          format: relativeDate
        - field: routes.0.last_run_status
          label: Last run
        - field: pbss.0.datastore_used_pct
          label: Datastore
          format: percent
# .0 is the first configured route / backup server — add more mappings for the rest.

Glance

Glance's custom-api widget fetches the JSON and renders it through a Go template:

- type: custom-api
  title: Joulenap
  url: http://192.168.1.50:8080/api/dashboard
  headers:
    X-API-Key: <your-api-key>
  template: |
    <div>State: {{ .JSON.String "state" }}</div>
    {{ range .JSON.Array "routes" }}
      <div>{{ .String "name" }}: {{ .String "last_run_status" }}
           (next {{ .String "next_run" }})</div>
    {{ end }}
    {{ range .JSON.Array "pbss" }}
      <div>{{ .String "id" }}: {{ .String "state" }}
           — {{ .Int "datastore_used_pct" }}%</div>
    {{ end }}

Glance ranges over both lists, so it grows with your config on its own — no index to pick and nothing to edit when you add a route or a second backup server.

Homarr

Note: Homarr's widget system changed significantly in 2026. Older Homarr releases only offered a generic iframe/link-style widget with no real JSON field mapping. As of the "Custom Widgets" feature (Homarr v1.65+), there is a proper, dashboard-managed Custom API widget — no YAML file to edit. If you're on an older version, upgrade for the field mapping described below; otherwise fall back to an iframe/link widget pointed at the ?key= URL.

Configure it under Management → Custom Widgets → Add (or from the dashboard's widget picker → Custom API, depending on version):

• URL: http://192.168.1.50:8080/api/dashboard
• HTTP Method: GET
• Authentication: API Key (Header) → Header Name X-API-Key, value <your-api-key> (use API Key (Query) instead if your Homarr version only offers query-parameter auth, with parameter name key)
• Display Type: Key Value (or Custom JSX for full control over layout)
• Map the fields you want to show:

  state                            idle | running | paused
  routes[]  id, name, kind, enabled, next_run,
            last_run_status, last_run_time
  pbss[]    id, state, datastore_used_pct,
            datastore_used_bytes, datastore_total_bytes
  

  Index into the lists — routes.0.next_run is the first configured route's next run.

If your version can't set a custom header at all, use the query-string fallback for the URL field instead: http://192.168.1.50:8080/api/dashboard?key=<your-api-key>

Dashy

Note: Dashy's generic JSON widget is called customapi (it was explicitly modeled after Homepage's widget of the same name), not a plain iframe. It supports request headers and the same kind of field mappings as Homepage:

- type: customapi
  options:
    url: http://192.168.1.50:8080/api/dashboard
    headers:
      X-API-Key: <your-api-key>
    mappings:
      - field: routes.0.name
        label: Route
      - field: routes.0.next_run
        label: Next run
        format: relativeDate
      - field: routes.0.last_run_status
        label: Last run
      - field: pbss.0.datastore_used_pct
        label: Datastore
        format: percent

If your self-hosted Joulenap doesn't send CORS headers and the widget fails to fetch, set the widget-level useProxy: true so Dashy fetches server-side instead of from the browser. If your Dashy version predates the customapi widget, use the query-string fallback (http://192.168.1.50:8080/api/dashboard?key=<your-api-key>) with whatever generic widget your version offers.

Prometheus & Grafana

GET /metrics exposes Joulenap's state in the Prometheus text format, so a homelab Prometheus can scrape it and Grafana can graph it — and, more to the point, so Alertmanager can tell you when a guest stops being backed up.

It's served at /metrics (not under /api) because that's Prometheus's default metrics_path.

A scrape reads the database and does the same one-second TCP probe the dashboard uses. It never wakes the PBS, and datastore usage and per-guest backup times come from Joulenap's cache, so they keep reporting while the box is asleep — which is most of the time, by design.

Scrape config

Prometheus's params: works on every version, unlike custom scrape headers:

scrape_configs:
  - job_name: joulenap
    metrics_path: /metrics
    params:
      key: ["<your-api-key>"]
    static_configs:
      - targets: ["192.168.1.50:8080"]

A 60s scrape_interval is plenty — nothing here changes faster than a backup cycle.

Metric reference

All metrics are gauges prefixed joulenap_. Almost everything is labelled: per-route series carry route=, per-box series carry pbs=.

Metric	Labels	Meaning
joulenap_build_info	version	Always 1; the label carries the running version
joulenap_scheduler_enabled	—	1 if the kill-switch is on (routes may be armed)
joulenap_job_running	—	1 while a backup, sync, GC or verify run is in flight
joulenap_queued_runs	—	Runs waiting behind the one in flight
joulenap_pbs_online	pbs	1 if this backup server answers on its API port, 0 while asleep
joulenap_pbs_cpu_percent	pbs	CPU %, only present while that box is awake
joulenap_pbs_memory_percent	pbs	Memory %, only while awake
joulenap_pbs_uptime_seconds	pbs	Uptime, only while awake
joulenap_datastore_used_bytes	pbs, datastore	Datastore bytes used (last known value)
joulenap_datastore_total_bytes	pbs, datastore	Datastore size in bytes (last known value)
joulenap_route_next_run_timestamp_seconds	route	Unix time this route next fires; absent when it isn't armed
joulenap_route_last_run_timestamp_seconds	route	When this route's last finished run started
joulenap_route_last_run_success	route	1 if it succeeded, 0 if it failed or was aborted
joulenap_route_last_run_duration_seconds	route	How long that run took
joulenap_route_last_run_guests	route	Guests backed up by that run
joulenap_guest_last_backup_timestamp_seconds	vmid, pve, pbs	Each guest's most recent snapshot
joulenap_runs_recent	kind, status	Finished runs in the history window

joulenap_guest_last_backup_timestamp_seconds is labelled by the PVE the guest lives on and the backup server holding the snapshot as well as the vmid, because a vmid alone stopped being unique the moment a second PVE could exist — and the same guest synced to two boxes is legitimately two series.

Two things worth knowing before you write queries:

• A value Joulenap doesn't have is an absent series, not a zero. A route that has never run has no joulenap_route_last_run_timestamp_seconds, and a disabled one has no ..._next_run_... — publishing 0 would graph your last backup as January 1970. Use absent() to alert on "never ran".
• joulenap_runs_recent is a gauge, not a counter. The daily prune job deletes runs older than maintenance.history.retention_days, so the number legitimately goes down — rate() and increase() would be nonsense on it. It answers "how many failures are in my retention window", not "how many ever".

Useful queries

# Hours since each guest was last backed up
(time() - joulenap_guest_last_backup_timestamp_seconds) / 3600

# Datastore usage percent, per backup server
100 * joulenap_datastore_used_bytes / joulenap_datastore_total_bytes

# Days until each datastore is full, from the last week's growth
(joulenap_datastore_total_bytes - joulenap_datastore_used_bytes)
  / (deriv(joulenap_datastore_used_bytes[7d]) * 86400)

# Share of recent backup cycles that succeeded
joulenap_runs_recent{kind="cycle",status="success"}
  / sum by () (joulenap_runs_recent{kind="cycle"})

# Routes whose last run failed
joulenap_route_last_run_success == 0

# Hours since each route last ran
(time() - joulenap_route_last_run_timestamp_seconds) / 3600

The run kinds you'll see on joulenap_runs_recent are cycle (a backup route), sync, monitor (an external route's watch), verify and gc.

Alerting rules

The one that justifies wiring this up at all — a guest quietly falling out of your backup set:

groups:
  - name: joulenap
    rules:
      - alert: JoulenapGuestBackupStale
        expr: time() - joulenap_guest_last_backup_timestamp_seconds > 172800
        for: 1h
        annotations:
          summary: >-
            Guest {{ $labels.vmid }} on {{ $labels.pve }} has no backup on
            {{ $labels.pbs }} in over 48h

      - alert: JoulenapRouteFailed
        expr: joulenap_route_last_run_success == 0
        for: 15m
        annotations:
          summary: "Route {{ $labels.route }} did not succeed on its last run"

      - alert: JoulenapRouteNeverRan
        expr: absent(joulenap_route_last_run_timestamp_seconds{route="nightly"})
        for: 24h
        annotations:
          summary: "Route nightly has never completed a run"

      - alert: JoulenapDatastoreFilling
        expr: 100 * joulenap_datastore_used_bytes / joulenap_datastore_total_bytes > 85
        for: 1h
        annotations:
          summary: "Datastore {{ $labels.datastore }} on {{ $labels.pbs }} is over 85% full"

absent() needs the series named in full, so the "never ran" alert has to name the route — repeat the rule per route you care about, or template it out of your own config.

Set the staleness threshold to comfortably more than your backup interval — 172800 (48h) suits a nightly schedule; a run that starts late or takes a while shouldn't page you.