arr-connect

Arr Connect

How to reach a *arr instance, what its API will lie to you about, and the two checks that stop most agent damage before it happens. Every other arr-* skill assumes this.

The one-minute setup

Every arr app uses a single API key, no OAuth, no session. Find it in Settings > General > Security, or read it out of config.xml in the app's config directory:

grep -o '<ApiKey>[^<]*</ApiKey>' /path/to/config/config.xml

Keep it in the environment, never inline:

export ARR_URL=http://arr-host:7878        # Radarr 7878, Sonarr 8989, Prowlarr 9696
export ARR_KEY=...                          # from config.xml or the UI
curl -sf -H "X-Api-Key: $ARR_KEY" "$ARR_URL/api/v3/system/status" | jq '{appName,version}'

If that returns app name and version, you are connected. A 401 means the key is wrong; a connection refused means the port or host is wrong; an HTML response means you hit a reverse proxy that is not forwarding /api.

The key can also travel as ?apikey= in the query string. Prefer the header: query strings land in access logs and shell history.

The endpoint map

Both apps expose API v3 regardless of the app's own version number. Sonarr v4 is still /api/v3. This surprises people; do not go hunting for /api/v4.

Shared shape across apps:

Purpose	Radarr	Sonarr
Library list	GET /api/v3/movie	GET /api/v3/series
One item	GET /api/v3/movie/{id}	GET /api/v3/series/{id}
Add	POST /api/v3/movie	POST /api/v3/series
Search metadata	GET /api/v3/movie/lookup?term=	GET /api/v3/series/lookup?term=
Files	GET /api/v3/moviefile?movieId=	GET /api/v3/episodefile?seriesId=
Quality profiles	GET /api/v3/qualityprofile	same
Root folders	GET /api/v3/rootfolder	same
Queue	GET /api/v3/queue	same
Trigger work	POST /api/v3/command	same
History	GET /api/v3/history	same
Health	GET /api/v3/health	same

Sonarr adds GET /api/v3/episode?seriesId= and the per-episode monitor endpoint, which have no Radarr equivalent because a movie is one item.