README.md

@@ -17,6 +17,7 @@ Based on the [Navicord](https://github.com/logixism/navicord) project.
 - Displays playback progress with start/end timestamps
 - Automatic presence clearing when track finishes
 - Multi-user support with individual Discord tokens
+- Optional image hosting via [uguu.se](https://uguu.se) for non-public Navidrome instances
 
 <img height="550" src="https://raw.githubusercontent.com/navidrome/discord-rich-presence-plugin/master/.github/screenshot.png">
 
@@ -49,13 +50,14 @@ The plugin implements three Navidrome capabilities:
 
 ### Host Services
 
-| Service       | Usage                                                               |
-|---------------|---------------------------------------------------------------------|
-| **HTTP**      | Discord API calls (gateway discovery, external assets registration) |
-| **WebSocket** | Persistent connection to Discord gateway                            |
-| **Cache**     | Sequence numbers, processed image URLs                              |
-| **Scheduler** | Recurring heartbeats, one-time presence clearing                    |
-| **Artwork**   | Track artwork public URL resolution                                 |
+| Service         | Usage                                                               |
+|-----------------|---------------------------------------------------------------------|
+| **HTTP**        | Discord API calls (gateway discovery, external assets registration) |
+| **WebSocket**   | Persistent connection to Discord gateway                            |
+| **Cache**       | Sequence numbers, processed image URLs                              |
+| **Scheduler**   | Recurring heartbeats, one-time presence clearing                    |
+| **Artwork**     | Track artwork public URL resolution                                 |
+| **SubsonicAPI** | Fetches track artwork data for image hosting upload                 |
 
 ### Flow
 
@@ -83,12 +85,15 @@ Discord requires images to be registered via their external assets API. The plug
 3. Caches the result (4 hours for track art, 48 hours for default image)
 4. Falls back to a default image if artwork is unavailable
 
+**For non-public Navidrome instances**: If your server isn't publicly accessible (e.g., behind a VPN or firewall), enable the "Upload to uguu.se" option. This uploads artwork to a temporary file host so Discord can display it.
+
 ### Files
 
 | File                           | Description                                                            |
 |--------------------------------|------------------------------------------------------------------------|
 | [main.go](main.go)             | Plugin entry point, scrobbler and scheduler implementations            |
 | [rpc.go](rpc.go)               | Discord gateway communication, WebSocket handling, activity management |
+| [coverart.go](coverart.go)     | Artwork URL handling and optional uguu.se image hosting                |
 | [manifest.json](manifest.json) | Plugin metadata and permission declarations                            |
 | [Makefile](Makefile)           | Build automation                                                       |
 
@@ -96,10 +101,11 @@ Discord requires images to be registered via their external assets API. The plug
 
 Configure via the Navidrome UI under **Settings > Plugins > Discord Rich Presence**:
 
-| Field         | Description                                                                                                     |
-|---------------|-----------------------------------------------------------------------------------------------------------------|
-| **Client ID** | Your Discord Application ID (create at [Discord Developer Portal](https://discord.com/developers/applications)) |
-| **Users**     | Array of username/token pairs mapping Navidrome users to Discord tokens                                         |
+| Field                 | Description                                                                                                     |
+|-----------------------|-----------------------------------------------------------------------------------------------------------------|
+| **Client ID**         | Your Discord Application ID (create at [Discord Developer Portal](https://discord.com/developers/applications)) |
+| **Upload to uguu.se** | Enable if your Navidrome instance isn't publicly accessible (uploads artwork to temporary file host)            |
+| **Users**             | Array of username/token pairs mapping Navidrome users to Discord tokens                                         |
 
 
 ## Building

coverart.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/navidrome/navidrome/plugins/pdk/go/host"
+	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+)
+
+// Configuration key for uguu.se image hosting
+const uguuEnabledKey = "uguuenabled"
+
+// uguu.se API response
+type uguuResponse struct {
+	Success bool `json:"success"`
+	Files   []struct {
+		URL string `json:"url"`
+	} `json:"files"`
+}
+
+// getImageURL retrieves the track artwork URL, optionally uploading to uguu.se.
+func getImageURL(username, trackID string) string {
+	uguuEnabled, _ := pdk.GetConfig(uguuEnabledKey)
+	if uguuEnabled == "true" {
+		return getImageViaUguu(username, trackID)
+	}
+	return getImageDirect(trackID)
+}
+
+// getImageDirect returns the artwork URL directly from Navidrome (current behavior).
+func getImageDirect(trackID string) string {
+	artworkURL, err := host.ArtworkGetTrackUrl(trackID, 300)
+	if err != nil {
+		pdk.Log(pdk.LogWarn, fmt.Sprintf("Failed to get artwork URL: %v", err))
+		return ""
+	}
+
+	// Don't use localhost URLs
+	if strings.HasPrefix(artworkURL, "http://localhost") {
+		return ""
+	}
+	return artworkURL
+}
+
+// getImageViaUguu fetches artwork and uploads it to uguu.se.
+func getImageViaUguu(username, trackID string) string {
+	// Check cache first
+	cacheKey := fmt.Sprintf("uguu.artwork.%s", trackID)
+	cachedURL, exists, err := host.CacheGetString(cacheKey)
+	if err == nil && exists {
+		pdk.Log(pdk.LogDebug, fmt.Sprintf("Cache hit for uguu artwork: %s", trackID))
+		return cachedURL
+	}
+
+	// Fetch artwork data from Navidrome
+	contentType, data, err := host.SubsonicAPICallRaw(fmt.Sprintf("/getCoverArt?u=%s&id=%s&size=300", username, trackID))
+	if err != nil {
+		pdk.Log(pdk.LogWarn, fmt.Sprintf("Failed to fetch artwork data: %v", err))
+		return ""
+	}
+
+	// Upload to uguu.se
+	url, err := uploadToUguu(data, contentType)
+	if err != nil {
+		pdk.Log(pdk.LogWarn, fmt.Sprintf("Failed to upload to uguu.se: %v", err))
+		return ""
+	}
+
+	_ = host.CacheSetString(cacheKey, url, 9000)
+	return url
+}
+
+// uploadToUguu uploads image data to uguu.se and returns the file URL.
+func uploadToUguu(imageData []byte, contentType string) (string, error) {
+	// Build multipart/form-data body manually (TinyGo-compatible)
+	boundary := "----NavidromeCoverArt"
+	var body []byte
+	body = append(body, []byte(fmt.Sprintf("--%s\r\n", boundary))...)
+	body = append(body, []byte(fmt.Sprintf("Content-Disposition: form-data; name=\"files[]\"; filename=\"cover.jpg\"\r\n"))...)
+	body = append(body, []byte(fmt.Sprintf("Content-Type: %s\r\n", contentType))...)
+	body = append(body, []byte("\r\n")...)
+	body = append(body, imageData...)
+	body = append(body, []byte(fmt.Sprintf("\r\n--%s--\r\n", boundary))...)
+
+	req := pdk.NewHTTPRequest(pdk.MethodPost, "https://uguu.se/upload")
+	req.SetHeader("Content-Type", fmt.Sprintf("multipart/form-data; boundary=%s", boundary))
+	req.SetBody(body)
+
+	resp := req.Send()
+	if resp.Status() >= 400 {
+		return "", fmt.Errorf("uguu.se upload failed: HTTP %d", resp.Status())
+	}
+
+	var result uguuResponse
+	if err := json.Unmarshal(resp.Body(), &result); err != nil {
+		return "", fmt.Errorf("failed to parse uguu.se response: %w", err)
+	}
+
+	if !result.Success || len(result.Files) == 0 {
+		return "", fmt.Errorf("uguu.se upload was not successful")
+	}
+
+	if result.Files[0].URL == "" {
+		return "", fmt.Errorf("uguu.se returned empty URL")
+	}
+
+	return result.Files[0].URL, nil
+}

coverart_test.go

@@ -0,0 +1,109 @@
+package main
+
+import (
+	"errors"
+
+	"github.com/navidrome/navidrome/plugins/pdk/go/host"
+	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+	"github.com/stretchr/testify/mock"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("getImageURL", func() {
+	BeforeEach(func() {
+		pdk.ResetMock()
+		host.CacheMock.ExpectedCalls = nil
+		host.CacheMock.Calls = nil
+		host.ArtworkMock.ExpectedCalls = nil
+		host.ArtworkMock.Calls = nil
+		host.SubsonicAPIMock.ExpectedCalls = nil
+		host.SubsonicAPIMock.Calls = nil
+		pdk.PDKMock.On("Log", mock.Anything, mock.Anything).Maybe()
+	})
+
+	Describe("uguu disabled (default)", func() {
+		BeforeEach(func() {
+			pdk.PDKMock.On("GetConfig", uguuEnabledKey).Return("", false)
+		})
+
+		It("returns artwork URL directly", func() {
+			host.ArtworkMock.On("GetTrackUrl", "track1", int32(300)).Return("https://example.com/art.jpg", nil)
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(Equal("https://example.com/art.jpg"))
+		})
+
+		It("returns empty for localhost URL", func() {
+			host.ArtworkMock.On("GetTrackUrl", "track1", int32(300)).Return("http://localhost:4533/art.jpg", nil)
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(BeEmpty())
+		})
+
+		It("returns empty when artwork fetch fails", func() {
+			host.ArtworkMock.On("GetTrackUrl", "track1", int32(300)).Return("", errors.New("not found"))
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(BeEmpty())
+		})
+	})
+
+	Describe("uguu enabled", func() {
+		BeforeEach(func() {
+			pdk.PDKMock.On("GetConfig", uguuEnabledKey).Return("true", true)
+		})
+
+		It("returns cached URL when available", func() {
+			host.CacheMock.On("GetString", "uguu.artwork.track1").Return("https://a.uguu.se/cached.jpg", true, nil)
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(Equal("https://a.uguu.se/cached.jpg"))
+		})
+
+		It("uploads artwork and caches the result", func() {
+			host.CacheMock.On("GetString", "uguu.artwork.track1").Return("", false, nil)
+
+			// Mock SubsonicAPICallRaw
+			imageData := []byte("fake-image-data")
+			host.SubsonicAPIMock.On("CallRaw", "/getCoverArt?u=testuser&id=track1&size=300").
+				Return("image/jpeg", imageData, nil)
+
+			// Mock uguu.se HTTP upload
+			uguuReq := &pdk.HTTPRequest{}
+			pdk.PDKMock.On("NewHTTPRequest", pdk.MethodPost, "https://uguu.se/upload").Return(uguuReq)
+			pdk.PDKMock.On("Send", uguuReq).Return(pdk.NewStubHTTPResponse(200, nil,
+				[]byte(`{"success":true,"files":[{"url":"https://a.uguu.se/uploaded.jpg"}]}`)))
+
+			// Mock cache set
+			host.CacheMock.On("SetString", "uguu.artwork.track1", "https://a.uguu.se/uploaded.jpg", int64(9000)).Return(nil)
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(Equal("https://a.uguu.se/uploaded.jpg"))
+			host.CacheMock.AssertCalled(GinkgoT(), "SetString", "uguu.artwork.track1", "https://a.uguu.se/uploaded.jpg", int64(9000))
+		})
+
+		It("returns empty when artwork data fetch fails", func() {
+			host.CacheMock.On("GetString", "uguu.artwork.track1").Return("", false, nil)
+			host.SubsonicAPIMock.On("CallRaw", "/getCoverArt?u=testuser&id=track1&size=300").
+				Return("", []byte(nil), errors.New("fetch failed"))
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(BeEmpty())
+		})
+
+		It("returns empty when uguu.se upload fails", func() {
+			host.CacheMock.On("GetString", "uguu.artwork.track1").Return("", false, nil)
+			host.SubsonicAPIMock.On("CallRaw", "/getCoverArt?u=testuser&id=track1&size=300").
+				Return("image/jpeg", []byte("fake-image-data"), nil)
+
+			uguuReq := &pdk.HTTPRequest{}
+			pdk.PDKMock.On("NewHTTPRequest", pdk.MethodPost, "https://uguu.se/upload").Return(uguuReq)
+			pdk.PDKMock.On("Send", uguuReq).Return(pdk.NewStubHTTPResponse(500, nil, []byte(`{"success":false}`)))
+
+			url := getImageURL("testuser", "track1")
+			Expect(url).To(BeEmpty())
+		})
+	})
+})

go.mod

@@ -3,7 +3,7 @@ module discord-rich-presence
 go 1.25
 
 require (
-	github.com/navidrome/navidrome/plugins/pdk/go v0.0.0-20260207003554-6fb4cd277ef7
+	github.com/navidrome/navidrome/plugins/pdk/go v0.0.0-20260207182358-29f98b889b11
 	github.com/onsi/ginkgo/v2 v2.28.1
 	github.com/onsi/gomega v1.39.1
 	github.com/stretchr/testify v1.11.1

go.sum

@@ -30,8 +30,8 @@ github.com/maruel/natural v1.3.0 h1:VsmCsBmEyrR46RomtgHs5hbKADGRVtliHTyCOLFBpsg=
 github.com/maruel/natural v1.3.0/go.mod h1:v+Rfd79xlw1AgVBjbO0BEQmptqb5HvL/k9GRHB7ZKEg=
 github.com/mfridman/tparse v0.18.0 h1:wh6dzOKaIwkUGyKgOntDW4liXSo37qg5AXbIhkMV3vE=
 github.com/mfridman/tparse v0.18.0/go.mod h1:gEvqZTuCgEhPbYk/2lS3Kcxg1GmTxxU7kTC8DvP0i/A=
-github.com/navidrome/navidrome/plugins/pdk/go v0.0.0-20260207003554-6fb4cd277ef7 h1:vA0PhcvJuaUGAtbNchGCmHNQ4NJ5z9whE+xxd6Jw9Z8=
-github.com/navidrome/navidrome/plugins/pdk/go v0.0.0-20260207003554-6fb4cd277ef7/go.mod h1:HijQ0Z0OeEa6LIwUJh6H9WqAptye096jHazmKXf+YV4=
+github.com/navidrome/navidrome/plugins/pdk/go v0.0.0-20260207182358-29f98b889b11 h1:VE4bqzkS6apWDtco9hAGdThFttjbYoLR0DEILAGDyyc=
+github.com/navidrome/navidrome/plugins/pdk/go v0.0.0-20260207182358-29f98b889b11/go.mod h1:HijQ0Z0OeEa6LIwUJh6H9WqAptye096jHazmKXf+YV4=
 github.com/onsi/ginkgo/v2 v2.28.1 h1:S4hj+HbZp40fNKuLUQOYLDgZLwNUVn19N3Atb98NCyI=
 github.com/onsi/ginkgo/v2 v2.28.1/go.mod h1:CLtbVInNckU3/+gC8LzkGUb9oF+e8W8TdUsxPwvdOgE=
 github.com/onsi/gomega v1.39.1 h1:1IJLAad4zjPn2PsnhH70V4DKRFlrCzGBNrNaru+Vf28=

main.go

@@ -91,21 +91,6 @@ func getConfig() (clientID string, users map[string]string, err error) {
 	return clientID, users, nil
 }
 
-// getImageURL retrieves the track artwork URL.
-func getImageURL(trackID string) string {
-	artworkURL, err := host.ArtworkGetTrackUrl(trackID, 300)
-	if err != nil {
-		pdk.Log(pdk.LogWarn, fmt.Sprintf("Failed to get artwork URL: %v", err))
-		return ""
-	}
-
-	// Don't use localhost URLs
-	if strings.HasPrefix(artworkURL, "http://localhost") {
-		return ""
-	}
-	return artworkURL
-}
-
 // ============================================================================
 // Scrobbler Implementation
 // ============================================================================
@@ -163,7 +148,7 @@ func (p *discordPlugin) NowPlaying(input scrobbler.NowPlayingRequest) error {
 			End:   endTime,
 		},
 		Assets: activityAssets{
-			LargeImage: getImageURL(input.Track.ID),
+			LargeImage: getImageURL(input.Username, input.Track.ID),
 			LargeText:  input.Track.Album,
 		},
 	}); err != nil {

main_test.go

@@ -3,7 +3,6 @@ package main
 import (
 	"errors"
 	"strings"
-	"testing"
 
 	"github.com/navidrome/navidrome/plugins/pdk/go/host"
 	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
@@ -15,11 +14,6 @@ import (
 	. "github.com/onsi/gomega"
 )
 
-func TestDiscordPlugin(t *testing.T) {
-	RegisterFailHandler(Fail)
-	RunSpecs(t, "Discord Plugin Main Suite")
-}
-
 var _ = Describe("discordPlugin", func() {
 	var plugin discordPlugin
 
@@ -36,6 +30,8 @@ var _ = Describe("discordPlugin", func() {
 		host.SchedulerMock.Calls = nil
 		host.ArtworkMock.ExpectedCalls = nil
 		host.ArtworkMock.Calls = nil
+		host.SubsonicAPIMock.ExpectedCalls = nil
+		host.SubsonicAPIMock.Calls = nil
 	})
 
 	Describe("getConfig", func() {
@@ -122,6 +118,7 @@ var _ = Describe("discordPlugin", func() {
 		It("successfully sends now playing update", func() {
 			pdk.PDKMock.On("GetConfig", clientIDKey).Return("test-client-id", true)
 			pdk.PDKMock.On("GetConfig", usersKey).Return(`[{"username":"testuser","token":"test-token"}]`, true)
+			pdk.PDKMock.On("GetConfig", uguuEnabledKey).Return("", false)
 
 			// Connect mocks (isConnected check via heartbeat)
 			host.CacheMock.On("GetInt", "discord.seq.testuser").Return(int64(0), false, errors.New("not found"))

manifest.json

@@ -11,7 +11,7 @@
     },
     "http": {
       "reason": "To communicate with Discord API for gateway discovery and image uploads",
-      "requiredHosts": ["discord.com"]
+      "requiredHosts": ["discord.com", "uguu.se"]
     },
     "websocket": {
       "reason": "To maintain real-time connection with Discord gateway",
@@ -25,6 +25,9 @@
     },
     "artwork": {
       "reason": "To get track artwork URLs for rich presence display"
+    },
+    "subsonicapi": {
+      "reason": "To fetch track artwork data for image hosting upload"
     }
   },
   "config": {
@@ -39,6 +42,11 @@
           "maxLength": 20,
           "pattern": "^[0-9]+$"
         },
+        "uguuenabled": {
+          "type": "boolean",
+          "title": "Upload artwork to uguu.se (enable if Navidrome is not publicly accessible)",
+          "default": false
+        },
         "users": {
           "type": "array",
           "title": "User Tokens",
@@ -73,6 +81,10 @@
           "type": "Control",
           "scope": "#/properties/clientid"
         },
+        {
+          "type": "Control",
+          "scope": "#/properties/uguuenabled"
+        },
         {
           "type": "Control",
           "scope": "#/properties/users",

plugin_suite_test.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestDiscordPlugin(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Discord Plugin Main Suite")
+}