feat(tracks): make ID3 tag query params opt-in via ?id3=true

api/dbv1/tracks.go

@@ -12,6 +12,11 @@ type TracksParams struct {
 	GetTracksParams
 }
 
+// IncludeID3TagsCtxKey is the request-context key used to opt in to ID3 tag
+// query params on generated stream/preview URLs. The id3 middleware sets it
+// from the `?id3=true` query param.
+const IncludeID3TagsCtxKey = "includeID3Tags"
+
 // Track is the standard track type containing all track data
 type Track struct {
 	GetTracksRow
@@ -128,9 +133,12 @@ func (q *Queries) TracksKeyed(ctx context.Context, arg TracksParams) (map[int32]
 		// Get access from the bulk access map
 		access := accessMap[rawTrack.TrackID]
 
-		id3Tags := &Id3Tags{
-			Title:  rawTrack.Title.String,
-			Artist: user.Name.String,
+		var id3Tags *Id3Tags
+		if includeID3Tags, _ := ctx.Value(IncludeID3TagsCtxKey).(bool); includeID3Tags {
+			id3Tags = &Id3Tags{
+				Title:  rawTrack.Title.String,
+				Artist: user.Name.String,
+			}
 		}
 
 		var stream *MediaLink

api/id3_middleware.go

@@ -0,0 +1,20 @@
+package api
+
+import (
+	"api.audius.co/api/dbv1"
+	"github.com/gofiber/fiber/v2"
+)
+
+// id3Middleware reads the optional `?id3=true` query param and stashes the
+// resulting bool on the request context so dbv1.TracksKeyed can decide
+// whether to embed ID3 tag query params on generated stream/preview URLs.
+//
+// ID3 tags are opt-in: when omitted, validator nodes can redirect straight to
+// presigned blob-storage URLs; when requested, the validator must proxy the
+// bytes so it can prepend the ID3 tag.
+func (app *ApiServer) id3Middleware(c *fiber.Ctx) error {
+	if c.QueryBool("id3") {
+		c.Locals(dbv1.IncludeID3TagsCtxKey, true)
+	}
+	return c.Next()
+}

api/server.go

@@ -390,6 +390,7 @@ func NewApiServer(config config.Config) *ApiServer {
 	app.Use(app.resolveMyIdMiddleware)
 	app.Use(app.authMiddleware)
 	app.Use(app.solanaWalletMiddleware)
+	app.Use(app.id3Middleware)
 
 	v1 := app.Group("/v1")
 	v1Full := app.Group("/v1/full")

api/v1_track_stream_test.go

@@ -12,5 +12,22 @@ func TestGetTrackStream(t *testing.T) {
 	req := httptest.NewRequest("GET", "/v1/tracks/eYJyn/stream", nil)
 	res, err := app.Test(req, -1)
 	assert.NoError(t, err)
-	assert.Contains(t, res.Header.Get("Location"), "tracks/cidstream/?id3=true&id3_artist=&id3_title=Culca+Canyon&signature=%7B%22data%22%3A%22%7B%5C%22cid%5C%22%3A%5C%22%5C%22%2C%5C%22timestamp%5C%22%3")
+	location := res.Header.Get("Location")
+	assert.Contains(t, location, "tracks/cidstream/")
+	assert.Contains(t, location, "signature=")
+	// ID3 tags are opt-in via ?id3=true; verify they are NOT present by default.
+	assert.NotContains(t, location, "id3=true")
+	assert.NotContains(t, location, "id3_artist=")
+	assert.NotContains(t, location, "id3_title=")
+}
+
+func TestGetTrackStreamWithID3(t *testing.T) {
+	app := testAppWithFixtures(t)
+	req := httptest.NewRequest("GET", "/v1/tracks/eYJyn/stream?id3=true", nil)
+	res, err := app.Test(req, -1)
+	assert.NoError(t, err)
+	location := res.Header.Get("Location")
+	assert.Contains(t, location, "tracks/cidstream/")
+	assert.Contains(t, location, "id3=true")
+	assert.Contains(t, location, "id3_title=Culca+Canyon")
 }