diff --git a/internal/domain/episodes.go b/internal/domain/episodes.go
new file mode 100644
index 0000000..735415a
--- /dev/null
+++ b/internal/domain/episodes.go
@@ -0,0 +1,36 @@
+package domain
+
+import "context"
+
+type EpisodeAvailability struct {
+	Sub []int
+	Dub []int
+}
+
+type EpisodeAvailabilityProvider interface {
+	Name() string
+	ResolveEpisodeProviderID(ctx context.Context, animeID int, titleCandidates []string) (string, error)
+	GetEpisodeAvailabilityByProviderID(ctx context.Context, providerID string) (EpisodeAvailability, error)
+}
+
+type CanonicalEpisode struct {
+	Number  int    `json:"number"`
+	Title   string `json:"title"`
+	HasSub  bool   `json:"has_sub"`
+	HasDub  bool   `json:"has_dub"`
+	SubOnly bool   `json:"sub_only"`
+	Filler  bool   `json:"filler"`
+	Recap   bool   `json:"recap"`
+}
+
+type CanonicalEpisodeList struct {
+	AnimeID       int                `json:"anime_id"`
+	Episodes      []CanonicalEpisode `json:"episodes"`
+	Source        string             `json:"source"`
+	NextRefreshAt string             `json:"next_refresh_at,omitempty"`
+}
+
+type EpisodeService interface {
+	GetCanonicalEpisodes(ctx context.Context, anime Anime, forceRefresh bool) (CanonicalEpisodeList, error)
+	RefreshTrackedDue(ctx context.Context, limit int) error
+}