diff --git a/web/public/api/activitypub/inbox.go b/web/public/api/activitypub/inbox.go
index ddb5e89..906cc6a 100644
--- a/web/public/api/activitypub/inbox.go
+++ b/web/public/api/activitypub/inbox.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	"regexp"
+	"strconv"
 
 	webutils "git.mstar.dev/mstar/goutils/http"
 	"git.mstar.dev/mstar/goutils/other"
@@ -83,6 +84,8 @@ func userInbox(w http.ResponseWriter, r *http.Request) {
 	switch objectType {
 	case "Like":
 		handleLike(w, r, data)
+	case "Undo":
+		handleUndo(w, r, data)
 	default:
 		webutils.ProblemDetailsStatusOnly(w, 500)
 	}
@@ -191,3 +194,128 @@ func handleLike(w http.ResponseWriter, r *http.Request, object map[string]any) {
 		webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
 	}
 }
+
+func handleUndo(w http.ResponseWriter, r *http.Request, object map[string]any) {
+	log := hlog.FromRequest(r)
+	_ = object["id"].(string)
+	_, ok := object["actor"].(string)
+	if !ok {
+		webutils.ProblemDetails(
+			w,
+			http.StatusBadRequest,
+			"/errors/bad-request-data",
+			"Bad activity data",
+			other.IntoPointer(`Request data needs to contain a field "actor" with a string value`),
+			nil,
+		)
+		return
+	}
+	rawTarget, ok := object["object"]
+	if !ok {
+		webutils.ProblemDetails(
+			w,
+			http.StatusBadRequest,
+			"/errors/bad-request-data",
+			"Bad activity data",
+			other.IntoPointer(`Request data needs to contain a field "object"`),
+			nil,
+		)
+		return
+	}
+	// TODO: I *think* undo is only actively used for likes, but could also be used for
+	// undoing create's and thus removing notes
+	var likeActivityId string
+	// I *think* the spec says that this must be an object. Not sure though
+	switch target := rawTarget.(type) {
+	case string:
+		likeActivityId = target
+	case map[string]any:
+		objType, ok := target["type"].(string)
+		if !ok || objType != "Like" {
+			webutils.ProblemDetails(
+				w,
+				http.StatusBadRequest,
+				"/errors/bad-request-data",
+				"Bad activity data",
+				other.IntoPointer(`Undone object is not of type like. If you receive this error for a valid undo for a different activity type,please contact the Linstrom developers with the activity type`),
+				nil,
+			)
+			return
+		}
+		likeActivityId, ok = target["id"].(string)
+		if !ok {
+			webutils.ProblemDetails(
+				w,
+				http.StatusBadRequest,
+				"/errors/bad-request-data",
+				"Bad activity data",
+				other.IntoPointer(`Missing id in undone object`),
+				nil,
+			)
+			return
+		}
+	default:
+		webutils.ProblemDetails(
+			w,
+			http.StatusBadRequest,
+			"/errors/bad-request-data",
+			"Bad activity data",
+			other.IntoPointer(`Request data needs to contain a field "object" of type string or object`),
+			nil,
+		)
+		return
+	}
+	// TODO: For above todo, get target resource via likeActivityId and remove approprietly
+	// Don't just assume it was a like being undone
+	act, err := dbgen.Activity.Where(dbgen.Activity.Id.Eq(likeActivityId), dbgen.Activity.Type.Eq("like")).
+		First()
+	switch err {
+	case gorm.ErrRecordNotFound:
+		return
+	case nil:
+	default:
+		log.Error().
+			Err(err).
+			Str("activity-id", likeActivityId).
+			Msg("Error while looking for find activity")
+		webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
+		return
+	}
+	reactionId := uint(other.Must(strconv.ParseUint(act.ObjectId, 10, 64)))
+	reaction, err := dbgen.Reaction.Where(dbgen.Reaction.ID.Eq(reactionId)).First()
+	switch err {
+	case gorm.ErrRecordNotFound:
+		return
+	case nil:
+	default:
+		log.Error().
+			Err(err).
+			Str("activity-id", likeActivityId).
+			Msg("Error while looking for find activity")
+		webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
+		return
+	}
+	tx := dbgen.Q.Begin()
+	_, err = tx.Activity.Where(dbgen.Activity.Id.Eq(act.Id)).Delete()
+	if err != nil {
+		_ = tx.Rollback()
+		log.Error().Err(err).Str("activity-id", act.Id).Msg("Failed to delete activity on undo")
+		webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
+		return
+	}
+	_, err = tx.Reaction.Where(dbgen.Reaction.ID.Eq(reaction.ID)).Delete()
+	if err != nil {
+		_ = tx.Rollback()
+		log.Error().
+			Err(err).
+			Uint("reaction-id", reaction.ID).
+			Msg("Failed to delete reaction on undo")
+		webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
+		return
+	}
+	err = tx.Commit()
+	if err != nil {
+		log.Error().Err(err).Msg("Failed to delete reaction and activity")
+		webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
+	}
+}